Deep Eutectic Solvents (DES) are known today as "green solvents," presenting attractive properties for the industry and meeting current sustainability requirements. These solvents are composed of a hydrogen bond donor component (HBD) and another hydrogen bond acceptor component (HBA). An important class of DESs that has gained prominence is Natural Deep Eutectic Solvents (NADES), derived from natural sources and fundamental metabolic reactions of living organisms. NADES possess desirable characteristics such as low toxicity, biodegradability, and low cost, which have drawn researchers' attention to their use in solubility processes, liquid-liquid extraction, among other applications. The continuous development of synthesis methods and a deep understanding of NADES properties will contribute to their successful application in various chemical processes. In this study, the viability of synthesizing NADES formed by organic sugars (fructose, sucrose, and glucose), citric acid, and choline chloride was investigated. Their fundamental physicochemical properties, such as density, viscosity, and electrical conductivity, were evaluated over a temperature range between 303 – 333 K. Refractive index and pH properties were obtained at 293 K and 1 atm. These properties were also assessed and studied for two mixtures based on fructose and citric acid with an alcohol (ethanol).

With the increase in population, we see new challenges emerging in different sectors of society. This changing scenario gave rise to the 2030 Agenda, which addresses the objectives of sustainable development. Issues such as the increase in domestic effluents, growing food demands and the consequent increase in industrial waste, including various biomasses, as well as the use of fossil fuels, stand out as important environmental challenges that require more sustainable solutions for the future. In this context, the electrorefinery appears as an attractive proposal to face these problems. By employing clean energy, it makes it possible to convert materials considered waste into value-added products. Therefore, this work aims to transform a real domestic effluent, in this case, the washing water from a washing machine, and an industrial residue, the liquid from the shell of cashew nuts, into value-added products, such as acids carboxylic acids, while simultaneously cogenerating green hydrogen. Cells divided by polymeric electrolytic membranes, types PEM and AEM, were used, with BDD/Nb electrodes as anode and Ni-Fe stainless steel mesh as cathode. In the treatment of washing machine effluent, two different electrolytes were tested (H2SO4 0.1 mol L-1 and Na2SO4 0.1 mol L-1), also varying the current densities. The results reveal the production of products with added value, especially carboxylic acids, with emphasis on selectivity to acetic acid, reaching 45.7 mg L-1. Furthermore, we observed the generation of green H2, with volumes of approximately 0.8 L. When using the liquid from cashew nut shells, different conditions were explored, such as current density, concentration and nature of the electrolyte (NaOH 0.125, 1.0 and 2.0 mol L-1 and Na2SO4 0.05 mol L-1), and substrate concentration. It was found that all variables influence the production of carboxylic acids and the energy efficiency of green H2, with the substrate concentration being the most significant variable in the production of acids and current density in that of green H2. As the substrate concentration increases, it was possible to achieve acetic acid production rates of 565.4 mg L-1, and at higher current densities, green H2 volumes of 1.8 L were observed. , the viability of technology based on electrorefinery is evidenced by the selective electrochemical transformation of organic pollutants from waste into value-added products, such as green H2 and carboxylic acids. This advance represents a promising step towards the circular economy, contributing to environmental sustainability.

The shrimp farming activity refers to the farming of shrimp and is very significant in the northeastern region of Brazil. To ensure the functioning of farms, an abundance of water is needed, which, if improperly disposed of, can cause various environmental damages. Another prominent activity in the country is the cultivation of sugar cane, which generates several by-products. One of them is molasses, whose sugar and nutrient levels are quite high. Thus, the use of microalgae to aid in the treatment of wastewater linked to the biorefinery process has been gaining prominence. Studies show that sugarcane molasses can be used as an economical and efficient supplement to microalgae growing media, offering substantial amounts of organic carbon. This work sought to evaluate the potential for reusing water from the organic shrimp production pond to dilute the Zarrouk medium (50%, 60%, and 70%) and the effect of adding molasses, compared with the traditional Zarrouk medium for cyanobacteria cultivation. Synechococcus nidulans, as low-cost cultivation media can enable the production of microalgae on large scales in an optimized way. It also sought to extract phycocyanin, a natural pigment present in microalgae of the genus Synechococcus. Cultivations were carried out in duplicate, under autotrophic and mixotrophic conditions, with a 12-hour light/dark photoperiod at 25°C and with mechanical air aeration. Cultivations of Zarrouk 70% SM (Without Molasses) and CM (With Molasses) generally showed better results compared to other diluted Zarrouk media, with biomass concentrations of 1.1005 g/L ± 0.1789 g/L and 0.9860 g /L± 0.0206 g/ L, respectively, but with lower results compared to traditional Zarrouk. It was found that the addition of carbon to the medium did not significantly interfere in favoring greater production. The pH of the medium remained in the range of 8.27-9.92. Biomass was characterized by carbohydrates, lipids, crude protein, and carotenoids. Carbohydrates were favored by the addition of molasses and the 70% CM test reached a maximum percentage of 21.24% ± 4.44%, while the lipid content was not affected so that it presented maximum values of 36.60% ± 0.00% (70% SM) and 31.80% ± 2.26% (70% CM). The protein content was also not affected, with maximum values reaching 21.55% ± 0.43% (70% SM) and 19.37% ± 0.56% (70% SM). Regarding the carotenoid content, a slight increase in concentration was observed in the CM experiments, with the highest value of 135.2238 mg/g ± 25.9163 mg/g (70% CM). The same occurred with phycocyanin, which was possible to extract and presented a concentration of 1.4919 mg/mL ± 0.2898 mg/mL in the 70% CM assay, with Extract Purity (PE) of 0.29.

Oil stands out as one of the precursors for the production of materials, fuels, and even medicines. Knowing this great importance, extraction, and refining processes are frequent and due to this great exploration, accidents can happen causing spills in soils and oceans. Due to its high carcinogenicity and mutagenic aspects, the presence of some polycyclic aromatic hydrocarbons (PAHs), present in the composition of the oil, poses risks to humans and wild animals. Thus, to mitigate the environmental problems caused by PAHs in the event of a spill, the use of microorganisms for biodegradation has been seen as a potential solution. One factor that hinders the microbiological decomposition of PAHs is the hydrophobicity of the molecules, which is why the industry invests in the development of dispersants that reduce surface tension at the hydrocarbon/water interface. In this context, the literature has demonstrated the advantages of biosurfactants (surfactants of biological origin) about surfactants from the chemical industry. The main objective of the present study is to evaluate the biodegradation capacity of 2-Methylnaphthalene and Phenanthrene (model hydrocarbons) by Pseudomonas aeruginosa AP029-GLVIIA in the presence of industrial biosurfactant using microcosm cultures. The biosurfactant was provided by chemical industry and was characterized in terms of surface tension and emulsification index (E%). Biodegradation tests were carried out by varying the concentration of hydrocarbons and biosurfactant for 10 days, monitoring pH, bacterial growth, and biodegradation rate, and also evaluating the degradation of the hydrocarbon mixture. The results demonstrate that the industrial biosurfactant presented satisfactory emulsification index results for toluene and lubricating oil, presenting values above 40% for concentrations of NaCl added and in small concentrations of biosurfactant, presenting these values after 240 hours of cultivation. The biosurfactant, in addition to acting as a dispersant, reducing the surface tension of the hydrocarbon/water interface, acted as a carbon source for growth for Pseudomonas aeruginosa AP029-GLVIIA, thus favoring its greater growth. The bacteria were able to degrade phenanthrene and 2-MN, obtaining degradation values of up to 61.43% and 100% respectively, under the same conditions, in the experiment that presented a concentration of 17.69 g/L of biosurfactant. It was also observed that the biosurfactant improved the biodegradation rate, with phenanthrene being the only variable that had a significant influence on the studied response, while for 2-MN the model presented all variables and their interactions as significantly related to the proposed model. Furthermore, the model developed from the results of the statistical analysis managed to explain 92.31% of the data presented for the degradation of phenanthrene and around 97.30% for the biodegradation of 2-MN. The mixture of the two model hydrocarbons studied presented a degradation rate of 6.41% and 100% for phenanthrene and 2-MN respectively.

Enzymes play an important role in biotechnological processes. However, to be industrially profitable, they need to allow easy handling, reuse, and operational stability. One way to ensure the efficiency and these characteristics of soluble enzymes is through the immobilization technique. The strategy of cross-linked enzyme aggregates (CLEAs) is particularly interesting because it allows direct contact of the enzyme with the substrate, due to the absence of solid supports in the immobilization process, or through the use of non-porous supports, such as magnetic nanoparticles, for the formation of magnetic CLEAs (mCLEAs). Among industrial enzymes, cellulases are a set of enzymes capable of hydrolyzing isolated cellulose or cellulose present in biomass, converting it into glucose, a product of interest for the production of lignocellulosic, or second-generation (2G) ethanol. Therefore, the present study aims to produce CLEAs from commercial cellulolytic cocktails (Celluclast and Cellic CTec 2). These cellulolytic cocktails are widely used in the hydrolysis of lignocellulosic materials, forming part of the 2G ethanol production chain. Initially, different precipitation agents were studied, such as ethanol (99.5%), acetone (a. grade), and saturated ammonium sulfate solution, using 5% glutaraldehyde (v/v) and magnetic nanoparticles covered with Aminopropyltriethoxysilane (APTES) for the production of CLEAs and mCLEAs, respectively. With the biocatalysts obtained, evaluation was carried out based on immobilization parameters, such as precipitation yield and recovered activity of precipitating agents, as well as the catalytic capacity of CLEAs and mCLEAs using different substrates, Carboxymethylcellulose (CMC) and Filter paper (FP), which allows obtaining the activities of endo-cellulases (CMCase) and total (FPase), respectively. The precipitating agents that proved to be most efficient were ethanol and acetone. The activity recovered for ethanol was 27.25 ± 1.67% (CMCase) and 100 ± 14.63% (FPase) for the Celluclast cocktail and 41.96 ± 3.66% (CMCase) and 14.29 ± 2.01% (FPase) for Cellic CTec 2. With acetone, it was possible to recover 34.24 ± 1.45% (CMCase) and 77.66 ± 7.83% (FPase) when using the Celluclast cocktail and 38 .59 ± 3.21% (CMCase) and 55.41 ± 12.61% (FPase) for Cellic CTec 2. From the evaluation of the enzymatic activity of CLEAs with the addition of the additive Bovine Serum Albumin (BSA) in the precipitation, it was possible to define acetone as the best precipitating agent. CLEAs precipitated with acetone and BSA achieved the best activity results, being 287.27 ± 42.59 U/g (CMCase) and 0.035 ± 2.059 U/g (FPase) for Celluclast and 425.37 ± 48.11 U/g (CMCase) and 1.54 ± 1.10 U/g (FPase) for Cellic CTec 2. To facilitate the separation process and foresee future use in an industrial environment, magnetic nanoparticles coated with APTES were added to the precipitation stage, producing magnetic CLEAs (mCLEAs). The mCLEAs that showed the best results were those produced with the Celluclast enzyme with BSA as an additive, showing activities of 149.65 ± 2.65 U/g (CMCase) and 5.30 ± 1.75 U/g (FPase). Therefore, it is highlighted that it was possible to efficiently produce CLEAs and mCLEAs using commercial cellulolytic enzyme cocktails, which could be applied in the hydrolysis stage of pretreated lignocellulosic biomass aiming at the production of 2G ethanol.

Biodiesel production through lipase-catalyzed transesterification is an alternative to traditional chemical catalysts. This clean technology offers greater conversion efficiency, eliminates side reactions and operates at lower temperatures. Enzyme immobilization is applied to improve enzyme stability, facilitating its recovery and reuse and promoting protection against inhibitory effects. The immobilization support can be from various sources, including lignocellulosic waste, such as green coconut fiber. Therefore, this work developed biocatalysts using waste as a support for immobilization, aiming for application in the synthesis of biodiesel via transesterification of residual frying oil. Lipase from Candida antarctica type B (CALB), Pseudomonas fluorescens (PFL) and Eversa lipase (EL) were chosen due to the heterogenicity of the substrate (oils). The use of enzymatic and co-immobilized mixtures has shown an advantage in the production of biodiesel. A solution of each lipase (0.05 mg/mL) was placed in contact with green coconut fiber (FC) (pretreated with steam explosion to increase surface area and facilitate interaction) to perform immobilization. The immobilization yields and recovered activity of the biocatalysts FC-PFL, FC-CALB and FC-EL showed that the individual immobilization of each lipase on coconut fiber was efficient. The biocatalysts obtained were subjected to chemical modifications post-immobilization with polyethylenimine (PEI), producing biocatalysts with FC-CALB-PEI, FC-PFL-PEI and FC-EL-PEI. Afterwards, treatment with glutaraldehyde (GLU) was carried out to produce enzyme-support covalent bonds, followed by modification with PEI, producing FC-CALB-GLU-PEI, FC-PFL-GLU-PEI and FC-EL-GLU- PEI. Through the characterization of these three categories of biocatalysts, the results showed that the predominant interactions between enzyme-support are predominantly hydrophobic, immobilization and coatings with GLU and PEI increased the thermostability of the lipases used and the presence of the covalent bond was observed by difference in the band pattern in the electrophoresis gel. For the application of these biocatalysts in the synthesis of biodiesel, the maximum enzyme load that can be immobilized in green coconut fiber was determined to be 5 mg/g for CALB biocatalysts, 10 mg/g for PFL and EL. In 5h of transesterification of residual frying oil, the FC-EL-GLU-PEI, FC-PFL-GLU-PEI and FC-CALB-GLU-PEI biocatalysts showed efficiency in reducing the acid number similar to the soluble enzyme. These results highlight the potential for the application of immobilized lipases in biodiesel production.

Considering the alternative sources of biofuels available, biodiesel production has a prominent place in postmodern society. Industrially, transesterification is the most used reaction to obtain biodiesel, obtaining fatty acid esters (biodiesel) and glycerol, as products. Due to the presence of glycerol, additional purification processes are necessary, which cause an increase in costs and production time for the final purified biodiesel, in addition to generating large volumes of effluents. Thus, problems associated with conventional biodiesel purification methods resulted in the exploration of new technologies to carry out this stage of the production process. The application of membranes has attracted considerable attention, being a very promising area, for achieving highly qualified biodiesel. The process has high separation efficiency, is environmentally safe, requires little energy expenditure and is operationally simple and flexible. In this context, this work aims to evaluate the applicability of the separation process using polymeric membranes in biodiesel separation stage, through the assembly of a bench system, as well as the formulation of blends that simulate the composition of biodiesel and subsequent separation using membrane technology. The membrane was duly evaluated through hydraulic permeability and solute rejection tests, also being characterized regarding its morphology and hydrophobicity. The developed module was used in separation experiments using blends similar to the composition of biodiesel, making it possible to determine the separation efficiency of the membranes compared to blends of known components and concentration. The results obtained in separating the blends are satisfactory. However, the data is still incomplete. With the completion of the next stage and experimental planning, it will be possible to characterize in more detail, in addition to evaluating the influence of concentration and pressure on the separation of the blends. And finally, determine the feasibility of applying the membrane separation process in biodiesel.

The growth of the global population and the increase in per capita consumption have driven the industrial sector to expand its production of goods and services. Consequently, the production of pollutants has also risen, and improper disposal of these pollutants into the environment can impact human health and ecosystems. Produced water from oil wells is a significant byproduct of oil extraction. This water is naturally present in subsurface reservoirs and is brought to the surface along with the oil during production. Typically, produced water contains a variety of substances such as salts, heavy metals, and organic compounds. Polluted water with dyes from the textile industry has also attracted researchers' interest due to its environmental relevance. During the dyeing process of fabrics and fibers, various chemical dyes are used to impart vibrant colors to clothing items. However, a significant portion of these dyes is not absorbed by the textile fibers and ends up being discarded with the wastewater, resulting in contaminated effluents. To mitigate these issues, recent studies have focused on using lignin as an adsorbent material for contaminant removal. Lignin shows promise due to its abundance in nature, being the second most abundant biopolymer after cellulose, and its presence of multiple functional groups along its polymeric chain. Brazil is one of the world's largest producers of corn, and associated with grain production is the generation of a large volume of corn cobs, which contains about 15% lignin. In this context, the present work aims to study the use of modified lignin extracted from corn cobs as an adsorbent material for pollutants in contaminated effluents. Initially, lignin was extracted from corn cob biomass through physical and chemical treatments. Subsequently, lignin was modified with various reagents to enhance its interaction capacity for contaminant removal. Regarding oil removal, spheres made from modified lignin showed better efficiency than those made from unmodified lignin or without lignin. The best result for removing total oil and grease (TOG) was observed with ELMC, achieving a removal percentage of 90%, followed by ELOX with 88.23%. ELNM achieved 84%, and EALG reached 45.83%. In terms of the adsorption process for Congo red dye, the adsorption kinetics study indicated that the pseudo-second-order model best fit the data. The PSO model showed R² values closest to unity and demonstrated the ability to predict the value of qeq_eqe. The qeq_eqe for LNM at concentrations of 50, 100, and 250 mg/L were 35.54, 66.58, and 155.24 mg/g, respectively, while for LMC at the same concentrations, the qeq_eqe values were 33.89, 65.95, and 165.79 mg/g.

In recent years there has been growing concern about the contamination of water by emerging contaminants, such as pharmaceuticals. Carbamazepine (CBZ) is a psychotropic drug widely used throughout the world and has been frequently detected in water bodies, including groundwater. Organoclays have been used as efficient adsorbents for pharmaceutical pollutants. In this study, four types of organoclays were prepared from the modification of national bentonite clay with two cationic surfactants: hexadecyltrimethylammonium bromide (HDTMA) and octadecyltrimethylammonium bromide (ODTMA). The synthesized materials were extensively characterized. X-ray diffraction analyzes showed that the basal spacing of organoclays varied from 1.54 to 2.93 nm, suggesting the intercalation of organic cations in the interlayer space of montmorillonite. Initially, the synthesized clays were evaluated as adsorbents for the sorption of CBZ through batch equilibrium experiments, under variation of the pH, contact time, dosage of adsorbent, and initial drug concentration. pH variation showed no adsorption influence. CBZ sorption by the organoclays followed a pseudo-second-order kinetics. The best sorption performance was obtained for the BCN1-HDTMA₁₀₀ clay, with a capacity of 34.34 ± 1.41 mg/g, about ten times greater than the unmodified bentonite under the same conditions. This may be attributed to the higher surfactant content. The adsorption isotherm at 25 ºC showed linear behavior. FTIR and TG analyzes on organoclay-CBZ hybrids confirmed the incorporation of the drug. Hydrophobic interaction was the dominant contribution evaluated to the adsorption of CBZ. Furthermore, toxicity tests were carried out on organoclays and the medium in the presence of CBZ before and after treatment. This is a novelty report. Most of the organoclays had no toxicity against Artemia salina. The toxicity of the medium after adsorptive treatment was eliminated. After batch study, two synthesized organoclays (BCN1-HDTMA₁₀₀ and BCN1-ODTMA₁₀₀) were selected for the study of continuous adsorption of CBZ through tests in a fixed bed column filled with a mixture of sand and organoclay aiming at application as a medium reactive Permeable Reactive Barriers (PRB) for groundwater remediation. At this stage, the performance of the synthesized clays was compared to that of a commercial organoclay, Spectrogel Type C. The adsorption performance was evaluated using breakthrough curves. The effects of the initial drug concentration, quantity and type of clay in the fixed bed were evaluated. In general, the synthesized clays performed better than Spectrogel Type C. The lower adsorption capacity of CBZ by commercial clay may be associated with effects related to the packing density of organic cations in the interlayer space. Under the conditions of 1.0g of clay in the bed, 95 mg/L of initial CBZ concentration and flow rate of 1.0 mL/min, the clays BCN1-HDTMA₁₀₀ and BCN1-ODTMA₁₀₀ presented breakthrough times of 505 and 525 min and adsorption capacities of 46.652 and 50.139 mg/g, respectively. Therefore, organoclays have demonstrated promising potential for use in groundwater remediation applications.

The exploration, transportation, and refining of oil are fundamental to the global economy. Occasionally, oil spills in the ocean are reported. Rapid containment and remediation are essential to prevent oil from being carried to the coasts by wind and wave action. The methods currently used to remove oils in water are not free of flaws, and because of that, constant research to develop alternative methods is necessary. In this context, this work proposed the use of post-consumer polyurethane foams to recover oils spilled in seawater. Surface modifications were carried out to increase the selectivity of foams for oils and resulted in increases up to 611% and 991% for modifications with MoS₂ and ZnO in systems with S46 lubricating oil and 20W40 engine oil, respectively. These results show the success of hydrophobization and lipophilicity added to the foams through the modifications made. The reuse and resistance to mechanical compression tests showed that even after 10 sorption/desorption cycles, the foams kept their oil recovery capacity without a statistically significant difference. This result demonstrates the economic potential of modified foams thanks to their high reusability capacity. Kinetic studies on seawater-oil systems showed that the saturation speed depends on the viscosity of the oil, but that the foam pores are saturated with fluids practically instantly and reach equilibrium in less than 40 seconds of exposure. The pseudo-second-order (Ho and McKay) and logistic (Richards and Verhulst) kinetic models were those (among all kinetics models studied) that most adequately described the behavior of the experimental data in all cases, presenting high coefficients of determination (R² > 0.97) and low sums of squared residuals. In continuous sorption, the modifications favored oil selectivity, but the vacuum pumping operating mode was the most relevant factor, reaching selectivity up to 90% for the spilled oil instead of seawater. After use in oil recovery, post-commercialized foams impregnated with oils can be used for co-processing in clinker kilns. In this way, part of the energy required for cement production is obtained by processing Refuse-Derived Fuel (RDF).

Acerola (Malpighia emarginata DC) fruit has carotenoids and phenolic compounds, besides high ascorbic acid content, which is higher than most of the fruits known so far. However, several acerola bioactive compounds such as anthocyanins and ascorbic acid are easily degraded by oxygen and light, among other factors. Thus, in order to maximize the use of acerola fruits, efficient and rational technological strategies are necessary to ensure the preservation of ascorbic acid and other bioactive compounds and their use in stable food ingredients. In fact, it has been demonstrated that sensitive phytochemicals may have greater stability when encapsulated. Therefore, the use of different encapsulation techniques and the combination of drying carriers have been tested to efficiently protect different bioactive materials. In addition, another challenge for the successful development of phytochemical-rich capsules is the maintenance of their bioavailability. Consequently, it is necessary to determine the bioactive compounds stability in the gastrointestinal tract during digestion and the nutrient absorption. In this context, the objective of this doctorate project is to evaluate the encapsulation of acerola pulp by spray drying and emulsion methods, using chitosan and whey protein as carriers, either combined or alone. The comparative study will clarify the advantages and potential of each technique with respect to drying/encapsulation efficiency, the final product characteristics, as well as the release of bioactive compounds, with emphasis on ascorbic acid, in the gastrointestinal system using in vitro techniques. This research intends to develop efficient techniques for the production of acerola-based functional ingredients, a tropical fruit with great economic value and abundantly produced in Brazil.

The Lignin is the second most abundant biopolymer on the planet and one of the main components of the plant cell wall, along with cellulose and hemicellulose. Lignocellulosic biomass consists of 18% to 35% lignin. For example, sugarcane bagasse contains an average of 23% lignin. This biopolymer is produced in large quantities as a by-product of lignocellulosic biorefineries and the pulp and paper industry. However, only 5% of the 50 to 70 million tons of industrial lignin produced annually are utilized in value-added products. Consequently, numerous studies have explored lignin's applications in various fields, including drug delivery systems, catalysis, and the encapsulation of sensitive nutrients. Notably, the production of lignin nanoparticles has shown promising results in stabilizing Pickering oil/water (O/W) and water/oil (W/O) emulsions, including for encapsulating bioactives. Pickering O/W and W/O emulsions have limitations, especially in probiotic encapsulation, low-calorie food production, and drug formulation with hydrophilic properties. Conversely, Pickering water/water (A/W) emulsions can mimic biological environments, with stability ensured by nanoparticles adsorbing at liquid-liquid interfaces. This study investigated using lignin from sugarcane bagasse, a cheap, non-toxic, and biodegradable polymer, as a source of nanoparticles for stabilizing Pickering O/W emulsions for quercetin encapsulation and Pickering A/W emulsions formed from maltodextrin (MD) and polyethylene glycol (PEG). Nanoparticles were prepared from alkaline lignin and oxidized alkaline lignin. The nanoparticles differed in size, with oxidized alkaline lignin nanoparticles (NPLOs) being smaller (327.8 nm) than alkaline lignin nanoparticles (NPLs) (689.8 nm). NPLs and NPLOs were used for quercetin encapsulation using the Pickering O/W emulsion template. The encapsulation results were promising, showing quercetin tended to become trapped in the oil phase droplets in the presence of lignin nanoparticles, giving the upper phase of the test tube a yellowish color. At pH levels below 3, both types of nanoparticles agglomerated and formed a layer in the upper phase. The stability of Pickering A/W emulsions formed from MD and PEG was evaluated with NPLs and NPLOs at different concentrations (0%, 0.1%, 0.3%, 0.5%, and 1%, w/w). Systems with NPLOs exhibited better emulsification rates and smaller droplet sizes than those with NPLs. The most promising stabilization results for the MD/PEG 6000 system were obtained at a concentration of 1% w/w of NPLOs, achieving an emulsification index of up to 63% even after two weeks. These results suggest lignin's great potential as a source of nanoparticles for bioactive encapsulation and position this biopolymer as a potential candidate for advanced studies of Pickering W/W emulsions.

Flushing fluid are fluids used during the well drilling process, which perform the function of cleaning the walls of the well, removing the plaster formed and ensuring that the next stage of cemeting is successful. Flushing fluids can be made up of water or oil, surfactants and dispersants, being able to thin and remove the drilling fluid. In this context, the use of vegetable oils in the composition of flushing fluid and the use of biodegradable surfactantes are important for formulations developed ecologically correct. Thus, this study aims to develop microemulsions which act as potential flushing fluid, to be used for cleaning and inversion wettability of wells, before an operation of cementing oil wells. Two diferente microemulsion systems were prepared using nonionic surfactante, the first one using bio oil as vegetable oil and the second using castor oil. Removal tests, termal stability, rheology, inversion of wettability and compatibility tests were realized to verify the efficiency of the flushing fluids formulated for future application in the oil industry. According to the removal test, using bio oil as vegetable oil, the microemulsions were able to removed completely the drilling fluid in up to 3 minutes (time less than 10 minutes of the test). However, meantime through reversing wettability tests, the sample wasn’t efficient. Castor oil based microemulsions were able to removed the drilling fluid, the removal was greater than 75% in all samples, ans they are all stable in the temperature gradient of the well and they are newtonian fluid. In addition, the system formulated using NP100, water/glycerin and castor oil diluted in a 1:1 showed satisfactory compatibility with drilling fluid.

The environmental impact generated by the continuous use of inert material, originating exclusively from petroleum derivatives, has favored the increase in research aimed at the development of biodegradable films, as they have been investigated as promising strictures due to their safety, versatility of use and obtainment. In addition, as a primary packaging, these films can increase the shelf life of food, play active roles, regulate oxygen exchange rates, moisture, improve sensory qualities, can play nutrient support roles, preserve bioactives, raising their quality and service life. The demand for new starch sources has been growing making the productive sector look for new Technologies, as well as natural starches with differentiated physicochemical characteristics. The objective of this work was to develop and characterize biodegradable active films from jackfruit seed starch (Artocapus heterophillus Lam), incorporated from acerola powder (Malphigia ermaginata) prepared by casting processes. In casting films, filmogenics solutions were prepared in fixed concentrations of jackfruit seed starch (4%), acerola power (0.5 and 1%) and glycerol (2%). One important step of this study was to evaluate the physical-chemical, structural and morphological. Initially, the physical-chemical, structural and morphological characteristics of the jackfruit seed starch were evaluated. Subsequently, after drying in an oven and lyophilization, the acerola residue was used in the preparation of biodegradable films, comparing their active performance through the analysis of phenolic compounds and antioxidant activity. In addition, they were characterized in terms of water vapor permeability, solubility, humidity, thickness, scanning electron microscopy (SEM). The results obtained showed that the films had a reasonable thickness ranging from 0.083 to 0.136 mm, high solubility (76.7% to 90.9%), low permeability to water vapor, the XRD showed starch as type A. In the analysis of bioactive compounds it was proved that it has an active function and that the way in which the acerola residue was dehydrated contributed to the results shown, phenolic compounds varied from 156.9 to 320.9 mg GAE/100 g, the antioxidant activities ranged (DPPH) 2830 to 3463 μmol TE/g and (ABTS) 48.6 to 66.28 µmol Trolox/g ABTS. For all these reasons, the formulation of films based on jackfruit seed starch showed potential in manufacturing, with barrier and bioactive properties.

Produced water management is a concern in the oil industry due to the toxicity of the effluent and its immense produced volume, so the optimization of contaminant removal techniques, such as adsorption and flotation, is necessary to keep the process sustainable and unexpensive. Therefore, the aim of this work was to develop eco-friendly and low-cost bioadsorbent composites to remove contaminants from produced water through the combination of adsorption and flotation techniques. The composite was produced from a mixture of chitosan, biochar and bentonite via wet-spinning and characterized by immediate analysis, Boehm titration, zeta potential, pH at zero charge point, infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). A mix design was carried out to optimize the composition of the bioadsorbent, evaluating its percentage of removal of Cu (II) ions. The adsorption tests were carried out in a finite bath using single and multielement solutions of copper, lead and cadmium. While the flotation tests were carried out through a system using dissolved air in a column (flotatest), with feeding of monoelementary copper solution in batches. The morphological and superficial characterization of the material evidenced the presence of organic functional groups and pores that can become adsorption sites for contaminants such as heavy metals. The adsorption tests in systems with only one metallic species obtained a removal percentage above 90% for cadmium, lead and copper. However, in multielementary system, Cu2+, Pb2+ and Cd2+ ions showed a reduction in the maximum removal percentages, with lead adsorbed more efficiently (above 80%), followed by copper (above 40%) and, finally, cadmium with less than 20% removal. Therefore, it can be stated that the composite developed has the potential to remove heavy metals, which are some of the highly toxic contaminants present in produced water.

The present work aimed to apply an electrochemical technology, in order to, evaluate and analyze the efficiency on the degradation from model organic compound toward to carboxylic acids, as well as the simultaneous production of H₂(g) in different electric current densities (15, 30 and 45mA/cm²) and for three different configurations on the electrochemical reactor. In first step, a three-compartment flow reactor in series mode was designed and fabricated, combining the electrocatalytic properties of two non-active anodes (PbO₂-F and BDD) and a stainless-steel mesh cathode separated by two Nafion 350® membranes. Moreover, a mathematical model was developed to represent the reactor, as well as the reactions involved in the electrochemical process. The dye methyl orange (MO) was chosen as a model pollutant because it is a monoazo substance with a dark orange color and soluble in water, commonly used by the textile industries. The MO degradation process was monitored by absorption spectroscopy in the UV-vis region, Electroanalysis and FTIR. Meanwhilw, the quantification of carboxylic acids production, Ion Chromatography was performed. The results showed that the reactor used in the present work presented excellent results for the degradation of the organic compound, reaching 100% color removal after 60 minutes of electrolysis for all conditions studied. The FTIR data showed that there was degradation of the dye, mainly because we did not observe the peak presence corresponding to the binding of azo group at 1422 cm ^-1. Under the same conditions for degradation, a simultaneous production of green H₂ of approximately 0.8 L was achieved. The carboxylic acids production was monitored over time for the different conditions tested, and it was observed that there was a selective production of malonic acid, the which opens up the possibility of future studies for the application of electro-refinery concept using these residues. The model showed good adherence to the experimental data, confirming that it can describe and predicting production under different operating conditions.

In an attempt to mitigate the environmental impacts arising from the burning of fossil fuels, many studies have sought to make biodiesel production even more feasible, since it is a renewable, biodegradable fuel that has a lower content of polluting compounds. In this sense, this work focuses on the description the vapor–liquid equilibrium (VLE) data of three systems that are of interest to the biodiesel industry. The following systems were studied: ethanol (1) and oleic acid (2) at isobaric data at 760 mmHg, isothermal at 318.15 K and activity coefficient at infinite dilution; n-hexane (1) and cottonseed oil (2) with isobaric data at 310 mmHg; ethanol (1) and soybean oil (2) with isobaric data at 760 and 600 mmHg. A thermodynamic modeling was carried out with the ideal (Raoult's Law), UNIQUAC correlation and UNIFAC prediction approaches. The vapor pressure data of the pure substances were extracted from the literature. The relative mean deviations of the fitted Antoine's constants for ethanol, oleic acid, n-hexane, cottonseed oil, and soybean oil were 0.34%, 3.30%, 0.55%, 5.00% and 2.53%, respectively. The activity coefficient at infinite dilution values and the VLE binary data for the ethanol and oleic acid system were extracted from the literature. For the other systems, binary data were obtained in a modified Othmer ebulliometer from a previous study in our laboratory (FOTEQ). The correlation study with the UNIQUAC model described with quality the behavior of all systems under the conditions of interest. This indicates that the obtained binary parameters can be used in process simulation studies, as well as in equipment sizing projects, such as distillation columns. The predictive study carried out with the UNIFAC model showed accurate descriptions as UNIQUAC model. Furthermore, for all systems, a deviation from ideality was observed, which reiterates the indispensability of using an activity coefficient model, such as UNIQUAC.

Waste is present in industrial processes; therefore, using this waste for a purpose other than disposal creates a new avenue for disposal and sustainable development in the processes. In this way, this study aims to assess the potential use of kaolin waste as an adsorbent for the removal of food dyes present in effluents. To achieve this, the kaolin waste was obtained from an industry in Equador/RN. Subsequently, the waste was characterized through particle size, XRF, XRD, and SEM analyses. Next, pellets were manufactured in the ratio of 10 g of kaolin waste to 3 ml of water, which were then calcined at 800°C for 2 hours with a heating rate of 10°C/min. This material was tested using an adsorption system constructed with easily obtainable laboratory materials such as a graduated cylinder, PET bottle, and faucets. It was verified in the characterization that the main mineral in the waste is kaolinite. In batch tests, the assay that showed the best adsorption capacity was with calcined kaolin powder and Tartrazine Yellow, which was 0.3658 mg/g. However, for a column test, it was observed that the use of calcined pellets was necessary due to their resilience for this operation. Thus, in batch tests with pellets, the one that exhibited the best adsorption capacity was with Tartrazine Yellow and kaolin waste in pellet form, which was 0.2023 mg/g. In comparison to the dyes, it was observed that Tartrazine Yellow exhibited a higher affinity for removal with the kaolin waste. During the column adsorption tests, it was noted that the effluent flow rate is an important factor in the process, as well as the resistance of the pellets. Finally, it is considered that each process has its advantages, and conducting further column tests with constant flow and recycling may yield additional complementary results.

Contamination derived from offshore oil production and oil spillage at sea has been a major environmental problem. Therefore, the search for effective, sustainable, easy-to-apply and low-cost methods to solve this problem has been the subject of many studies in the last two decades. In addition, research and innovation as a goal in sustainable development, in protecting the environment and the climate and in guaranteeing life in water, are objectives defined by the United Nations so that the 2030 Agenda can be achieved in the world. Thus, synthesizing materials using nanotechnology tools has contributed to achieving these goals. One of the most promising 2D nanomaterials in studies involving environmental issues is reduced graphene oxide (RGO). Produced water (PA) as well as oil removal in seawater. This work was carried out in two stages and in the first, a fluoropolymer/RGO/PA nanocomposite was developed using an HP/HT process followed by spray coating applied in the removal of engine oil in seawater. In the second stage, a nanocomposite was developed in a semi-continuous HP/HT process with in situ reduction of graphene oxide, followed by infrared polymerization. In this step, a 2⁴ factorial design using Design Expert software was used evaluating the factors: temperature (ºC), RGO concentration (mg/L), reaction time (min) and pH were optimized. In both stages, the RGO and the nanocomposites were characterized using DRX, Raman Spectroscopy, SEM-FEG, HRTEM, FTIR and XPS. The results obtained in the first one demonstrated a significant efficiency in the separation of semi-synthetic motor oil in sea water, with an oil removal rate superior to 95%. In the second stage, the results demonstrated a significant efficiency in the contact angle greater than 120° being 55% higher compared to the uncoated polyamide fabric, with a water permeability between 10.1-16.9 mg/cm².h and an increase in the Oxygen content in the water of 81.8%. It is concluded that the developed nanocomposites present a significant advance in oil/water separation and also in the treatment of produced water from produced water, contributing to environmental preservation and sustainability at sea.

Topic drug administration is a non-invasive, easy and advantageous route for the absorption of an active ingredient in the body. As well as in the pharmaceutical area, the cosmetics industry uses this material transfer mechanism in order to prevent degradation caused by interactions with other compounds before absorption through the skin. Among the variety of bioactive delivery systems, organogels have stood out as materials with an interesting structure for the controlled release of bioactive compounds. These materials are semi-solids formed by the mixing of small concentrations of gelator (<15%) and organic solvent. In parallel, an active compound of interest in these areas is vitamin E, an important fat-soluble nutrient, which has antioxidant, humectant and emollient properties, to name a few. In this context, this study aims to prepare and characterize organogels for the delivery of vitamin E for applications in the cosmetics and pharmaceutical industry. Coconut oil (OCO), canola oil (OCA) and oleic acid (AO) were investigated as organic solvents, whereas Tween 80 (T80) and PEG 300 (P300) were investigated as gelators. Firstly, the phase behavior of the systems was studied, and the pseudo-ternary diagrams were constructed. Next, vitamin E was incorporated into the gels, and these systems were characterized through Zeta potential and pH analyses, and the stability and potencial for vitamin E delivery through the gels were evaluated. Finally, the possibility of quantifying vitamin E in the formulations was assessed using the UV spectrophotometry technique.  Solubility tests of the P300-OCO binary mixture indicated a lack of affinity between this structuring agent and the organic solvent. Consequently, PEG-300 was excluded from further investigation. Tween 80 successfully structured the organic solvents in all three studied systems (OCO/T80/water, OCA/T80/water, AO/T80/water), and the gels obtained with the lowest concentration of structuring agent in each system were characterized. Lastly, UV spectrophotometry was not suitable for quantifying the vitamin E incorporated in the gels due to interference caused by the excipients in the absorption of UV radiation at the same wavelength as vitamin E.

Sodium diclofenac (DCF) is an anti-inflammatory with high toxicity and frequently detected in effluents and wastewater treatment plants. Ciprofloxacin (CIP) is an antibiotic that is widely used in clinical and veterinary treatment to prevent bacterial infections, with a high polluting potential. Adsorption using activated carbon has been widely used to remove micropollutants, but this adsorbent requires an expensive and inefficient phase separation step, compromising the efficiency and cost of the adsorptive process. Thus, an innovative and unprecedented process based on ionic flocculation-assisted adsorption (IFAA) using the surfactant sodium dodecanoate was proposed, aiming to increase the adsorption capacity of the process and facilitate phase separation. In the context of the search for bioadsorbents, the potential of sweet sorghum bagasse (NSB) and chemically treated with sulfuric acid (TSB) as adsorbents was also evaluated, aiming to remove DCF and CIP from synthetic wastewater. The efficiency of the processes of adsorption and adsorption assisted by ionic flocculation was evaluated from a kinetic study, equilibrium isotherms, thermodynamic properties and for activated carbon as adsorbent, the kinetics of separation through the sedimentation process was studied. In the study of direct adsorption and IFAA using activated carbon as adsorbent and DCF as a contaminant, the adsorption kinetics followed the pseudo-second order model in both processes. From the equilibrium isotherms, the maximum adsorption capacity obtained was 49.43 and 51.85 mg.g^-1 in direct adsorption and IFAA, respectively, being best represented by the Langmuir model. In the sedimentation analysis, it was noticed that the higher the surfactant concentration, the higher the compaction height, the higher the decantation speed and the shorter time to obtain the clarified effluent. In the adsorption of DCF and CIP in NSB and TSB, the chemical treatment carried out in the NSB modified the lignocellulosic composition of this material, reducing the percentage of lignin by 35%, hemicellulose by 26% and increasing the alpha-cellulose content by 20%. The pseudo-second order model was the one that best fitted the adsorption kinetics of DCF and CIP in both adsorbents, as evidenced by the correlation coefficients and the sum of squares of the residues. The equilibrium isotherms obtained with the adsorbents (NSB and TSB) and the CIP were better fitted with the Langmuir model (R² > 0.98). In the case of DCF adsorption, the Freundlich model provided the best fit (R² > 0.99). The thermodynamic analysis revealed that the processes occurred spontaneously, exothermically and that there is a reduction in randomness at the solid-solution interface. The use of IFAA proved to be effective by increasing the adsorption capacity of the DCF, promoting a better phase separation of the constituents (adsorbent and DCF), making the separation faster and more efficient. The ability of NSB and TSB to adsorb DCF and CIP from water was evidenced, highlighting its potential as an efficient, environmentally friendly and low-cost bioadsorbent.

The problem of water scarcity is worldwide and reaches considerable proportions in some areas of the planet, due to the significant increase of population in these places and the constant climatic changes that have occurred in the last decades, leading to the need to develop some strategies that can achieve development Desalination is a process whereby seawater is transformed into water that can be used for human consumption, agriculture and industry. Currently, this technique has been increasingly used all over the world. It is worth noting that the use of elephant grass coal and domestic sludge for water desalination is a very attractive option considering that both are low cost materials and an abundant source. The high carbon content in these biomasses makes them economically a precursor material for the production of activated carbon, with good applications for the removal of organic and inorganic compounds, in the treatment of water, wastewater and atmospheric emissions. Thus, the present work is motivated to evaluate the efficiency of the desalination of sea water, using as adsorbent coal from elephant grass and domestic sewage sludge

Most solid waste ends up in landfills around the world, which hurts the environment in a number of ways. In particular, rain and waste decomposition in landfills result in the production of an aqueous leachate containing compounds with low biodegradability, high toxicity, and high organic load. To prevent the introduction of this toxic mixture into the environment, remedial measures are necessary. Electrochemical technologies are particularly suitable for wastewater purification and contaminant reuse. Therefore, in this study, the application of electro Fenton (EF) and photo electro Fenton (PEF) processes was investigated to treat local landfill effluent with high conductivity (k = 15.8 mS cm^-1) and high organic content (total organic carbon (TOC) = 1220 mg L^-1). Specifically, a flow cell containing a boron-doped diamond (BDD) anode and a carbon felt (CF) cathode was developed to evaluate the effects of applied current density (30, 60 or 90 mA cm^-2), production of H₂O₂, and the source of UV radiation (UVC and UVA) on the chemical oxygen demand (COD) of the effluent. In addition, acetic and formic acids (final organic by-products of effluent degradation), as well as inorganic ion concentrations (Cl^-, NO₂^-, NO₃^- and NH₄⁺ and PO₄^3-) were evaluated. Maximum degradation and mineralization of the effluent were obtained with increasing applied current density, at which more than 90% of the total organic carbon (TOC) was removed after 240 min of PEF UVC with the BDD anode at 90 mA cm^-2. Therefore, EF and PEF are efficient and effective solutions for the remediation of organic pollutants in landfill effluents, especially when using the BDD anode. The integration of technologies for wastewater treatment can significantly increase the degradation efficiency of organic compounds, as well as make electrochemical technologies a sustainable alternative, through the use of renewable energy for the treatment of leachate from landfills in low-income countries.

Currently, waste electrical and electronic equipment (WEEE) has become an environmental problem that must be managed responsibly, as well as an economic resource that must be exploited in a viable way. For example, printed circuit boards (PCBs), which form part of most WEEE, are made up of hazardous materials such as heavy metals and flame retardants, as well as valuable materials such as base and precision metals, so they must be treated properly. In view of this, the scientific community has dedicated itself to the recovery of this residue. Therefore, the objective of this work is to study the recycling of PCBs from obsolete desktop computers through hydrometallurgical processes, more precisely the modeling and optimization of copper leaching with nitric acid and depolymerization with benzyl alcohol and potassium hydroxide through an experimental design composed central. Therefore, the PCBs were initially pre-treated (dismantled, cut, milled and sieved) to obtain a pulverized material with a granulometry smaller than 2 mm. After that, the pulverized PCBs were characterized through different analyzes (granulometric classification, incineration, digestion in aqua regia, XRF, XRD, ICP-AES, SEM and EDS). Then, the first study evaluated the effects of acid concentration (from 0.2 to 4.2 mol/L), temperature (from 30 to 90 °C), solid/liquid ratio (from 10 to 90 g/ L of PCI/solution) and time (from 30 to 150 minutes) on the copper leaching efficiency determined by molecular absorption spectroscopy analyzes in the ultraviolet-visible (UV-Vis) region. The second study evaluated the effects of hydroxide concentration (from 0.10 to 0.90 mol/L), PCI mass (from 1 to 9 g) and temperature (from 50 to 150 °C) on the efficiency of depolymerization in benzyl alcohol determined by mass balance. The adjusted statistical models for both processes proved to be significant and predictive (R² close to or greater than 0.9) and their optimization resulted in complete recovery of the copper and polymeric fraction of the PCI. Finally, the present study contributed to the development of two viable hydrometallurgical routes for PCB recycling.

The main goal of this doctoral dissertation work was to apply the Excel® spreadsheet tool in the development of photocatalytic transformation process simulators. Toluene photodegradation and methane photoreform were the study cases evaluated for the process simulator. The Visual Basic for Applications (VBA) programming language has been applied to numerical methods and the generation of graphs and an user-friendly interface. The accessibility of Microsoft® programs is also noteworthy, making it more available tool for solving process engineering problems. A model system of the literature describing the kinetics of the catalytic oxidation reaction of toluene was simulated. The concentration profile of the contaminant (toluene) was obtained as a function of the position in the reactor and also of the input data. In explanation, the system and reaction information can be changed to allow the analysis of different reactor dimensions, flow rates, initial concentrations, reaction rates and catalyst characterization parameters. The photocatalysis study was also performed considering a photoreform between methane and water vapor for methanol production. The catalyst is in a fixed bed and accessible to radiation. The simulation was performed considering the model as one-dimensional and steady state. The obtained results were satisfactory for the methane conversion velocity, as well as photoreactor dimension values. For the initial operating conditions the photoreactor length values were 20 cm and radius of 4 cm. The results showed that the developed tool allows the simulation and analysis of the photocatalytic reactions of the systems in relation to the most significant variables and parameters of the process under study.

The concern with global warming has turned necessary the development of viable alternatives to fossil fuels. So, the development of renewable fuels, also known as biofuels, has gained importance. Among the existent biofuels, biodiesel can be highlighted. Biodiesel is a chemical compound formed by esters, which can be methyl or ethyl. Due to their physical and chemical properties, they can be used as a substitute to diesel of fossil source in Diesel cycle motors. Nowadays, the biodiesel production in industrial scale is made, mainly, in batch or continuous stirred tank reactors, which present several dificulties and limitations in productivity and conversion, besides the need for various posterior separation steps. Much effort is being done to develop novel processes that unite reaction and separation steps in one. As result, the membranes emerge as an alternative with great potential of application in the production of biodiesel as a reaction media. Membranes can be defined as selective, partially permeable mediums and are vastly used in many separation processes. In this context, the present work has the aim to develop a continuous process for the production of biodiesel using a membrane reactor from soybean oil, in addition to propose a mathematical model which describes the process in question, from mass and energy balances.

Contamination of water bodies by organic compounds has been a matter of great concern due to its impacts on human health and the environment. Phenol is a highly toxic compound commonly found in industrial effluents due to its high use in several segments. Advanced Oxidative Processes (AOP), which encompass a wide range of techniques for generating reactive radicals, have shown satisfactory efficiencies in the degradation of recalcitrant organic compounds. The heterogeneous Fenton reaction is a type of AOP that employs hydrogen peroxide and solid catalysts containing iron for generating reactive species. This study aimed to investigate the potential application of two industrial waste materials as alternative catalysts in the Fenton reaction for the degradation of phenol in water: coal bottom ash from a thermoelectric power plant and amethyst mining residue (AMR). The materials were characterized using different techniques, such as X-ray diffraction, X-ray fluorescence, scanning electron microscopy coupled with energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and textural analysis. Bottom ash was applied in the Fenton reaction, while AMR was used in the photo-Fenton system. The effects of different operational parameters, including solution pH, catalyst dosage, and H₂O₂ concentration, were investigated. The characterization results indicated that both materials have mesoporous structures with well-distributed active iron species. Regarding the bottom ash, under optimal conditions, which involve the use of 1 g L^-1 of catalyst, 6 mM H₂O_2, and pH = 3, a phenol degradation efficiency of 98.7% was observed after 60 min of reaction, along with 71.6% organic carbon removal after 150 min. AMR, used in the photo-Fenton reaction, exhibited 96.5% degradation under optimal conditions (0.75 g L^-1 of catalyst, 7.5 mM H₂O_2, and pH = 3) after 180 min, removing 42.3% of the organic carbon after 240 min. Through tests with the addition of isopropanol, it was verified that the hydroxyl radical is the main oxidizing agent involved in the cleavage of the phenol molecule for the two studied systems. Regarding the reuse tests, both catalysts showed stability and satisfactory catalytic activity through four consecutive cycles. Therefore, the obtained results demonstrate that the two waste materials displayed potential activity for application in Fenton reactions for degrading phenol.

During the different stages of well development and reservoir exploration, there is the possibility of the occurrence of unwanted phenomena that alter the permeability of the region (formation damage), compromising the production of hydrocarbons. The well stimulation techniques seek to bypass or reverse this damage and, consequently, increase production. Matrix acidizing in carbonates consists of injecting an acidic fluid into the well to increase its production by dissolving the rock matrix itself, creating pathways known as wormholes. Hydrochloric acid (HCl) is the most used substance to stimulate production or injection wells in carbonate reservoirs. However, the high reaction rate of HCl with carbonate reduces its penetration into the rock formation since the acid reacts excessively with the surface of the reservoir (face dissolution). Thus, to minimize acid consumption and increase the depth of wormholes, it is necessary to develop stimulation fluids containing additives that reduce the dissolution rate of the carbonate matrix by acid. The present study aims to develop stimulation fluids and investigate the physicochemical phenomena of alcoholic micellar systems containing ethanol, 15% HCl (w/w) and polyethoxylated nonylphenol with 11, 40 or 100 ethoxy groups (NP 11EO, NP 40EO or NP 100EO, respectively) in the creation of wormholes in acid stimulation processes in carbonates. To do so, characterization analyses will be carried out for the fluids developed and carbonate samples. In addition, compatibility tests of the components of the developed fluids, reactive flow in porous media tests (injection of the formulations in rock samples) and computerized microtomography of acidified rocks will be performed. Therefore, it is expected to obtain delayed action stimulation fluids that are stable, easy to prepare and with adequate physicochemical characteristics for a more efficient acid stimulation of carbonate matrices.

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One way for coconut companies to increase their cost-benefit and reduce the dependence on non-renewable energy sources is by using green coconut fibers (GCFs) in value-added products. In this study, GCFs were pretreated with choline chloride ([Cho][Cl]) in an acidified medium with diluted sulfuric acid to enrich cellulose on the solid fraction and lignin on the liquid fraction. The aim was to evaluate the feasibility of obtaining 2G ethanol from simultaneous (SF) and semi-simultaneous fermentation (SSFS) strategies. The study also examined the recycling of pretreatment effluents and their impact on enzymatic hydrolysis and fermentation stages. The pretreatment was conducted in an autoclave (1 atm, 121 °C) without or with diluted sulfuric acid (1.0%, w/w), using different concentrations of [Cho][Cl] (50 and 75%, w/w) and incubation times (25 and 50 min). The pretreated GCFs were then submitted to enzymatic hydrolysis (20 FPU/g), and the best condition was chosen for the SF and SSFS fermentation processes. Additionally, the research has investigated the removal of lignin from the liquid fraction for use as a coagulating agent in oil-contaminated water. The results showed that pretreatment with [Cho][Cl] at a concentration of 75% (w/w) in 50 min of reaction time and an acidified medium with 1% (w/w) of diluted sulfuric acid (C75/50m/H) as the best pretreatment to increase the conversion of cellulose into glucose, reaching 22.6 g/L of free sugar. The SSFS achieved the best efficiency of 32.43% (23.2 g/L alcoholic concentration) and a productivity of 0.483 g/L.h for the condition of 20% solid load in obtaining 2G ethanol. Furthermore, 82.6% of the lignin was recovered from the liquid fraction of this same pretreatment, wherethe application of lignin in the treatment of water contaminated with oil achieved removal of 99% of oil from the aqueous phase. Therefore, GCF pretreated with choline chloride has the potential for 2G ethanol production. Furthermore, the use of lignin generates an adsorbent with the potential to be used in different processes, including in the petroleum industry.

Keywords: green coconut fiber, pretreatment, choline chloride, ethanol 2G, contaminated water.

In recent years, humanity has advanced in many ways, but it has also caused serious damage to the environment. Human activities such as burning fossil fuels, deforestation and waste production have generated pollutants that affect air, water and soil quality. In this scenario, the contamination of water bodies has become a serious environmental problem due to issues related to the improper disposal of effluents contaminated by heavy metals. As a result, this heavy metal pollution has serious consequences for the health of people and ecosystems. In light of these facts, this thesis aimed to evaluate the potential of using bioadsorbents obtained from cashew leaves (CL), carnauba straw (CS) and the extraction of lignin from green coconut fiber (GCF) to remove copper ions from synthetic effluents. Nevertheless, the feasibility of using an organic molecular sensor obtained from the synthesis of sodium levulinate (NaLev) for the colorimetric detection of copper ions was evaluated, which constitutes a simple and efficient alternative for on-site analysis of metal ions in aqueous solution. To this end, adsorption studies were carried out in a batch system and the effects of pH, adsorbent concentration, particle size and initial adsorbate concentration were evaluated. In order to extract the lignin from the GCF, an alkaline pre-treatment with 2% sodium hydroxide was carried out, followed by impregnation with sodium octanoate to improve the adsorption capacity of this bioadsorbent. NaLev was synthesized by hydrating levulinic acid with distilled water and adding 20 g of sodium hydroxide.  The concentrations of copper, NaLev and then the Cu-NaLev mixture were determined by molecular absorption spectroscopy in the ultraviolet and visible (UV-Vis) regions. The effects of different concentrations of copper ions and NaLev on the maximum absorbance and wavelength were evaluated. The experimental CS data were best fitted by the Langmuir monolayer model, while the CL data were fitted by the Freundlich model. For the same experimental conditions, the maximum adsorption capacity for copper (II) was 9.51 mg.g-1 and 1.73 mg.g-1 for CS and CL powders, respectively. For GCF lignin impregnated with surfactant, the results of the adsorption study revealed that the adsorption capacity improved due to the increase in the number of functional groups on the bioadsorbent surface. The results of the calorimetric sensor evaluation showed that the addition of NaLev significantly increased the absorbance as the wavelength decreased from 810 to 575 nm in the samples without and with NaLev, respectively. In addition, the color intensity of the solution containing copper ions increased as the concentration of NaLev increased. The results showed that it is feasible to use lignocellulosic biomass to remove copper ions since the removal capacity is similar to other traditional sources of adsorbents. It was also observed that alkaline pre-treatment and impregnation using the surfactant carried out in the GCF was effective in obtaining a bioadsorbent with adequate copper ion removal capacity. Finally, the NaLev colorimetric sensor for detecting copper ions appears to be a promising class of biobased heavy metal-free colorimetric sensors

The problems of access to water, energy and food tend to worsen in the coming decades as a result of the increase in the world population, which is expected to reach 9.7 billion people in 2050. The solutions to these problems are the treatment of contaminated water and the use of renewable energy sources. However, a high number of synthetic organic compounds, such as industrial chemicals, pesticides, dyes and pharmaceuticals are released daily into many wastewaters and enter the aquatic environment in different ways, including the direct disposal of industrial effluents and wastewater or from wastewater treatment plants that do not meet their obligations. Electrochemical Advanced Oxidation Processes (EAOPs Electrochemical Advanced Oxidation Processes) have some advantages over AOPs. The addition of chemical reagents is not necessary, as •OH is directly generated by the oxidation of water and contaminants that do not react with the hydroxyl radical can be degraded by EAOPs via direct electron transfer reactions. In addition, the acid boundary layer, which is produced on the surface of the anode due to water oxidation, protonates the HC to H2CO3 and thus prevents the scavenging of hydroxyl radicals associated with HC present in natural waters. From an economic point of view, it is necessary to plan electrolytic devices that make the electrochemical oxidation of organic pollutants coupled with the cathodic hydrogen production a productive and viable process.

The Brazilian semi-arid region, in certain periods, suffers from water scarcity. In addition to insufficient rainfall, another factor that contributes to this scenario is the presence of shallow crystalline soils, which impair water storage in underground aquifers. However, even if stored in high amounts in aquifers, due to the high amount of salts, the water becomes unfit for human consumption. According to Ordinance 2,914/2011 of the Ministry of Health, in the long term, water with a high amount of ions in solution may lead to health complications for individuals who consume it. To solve this problem, the use of desalination techniques is recommended. The present study was carried out based on physical-chemical data from well water in the community of Boa-Fé in Mossoró/RN, based on data collected by Antas (2017), and a strategy for recovering salts and obtaining drinking water. A fractional crystallization study was then carried out based on solid-liquid equilibrium diagrams, applied to the NaCl-CaCl2-H2O system at different operating temperatures (50 °C and 75 °C). The first stage of the project was based on the study of the system at 75 °C, from which it was possible to define crystallization routes (Strategy A1, B2, C3, and D4). In this condition, the route that showed the best performance in removing the salts was Strategy B2, which showed extraction of 83.85% of NaCl and 72.16% of CaCl2.2H2O. Even though the percentages were high, they were not enough to bring the system to the value established for the potability standard. It was, therefore, necessary to start the second stage of the study, in which optimization strategies were defined that would lead to greater recovery of these salts: cooling the process to a temperature of 50 °C (Optimization 1); dilution of the output current to the system at 75 °C (Optimization 2); the dilution of the output current for the system cooled from 75 °C to 50 °C (Optimization 3). Strategy B2 plus Optimization 2 proved to be sufficient to obtain water within potability standards. This strategy resulted in a recovery of 95.48% of NaCl and 92.20% of CaCl2.2H2O. However, among all of them, the one with the best recovery rates was Strategy B2 plus Optimization 3, which extracted 97.09% of NaCl and 94.82% of CaCl2.2H2O. In a third moment, the simulation of the fractional crystallization process was carried out in the SPECS v5.63© program, to compare the methodologies and validate the strategy established through the equilibrium diagrams. However, the thermodynamic model extended UNIQUAC and the equation of state SRK, used by the program, are not suitable to describe an electrolytic system. For this reason, the comparative study carried out revealed a significant difference between the methods, of approximately 11.15%. In conclusion, it was found that the study proved to be effective in proposing strategies for recovering salts and obtaining water within potability standards.

A challenge upon nowaday’s society is the reuse of electric wire and cable, which most of the efforts are directed in the recovery of the metal, while the polymeric fraction is incinerated. This method is, however, causing environmental issues, therefore, being necessary research for alternative ways of recycling. Cross-linked polyethylene (XLPE) is used as an insulator in high voltage electrical cables and wires and recycling it requires bigger efforts, once its thermoset nature precludes the utilization of traditional process. The present work aims to evaluate the efficiency of fast and catalytic pyrolysis as an alternative for XLPE conversion into fuel material with high energy density and economic value. Thereunto, it will be done characterization of XLPE, in order to determine its energetical potential by thermogravimetric analysis (TG), volatile content, ashes content, X-ray fluorescence (XRF) and calorific value. Kaolin was used as catalyst and characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis, with the goal to study its application as a low-cost catalyst in the pyrolysis process. XLPE pyrolysis analysis were developed in a HP-R 5200 CDS Analytical micropyrolyzer linked to a  gas chromatographer  with mass spectrometer detector (GC-MS). XLPE characterizations assessed that this is a low ash (1,0%) and volatile (98,70%) content polymer, being, therefore, a good material capable of generating liquid products by pyrolysis. This process is important to raise energy density of this material, which was quantified in 44,58 MJ/kg, by converting its molecules into the ones contained in the most popular fuels for commercial use. The use of kaolin as a catalyst led to a decrease in the relative concentration of hydrocarbons in the range of diesel (C₈-C₂₄) from about 87% to 28%, and lubricating oils (C₁₄-C₅₀) from about 70% to 13%, in detriment of an increase in lighter hydrocarbons in the gasoline range (C₈-C₁₂) from around 28% to 87%. . Lastly, this process showed a great potential to transform  the studied material into commercial use fuel and can be considered as a sustainable alternative for the management and reuse of this plastic waste.  

The residue generated by the green coconut production chain has caused a series of environmental and public health problems as it is a bulky organic material with slow decomposition. An alternative for its use would be in the application in production processes of lignocellulolytic enzymes via semi-solid fermentation (FSS), but a pre-treatment step is necessary to reduce the lignocellulose recalcitrance and the lignin and hemicellulose content in the material, because of that these compounds limit the accessibility of microorganisms. Studies indicate that, for a better induction of cellulase production by FSS processes, pre-treatment or their combination more efficiently exposes cellulose to filamentous fungi. In addition, the use of a suitable solvent during enzyme extraction after FSS also has a strong impact on the performance of cellulase production. Therefore, this study aimed to evaluate the production of cellulases using coconut fiber pretreated by steam explosion combined with alkaline pre-treatment (PV+A) by FSS using filamentous fungus Trichoderma reesei CCT-2768, evaluating the culture conditions (water activity and amount of substrate) through central rotational composite design (CCR), with Carboxymethylcellulase (CMCase) and Filter Paper enzyme activity (FPase) as responses. The combination of pre-treatments was more favorable for the removal of hemicellulose from green coconut fiber, reducing the content of this polymer from 10.15%, about the untreated biomass, to 5.38%, while the content of lignin increased from 21.32% to 34.82%, which may be associated with the lignin rearrangement effect during the biomass cooling process in the pre-treatment. Regarding the SSF of the pre-treated PV+A coconut fiber, it was observed that the solids load significantly influenced the behavior of CMCase in the cultivation, and water activity was shown to be a significant factor in both analyzed enzymes. It could be noticed that greater production of cellulolytic enzymes occurred in the semi-solid culture conditions in which the water activity is 0.995 and 5.25 g of substrate, obtaining an enzymatic activity of CMCases close to 3.0 IU/g, and for FPases, a value of 0.31 IU/g. When the best solvent for cellulase extraction was evaluated, the saline solution of 154 mM NaCl was more efficient in the recovery of the enzymes, producing an extract with the activity of 5.19 IU/g for endoglucanase and 1.19 IU/g for the FPase. Therefore, the best conditions of water activity and solids loading for the production of cellulases were identified, when using the fungus Trichoderma reesei CCT-2768 and coconut fiber pretreated by a steam explosion followed by alkaline pre-treatment, achieving good values of CMCase and FPase activities are found.

Endophytes, which can be bacteria, fungi or protozoa, are poorly studied. It is estimated that there are more than 250,000 different species of plants and one million endophytes in the world, which characterizes an average of four species associated with a plant species. Because they are inside the plant, these microorganisms can be a rich source of biomolecules of industrial interest, such as the production of hemicellulolytic enzymes. In this context, this study has the general objective of studying the ability of the endophytic fungal species, Achaetomium lippiae URM 7547, little mentioned in the literature, to produce cellulases and xylanases by means of a submerged cultivation using the fiber of the pre-green coconut husk as a substrate. - Treated by steam explosion. Initially, the potential of A. lippiae URM 7547 to produce hydrolases (amylase, lipase, protease, cellulase, xylanase and pectinase) in solid culture medium (72h at 30°C) with substrates in each specific enzyme was evaluated. configure it as an enzyme producer. For comparison of results, growth of CCT 2768 under the same induction conditions was used. A. lippiae URM 7547 presented itself as a potential producer of amylases, proteases and cellulases, with an enzymatic index greater than 1.5 (IE > 1.5) as well as T. reesei CCT 2768. It was also quantified, the yield of substrate conversion into cell biomass (Y_x/s) of A. lippiae URM 7547 and its maximum growth rate (µ_max) in liquid medium containing glucose and xylose and three concentrations of substrates and nutrient media with carbon sources and nitrogen in order to verify if the fungus is adept to submerged crops and what is the best condition for its growth. The best results for the liquid medium containing glucose were in 96h of culture in medium 3, containing peptone and yeast extract, with Y_x/s equal to 0.062 ± 0.04 g.g^-1, 0.072 ± 0.04 g.g^-1, and 0.076 ± 0.03 g.g^-1, for concentrations of 5, 10 and 20 g.L^-1 of substrate, respectively. For the medium containing Xylose, the best result was during 144h of cultivation with Y_x/s values equal to 0.52 ± 0.08, 0.59 ± 0.09 and 0.65 ± 0.03 g.g^-1 for 5, 0, 10.0 and 20.0 g.L^-1, respectively, also in medium 3. Finally, the submerged fermentation was started to produce cellulases and xylanases. The lignocellulosic characterization of green coconut fiber in natura and post pre-treatment by steam explosion carried out with the purpose of verifying the performance of the pre-treatment was the penultimate step of the dissertation. After pre-treatment, there was a 14% decrease in extractables in relation to in natura fiber, since it is easily removed by solvents; an 8% increase in cellulose and a 6% decrease in hemicellulose; lignin remained statistically the same (p>0.05). In FSm, the Q Assay with condition of 33°C, 10⁹ spores.mL^-1, and 30.0 g.L^-1 of substrate, was the one that presented the best yield in relation to the four quantified enzymes, with enzymatic activities (U.mL^-1) of 0.41 ± 0.06, 5.94 ± 0.31 and 0.08 ± 0.035 and 9.12 ± 0.28 for FPase, CMCase, Cellobiase and Xylanase, respectively. Finally, A. lippiae URM 7547 was a good producer of cellulases and xylanases, in addition to other hydrolytic enzymes such as amylases and proteases, with an excellent growth performance in submerged media.

In artificial lift, Automation techniques are also used in order to increase the efficiency and production of oil wells. In the Electrical Submersible Pump (ESP) lift method, the use of Automation tools becomes essential in the interpretation of data available in the field, since the analysis of these data is not always sufficient to analyze, interpret, monitor and diagnose the performance. and well integrity, in addition to ESP operation and real-time efficiency. However, even though these wells operate with automated systems, some production damages can be identified decreasing the efficiency of the ESP pump and even having significant production losses. Initial diagnosis of the ESP system can lead to great cost savings and less maintenance due to technologies implemented in production fields. In oil fields, to identify the operating conditions of a ESP well, amperimetric charts are used, which are current versus time graphs. The analysis of these charts is usually performed by operators who have a large number of wells to examine, and this overload often decreases the efficiency in the process of reading the operating conditions of the ESP pump. Currently, real-time technologies based on Machine Learning algorithms (ML) have challenged and encouraged companies to create solutions for early diagnosis of abnormalities in well operation. Thus, this work aims to provide a proposal for detecting the operating conditions (normal operation, normal operation with gas, gas interference and gas blockage) of the ESP pump from the analysis of electrical current data obtained from 24 wells from Mossoró, RN, Brazil. Machine Learning classification algorithms were implemented in the Python programming language in the Google Collaboratory environment. The classification algorithms used were Decision Tree (DT), Support Vector Machine (SVM), K-Nearest Neighbor (KNN) and Multi-Layer Perceptron Neural Network (MLP). As the data sets had points ranging from 159 to 344, a standardization was performed with an interpolation technique so that all data sets had 344 points, the maximum number of points collected. The algorithms were tested without and with hyperparameter tuning, in which the hyperparameter set was specific for each ML technique. In addition, balancing tests (oversampling) of the training datasets were performed to identify the difference in relation to the unbalanced dataset. The results obtained and presented throughout the work confirm that the application of the ML algorithm is viable for the classification of the operating conditions presented, since all of them had an accuracy greater than 87%, with the best result being the application of the SVM model, which reached an accuracy of 93%.

The search for process intensifying methods is one of the targets of chemical engineering, including in classical processes such as liquid-liquid extraction. The separation of biomolecules uses this type of extraction and the search for intensification has gained prominence in the literature. However, studies on the evaluation of the impact of flow patterns on extraction performance are still scarce, especially in complex environments with multiple target molecules such as the products of cell lysis. Thus, in this work, invertase from Saccharomyces cerevisiae was separated using the liquid-liquid extraction technique in a microsystem through a aqueous two-phase system (ATPS) formed by polyethylene glycol (PEG) 1500 (15% w/w), magnesium sulfate ( 20% w/w) and distilled water (65% w/w). The study was carried out using different operating conditions, including variations in total flow from 9.30 μL/min to 324.45 μL/min, volumetric ratio between top and bottom phases from 1:2 to 2:1, diameter of 0.51 to 2.06 mm and tube lengths from 0.58 to 9.40 m. The arrangement of the phases was observed during the course in the microsystem using a wide range of total flow and a flow pattern map was obtained. The patterns observed were short-slug, slug and parallel, with the short-slug pattern for low flows and parallel for high flows. It was found that increasing the total flow negatively affected the recovery of invertase during extraction, while higher values of residence time and volumetric ratio improved the recovery and the enzyme purification factor. Using 35 min residence time, 2:1 volumetric ratio and 1.14 mm tube diameter, the short-slug and slug patterns showed the best process performances. These results reached, numerically, the values of 53.95% and 51.15% of invertase recovery and purification factor of 1.84 and 2.78, respectively. The effect of the channel diameter was also studied and it was concluded that in smaller diameters, the recovery obtained better results, highlighting the value of 57.01% of invertase recovery and a purification factor of 4.16 in the 0. 51 mm diameter when the residence time was 35 min and the volumetric ratio was 2:1. The best result can also be justified by the value of the maximum volumetric mass transfer coefficient (kLa) obtained of 8.86 x 10^-4s^-1 when compared with the resulting values for the other operating conditions. Thus, the present study contributes to the development of knowledge in the area of microsystems in problems of enzyme separation through liquid-liquid extraction.

Plants began to be used for therapeutic purposes from the beginning of human history and it was in the search for food for their survival that many toxic or healing properties of various plants were discovered. Many plants of the Brazilian flora have been used to treat diseases and natural products are becoming increasingly important and becoming an alternative to synthetic remedies. Copaiba oil-resin is a natural antibiotic with great potential for effectiveness against gram-positive bacteria, being widely used as a healing and anti-inflammatory in the treatment of infections. The study will be carried out by developing emulsions using copaiba oil resin, Tween 20 and distilled water, through an experimental design called Scheffé Network to evaluate which formulation has the best performance. The emulsion with the best performance will be submitted to rheological tests, pH tests, stability tests and evaluation of the synergistic effect of the antioxidant activity. The project will be carried out at the Laboratory of Technology of Surfactants and Separation Processes (LTT-IQ) in partnership with the Laboratory of Biotechnology of Natural Polymers (BIOPOL-CB), the collaboration enables the performance of the proposed analyses.

Biogas has a huge potential for applications, which can be of the most varied. The high content of methane in its composition makes it an extremely interesting gas for use as a source of thermal energy. However, the presence of hydrogen sulphide poses a problem for the use of biogas. Taking into account the rural context in Brazil, the benefits that can be obtained by the application of technologies based on biogas can be immense, but first of all, it is necessary to be concerned with safety in the use of this mixture of gases, then methods for removal of hydrogen sulphide become of great interest, mainly methods that are accessible, given the difficulty of access to products and equipment to carry out the removal process. Industrially, there are already some well-known and widespread methods for the removal of hydrogen sulfide, highlighting chemical absorption, through the use of amines in the process, which can then be recovered, but bringing to the context of the brazilian semi-arid, industrial methods, despite being effective, require a large amount of resources in this context. Using a sodium hydroxide solution as a solvent in the hydrogen sulfide absorption process presents itself as an alternative that can have a good application potential, both in terms of cost and in terms of reagent accessibility, thus determining better operating conditions, using experimental planning techniques to carry out the experiments, is very important in the application and diffusion of this type of technology.

In view of the environmental conditions in the world today, the demand for renewable energy sources has increased more and more due to the need to reduce the pollution generated to the environment when using fossil fuels. Biodiesel stands out as one of these new energy sources due to its great variety in the raw materials that can be used in its production and also because of its biodegradability. The sesame seed presents in its Composition a high oil content and its cultivation is favorable due to its ability to adapt to regions with a dry climate. Initially used in the food industry, the oleaginous seed shows potential as a natural source for biodiesel production, and this process has received substantial incentive through tax benefits on the purchase of biofuel from this plant. The transesterification reaction of sesame oil under supercritical conditions appears as an alternative to the most common method of biodiesel production, the catalytic transesterification, because there is no need to use a catalyst in the reaction, resulting in a simplification and possible savings in the process. This study used sesame oil and ethyl alcohol to produce biodiesel under supercritical conditions. The sesame oil physicochemical properties were determined, such as: density, acidity index, fatty acid content, viscosity and humidity. In the assays a continuous flow reactor of 15 mL volume was used, the system pressure was kept at 100 bar, varying the reaction temperature in the range 310-390 °C, with a residence time of 15-45 min and a molar ratio oil:ethanol of 1:30-1:50. From the results obtained in the variation of the operational parameters a statistical analysis was performed in order to verify the influence on the reaction yield. The best result obtained
was 87.45 %, at a temperature of 390 °C, residence time of 45 min and molar ratio oil:ethanol of 1:40. The statistical analysis revealed a greater influence of temperature and residence time on the results.

Soil and groundwater pollution is a problem that affects developed and developing countries due to acceleratedindustrialization and urbanization in the last decades. In this context, the aim of the present thesis is to use combined technologies (soil washing in pre-pilot system on a laboratory scale and on a pre-pilot scale using a fixed bed column, investigating the use of anionic, cationic and nonionic surfactants. the use of reactive permeable barriers of cork in order to remove the organic compounds in the fixed bed column in laboratory scale and pre-pilot.However, another important parameter to be studied is the treatment of the effluent generated during the process of washing the soil, for this reason will be investigated the advanced electrochemical oxidative processes, in order to remove the organic compounds present.

The selective production of valuable products for chemical industry such as γ-butyrolactone (GBL), tetrahydrofuran (THF) and 1,4-butanediol (BDO) that results from the catalytic hydrogenation of fumaric acid (Ac.FUM) is a quite interesting subject in the field of biomass valorization. In fact, these products can be considered bioplatforms of molecular construction, functioning as a starting point for countless synthesis processes. From the point of view of green chemistry, water and CO₂ are considered ideal solvents to drive this type of chemical transformation. Although achieving good conversion rates and selectivity in these reaction media the catalytic performance of this hydrogenation reaction can be a challenge, even when a suitable catalyst is employed. In this context, this process was studied and optimized, firstly through experimental design using a catalyst based palladium-rhenium on silica (Pd-Re/SiO₂), and a second catalyst  based iridium-rhenium on silica (Ir -Re/SiO₂), barely used in the literature, for selective hydrogenation of Ac.FUM in GBL is an aqueous medium. The catalysts were synthesized by sequential wet impregnation, and characterized by XRD, RTP, ICP, TEM and surface area analysis. Reaction products were identified by GC-FID and HPLC-RI. In a second moment, supercritical CO₂ was used as a reaction medium to optimize the process, varying pressure between 105-300 bar under the temperature conditions of 60-250 ºC. Finally, solvent evaluation was studied in the reaction selectivity, where methanol was also used under conditions 60-250 ºC and 10-300 bar. The results of Ac.FUM hydrogenation using catalysts based on palladium-rhenium and iridium-rhenium showed that GBL was produced with 91 and 90% selectivity, respectively, under the optimized conditions of pressure and temperature predicted by the empirical model of 188 °C and 41 bar of H₂ for Pd-Re/SiO₂ and 210 °C and 25 bar of H₂ for Ir-Re/SiO₂. Thus, the experimental design allowed a high selectivity to be obtained in an aqueous medium, providing better rationalization of the combined effect of the temperature and pressure variables. Furthermore, statistical analysis in experimental design showed that temperature has a greater effect on GBL selectivity in relation to H₂ pressure, being non-linear for both catalysts. In studies using supercritical CO₂ it was possible to model the catalytic activity, suppressing the formation of by-products and obtaining 89 % and 64% selectivity for GBL using Pd-Re/SiO₂ and Ir-Re/SiO₂, respectively, under optimized operating conditions. The addition of methanol as solvent changed the composition of products, obtaining THF as the major product, with a maximum selectivity of 97 % under the conditions of 175 °C, 50 bar of H₂ and 150 bar of total pressure for Pd-Re/SiO₂, and 89 % under conditions of 175 °C, 50 bar H₂ and 300 bar total pressure for Ir-Re/SiO₂.

Spinels are magnetic semiconductor ceramics where the cationic distribution is given by the equation M 1-x 2+Fe x 3+[M x 2+Fe 1-x 3+] O42-. Due to the variable atomic arrangement, determined by the type of cation present in the structure and the method of obtaining it, ferrites are multifunctional materials. The application of these materials in electrochemistry has been growing over the years and the possibility of using ferrites as electrodes, either for charge storage devices or in water splitting reactions, brings great opportunities for nanotechnology researchers. In this work we present the synthesis of nickel ferrite nanoparticles (NiFe2O4) by the combined EDTA-Citrate complexation method. We studied the influence of reaction pH (3, 5, 7 and 9) on powder properties and the influence of temperature on phase formation when the reaction pH was set at 7. Structural, morphological, optical, magnetic and electrochemical properties were evaluated. The results confirmed the obtaining of single-phase NiFe2O4 powders at all pH studied (3, 5, 7 and 9) with nanoscale particle size (15-93nm). The morphology of the powders was affected by the reaction pH and exhibited rounded shapes, undefined shapes and triangles. UV-vis analysis reveals an inversely proportional relationship between crystal size and band gap. The isothermal hysteresis at 5 K and 300 K showed ferrimagnetic behavior for all samples obtained. The samples obtained without pH 3 and 9 were tested in an electrochemical cell in alkaline solution and it was found that for the purpose of use in energy storage devices the material was classified as battery-like electrodes. The improved electrochemical behavior of the NF9 sample (Qs = 65 C g-1 in 3 A g-1) was attributed to an increase in faradaic reactions driven by the porosity difference on the surface of the sample agglomerates and the boundary limits of the grains responsible for lower resistance to charge transfer. The NIFe2O4 powders, obtained at pH 7 at 400, 500 and 600 °C, were studied in alkaline solution as electrodes in oxygen evolution reactions reaching an overpotential of 326 mV vs. RHE to generate a current density of 10 mA cm-2 for samples calcined at 400°C. The improved electrochemical behavior compared to literature data was attributed to the microstructural characteristics that affect the charge and mass transport processes and to the reduced particle size.

In addition to heavy metal pollution, the environment faces contamination through organic components. Related to the oil industry, soil fuel pollution is generally related to accidental spills during handling, transport or storage activities in underground storage tanks, distribution systems or industrial crude oil refining activities. This is a serious environmental issue, due to the high negative impact of fuel contamination on the quality of water reservoirs, which prevents the use of this water for human consumption and the dangerousness of the chemical species contained in the fuel for the organisms that live in the soil. In order to fulfill these objectives, electrokinetic remediation combining granules of cork as a reactive permeable barrier and surfactants / chelating agents with low environmental impact are the technologies chosen for the study of the removal efficiency of the contaminants presented in this project, with the purpose of producing and contributing with new data on soil decontamination to be applied on a large scale.

The green coconut fiber has been pointed out as an interesting alternative for the production of bioethanol, as Brazil has one of the largest global productions of the fruit and its inadequate disposal causes environmental problems. However, the high recalcitrance of green coconut makes it difficult to convert it into large volumes of bioethanol. Pretreatments are necessary to destroy the crystalline structure of cellulose and increase the efficiency of enzymatic hydrolysis. Steam explosion pretreatment has a low environmental impact and whose main consequence is the removal of hemicellulose. Furthermore, the addition of non-ionic surfactants in the bioethanol production process has been studied as a strategy to increase its production and yield. Among these, Tween 80 stands out because it has a lower cost than other additives. The goal of this study was to evaluate the ethanol production from green coconut fiber using a combined steam explosion and alkaline pretreatment, comparing the simultaneous saccharification and fermentation (SSF) and semi-simultaneous saccharification and fermentation (SSSF) strategies. The use of Tween 80 in the pretreatment, enzymatic hydrolysis, and fermentation steps was also investigated. Initially, the influence of the temperature and humidity in the steam explosion pretreatment were evaluated in the glucose production. As there was no delignification after steam explosion, and to increase enzymatic digestibility, an alkaline pretreatment with sodium hydroxide was carried out in sequence. The combination of steam explosion pretreatment and alkaline pretreatment of green coconut fiber led to cellulose contents above 47.22 ± 1.06% (w/w), which initially were 30.68 ± 0.52% (w/w), and maximum glucose yield equal to 54.74%. Surfactant did not increase delignification in the steam explosion pretreatment, however it increased the conversion to glucose when compared to experiments without Tween 80. The use of surfactant in enzymatic hydrolysis increased glucose production reaching a maximum value of 20.31 ± 0.48 g/L with combined pretreated biomass when 1.0% (w/v) surfactant was added. In the absence of surfactant in any steps, the SSSF strategy stood out over the SSF. SSSF increased the yield and ethanol production and the strain that obtained the best production was Saccharomyces cerevisiae PE2, reaching a maximum ethanol production equal to 24.88 ± 1.04 g/L under 15% (w/v) solids. Different effects of Tween 80 were observed during fermentation. The use of 2.0% (w/v) Tween 80 reduced cell viability as well as reduced ethanol production in simulated medium, in SSF and SSSF. On the other hand, the use of 1.0% (w/v) Tween 80 increased the average ethanol production, although not enough to be statistically significant. To increase ethanol production under 30% (w/v) solids loading, SSSF variations were performed, including batch addition of biomass, batch addition of enzymes and temperature variation every 6 h. SSSF with non-isothermal batch feeding and gradual addition of enzymes stood out, reaching a maximum ethanol produced of 48.21 ± 1.13 g/L in the presence of 1.0% (w/v) Tween 80. Therefore, the results show that the use of the combined pretreatment generated a biomass with high cellulosic content that has a great potential for cellulosic ethanol production when fermentation strategies with Tween 80 were evaluated.

In recent years there has been growing concern about the contamination of water by emerging contaminants - substances that are not completely degraded by conventional processes of water and wastewater treatments and are not biodegradable. For this reason, several techniques have been developed to efficiently treat such compounds. In this work, different heterojunctions of ZnO/g-C₃N₄ and ZnFe₂O₄/g-C₃N₄ in different mass proportions of g-C₃N₄ (10, 50, and 80 %) were synthesized through a simple method of mixing, sonication and heat treatment. The influence of the amount of g-C₃N₄ in the heterojunctions as well as the influence of the type of zinc-based catalyst on the structural, morphological, optical, and photocatalytic properties of the materials were investigated. The XRD, FTIR, and SEM/EDS results confirmed the achievement of the desired heterojunctions. The incorporation of g-C₃N₄ was relevant in modifying the textural and optical properties of the heterojunctions produced. The 50-Zn/gCN heterojunction showed better photocatalytic degradation of the antibiotic cefazolin (78 %) and the dye RB5 (95 %) in 120 min of the experiment, when compared with the pure materials and with the other heterojunctions. In addition, it exhibited faster reaction kinetics and good photostability. The best photocatalytic performance presented by this material can be attributed to the real synergistic effect between ZnO and g-C₃N₄, which promoted relevant interaction in a possible mechanism of Z scheme type, as verified in the PL analysis. The results of the experimental design showed that the catalyst concentration and the pH are the variables that most influence the cefazolin photodegradation, whereas for RB5, all the evaluated variables were significant for 95% confidence. 50-Zn/gCN exhibited 100% degradation for both contaminants evaluated in 90 min of reaction for cefazolin and in 10 min for RB5, under the following conditions: catalyst concentration 0.5 g L^-1, contaminant concentration 5 mg L^-1 and pH 2.5. Adsorption played a key role in the photodegradation of RB5. However, the degradation of the dye (adsorbed and remaining in the solution) and the regeneration of the catalyst surface were due to photocatalysis. The Z-scheme mechanisms for the photocatalytic reactions of cefazolin and RB5 have been adequately proposed, in which the photogenerated holes in the valence band of ZnO and the electrons in the conduction band of g-C₃N₄ were the main degradation pathways of cefazolin and RB5, respectively. The evaluated heterojunction showed good photostability for both contaminants. Finally, the promising character of 50-Zn/gCN synthesized for application in photocatalytic reactions mediated by sunlight for the degradation of contaminants of different classes, as well as the possibility of its use as an efficient alternative to minimize water pollution caused by overuse of medication during the COVID-19 pandemic. 

The increase in the consumption of pesticides, including herbicides, has caused a series of discurssions regarding its application and their consequences for humans and the environment. One of the most widely used herbicides in the world is 2,4-dichlorophenoxyacetic acid (2,4-D), however, its presence has been reported to be present in water bodies, causing impacts on the health of animals and humans. To degrade this contaminant, in this work copper ferrite (CuFe2O4) was synthesized using coprecipitation method and tested in photocatalytic reactions for the degradation of 2,4-D herbicide in aqueous solution, through heterogeneous photocatalysis with and without the addition of auxiliary oxidizing agents. The samples were was synthesized using the ratio 0.1 and 0.5 metal / base, using two types of salts, one with the Fe2+ ion and the other with the Fe3+ ion. A sample by the Pechini method was synthesized for comparative purposes. The catalysts were collected in a thermogravimetric test and calcined at 600°C. X-ray diffractograms were performed to determine the formation of the copper ferrite phase. A preliminary photocatalytic test was carried out to choose the catalyst with the best performance, the best sample being 0.1_Fe3+Cu, which with H2O2 degraded a large amount of 2,4-D. The parameters of the photocatalytic experiments were studied, such as: pH, concentration of catalyst, concentration of herbicide, concentration of oxidizing agent. The catalyst degraded 100% of the herbicide in 60 min of reaction. With the experimental data, following the law of the initiates, a law of speed was created that represents the model of the system. The law of speed followed a Langmuir-Hinshelwood kinetics and the reaction mechanism was studied, being possible that the catalyst obtained high performance in the degradation of 2,4-D with H2O2.

Gas hydrates are crystalline solids formed by the combination of small gas molecules (e.g. CO₂ and methane) and water. These solids may form in Natural Gas production lines, causing great damage, such as partial or total obstruction of the production flow and rupture of the pipelines. Monoethylene glycol (MEG) is a thermodynamic gas hydrate inhibitor widely applied for natural gas flow assurance. To ensure financial and environmental feasibility the MEG needs to be regenerated and reused. A series of density and electrical conductivity measurements of water+MEG+NaCl mixtures was reported allowing indirect supervision of the MEG regeneration unit (MRU). Density (610 data points) and electrical conductivity (250 data points) measurements were performed from 278.15 to 363.15 K, the complete concentration range of solvents and NaCl up to almost saturation. The solution theory was applied for density modeling purpose, using the excess volume ( ). The  was correlated with the aid of the Redlich–Kister equation. A semiempirical correlation with five adjustable parameters was applied for electrical conductivities of water+NaCl and MEG+NaCl binary mixtures. To describe the ternary system, a quadratic mixing rule with a correction parameter accounted for the solvent composition. Accurate thermodynamic correlations for density (ρ) and electrical conductivity (κ) as function of water, MEG and, NaCl concentrations and temperature were obtained. These functions allowed the determination of VLE data for water+MEG mixtures in the presence of NaCl at low pressures, which are important to describe the effects of composition, temperature, and pressure in the MRU. A modified version of the Othmer ebulliometer was applied to measure reliable VLE data for water+MEG+NaCl at 101.325, 65, and 35 kPa. The Electrolyte Nonrandom Two-Liquid and Universal Quasi-Chemical Activity Coefficient models were parameterized to describe the VLE behavior of water+MEG+NaCl. MEG+NaCl solutions presented an inverted colligative property, i.e., the addition of salt decreases the boiling point. VLE data indicated that water separation is less efficient due to the addition of salt. The ρ and κ functions also presented an approximately orthogonal behavior to each other, allowing the determination of mixture composition. The Matlab environment was considered to solve the nonlinear system of two equations with constraints. The fmincon built–in function was found robust for composition determination from the experimental density and electrical conductivity data. The proposed methodology was extensively tested (860 data points) and deviations less than 0.0060 and 0.0011 in solvents and NaCl mass fractions were obtained, demonstrating the required accuracy.

Despite the advances in science and technology, toxoplasmosis does not yet have a vaccine capable of immunizing humans and animals against all isolated types of T. gondii. The treatment of this disease is based on the use of drugs that have some toxicity and can cause serious side effects justifying the need for the development of vaccines or immunotherapeutic as preventive measures. Due to the great diversity of antigens presented by Toxoplasma gondii, a vaccine and diagnostic kit containing multiple antigens is quite promising. Among the bacteria used to produce recombinant proteins, Escherichia coli is the most widely used because of its well described genetic characteristics. In this context, the present work has as main focus to evaluate discontinuous cultivation strategies in the production of Toxoplasma gondii multi-antigenic chimeric protein TgAGS / BsT performed in a rotary incubator. To achieve the proposed objective, several assays will be performed to observe the kinetic behavior of the E. coli XL-1 Blue strain in five different medium compositions (2xTY, glucose supplemented TB, glycerol supplemented TB, LB and M9) without addition of inductor in rotary incubator. In addition, the stability of the plasmid, the influence of the medium on the kinetic parameters of E. coli cell growth will be evaluated. and TgAGS / BsT multi-antigen chimera protein expression and acetic acid formation.

Due the growth of demand for new food sources, shrimp farming has become one of the main aquaculture activities. However, the high amount of non-treated effluent released into water bodies  generate a growing concern about the environmental impacts. Activated sludge system is a good alternative treatment for shrimp farming effluent. Thus, the objective of this work is evaluate the efficiency of organic matter removal from a real shrimp farming effluent by activated sludge treatment system in different operational and process conditions. The optimum condition of operation will be determinate for the release of the effluent in concordance with the legislation.

Aware of the global need to ensure access to drinking water and that most of the water on the globe contains salinity levels that make it impossible to consume and use it in the home, we propose, in this work, simulations that allowed us to understand some of the phenomena relevant to the functioning of solar desalinators, mainly aimed at optimizing the water production capacity from conventional equipment to modified equipment. For this, simulation in EMSO software was used, starting from the mathematical modeling of energy balances. Daily productivity results were obtained of 1.5671 L/m² for the conventional model, 1.8604 L/m² for the modified model with low pressure, 1.7416 L/m² for the modified model with a 50W heat source , 1.9646 L/m² for the modified model with a 100W heat source and 2.1970 L/m² for the modified model with a 150W heat source. The results of nanofluids did not fit the proposed model, since the model used in the literature is not, according to what we have seen, capable of describing the phenomena. Furthermore, the results were compared with experimental data from the Northeast region, obtaining 2.7310 L/m² of daily production. The results made it possible to understand the characteristics of the different models regarding heat transfer, as well as it was possible to evaluate the best equipment represented by the model and its cost-benefit ratio. Within these characteristics, the modified model with a 150W heat source was the best fit.

The produced water (AP) is one of the main sources of pollution derived from the oil industry and represents one of the most important environmental concerns. In this work, surfactants and microemulsion systems were used to remove dispersed oil from the AP by ion flocculation and liquid-liquid extraction methods. For experiments involving ionic flocculation, an alternative was presented for the removal of oil from the water produced using the ionic surfactant babassu coconut oil (OCBS) as part of the capture of oil by micellar solubilization, followed by ionic flocculation by Ca₂ + ions. A factorial experimental design was applied in order to optimize the oil removal process (E_R). The experiments investigated the influence of the surfactant concentration + CaCl₂ (C), temperature (T) and agitation speed (v), obtaining E_R = 70.02-91.49%. Subsequently, the influence of pH, CaCl₂/surfactant ratio and oil removal kinetics (t) on the system with the highest E_R was evaluated, obtaining E_R = 100%. Then, the optimal system for greater oil removal was reproduced using microemulsions as flocculants having OCBS as surfactant, presenting E_R = 100%. Thus, it can be said that the application of ionic flocculation using OCBS is an efficient technique in the treatment of PA. For experiments involving liquid-liquid extraction, the systems used were composed of AP as an aqueous phase; aviation kerosene as an oily phase; isoamyl alcohol and 1-butanol as co-active agents; and Dissolvan^® and Lipesa^® as surfactants. An experimental plan was applied to optimize the process and the experiments were carried out according to the Scheffé network, showing oil removal efficiencies (E_R) between 24-99%. The microemulsion extraction point used for the optimization of the process was composed of 60% by weight of AP, 5% by weight of kerosene and 35% by weight of the cosurfactant/surfactant ratio (C/S = 9 ratio). The effects of the C/S ratio, microemulsion load capacity, oil removal kinetics, temperature, and phase separation speed were evaluated. From these tests, it was possible to obtain 100% oil removal using C/S = 9, t = 25 min, T = 50–60 ° C, demonstrating the viability of the evaluated systems. Comparing the two techniques, it was possible to verify that the ionic flocculation presented greater advantage for using fewer components obtaining high values of oil removal.

The Enhaced Oil Recovery (EOR) process using chemical methods, among them, Chemical systems containing Alkali, Surfactant, and Polymer (ASP), has been widely investigated, due to the good synergy between the three chemical agents and for presenting a 20% increase in the percentage of recovered oil in place. In this context, the present work aims at the experimental study of chemical systems, consisting of saponified coconut oil (surfactant), Butan-1-ol (co-surfactant), kerosene (oil phase), Na₂CO₃ (Alkali), water and different percentages of polymer AH 912 SH, applied as an alternative method in EOR in sandstone rock from the Botucatu sedimentary formation. Chemical systems were characterized by analysis of particle diameter, surface tension and viscosity. Rheology and adsorption tests were carried out in order to evaluate their influence on oil recovery. The flow tests in porous media were carried out in a confinement system that simulates the conditions of an oil reservoir, using sandstone rock plugs with permeability in the range of 15.70 mD to 27.66 mD and oil from the Potiguar Basin of the Ubarana field. The droplet sizes showed characteristic values of micellar aggregates, with a maximum dimension of 2.63 nm. Surface tension increased as the percentage of polymer in the systems increased. Advanced recovery tests using chemical systems showed oil displacement efficiencies with values directly proportional to the increase in viscosity of ASP chemical systems. The system with the highest percentage of polymer obtained the best percentage of oil displaced (79.12%), resulting in greater total displacement efficiency (96.07%). It was also observed that it is possible to obtain satisfactory recovery results by injecting smaller volumes of the system, followed by brine injection. This study showed the potential of ASP microemulsion chemical systems in oil recovery.

The intense human activity, the population growth and the adverse effects of climate changes have impacted the planet's water supply, especially in the poorest countries. This is mainly due to the lack of rainfall and the contamination of water bodies by organic and inorganic pollutants, such as dye effluents from various industrial activities. Adsorption processes have been shown to be an economically advantageous alternative in the treatment of these wastewater. This work aimed to study the synthesis of MCM-41 type mesoporous molecular sieves modified with the inclusion of niobium and tantalum atoms from the hydrometallurgical processing of columbite ore, varying the molar ratio Si/M = 15, 30 and 60 (M = Nb and Ta). The materials obtained were characterized by XRD, SEM, TEM, FTIR, N₂ adsorption and diffuse UV/vis reflectance, and the replacement of silicon atoms in the MCM-41 structure by Nb and Ta atoms was demonstrated, with no prejudice to the characteristic hexagonal ordering of these materials. The molecular sieves were used as adsorbents to remove Methylene Blue dye. The effect of pH, adsorbent dosage and initial dye concentration on removal were evaluated. The adsorption kinetics and the equilibrium isotherm models showed a good fit of the experimental data to the pseudo-second order and Freundlich models, respectively, indicating the heterogeneity in the surface of these adsorbents. Furthermore, thermodynamic parameters indicated a spontaneous endothermic process. The materials obtained proved to be promising adsorbents for MB removal at pH=10, reaching high removal percentages (>99%) even in short contact times

The present study aimed to obtain lipo-molecules by a bioprocess using Rhodotorula mucilaginosa CCT3892 cells as catalyst and sugarcane molasses as carbon source, evaluated a green extraction process of them using Deep Eutectic Solvents and lastly to obtain nanoemulsioned systems containing these biosubstances in view of a future application in the cosmetic industry. The results obtained in the first part of this work showed that the use of molasse (CM) in the bioactive simultaneous production by the yeast was able to produce the same content of total lipids and total carotenoids (16.50 % ± 0.68% e 0.053 ± 0.001 mg.g^-1)  as a synthetic medium (CS) (15.36 ± 1.36 % e 0.051 ± 0.001 mg.g^-1). With regards to the fatty acids production, the CM cultivation showed the most prominent profile once it present a great content of oleic acid (74,05%). The yeast extract supplementation (CMEL) did not provide an improvement in microbial oil-production once it redirected the yeast metabolism to others actives instead of secondary metabolites obtainment. In the second part of this research, the use of four choline chloride based Deep Eutectic Solvents was verified in relation to their ability in to improve the yeast cell permeability and total carotenoids recuperation. The best result for the total carotenoid recovery (0.110 ± 0.005 mg.mL-1) was achieved using the solvent synthetized with glycerol (ChGy). The results of the fatty acids analysis showed that DES treatments did not influence in the oil composition. The thermogravimetric analysis of the yeast cells, before and after the treatments, revealed that the solvent interaction with the cells were conditioned to the chemical specie used in DES synthesis. An experimental design (2³) evidenced the process dependence in relation to the temperature, etanol addition in the solvent and extraction time.  In the last part of this research, it was found a strong antioxidant activity for the eutectic extract obtained from the Rhodotorula cells and it was conclude that this characteristic was not only due the carotenoid presence (0.10 ± 0.02 mg.g^-1) but also because of the content of reducing sugars, such as: xylose (2.19 ± 0.02 mg.g^-1), glucose (1.03 ± 0.00 mg.g^-1) and arabinose (0.36 ± 0.00 mg. g^-1). After the IC₅₀ determination (10.84 mg.mL^-1), the extract was added at 2,5% in an oil phase formed by caprylic/capric triglycerides and preservative. The phase was emulsified with distilled water (aqueous phase) and Tween 20 (surfactant) and the formation of nanoemulsions was noticed, F1 (42.90 ± 8.17 nm) and F2 (118.85 ± 1.44 nm). Both systems were characterized in relation to their pH, zeta potential and polydispersity index (PDI). After the stability tests, the systems showed to be stable in relation to the centrifugal action and variant in kinetic terms according to the storage temperature (30 days). The rheology of the nanoemulsions was also investigated and it revealed that the behavior in ration to a shear stress was conditioned to the oil content, which varied from Newtonian (F1) to non-Newtonian (F2) as a function of the oil phase content. 

Protein separation is a complex process and involves several processing steps, making the process expensive and slow. In this work, a microsystem was built to separate model proteins using the liquid-liquid extraction technique using a two-phase aqueous system (ATPS) of polymer and salt. ATPS was formed by the mixture of the polyethylene glycol-PEG polymer (25% w / w), potassium phosphate (10% w / w) and distilled water (65% w / w). The microsystem channels have diameters of 0.51 mm, 1.14 mm and 1.8 mm. The total flow range ranges from 20 to 700 μL / min. The effect of the flow pattern on the extraction of biomolecules (protein and ampicillin) was investigated. Flow patterns were determined using SAB composed of PEG / phosphate with different molecular molecular weights (PEG 1500, PEG 4000 and PEG 6000) and silicone mini-channels with circular geometry arranged in sinusoidal shape and diameter 1.8 mm. As expected, the gradual increase in liquid flow made it possible to achieve the following flow patterns in sequence: slug, droplet and parallel flow. The high viscosity of the polymeric phases prevented the parallel flow from occurring in systems with higher molecular weight of PEG. Initially, the effect of flow patterns on the recovery of bovine serum albumin protein (from English bovine serum albumin-BSA) was studied for the three flow patterns obtained in the PEG 1500 / dibasic potassium phosphate system in the residence times of 3, 5 and 10 min in the 1.8 mm mini channel. In this condition, the highest BSA recovery efficiencies were 38%, 56% and 32% for 10 min incubation and using slug, droplet and parallel flow patterns, respectively. Then, the recovery of a smaller molecule (ampicillin), whose molar mass is 349 g / mol, was tested for comparison with the BSA protein which has a molar mass of 66500 g / mol (large molecule), with a greater recovery of the smaller molecule. BSA recovery tests were also performed using a 1.14 mm mini-channel and 0.510 mm microchannel using the droplet flow pattern and residence times of 3, 5 and 10 min. The volumetric mass transfer coefficients () were obtained in the range of 0.41-2.75x10^-3 (s-1) for all microchannels and flow patterns. The flow regimes affected the BSA recovery, with the droplet regime providing the greatest recovery. The same was not observed for the smaller molecule, antibiotic ampicillin, which recovered independently of the flow regime. The reduction in the diameter of the channels and the increase in residence times had a positive effect on the extraction efficiency and the maximum efficiency value obtained was 69% for the 0.510 mm microchannel and 10 min residence time for the BSA protein. The flow and scale reduction regime had a positive effect for , with higher values being obtained for the droplet and 0.510 mm microchannel regime.

The use of frying oils presents important characteristics for any proposal that seeks economic viability and is 

environmentally friendly to the environment for the production of biodiesel. Economically, the residual oils are

 cheap because they are raw materials of low quality and inexpensive compared to the oils commercialized in 

Brazil today. Regarding the environmental aspect, studies on the environmental impact of incorrect disposal of 

discarded oils in the waterof rivers or surface aquifers show that one liter of discarded oil can pollute about 500,000

 liters of water. Another very serious problem of incorrect disposal of waste oils is the inlays in pipelines and pipelines

 of sewage networks in large urban centers. The accumulation of these wastes produces the formation of a biomass

 (solid waste and microorganisms) that causes restrictions and difficulties in the effluent flows to the treatment 

stations and produce clogging and generation of odors exhaled by the decomposition of this material. These 

problems cause great economic impacts in the treatment and recovery of these water sources, cleaning, replacement

 and clearing of these public sanitation equipment. In view of these findings, it was proposed the development of a 

reactive route that could use cheap and low quality raw materials such as residual oils, that would be economically 

feasible and that would help in reducing the environmental impacts produced by the incorrect disposal of these oils. 

We performed reactions of frying oils with constant pressure of 100 bar, oil / ethanol molar ratios of 1/10 and 1/30 

and mass percentages of water of 10%, 20% and 30%, temperatures of 250 ° C, 290 ° C and 310 ° C and residence

 times of 15 min, 30 min and 45 min in continuous flow tubular reactor. The results obtained in these reactions 

showed conversion rates of total esters (biodiesel) good results, comparable with the literature. The results obtained

 showed that the experiments with higher temperatures (290 ° C and 310 ° C) and residence time (45 min) showed

 yields of 66% and 71% respectively.

The textile industry demands an enormous amount of water resources, thence generates large volumes of wastewater with a high polluting potential. Among these contaminants, textile dyes, since they give color to recipient bodies, appear to have a distinctive role in the environmental approach. Regarding this, the present work proposes a cyclical reuse of the solid textile waste, whose usual destinations point to low added value products, for the synthesis of activated carbon and removal of dyes from textile wastewater. Therefore, 100% cotton fibers (RFA), which are the main natural matrix of the textile industry, were used. The RFA was impregnated with H₃PO₄ and pyrolyzed in a vertical tubular oven at a rate of 5 °C/min and remained for 3 h at 500 ° C under N_2(g) flow, obtaining the activated carbon (CAT). A commercial activated carbon (CAC) was used as a direct comparison parameter. Novacron Red S-B was used as adsorbate for fitting in categories that are highly used in that sector. The RFA showed low fixed carbon content (C_fixo = 2.98%), semicrystalline structure (IC = 77.88%) of type Iα cellulose and flat twisted ribbon morphology with no pores on its surface. On the other hand, RFA+H₃PO₄ showed an increase in its stability and carbon availability for the synthesis of activated carbon by the appearance of phosphate bridges that promoted crosslinking of cellulose chains, resulting in a satisfactory pyrolysis yield (η_pir = 60,145 %). CAT and CAC coals showed irregular morphologies, amorphous structures and close isoelectric points (pH_iso = 2.62 and 2.29, respectively), with CAT showing better textural properties (S_BET=1096 m²/g; V_TP = 0.81 cm³/g; d_Pm = 1.5) when compared to CAC and similar to others reported in the literature. The adsorption tests reached a maximum removal of 75.41% and 65.36% for CAT and CAC, respectively, in 12 h. Both systems fitted better to pseudo-second order kinetic model (R²_CAT = 0.99518 and R²_CAC = 0.99746) with k₂,_CAT = 2194.16336 g/mg*min and k_2,CAC = 2194.16336 g/mg*min. The equilibrium isotherm data denoted a physical and favorable adsorption process with maximum adsorption capacities of q_max,CAT = 131.23844 mg/g and q_max,CAC = 58.91475 mg/g. A better fit was obtained for the Freundlich model for CAT (R² = 0.9908) and for Langmuir for CAC (R² = 0.999917), indicating heterogeneous and homogeneous adsorptions sites, respectively. Therefore, these results suggest the viability of those residues as carbon sources for activated carbon production and its suitability for dye removal. 

This paper consists in the synthesis and characterization steps in order to obtain a mixed nickel and copper ferrite (Ni_xCu_1-xFe₂O₄), in which the nickel’s presence varies from 0 to 100%, with gaps of 20% between each sample. As a synthesis route, complexation by EDTA and citric acid as chelating agents was the chosen method. Once the process began with the EDTA dissolving by ammonium hydroxide, hydrated iron III, copper II, and nickel II nitrates, at stoichiometric proportions, were added. Then citric acid was added to the mixture, with the intent that the proportion between EDTA, citric acid and the metallic cations corresponded to  1:1.5:1, and that was heated to 80 ºC. Succeeding the formation of a gel, the precursors were taken to the muffle at 230 ºC for three hours and, afterwards, incinerated for four hours at three different temperatures, 500 ºC, 600 ºC e 700º C, creating distinct samples. X-ray diffraction (XRD) analysis was performed on the samples following two procedures, one slower and one faster, aiming to obtain the crystalline structure profile and to compare than with models from the Xpert software and, then, refined on GSAS/EXPGUI. Two different scanning electron microscopy methods (SEM) were utilized, for two distinct magnification spectra: a desktop device and one with a field emission gun (FEG), attached to a energy dispersive spectroscopy (EDS). In both situations, imagens containing the synthetized ceramics were obtained and, aided by the EDS, it was possible to analyze the ratio between each ferrite’s atomic components. As a result from the XRD analyses and refinement, it was possible to notice that the peaks present better definition at higher incineration temperatures, correspondence to the materials’ cards found on X’Pert and the absence of multiple phases on the final products. Regarding the microscopies, the desktop device provided images with low resolution, because the synthetized materials has smaller dimensions than those of the method’s limitations. The SEM-FEG, on the other hand, allowed a better visualization of the particles, whose size is nanometric and forms, in some cases, an octahedra structure. In order to evaluate the obtained solids, this paper recommends further characterization application studies.

The search for new sustainable energy sources that are renewable, environmentally friendly, economically profitable and with a high capacity for regeneration in the environment with the aim of initially reduce and subsequently eliminate the energy dependency of fossil fuels, has promoted studies on the viability of solar hydrogen production with high conversion rates, safely and economically feasible for large-scale application. Among the multiplicity of options for its production, heterogeneous solar photocatalysis involving the breakdown of water molecules has been a promising area in this context, presenting challenges related to the synthesis of photocatalysts with high conversion rates of luminous energy into hydrogen, durable and with low cost of production. In this prism, this work intends to produce nickel ferrite (NiFe2O4) by the co-precipitation synthesis method to act as a photocatalyst, in which the influence of the reagents concentration and the heating rate, temperature and time of the plateau in the calcination will be evaluated. In addition, a photoreactor will be produced to conduct the reactions under solar radiation, in which parameters such as low cost of production and scalability will be prioritized, once in operation the phenomenon of mass transfer of water to the surface of the photocatalyst in the process and the influence of the water flow rate on the hydrogen production rate will be studied together with the evaluation of the reuse and regeneration capacity of the semiconductor. The materials studied will be characterized by thermogravimetric analysis (TG) and differential thermal analysis (DTA), atomic force microscopy (AFM), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Mössbauer spectroscopy, diffuse reflectance spectroscopy (DRE) and Specific Area Analysis by the nitrogen adsorption method (BET).    

Biodiesel is considered an alternative source of fuel, that consists of fatty acid alkyl ester. Industrially, transesterification is the route most used to produce it, that is a chemical reaction between triglycerides and alcohol, with a homogeneous or heterogeneous catalyst. Surfactants are substances that have at least two parts, one hydrophilic, and the other hydrophobic, and are characterized by their tendency to absorb surfaces and interfaces. Thus, this work aims to evaluate the use of surfactant Nonylphenol ethoxylated in a transesterification reaction of soybean oil with methanol, catalyzed by the calcium oxide (CaO) synthesized from chicken eggshell. Two experimental factorial design were performed, both with the addition of three central points. In the first one, 22, it was evaluated the ethoxylation number and the surfactant concentration. In the second one, 23, with 1% of Nonylphenol with 7 moles ethoxylated (NP7EO), it was evaluated the reaction time, catalyt concentration and methanol to oil molar ratio. Moreover, two different types of study were performed, one with NP7EO, and in the other NP7EO was not used, their kinetic constants were compared. The ethoxylation number and its concentration did not influence significantly in the biodiesel conversion. In the factorial design 23, the predicted model using 1% de NP7EO was significant in the biodiesel conversion, the maximum was 98,95%, with 5% of CaO, methanol to oil molar ratio of 7/1, 65 ° C, 3 hours reaction. In the study with and without NP7EO, the kinetic constants, 0,012 min-1 and 0,0089 min-1, were obtained, respectively, and the reactions were shown to be pseudo-first order. Furthermore, the results have shown higher conversions in the reactions with NP7EO. Thus, the surfactant influenced better biodiesel conversions and improved the transesterification reaction rate, incrising its velocity. Probably due to its ability to improve the dispersion between the phases of the mixture reagents.

One of the biggest difficulties in working with raw materials and inputs from natural sources is meeting the purification standards. In this sense, the study of the extraction and distillation of the essential oil of patchouli was performed, to improve its quality without causing the degradation of its components. First, a comparative study was conducted between the Pogostemon Cablin and Pogostemon Heyneanus species, cultivated in the Brazilian Northeast, through parameter analysis using the hydrodistillation process. The parameters studied were extraction time, volum and pH of the solvent and part of the plant The extraction yield from leaves of P. Cablin was 4.45 times higher than P. Heyneanus. The optimum conditions for extraction from P. Cablin species were: extraction time 180 min, solvent volum 700 mL and extraction from leaves. For P. Heyneanus species, extraction time of 150 min, extraction volume of 700 mL and extraction from leaves were the optimal extraction conditions. Chromatographic analyzes revealed that extracts in neutral, acid and basic medium from P. Cablin showed patchoulol percentages of 60.45%, 7.10%, and 61.05%, respectively. While for P. Heyneanus species, the percentages of patchoulol were 14.72%, 13.79% and 36.06%, respectively. In the study of extraction kinetics, two kinetic models (pseudo first order and non-stationary diffusion) were applied to adjust the experimental data. The variation of two parameters (solute/solvent ratio and heating power) were analyzed on the kinetics. The results showed that the non-stationary diffusion model best described the patchouli essential oil hydrodistillation process. The highest amount of essential oil was obtained at a ratio of 1:23 solute/solvent (g.mL^-1) and a heating power of 470 W. After optimization of the extraction process, molecular distillation of the oil was performed to obtain fractions. rich in patchoulol using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Three variables were studied: evaporator temperature, condenser temperature and agitation speed. The optimal conditions obtained by the experimental design were: evaporation temperature of 85 °C, condenser temperature of 10 °C and agitation speed of 600 RPM. These conditions generated a concentration of 62.344% of patchoulol in the residue, reaching a recovery of 74.22%. The results obtained by ANN have demonstrated good predictability and can be used in conjunction with RSM for modeling the patchoulol enrichment process. The study of the influence of temperature and percentage of patchoulol on the oil viscosity was carried out for the residual streams. It was observed that percentage of patchoulol is one of the factors that influences the viscosity of the samples. The study showed great relevance with possible industrial application, because it promoted the concentration of patchouli oil in patchoulol.

Studies of drugs as emerging pollutants have been gaining importance in the scientific community. Acetylsalicylic acid (AAS) is a model pollutant and a representative of emerging pharmaceutical micropollutants whose mineralization through various advanced oxidative processes (POAs) takes hours to complete. Hydrochlorothiazide (HCT) has been found in final waters for consumption due to its persistence. This work is dedicated to optimize and understand the kinetic conditions to mineralize AAS and HCT using the Foto-Fenton process with UVA radiation in a tubular photochemical reactor and mixing reactor, respectively. The optimization employs a statistical factor planning tool that studies how the concentrations of the pharmaceutical contaminant, Fe2 + and H2O2 affect mineralization over a range of concentrations. The factorial design indicates that the initial concentration of H2O2 is a crucial variable to achieve a rapid rate of AAS and HCT mineralization. Using optimized content of H2O2 and Fe2 + in the photo-Fenton process (H2O2 / Fe2 + / UVA and H2O2 / Fe2 + / UVC, respectively), a mineralization of more than 90% for AAS and 100% for HCT is achieved in about 10 minutes and 30 minutes, respectively. The underlying reason for such remarkable performance is attributed to the optimized excess of [H2O2], which varies according to the contaminant, that is, the H2O2 concentration ratio used in the initial time for the required complete mineralization of the theoretical TOC. Measurements of the remaining H2O2 concentration strongly indicate that the excess of [H2O2] optimizes the instantaneous concentration of the radical • OH. Among the applied POA's, the comparison of UV-H2O2 oxidation (H2O2 / UVA and H2O2 / UVC) with photo-Fenton oxidation (H2O2 / Fe2 + / UVA and H2O2 / Fe2 + / UVC) stands out. When using the optimized peroxide in the first composition, almost 100% degradation of AAS and HCT was obtained, but in this case, there was no good mineralization. To obtain a high degree of mineralization, close to 100% it was crucial to add Fe2 + together with the aid of light. In addition, a toxicology study was conducted with HCT. HCT has been shown to be toxic at certain concentrations for the Mysidaceas group. The LC50 of 37.25 mg.L-1 of HCT was determined. The POA’s were applied to determine the possibility of generating their own means for the survival of the Mysidaceas. It was obtained that among the POA’s, as only the photo-Fenton (H2O2 / Fe2 + / UVC) was able to mineralize the HCT, it was the only POA to make the medium no more toxic. This fact corroborates with results of the total non-mineralization of the other applied POA's, comparing that in these cases there was the formation of toxic intermediates. And the only really efficient process for HCT was photo-Fenton (H2O2 / Fe2 + / UVC). In conclusion, the stoichiometric excess of [H2O2], is the most important parameter to be optimized in order to achieve the highest degree of mineralization in the shortest time of use of the photochemical reactor, also decreasing the costs related to the total energy consumed by both the lamp and pumping.

In view of the environmental problem of the pollution of water bodies by heavy metals, caused by human activities in general, and the inadequate destination of certain solid agro-industrial residues, there is a great need to develop research that improves the technique of removing these inorganic pollutants from aqueous solutions. One way would be to take advantage of agro-industrial waste as agents that remove these pollutants. As the coconut shell powder (CP) is a residue generated from its processing, the present work aims to provide studies related to three treatment methodologies so that the CP adsorption capacity be empowered and then be reused to remove two toxic metals widely found in wastewater, Cu^{+ 2}  and Cd^{+ 2} that are widely found in wastewater from effluents from the mining, metallurgy and dye industries. The applied methodologies included the physical and chemical treatment of the PC surface, developed separately, according to the sequence: chemical treatment through the impregnation of Monoethanolamine in the proportion 1: 1, using ethanol as solvent; chemical treatment through the impregnation of the sodium octanoate surfactant by microemulsion; and physical modification using the steam explosion technique (T = 210 °C and P = 20 atm). The efficiency of the proposed treatments was evaluated through characterization analyzes, where changes were observed in the specific contact area, chemical composition and crystallinity of the adsorbent material. The evaluation of the monocomponent adsorption capacity of Cu⁺² and Cd ⁺² ions in the PC was performed using a batch mixing reactor of the synthetic solutions of CuSO4.5H2O and CdSO4.8 / 3H2O. After chemical treatment, the insertion of functional groups increased the metal - adsorbent interaction confirmed by the values of the kinetic constants of the studied models. It was observed that the coconut shell powder impregnated with OS (PCµE) adsorbed more Cu + 2 ions in relation to the impregnated with MEA (PCA). The treatment with steam explosion, depolymerized the coconut shell powder (PCD), which caused an increase in the total pore volume and crystallinity, consequently, making the adsorbent surface more accessible for adsorption. The behavior of equilibrium isotherms is satisfactorily represented by the Langmuir model and the adsorption capacities (mg / g) of the coconut shell powder after treatments follow the order: PCµE (26.32)> PCD (18.86)> PCA (15.94)> PC (7.88) for Cu⁺² and PCD ions (17.90)> PCA (14.02)> PC (4.91) for Cd⁺² ions, respectively, emphasizing that the impregnation methodology with surfactants did not significantly improve the interaction of PC with Cd⁺². The stability of the impregnation with MEA and OS was evaluated from the desorption study. After the adsorption-desorption cycles, the amount of Cu⁺² adsorbed on the PCµE decreased by 36.6%, while for the PCA the reduction was 22.8%. Regarding the adsorption of Cd⁺², a reduction of 14% and 10% was observed for PCµE and PCA, respectively. This shows that, after the five adsorption-desorption cycles, the impregnation of monoethanolamine in the coconut shell powder is stronger, remaining with greater removal than the PCµE and thus, it can be reused for more cycles in the adsorption-desorption process.

Plum is a seasonal fruit with low durability after harvest, requiring the application of techniques that prolong the shelflife of this food. Among the methods that can be applied is the drying in foam mat that consists of the transformation of liquids or semi-liquids into a stable foam from the addition of a foaming agent and application of agitation so that there is the incorporation of air. In this work, the plum foam was produced from the addition of egg albumin and the drying was carried out in an air recirculation oven with a speed of 2 m / s. The study of the drying of the plum in a foam layer was divided into stages, the first part of which is the investigation of the effects of the process variables, whipping time and albumin concentration, on the physical, thermal properties and drying time in order to optimize the operational conditions for the production of plum foam, whose values found were 3% albumin concentration and 12 minutes of whipping time. In the next step, the influence of temperature and foam mat thickness on the moisture, water activity and drying time of the plum foam was evaluated in order to define the best operational condition for drying this fruit, being observed that the higher temperature and less foam mat thickness are more suitable for the process, since they provided the best results for powder moisture (2.690 g water / g dry powder), water activity (0.245), drying time ( 70 minutes) and average drying rate (0.0631 g water / g dry powder / min). The last phase of this work investigated the influence of temperature on the physical-chemical properties, bioactive compounds and antioxidant activity and performed a comparison of the powders obtained by foam mat at four temperatures with the powder obtained by freeze drying, since the latter is widely used. known as the method capable of preserving the original characteristics of the fruit. The experiments were carried out using the foam in the previously optimized process condition (3% egg albumin in the formulation, 12 minutes of whipping and 0.8 cm layer thickness) and four drying temperatures: 50, 60, 70 and 80 ° C. For lyophilization, about 280 grams of pure plum pulp was used, without the addition of egg albumin (it was not foamed). The analysis of the produced powders showed that the higher temperature (80 ° C) provided a product with low cohesion between the particles (1.153) and good fluidity (13.235), in addition to low absolute density (0.637 g / cm³), important characteristics for particulate materials. All powders showed good solubility in the range of 75.737 and 76.842 g / 100 g and low water activity (0.245 to 0.386). The phenolic compounds were not impacted by the process conditions, the antioxidant activity was favored by the temperature, but the amount of ascorbic acid and carotenoids was greatly reduced by the action of this variable. Based on the results and because the lyophilization process is costly, the condition that provided the best results for both the drying process and the quality of the plum powder was the temperature of 80 ° C.

This work proposed a new alternative route of synthesis of nanostructured molybdenum carbide from the base mineral extracted from the city Carnaúba dos Dantas - RN, through gas - solid reactions at low temperature, as well as provided a integrated theoretical view of the morphologic formatation of the synthetized materials. Initially, this starting ore were into a grinding process, followed by milling and sieving, and its characterization performed through X-ray fluorescence (XRF) and X-ray diffraction (XRD), to analyze if its characteristics are satisfactory for the synthesis. In the sequence, the ore treatment was carried out through leaching and hydrothermal treatments. Therefore, it was done synthesis of the precursor, a more reactive reagent, used in the synthesis of the carbide by the gas-solid reaction. The precursor was characterized by granulometric analysis (AG), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric, thermodifferential and calorimetric (TG/DSC) analysis, infrared (IR) spectroscopy, electron microscopy (SEM) and dispersive energy spectroscopy (EDS). The synthesis reaction occured between the precursor and a gas mixture of H2 / CH4, where hydrogen is the reducing gas and methane is the carbon source. The synthesized nanostructured molybdenum carbide was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) with refinement by Rietveld method, specific surface area analysis (BET), scanning electron microscopy (SEM) and spectroscopy of dispersive energy (EDS).

Brazil holds more than 90% of the world's niobium reserves and is the largest producer and exporter of this material, such as ferro-niobium alloy, niobium oxide and other products. Nevertheless, there is a need to expand the use of niobium in the country in order to make better use of it economically. The Brazilian Ministry of Mines and Energy encourages the development of technological applications to add value to niobium and its derivatives through research. The remarkable chemical and physical properties of Nb₂O₅ make this material promising for application as adsorbent, gas sensor, solar cells and electrochromic components. Some recent research studies have verified the possibility of several catalytic applications of niobium oxides, either as active phase or as support. Considering the above arguments, a study of the consolidation of Nb₂O₅ suspensions by the centrifugal casting method was carried. The purpose of the present work was to investigate the efficiency of this simple and low-cost method in the preparation of ceramic supports. Initially, the slip casting method using gypsum molds was tried, but the methodology using centrifugal force proved to be much more effective. The slurries were prepared by mixing Nb₂O₅ or Nb₂O₅.xH₂O, PVA, agar, deionized water and boric acid dissolved in glycerin. Rotational speed was set at 10,000 rpm during various deposition times (5, 10, 20 and 30 min). Heat treatment was performed at various sintering temperatures varying from 1100 °C to 1400 °C. The dwell time was 4 h. Both green and sintered bodies were characterized by scanning electron microscopy with field emission (SEM-FEG), X-ray diffraction (XRD). The density of green and sintered bodies was determined by the Archimedes method. The results showed significant influence of the sintering temperature on the contraction of the pieces, resulting in an expressive increase of the sintered density with the increase of temperature. The centrifugation time of 20 min was considered more adequate as it resulted in a green density higher than that obtained with 30 min. The packing was also evaluated through the micrographs, which evidence internal and external surfaces with good qualities compared to other ceramics in the literature. Finally, it is concluded that the methodology studied has the potential to produce substrates in specific shapes, obtaining Nb₂O₅ ceramics that reached 90.9% of theoretical density after sintering at 1400 °C for 4 h.

 This work aims to investigate the efficiency of phytoremediation integrated to electrokinetic (ER) remediation processes using graphite electrodes to remove petroleum in contaminated soils. In this sense, the influence of the applied electric field, the growth of the sunflowers, and the type of fluid used to maintain soil moisture were evaluated. The phytoremediation, electrokinetic remediation, electro-phytoremediation with direct current application, electro-phytoremediation with application of inversion of polarities of the electrodes were evaluated, applying 1 V cm-1 for 20 days. Based on the results, it was possible to observe that the integration of ER with phytoremediation promoted higher percentage of germination of sunflower seeds, as well as for plant growth. The removal of petroleum was evaluated considering the total petroleum hydrocarbons (TPH) after 20 days of treatment. The best removal efficiencies were obtained for electromagnetic remediation with inversion of polarity of the electrodes. Finally, at the end of the 20 d of soil treatment, the electrochemical oxidation processes with H2O2 and electro-Fenton were compared for the treatment of residual fluid.

With the increase of environmental problems generated by using fossil fuels the search for more renewable and less harmful alternatives have increased, thereby biodiesel rise as a biodegradable option originated of natural sources. Biodiesel can be defined as alkyl esters formed in a transesterification reaction between an alcohol and triglyceride, usually vegetable oils. In Brazil, soybean oil is the raw material most used in biodiesel production, however it is necessary to search for other oilseeds to diversify production, so sesame oil appears as likely raw material. Sesame has a high oil content in its seed and is suitable for warmer and drier climate. The main way to produce biodiesel is transesterification using basic catalysis, this kind of process has drawbacks about water content in the reaction and in the product purification. Transesterification using alcohol in supercritical conditions does not need catalyst becoming a simpler method. In this work, it is proposed utilize sesame oil as triglyceride source in transesterification reaction with ethyl alcohol in supercritical conditions. Temperature, reaction time and molar ratio oil: alcohol were studied as reaction parameters. The temperature range was 260-290 ℃, reaction time between 7,5-30 minutes while molar ratio varied of 1:36-1:48. In the end, the best ethyl esters yield was 56,62% at temperature of 290 ℃, in a time of 30 minutes and molar ratio of 1:48. 

This study investigated the encapsulation of curcumin into Saccharomyces cerevisiae cells through osmoporation as an efficient way of increasing curcumin stability. The influence of three process parameters (cell, ethanol and curcumin concentrations) on the encapsulation process were evaluated and the obtained bio-capsules were characterised with regard to physical and photochemical stabilisation. Results showed that the encapsulation efficiency was favoured by the increase of cells/curcumin ratio and ethanol concentration up to 60%. Differential scanning calorimetry (DSC) curves revealed that yeast-encapsulation increased curcumin melting point up to 207 °C. Encapsulated curcumin retained over 80% of antioxidant activity after thermal treatment (150 °C) and over 70% after a 50-day exposure to artificial light. Photochemical stability of yeast-encapsulated curcumin was increased by 5.7-fold and the half-life time reached 181 days when bio-capsules were exposed to light. Overall, osmoporation-produced yeast bio-capsules confirmed the versatility and efficiency of osmoporation as an encapsulation technique that could successfully improve curcumin stability.

Gas explotation in deep water in Brazil brings challenges due to high pressures, low temperatures, high content of CO₂ and NaCl carried to the production fluids. The regeneration process of ethylene glycol (MEG), used as a hydrate inhibitor, also presents a field of study regarding the solubility and precipitation of NaCl salt. In this context, this work included the assembly of an experimental apparatus for the evaluation of phase equilibrium in mixtures, under conditions of temperature and pressure, close to those of gas exploration in deep waters, evaluating parameters such as density and solubility, at pressures from 4,0 to 31.0 MPa and temperatures of 293.15 and 323.15 K. The experimental apparatus was assembled through the interconnections between an Anton Paar 4200M densimeter, a syringe pump and thermostatic baths with two types of pressure vessels: the Parr reactor 4561 and a variable volume equilibrium cell. The density points obtained with the experimental apparatus were validated with data and models from the literature. For this purpose, simple systems such as the pure CO₂ and water were used (mean deviations of 0.02% for CO₂ and 0.15% for water when compared to specific equations for these components), and the CO₂ + water (mean deviations below 0.07% when compared with models obtained from literature data). The calibration of the densimeter was carried out to allow using at temperatures between 293.15 and 329.85 K, and pressures between 1.0 and 31.0 MPa, with tetrachloromethane and ethanol, resulting in an uncertainty of 0.09%. In addition to the experimental data obtained from the previously mentioned pure components and the CO₂ + water binary system, data were also obtained for the water + NaCl binary system, for the CO₂ + water + NaCl ternary system (1 molal and 4 molal saline solutions) and the CO₂ + water + MEG (30%, 50% and 80% m/m MEG aqueous solutions concentrations). The software Specs v5.63 and a code made in MATLAB were used to verify which equation of state (Soave-Redlich-Kwong or Peng-Robinson cubic equations or Cubic Plus Association equation) was more adequate to predict the aqueous phase density of the binary and ternary systems with absence of electrolytes under experimental conditions; it being concluded that the use of Cubic Plus Association equation (CPA) resulted in more coherent values of the density of the aqueous phase. In the case of systems containing electrolytes, models developed from literature data were used for comparison with the experimental data of this work.

In the recent global warming increase, the demand for less pollutants energy sources and fuels is growing substantially. For this reason, the hydrogen production has been targeted by research and studies. The production of this gas from methane partial oxidation in membrane reactors is showing to be a good alternative. In this work, hydrogen production process through a membrane reactor should was studied by a simulation and modeling point of view. A mathematical model of a membrane reactor assuming one dimension, isothermal and steady state conditions was used. Simulations were made to compare the reactor conversions in different membrane dense type compositions. The molecular structures of the membranes perovskite-type were considered, that is, ABO₃. Mathane and hydrogen conversions were evaluated, as well as the composition profiles through the reactor length. A comparison between the performances of the partial oxidation and steam reforming processes was made. In membrane reactors, the reaction process and the separation step are combined in the same device. This provides a cost reduction in production of many important substances, as for example, syngas

Lost circulation is a serious and costly problem for the oil industry and it may happen during a drilling in permeable formations, natural fractions or caves. To mitigate this lost, gel systems combined with Lost Control Materials (LCM) is used, this combination is called buffers. However, sometimes these buffers are not effective, and there is a need for new technologies to solve this problem. Approximately 85% of the gross weight of the coconut consists of the husks, which is accumulated in dumps or in the banks of roads, then its hernessing becomes necessary. This work aimed to develop a new generation of buffer using surfactant-based gels and coconut fibers in different granulometries, treated with microemulsions, to prevent losses in carbonates, oil-wettable microfractures and to study the interactions between fiber-emulsio, gel-rock, fiber-rock and analyze the capacity of remediate the lost and in situ gelling ability. For the tests with the surfactant-based gels, two anionic surfactants were tested one of them was soap base, used in the systems,1 (S1) and 2 (S2) and the other one was saponified castor oil - SCO, which generated the third system, S3. Two microemulsion systems were tested for the treatment of coconut fiber, one with cationic surfactant (CTAB) with three types of micelles (direct micelle (MD), bicontinuous (MB) and reverse (MR)), another with anionic surfactant (soap base) at the point of bi-continuous micelle (SB). These fibers was analyzed through the TG-DTA, SEM, XRD, FRX and contact angle analyzes. The buffers were characterized by rheology, weight and filtration. A lost circulation apparatus was developed and used with the better buffer, and an in situ gelling test was performed. The best buffer was S2 with fibbers mesh sizes # 35, # 100 and # 200 because presented a pseudoplastic behavior, with high viscosities and tensions, characteristic of buffers, low filtrate volumes below 10 mL, and a rapid formation of filtercake (15 minutes). In the loss simulator apparatus, the S2 with granulometric fibers # 35, # 100 and # 200, treated with the SB, was able to reduce the permeability by 50% with the minimum mass (50 g) of the studied fluid. The fibers treated with the SB, presented affinity for the developed gel and allowed the gel spread on the surface of the pores of the rock, and presented the chemical affinity for the surface, facilitating the process of deposition and buffering of the fractures. For this reason, fibers treated by SB were chosen as the LCM of the new product. In situ gelation test showed that at 70 ℃ the gelling happen in 40 seconds, excellent result, making operation quick, efficient and less costly, with less probe time support.

Currently one of humanity's biggest concerns today is the fate of industrial waste and the study of alternatives to sustainable energy. In this context, the aim of this work was to obtain chitosan from the discards of carniciculture, the biopolymer chitin and it is deacetylation by means of alkaline hydrolysis. The demineralization steps were performed through deproteinization to obtain chitin, and deacetylation to obtain chitosan, were characterized by X-ray diffraction (XRD), X-ray fluorescence (FRX), scanning electron microscopy (SEM), thermogravimetry (TG), UV visible and Fourier transformer spectroscopy (FTIR) for confirmation of  obtain  chitin and chitosan with an acetylation degree of DA of 70 and 75%, respectively.. The biopolymers, it was possible to perform the hydrothermal carbonization synthesis, which is a low cost process, of two renewable precursors, which are materials derived from biomass (chitin and chitosan) and graphite as a third material used to obtain two solid phase and liquid. The liquid phase would be for the formation of carbon quantum dots (CQDs) with application in solar cells and photocatalysis, and the solid phase for the formation of heterogeneous catalysts for reactions of transesterification of biodiesel. The phases were characterized according to the needs of their applications obtaining for the liquid phase a CQDs with quantum yield of 17.1% with doping in ZnO / CQDs with photocatalysis property. And for the solid phase a heterogeneous graphite-chitosan catalyst obtained process efficiency by gas chromatography with 36% conversion. Obtaining chitin and chitosan biopolymers is a great solution for the tons of waste produced in the shrimp industry. The realization of hydrothermal carbonization synthesis to obtain two products, the CQDs and graphite-chitosan catalysts demonstrate great alternatives for the use of sustainable energy in photocatalysis and transesterification reactions.

Development of new cutting fluids constitutes an important field of scientific and technological activity, since most of the fluids are part of the consumption of petroleum source, and this source is limited and not renewable. Recently, emulsion systems have been studied as an alternative to improve tribological applications as fluids that improve lubricity. Thus, this work aimed to formulate, characterize and study the tribological performance for O/A emulsions and A/O microemulsion systems with different anionic surfactants (soap base) and non-ionic nonylphenol polyethoxylates with different degrees of ethoxylation to apply as cutting fluids. Epoxidized vegetable oil was use for the development of emulsion and microemulsion systems. The main physico-chemical properties were determined for the formulations, such as density, acidity, iodo index, oxirane index, small angle X-ray scattering analysis (SAXS), particle size, rheological measurements and contact angle. In order to evaluate the tribological performance of the systems, a High Frequency Reciprocating Rig (HFRR) tribromometer, consisting of a plane type ball wear test. Based on the results presented above, it can be concluded that the physicochemical properties analyzed are suitable for the fluid as lubricants. The lower concentration of anionic surfactant (1%) presented lower coefficients of friction for the studied emulsions. The emulsions developed with 5% surfactant showed higher coefficient of friction and wear rate. The microemulsion systems have cylindrical shapes, in which it contributes to higher viscosity in the systems. When comparing the coefficient of friction in systems formulated with different surfactants NP4EO, NP6EO and NP9.5EO, it was observe that the coefficient of friction tends to increase in the systems (M1-M3) as the degree of ethoxylation increased and as increased the concentration of surfactant.

Currently, the search for the integral use of lignocellulosic materials is necessary in the attention to the environment, as well as in the reduction of costs and valorization of this raw material. Among these materials are agro-industrial waste widely used to obtain various products such as oil, extracts, and enzymes, among others. This study investigates the use of the characterized mangaba waste (Hancornia speciosa Gomes), highlighting its oil content, and using it as a substrate for the production of enzymes (lipases, pectinases and polygalacturanases (PG)). Solid-state fermentation (FES) using the filamentous fungus Aspergillus niger IOC 4003. Mangaba residue and its ethanolic extracts were evaluated for physicochemical and bioactive aspects, especially the total phenolic content and antioxidant capacity. Among the evaluated enzymes, polygalacturonase was submitted to stability tests under different temperature and pH conditions and applied at a concentration of 1.0% in the clarification process of mangaba juice. It is noteworthy that the post-fermentation residue was used for lignin extraction that was applied to obtain chitosan biofilm, evaluating their antioxidant capacity as well as their capacity to increase the shelf life of papaya (Carica papaya) after coating. The results showed that mangaba residue has antioxidant activity with total phenolic compound concentrations of 564.1 ± 0.047 mg gallic acid equivalent / g extracted oil and Total Antioxidant Activity - TCA of 95.46 ± 1.58 mg equivalent of ascorbic acid / g residue. Furthermore, by FES it was possible to produce lipases (50.11 ± 0.02 U / g), pectinases (0.45 ± 0.01 U / g) and polygalacturonases (76.32 ± 0.11 U / g). The extract showed stability to PG activity above 80% for temperatures of 20 and 25 ° C, maintaining this activity level for up to 1 hour. However, with significant reduction at temperatures above 40 ° C. In relation to pH, PG activity was considerably reduced at alkaline pH and, at pH 4 and 5, PG kept its relative activity above 50% for up to 120 minutes. When applied with enzymatic load of 1.0 U / mL, the enzymatic extract presented satisfactory results in the clarification process of mangaba juice allowing a 34% reduction in turbidity and 11% viscosity. The 2% chitosan biofilms added with 0.1% and 0.05% (w / w) alkaline lignin showed antioxidant activity, based on the capture of the DPPH radical. The fruits coated with filmogenic solutions had their shelf times increased. Thus, mangaba waste is presented as a low cost raw material with potential for the production of biotechnological products of interest to society.

The objective of this study was to evaluate the application of ethyl octanoate and ethyl oleate in different concentrations as gasoline additives based on characterization analyzes, consumption in Otto cycle engine and the effect of additives on fuel lubricity. The analysis results of vapor pressure, distillation curve and corrosiveness were within the values required by Brasilian legislation. In relation to the rheological study, the Oswald de Waele model best fitted the experimental values of the gas + ester systems, which was also the model that best fitted the experimental data for pure gasoline data. Both esters increased the density of the fuel with increasing their concentration in gasoline. The results for heat of combustion of the obtained fuels were better than results reported in the literature for other oxygenated additives. Through measurements of the octane number MON (Motor Octane Number) and RON (Research octane number) it was found that the octane of the ethyl octanoate containing formulations was higher when compared to the formulations containing ethyl oleate. The lubricity tests were carried out using a HFRR (High Frequency Reciprocating Test Rig) equipment. The WSD (wear scar diameter) values have decreased as the esters proportions have increased in the samples. The percentage of lubricant film presented values above 85% for formulations with 10% and 15% ester concentration. The values of the coefficient of friction have shown a similar behaviour, they have decreased as the esters fractions have increased. The analyzes of fuel consumption were performed using a Otto cycle engine four-stroke, in which the rotation was conserved at 4400 rpm and wheel power varied from 3 kW to 12 kW, with intervals of 3 kW to obtain hourly fuel consumption curves and brake specific fuel consumption. Even esters having lower heat of combustion, hourly fuel consumption was similar to pure gasoline (type A). In relation to the brake specific fuel consumption, increasing the wheel power had a better conversion of the mass of fuel burned into energy. The results also showed that ethyl octanoate presents better characteristics to be added in gasoline when compared to ethyl oleate.

The Malay apple tree is found in the Northeast region of Brazil and the little knowledge about the composition of its fruits, which may have their properties better explored, motivated this study. Among naturally occurring antioxidants, anthocyanins are dyes responsible for the bluish-red coloration of a wide variety of vegetables. There is a growing interest in its use by the food industry, but its vulnerability to environmental factors makes processing necessary to make them stable. In this sense, spray drying is applicable and the spray dryer has been shown to be effective in this process. The objective of this work was to perform drying tests of jambo bark extract in spray dryer and lyophilizer and to analyze the product obtained through physical chemical analysis, images and particle size, proceeding to the quantification of bioactive compounds. in order to prove the preservation of antioxidants and to carry out a preliminary study on their possible encapsulation.

The wish for economic development is linked to the increased consumption of fossil fuels and consequently a growing generation of toxic waste to the environment. Drill cuttings is one of these wastes, which in addition to being highly toxic, due to the presence of n-paraffin from the drilling fluid adsorbed to it (waste class I - NBR 10004: 2004), is also generated in large quantities. This study presents an alternative to the treatment of drill cuttings (vertical drill cuttings dryer) using microemulsion systems, aiming at the removal of this n-paraffin and thereby reducing environmental impact. For this task it was necessary to study the solid-liquid extraction between the systems (solvents) and drill cuttings. The variables of the solid-liquid extraction (solvent, solvent/drill cuttings ratio, stirring speed and contact time) were studied, as well as the methodology of ultrasonic extraction, used as the best possible extraction. Gas chromatographic analysis with flame ionization detector (GC-FID) was used to quantify the extracts. The obtained results showed that the microemulsion using the L90 surfactant (AP= 83%, C/S=16% e OP=1%) obtained better performance with 55.6% extraction of n-paraffin. In the study of the microemulsion/drill cuttings ratio, the ratio equal 1.0 obtained better result (55.39% extraction), whereas using 2.0 the extraction was 56.32%. In the study with the stirring speed was identified that the higher the speed the better extraction (56.24%), but it was identified that small stirring speed is reduced to extraction (46.12%). In the parameter of contact time an increase in the percentage of extraction with the increase of the time was also found, reaching levels higher than 80% of extraction with time of 160 minutes, but with time of 80 minutes has already reached percentage of extraction of 76%. It was concluded that the use of microemulsion systems promoted the treatment of drill cuttings at high levels, for chemical extraction, allowing a viable alternative for waste treatment and placing it at levels of acceptable contaminants (6.9% of fluid retained in the drill cuttings - US EPA, 2000).

Keywords: solid remediation, solid-liquid extraction, microemulsion, n-paraffin, ultrasonic extraction.

Currently petroleum-based fossil fuels are widely used for power generation and work. One of the main applications is in the transportation sector, especially mineral diesel. The widespread use of this fuel has increased emissions of polluting gases into the atmosphere such as CO_x, NO_x, SO_x and soot. These gases directly influence the aggravation of the greenhouse effect, cause acid rain and decrease the air quality we breathe. To reduce SOx emissions to the atmosphere, for example, sulfur concentration in Brazilian mineral diesel is currently limited to 10 ppm, according to CONAMA Resolution 403/2008. This ultra low sulfur diesel (ULSD) is also required in other countries. Another way used in Brazil to reduce emissions of air pollutants is the 10% volume mixture of biodiesel with mineral diesel consumed at gas stations. However, glycerin (a byproduct of biodiesel production) has become a problem for producers due to the large amount generated, where for every 100 liters of biodiesel produced, about 10 kg of glycerine results. The treatment process for sulfur reduction, oxygenated and nitrogenous compounds causes a decrease in lubricity in mineral diesel and lack of lubricity will affect engine performance such as accelerated wear, insufficient power, reduced service life, cause energy dissipation by friction and failure of parts such as fuel injectors and pumps. Therefore, in this work were developed microemulsionated mineral based diesel fuel ULSD systems with glycerine solution and two non Ephenylated ethoxylated surfactants with 4 EO and 6 EO that were able to harness the energy potential of glycerin, promote improvement in diesel properties and reduce emissions. of pollutants. Firstly, an experimental factorial design of type 2³ was developed to identify the most influential variables in the process, as well as the optimal value ranges. Seven fuel systems were determined with the aid of a previously elaborated pseudo-ternary diagram, namely: mineral diesel S10 (white of the experiments) and six formulations with a fixed surfactant concentration of 0.11 g R4 / R6 / mL diesel and with quantities of 15% glycerine solution added to each system ranging from 0 to 0.10 g / mL diesel in 0.02 g / mL increments. The thermogravimetric analysis suggested similar profiles for the different formulated fuels and the addition of surfactants R4, R6 and glycerine solution 15% increased the maximum decomposition and burning temperatures. All microemulsion fuel systems presented similar activation energies, calculated by the Ozawa – Flynn – Wall (OFW) method, of the order of 60 kJ / mol and when compared with the activation energy value of mineral diesel S10, A reduction of about 6 kJ / mol is obtained. The reduction in activation energy of these fuel systems suggests a reduction in ignition delay, improved burn and emission reduction when used in engines. In the lubricity tests developed in the HFRR (Hight Frequency Reciprocating Rig) it was observed as general behavior, an increase of the formation of the lubricating film, a decrease of the coefficient of friction and a reduction of the eschar formed in the balls. The best results were: double the percentage of lubricating film formation, 0.053 reduction in the coefficient of friction and 187 µm reduction in the size of the eschar formed when comparing the formulation with higher amounts of additives with the mineral diesel S10. The results of specific consumption tests for the different microemulsed fuels performed on a BD 7.0 engine at a fixed speed of 3500 rpm and six power load conditions show that increasing the water and glycerin concentration in the systems increased the consumption. of fuel at a specific load but this consumption becomes almost equal under the conditions of higher power loads. As for the analysis of CO, CO2, NOx and Gas Exit Gas emissions, the overall behavior was to reduce CO emissions and increase CO2 and NOx emissions and increase the gas exit temperature, when All power loads tested for S10 mineral diesel are analyzed. But for an analysis of each specific load, the behavior of reduction of CO, CO2, NOx emissions and Gas outlet temperature can be observed, being obtained in the best condition a reduction 19%, 5%, 11% and 10, 5% respectively.

In the petroleum industry, in the segment represented by petroleum extraction, the most relevant pollutant, is the water produced, due to their complex chemical composition of contaminants and quantity generated that can vary considerably. The inadequate discard of this wastewater implicate environmental damage, penalties and negative repercussion on producing companies, contrary to environmental legislation present. In this context, the flotation technique has been quite used in the treatment of this effluent, in order to reduce the

Content of oils and greases, associating the pretreatment stage operation of flocculation. In order to improve the final quality of this effluent, is it necessary to have another phase of post-treatment, which can be the use of activated carbon adsorption processes, that has been

widely studied, to remove dissolved part of oil which has in its composition monoaromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene. In this case, this research proposed to perform the treatment of synthetic wastewater with flocculation/flotation technique and adsorption by activated carbon, with the combined application of flocculation/ flotation dissolved air, using natural flocculants obtained from the seeds of the plant Moringa oleifera. Such flocculants were obtained by protein fractionation with ammonium sulfate extractant, that went called of crude extract, fraction 1, fraction 2 and fraction 3. And for the adsorption study were used three types of carbons by-products obtained from this plant, being coal in-natura, which was chemically activated in two ways, employing the phosphoric acid and ammonium hydroxide reagents. The main techniques and the parameters considered to characterize such coals were: hydrogen potential, point of zero charge, basic and acidic functional groups, thermogravimetric analysis, differential thermogravimetric, x-ray diffraction, x-ray fluorescence, scanning electron microscopy and infrared spectroscopy. The experiments of removal of oils and greases with combined technique flocculation/flotation were performed according to factorial and central planning, through which he statically verified the influence of process variables for the three flocculants: flocculant concentration and flotation time. From the adsorptive and equilibrium study, it was found that fresh coal

presented removal efficiency about 79.33% and the maximum benzene adsorption capacity was 65.07 mg.g^-1, values considered high when compared to other adsorbents. While, the chemically activated carbons presented removal efficiency of 51.56 and 84.61% and maximum adsorption capacities of 50.59 and 78.89 mg.g-1, respectively, with similar equilibrium time of 20 minutes. The natural flocculants produced presented potential for removal of oil and grease, to the point of reach the environmentals requirements for discard this effluent in natural bodies of water. The rapid removal of benzene and the range of the equilibrium in a short period of time, when compared to other precursors, these results may be indications that flocculants and adsorbents of Moringa oleifera are viable and efficient, and can constitute a promising alternative or the treatment of industrial effluents, making the process more economical.

The natural gas associated with the oil extracted from the pre-salt layer presents expressive CO₂ contents (> 30 mol%), which makes it unfeasible to commercialize directly from the platforms, so that the gas must be removed at least to the maximum concentration (3 % molar) required by the ANP to make it profitable. The microreaction system has reached great interest in the last decades due to the intensification of the process. In this configuration, the process occurs continuously, with the reactions and the transfer phenomena occurring in the individualized form with maximum gradients. A feature to be highlighted in these reactors, compared to conventional chemical reactors, is the higher surface area / volume ratio, which favors a higher yield, selectivity and energy efficiency of the reaction. The evaluated microreactors are formed by microchannels with square cross-section with hydraulic diameter between 0.28 to 1.5 mm. The microreaction system consists of pumps, valves, pressure and temperature sensors, microreactor and a microsseparator. The gas-liquid mixture occurs in the microreactor at atmospheric pressure and ambient temperature, and then is separated in the microsseparator, the gas in turn is directed to a gas chromatograph to check the percentage of absorbed CO₂. In this work, the CO₂ absorption process in water and amine (MEA) was studied in different types of microreactors (T-system, funnel type microreactor, T-type microreactor and microreactor T-junction) and evaluated different compositions for the gas phase with N₂, CO₂ and CH₄). Also, experiments were performed under operational conditions with different gas / liquid volumetric ratio values. In general, the flow regime was slug-like, and the results indicated that the maximum CO₂ removal efficiency using the T-junction microreactor occurred with removal efficiency greater than 90% and gas / liquid volumetric ratio of 7:30 without MEA and was 100% for concentrations of MEA above 0.5 M in all gas / liquid volumetric ratios studied.

The antigen 503, a protein found in the amastigote phase of Leishmania i. chagasi, can integrate vaccines and specific diagnosis assays for visceral leishmaniasis (VL). However, a problem on the protein purification is the presence of endotoxins (LPS), natural compound of bacterial expression systems, which triggers immune response in human body and interacts with the proteins impairing possible chromatography steps. To solve this problem, Aqueous Two-phase Systems (ATPS) can be employed with the advantages of eliminate clarification steps on the whole process, indeed it also concentrates the molecule of interest and reduces the concentration of LPS, preparing the product for a more efficient adsorption in the following steps. Thus, the present work aimed evaluate ATPS based on PEG1500/Salt, Ethanol/Salt (K₂HPO₄ and (NH₄)₂SO₄) and Acetonitrile/Dextrose on the partial purification of antigen 503 expressed in recombinant E. coli M15 and simultaneous removal of LPS. For that, firstly, binodal curves of these systems were constructed by cloud point titration method at room temperature (25 ± 2 ºC). The parameters of the equation purposed by Merchuk were calculated by these experimental data and the Tie-Line Lengthes (TLL) were obtained. Generally, the TLL rose with an increase of the concentration of organic solvent. When the cell homogenate from E. coli was applied, the system which exhibited the best results was 30% PEG1500 and 10% K₂HPO₄ (m/m) achieving 116,96% of recuperation and 1,55 of purification factor (assay P3). The removal of endotoxins was promising for all the systems evaluated, as it was kept above 90,0%. The assay P3 also stood out for the LPS removal, being able to remove 99,90%. Thus, ATPS can be a precedent step to the chromatography for the removal of high LPS concentration and grow the purity of recombinant proteins from E. coli.

With nearly 900,000 to 1.3 million new cases annually, Leishmaniosis is a complex of diseases that can be fatal if not given proper attention. Despite its relevance in the public health system, there is no vaccine capable of preventing disease in humans so far, and its treatment is expensive and aggressive to human health. Vaccination remains the most practical and realistic way of fight against the disease, thus, the production of recombinant antigens as a pathway towards a vaccine acquisition is necessary. In addition, the optimization of the strategy of the recombinant antigen’s production is of interest so it can make the process viable. Therefore, the present study aims to optimize the induction parameters of the 503 Leishmania i. chagasi antigen expressed in recombinant Escherichia coli. Hence, the induction at different cell densities (optical density at 600 nm of 0.5 and 1.0) was evaluated in order to analyse the influence of the induction time on the yield of the protein of interest. In this segment, lactose and isopropyl-β-D-thiogalactopyranoside (IPTG) were used as inducer molecules, using various concentrations: 0.1 g/L, 1.0 g/L and 10 g/L for lactose and 20 μM, 100 μM, 500 μM and 1000 μM for IPTG. The results presented that the concentration of IPTG that obtained the higher antigen levels was that of 100 μM (0.087 g/L), a 10-fold lower concentration than was being previously used in this type of system, and for lactose it was 1 g/L (0.016 g/L). Thus, the induction with 100 μM of IPTG allowed to obtain the antigen with a concentration 5.6 times higher than the lactose induction maximum concentration.

Biosurfactants are amphiphilic compounds of microbial origin, which have aroused as an alternative to the use of chemical surfactants once its use is very aggressive to the environment. On the other hand, biological surfactants have properties similar to the chemical surfactants and also have some advantages over them such as biodegradability, stability in different pH, temperature and salinity conditions, and low toxicity. In face of this situation, several studies have been developed in order to make the production of biosurfactants viable for commercialization. The most researches aims to analyze the production of these compounds using different renewable sources and investigate their surfactant properties. The rhamnolipids, that are biosurfactants produced by bacteria and belonging to the group of glycolipids, are applied in several industrial areas due to its various properties as emulsifying, solubilizing, wetting, so on. Thus, this work aims to verify the production of rhamnolipid by Pseudomonas aeruginosa P029-GVIIA, changing the following parameters: the concentration of glucose (10, 18 and 26 g / L) and the inoculum percentage (3, 10 and 17%) for 72 hours. Along this time the cell growth (X), the glucose concentration consumed (S), the produced rhamnolipid (P), the pH of the system and the production of total proteins were assessed. Five trials were performed and the best condition (26 g / L glucose and 3 ml inoculum) produced 0.838 ± 0.064 g/ L ramnolipid in 24 hours, biomass conversion factor in product (Y_P/X) of 0.260 g/g, substrate conversion factor in product (Y_P/S) of 0.034 g/g and product productivity (P_P) of 0.021 g/L∙h. At this assay, the biomass reached the highest value among all cultures (2.5 ± 0.041 g/L), pH ranged from 5.8 to 8 and substrate consumption reached 82.45% at the end of the experiment. From the best outcome, there were studied the emulsification index and the emulsifying activity with six different solvents: kerosene, hexadecane, toluene, soybean oil, corn oil and motor oil. The last one presented the best responses with emulsification index of 77.55% in the first 24 hours and high emulsifying stability, 2.23 U. Then, the efficiency of the biosurfactant in the removal of oil present in sand was evaluated in 16.8% and the antimicrobial activity of the ramnolipid against different bacterial and fungal species were determined, showing its ability to inhibit fungi of the species Candida tropicalis and Candida albicans. In this way, the results obtained prove the potential of the rhamnolipid produced for biotechnological applications.

The continuous process of transesterification at supercritical conditions in tubular reactors rises as a new technology that will ensure viable large-scale biodiesel production. The idiosyncrasies of this process are related to the simplified separation processes, use of low quality feedstock, catalyst free and short reaction time (compared to the conventional processes). In these types of studies, the recent breakthroughs demonstrate that an inert bed (mixing promoters) may be a feasible alternative to enhance tubular reactor performance when operated at supercritical conditions. However, a rigorous phenomenological analysis of this new process layout is scarce in literature, which creates some limitations for a complete understanding of the process. Thus, the main objective of the current work is to develop a mathematical model of the process and analyze triglyceride alcoholysis at supercritical conditions using a continuous tubular reactor packed with glass spheres. The operating variables evaluated are temperature (300, 350 and 400°C), volumetric flowrate (0.5 mL/min and 1.0 mL/min) and bed porosity (0.42, 0.38 and 0.32). The experimental data were evaluated for the oil /alcohol molar ratio of 1:40 and operating pressure of 15 MPa. The model parameters were estimated using the particle swarm optimization algorithm (PSO), which is a classical heuristic optimization technique. The phenomenological characteristics were analyzed based on the description of multiple gradients along with the false-transient method. The results obtained by the model were able to predict 89% of the experimental data. The higher conversions in esters were achieved for the highest temperature and lowest porosity. Therefore, the use of inert bed intensified the ester production, decreased reaction time as well as the thermal degradation of esters.

The ever-greater development of alternative energy sources in substitution to petroleum-derived fuels has forced this industry to optimize its costs, while keeping health, insurance and environment focus. Due to the high produced water rates in mature onshore fields, the reduction of chemicals while treating this residue provides important financial savings perspective to oil industry. The present study aims to evaluate the synergistic effect of the combined use of a conventional tanine based polyelectrolyte in association with a coconut oil derived surfactant, to better use locally available resources for produced water treatment. Due to produced water intrinsic instability, a method for producing stable oil in water emulsion (with ~50 mg/L of grease and oil content) was developed. Samples were subject molecular absorption analysis in visible region and compared to a standard built with solvent and oil. Chemical treatment’s efficiency were evaluated on jar-tests with controlled stirring basis’. Treatment with only polyelectrolyte presented results in good agreement with literature, where 40 mg/L were able to withdraw 81 and 85% of the oil content of the produced water residue, fully meeting law requirements. Treatment using only the coconut oil surfactant was able to achieve this level of treatment only with 200 mg/L of active matter, providing 86% efficiency. Combined polyelectrolyte and surfactant treatment managed to produce greater efficiency than isolated methods (92%) by using 20 mg/L of the polyelectrolyte and 100 mg/L of the surfactant. It was verified the dependency between tested variables (concentration and efficiency) by the use of deviation analysis (F-test) with 95% confidence. Therefore, it was possible to observe that the combined use of both products could lead to financial savings in produced water treatment while maintaining process sustainability and providing economic use for locally available low cost surfactants.

At the last decades, it has increased significantly the demand for microbial enzymes on biotechnological applications. The pectinolytic enzymes, responsible for cleaving both pectin and other pectic polysaccharides in galacturonic acid residues, have application in several sectors such as fruit and wine juice processing, recovery of essential oils, extraction of vegetable oils, as well as the textile and food industries.paper and cellulose. In this context, the aim of this work was to evaluate the production, stability and application of pectinolytic enzymes by Aspergillus niger IOC 4003 using acerola and cajá residues as solid state fermentation substrate (SSF). Initially, residues of acerola and cajá, washed and unwashed, were submitted to drying and determined their chemical and physicochemical composition. The percentage of calcium pectate, pectin indicator, found in residues was 3.46 ± 0.11%; 2.94 ± 0.18%; 5.85 ± 0.01% and 5.34 ± 0.23% for unwashed acerola, washed acerola, unwashed cajá and washed cajá, respectively. Then, the potential of these substrates as inductors for the production of pectinolytic enzymes by FES was evaluated during 240 h with initial pH of 4.5; humidity at 40% and spore concentration of 1 x 10⁷ spores / mL. In the fermentation stage, the greatest polygalacturonase production was observed using washed cajá residue reaching enzymatic concentration of 38.22 ± 0.63 U / g in 72 h of cultivation. Next, the optimization of enzyme extraction was studied and the best condition of extraction occurred using contact time of 30 minutes and acetate buffer at concentration of 50 mM and pH 5.4. On subsequent step, the stability of enzyme complex was evaluated against temperature and pH. The best condition on stability of polygalacturonase occurred at temperatures of 30 and 40 ° C, and among pHs 4 and 6 for up to two hours of incubation. Thus, the synthesized enzymatic extract by Aspergillus niger IOC 4003 from washed cajá or unwashed acerola residue was applied in the process of clarifying cajá juice. In the clarification stage, the outcomes that stands out were 40% reduction in turbidity, 30% of clarification and 85% increasing of antioxidant capacity of the juice. In this way, the present work demonstrates the feasibility of using fruit industry residues as substrates for production of interest enzymes and its application in food industry.

The contamination of waterbodies by pesticides that are resistant to conventional water treatment processes consists a serious environmental problem, making urgent the development of alternative technologies capable of degrading them. Among these pesticides is Atrazine (ATZ), which is of special concern due to its endocrine disrupting character, being classified as a priority substance to be monitored for water quality purposes in the European Union. Advanced oxidation processes (AOP) have been pointed as a promising technology against this kind of pollutant. However, as an organochloride, ATZ contains electron-deficient groups, making it more easy to reduce than to oxidize. Therefore, a pre-reducing step is preferred to an oxidative one for the removal of these class of contaminants. Given that, in this study was investigated the application of zero-valent copper as a reducing agent for the degradation of ATZ. Then, this was combined with a sulfate radical (SO4●-)-driven AOP. To study the influence of different operational conditions in the pre-reducing step, a Doehlert experimental design was followed. Then, the mineralization of the solution that presented the highest ATZ degradation was studied by varying the oxidant concentration – sodium persulfate (1, 5 and 10 mmol L^-1) – and the UV source of radiation (UVC and UVA). During the oxidative stage, samples were collected after 30, 60 and 120 minutes of reaction. Toxicity assays with the microalgae Chlorella vulgaris and the bacteria Vibrio fischeri were performed with the samples that obtained the highest degradation and mineralization results after each step. For the pre-reductive stage, the Doehlert design showed that the best conditions are those that combine low pH and high copper concentration (>0.2% m/v). The oxidative step was then applied on the most degraded solution and about 70% of mineralization was achieved after 2 hours of reaction when 5 mmol L^-1 of persulfate and UVC radiation were used. Regarding toxicity assays with C. vulgaris, the reduced solution was 30% less toxic than the parent-ATZ initial solution. For the test with V. fischeri, it was found that ATZ initial solution did not cause inhibitory effects, but a significant increase in toxicity was observed after the reductive step. For both organisms, it was verified that, among the three reaction times tested, the toxicity reached a minimum value after one hour of reaction of the pre-reduced solution with persulfate. However, for longer reaction times the toxicity has increased again, even though higher mineralization values were achieved. In this way, results indicate that a higher mineralization does not necessarily mean low toxicity and, therefore, additional studies are required to understand the relation between these effects.

The first part of this work examines electrokinetic remediation (ER) processes for removing Pb2+ in contaminated soils. For this purpose, different cathodic supporting electrolytes (NaNO3 0.1 M, EDTA 0.1M and citric acid 0.1 M) were used into the catholyte reservoir, while in the anodic compartment, a solution of NaNO3 0.1M was used. Additionally, the application of direct current (DC) and reverse polarity (RP) for removing of Pb2+ from the soil was also evaluated. Regarding to results obtained in this study indicated that RP and citric acid favored an efficient electromigration of Pb2+, favoring its elimination from the soil. This behavior can be explained because the elimination of Pb2+ depended on the dissolution/precipitation ionic species as well as the pH in the soil, which were maintaining in different sections in the soil, contributing to maintain the pH conditions, by using RP and citric acid, promoting the lead elimination. In order to use a feasible approach for monitoring Pb2+ concentration, adsorptive stripping voltammetry (AdSV) technique was used, obtaining acceptable confidence and good sensitivity for the concentration of Pb2+ with LOD about 0.1 mg L−1. Phytotoxicity tests showed that the ER process could be useful as a treatment technique for reducing hazardous soil toxicity polluted with Pb2+. The results confirmed the significant reduction of the germination in the anodic and cathodic regions for ER by applying DC with NaNO3 and EDTA as cathodic solutions. However, high germination (60–80%) was obtained for ER by using NaNO3 and citric acid solutions in cathodic compartments by applying RP or DC, respectively. Finally, the effluent generated by ER technology, in each one of experiments, was treated by electrocoagulation with Al electrodes, obtaining complete removal of Pb2+ from liquid after 60 min. The second part of this work studies integrated technologies for the treatment of soil, using ER with permeable reactive barriers (PRB). For this purpose, different cathodic supporting electrolytes (NaNO3 0.1 M, and citric acid 0.1 M) were used into the catholyte reservoir, while in the anodic compartment, a solution of NaNO3 0.1M was used. Additionally, the application of direct current (DC) and reverse polarity (RP) for removing of Pb2+ from the soil was also evaluated. The PRB used was made of cork with 2cm of thickness, 10cm of height and 10cm of length, located in the region near the anode. In order to use a feasible approach for monitoring Pb2+ concentration, adsorptive stripping voltammetry (AdSV) technique was used, obtaining acceptable confidence and good sensitivity for the concentration of Pb2+ with LOD about 0.1 mg L−1. The results obtained in this study indicated that the removal of Pb by adsorption in cork is influenced by the pH of the medium as observed in adsorption tests. The contribution of the addition of citric acid and RP contributed positively to the transport of Pb, avoiding precipitation in the form of Pb(OH)2. At the end of the 14 days, it was possible to observe that the integration of PRB and ER resulted in a higher removal efficiency (80%) associated to pH control in the cathode reservoirs.

Whey is a by-product of the dairy industry which has excellent nutritional, functional and physiological properties, associated with a high protein content. However, for it to be industrialized, it is necessary a complex treatment, limiting its use, especially for small farmers. As a consequence, whey is sometimes disposed inappropriately in the environment, causing environmental problems. β-lactoglobulin (β-Lg) and α -Lactalbumin (α-La) are the most abundant proteins in whey, their characteristics make possible their application in food products, mainly with the purpose of increasing the nutritional value and promoting functional characteristics. Although they are present in the whey of almost all ruminants, they can have variants from one species to another, conferring different characteristics according to the animal species. The study of thermal analysis of proteins has fundamental importance due to the influence of temperature on the behavior of proteins and their properties. The techniques of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are some of the most used in the thermal study. Thus, the objective of the present study was to perform the comparative analysis of goat and bovine whey in natura, with emphasis on the thermal characterization of α-La and β-Lg proteins from goat and bovine whey in natura. For this, analyzes of physical-chemical characterization and thermal analysis of goat and bovine whey in natura were carried out. Thermal analysis was conducted using a simultaneously apparatus of analyzes of TGA and DSC with whey samples and solutions of standard proteins previously treated. The results obtained in this study demonstrated that the samples of whey of different origins have similar thermal behavior, with the existence of an endothermic process accompanied by an exothermic process and values of ,  e  close, 83,4±0,7, 106,3±0,7 e 62±2 J/g from caprine whey, respectively; e 82±3, 107±1 and 65±4 J/g from bovine whey, respectively; and  , 144±3 J/g and 151±3 J/g, from caprine and bovine whey, respectively. The non-frozen caprine whey had higher values of ,  e  when compared to the frozen caprine whey, 89±2 , 108 ±1 and 149±28 J/g, respectively.

With the continuous increase in the energy demand for natural gas and the growing concern
with environmental aspects, mainly related to greenhouse gases, CO 2 capture became a
target of relevance for research and industrial interests. The microreactors, in front of
diverse options of application, have been emphasizing in the absorption of CO 2 . In this work,
there was a study of microreactor modeling in the capture of CO 2 of a multicomponent
mixture with characteristics similar to natural gas, composed of CH 4 , N 2 and CO 2 under
atmospheric pressure and ambient temperature. A parameter estimation step was performed
to correctly represent the mass transfer and chemical reaction phenomena. At first, the
physical absorption, in which distilled water (H2O) was present as solvent, was evaluated. It
was also verified the interference of a new component (CH4) in the absorption of CO2. The
influence of variables such as gas velocity, liquid stream velocity, total flow and gas-liquid
ratio were evaluated in several initial compositions. In a second moment, the chemical
absorption of CO2 in experiments with different amine reagents (MEA, EtilEA and TEA) in
H2O as solvent in several concentrations was analyzed. The phenomenological
mathematical model was implemented in MATLAB® to describe and analyze the process.
The parameters were estimated using the Interior Point Method. In the validation step of the
mathematical model, mean absolute errors (MAE) of less than 2% were obtained, showing
an excellent predictive capacity, which made possible a simulation and study of the process.
It was observed that the addition of CH4 did not significantly alter the absorbed amount of
CO2, although the mass transfer resistances were modified. Higher CO 2 uptakes were
obtained at lower gas velocities, higher liquid velocities. It has also been found that a lower
gas-liquid ratio increases the absorption yield, while a higher total flow results in lower mass
transfer resistances. The presence of a chemical reaction intensified the mass transfer,
resulting in enhancement factors greater than 1. Higher concentrations resulted in better
CO2 absorption results. The best-performing reagent was EtilEA.

The objective of this work is to analyze the influences of the physical characteristics of formulated mixtures and the operational conditions for a definition of mathematical equations, macroscopic heat and mass balances, that describe a production of powder and the behavior dryer the pulp of soursop-milk or soursop-albumin in spouted bed with intermittent feeding and HDPE or PP as inert particles. The drying tests were carried out following 2³ factorial planning with 4 repetitions at the central point. The following independent variables were considered: inlet air temperature (60 - 80ºC) and solids concentrations (30 - 50%). From the physical properties of the mixtures, the models that represent the flow of powder in the function of time were determined. Considering suspension accumulation inside the device, develop models to evaluate a temperature and humidity of the air at the dryer outlet. The system of ordinary differential balances, implemented and resolved numerically using Fortran routines, in which the influence of process variables on drying dynamics were assessed. The results obtained in modeling and mathematical simulations were compared with experimental data, indicating that the model fits the process well, based on outlet air temperature and moisture.

The field of renewable energies has attracted much interest from world-wide research because of the need to minimize damage to the environment and reduce dependence on fossil fuel energy. Biodiesel has established itself as a promising source of renewable and substitute energy for oil and diesel because of its high energy, biodegradable and "clean burning". The interesterification with methyl acetate is a new technique and has the advantage of producing, in addition to methyl esters (biodiesel), triacetin (product of great market value). Supercritical technology enables the production of biodiesel without the presence of catalysts, eliminating the need for further purification processes. The sesame (Sesamum Inducum L.) is one of the oldest oilseeds used by mankind (from 4300 BC). Its seeds provide a large amount of unsaturated fatty acids, especially oleic (from 35.9 to 42.3%) and linoleic (from 41.5 to 47.9%). Thus, the present work seeks to analyze the viability of biodiesel production through the reaction of non-catalytic interesterification of sesame oil with methyl acetate under supercritical conditions, the oil yield, the parameters that influence the reaction (oil / acetate molar ratio of methyl, pressure and operating temperature, ...) and the optimum conditions using this technique.

The present thesis aims to study the cobalt ferrite (Co_xFe_3-xO₄) nanocrystallites morphology and composition effects on their catalytic and detection properties. Different synthesis methods such as hydrothermal, solvothermal and thermal decomposition were used to control nanoparticles shape and composition. Moreover, the effect of synthesis parameters variations, such as addition of different surfactants, different solvents, surfactant concentration, temperature and time of synthesis were also investigated. The powders were characterized by X-ray Diffraction and Transmission Electron Microscopy and analyzed by Dispersive Energy Spectroscopy. The catalytic and detection properties were evaluated in CO atmosphere in the range of 100 to 300°C and in NO₂ atmosphere at 150 and 200°C. CoFe₂O₄ nanooctahedra with 15-20 nm were produced by hydrothermal synthesis using different surfactants (CTAB, SDS and PVP). Co_xFe_3-xO₄ with x = 1.5 and x = 1.8 were also synthesized by hydrothermal method. However, the TEM analysis showed that the amount of Co present in Co_xFe_3-xO₄ is limited at x = 1.5. When ethylene glycol was used as solvent, Co_1,8Fe_1,2O₄ of 4 nm with irregular shape and homogeneous composition was obtained. A mixture of nanocubes (18 nm) and nanospheres (10 nm) of CoFe₂O₄ were produced by solvothermal synthesis using oleylamine as surfactant. In the thermal decomposition, nanospherical CoFe₂O₄ were produced in benzyl alcohol, while nanooctahedra of Co_0.5Fe_2.5O₄ were produced in dibenzyl ether. The nanooctahedra with composition x = 1.5 and the mixture of nanocubes and nanospheres were tested in the CO catalysis. The nanocubes and nanospheres mixtures were also tested in the detection of NO₂. The results were compared with those obtained for the nanooctahedra with x=1 existent in the literature.  The applications results showed that the shape and composition have an effect on the nanoparticles catalytic activity. The powder of Co_xFe_3-xO₄ with x = 1.5 has higher activity and lower temperature needed for the maximum CO conversion. For the detection test, the mixture of cubes and spheres presented lower sensitivity than the nanooctahedra for all temperatures analyzed. The maximum sensor response obtained was 52% when the sensor was subjected to 50 ppm of NO₂ at 200 °C.

The search for processes of production of low cost materials has been studied in recent years, mainly by the industries, in order to relate the cost / benefit associated with low risk to the environment, and the ease of transport and its use. The transition metal carbides are gaining emphasis, due to their catalytic activity, stability and selectivity in a wide range of reactions. The purpose of performing doping with cobalt and nickel on the molybdenum carbide is the search for the alteration in the carbide structure in order to improve its catalytic activity. The process of photocatalysis is based on a reaction that a semiconductor material is activated by the emission of sunlight or artificial on the particles with sufficient energy to excite the electrons of the band of valence for the conduction band that region between the bands is called " bandgap ". This work aims to develop the study of the synthesis, characterization and photocatalytic/adsorption application of semiconductor materials with carbide type structure, using the gas-solid reaction method in a fixed-bed reactor. These materials were characterized using the techniques of XRD, crystallite size, TGA, BET, grain size and SEM/EDS. With its characterization, it is possible to understand the relation between its structural properties and its activities as heterogeneous catalysts. The results of photocatalysis were satisfactory, the studied carbides obtained good yield in the process of degradation and adsorption of the dye. The best result was for Mo2C_Ni 5% in acid medium with yield around 97% degradation / adsorption of the dye.

Electronic waste is becoming one of the most serious environmental and social problems today. To take aware of the problem, we need to discuss disposal and recycling alternatives. In this thesis, a new methodology for the removal of metals from printed circuit boards (PCB) is presented. This methodology contributes to the minimization of environmental impacts by recovering metallic elements of PCB, which reduces the exploitation of mineral deposits. The process of recycling of the PCB presented in this thesis consisted of the application of chemical and physical technologies, involving the leaching stage in acidic (nitric and hydrochloric) environments and the removal of copper, silver and tin by electrodeposition using copper electrodes. The initial electrodeposition reactions were performed in three current conditions (0.5 - 1.0 - 1.5 A) and time variations (15 - 30 - 60 - 90 and 120 min), respectively, with the original solution. For all conditions, the process was accomplished out without mechanical stirring and with mechanical agitation at 550 rpm. In another stage of reactions, the solution was diluted in 1: 3 and 1: 7 proportions, and electroplating tests were carried out under the same current conditions, with and without stirring and a constant time of 60 minutes. The electrodeposition of copper has been shown to be efficient at all applied times and currents. For silver, the best deposition rates occurred at a current density of 0.022 A / cm2 and time of 60 minutes. In the diluted solutions, the copper removal was significant in all studied parameters. For the tin, the best removals proceeded in the process without agitation, presenting high rates of removel in current of 1.5 A and without agitation. The concentrations of silver and tin, at the end of each process, were analyzed by X-Ray Fluorescence (FRX), Atomic Absorption Spectroscopy (EAA), X-Ray Diffraction. The morphology of the deposits, analyzed by Scanning Electron Microscopy (SEM) coupled to the Dispersive Energy Spectroscopy.

The development of new materials with improved properties is interesting for several industrial segments from the catalysis of chemical reactions for environmental legislation compliance, to the development of new electronic devices. Carbides and Mo oxides with cobalt addition may exhibit a diversity of intrinsic properties of great interest. In this work two methodologies for the addition of Co in these compounds with Mo (CoMoO₄ and Mo₂C-Co) were studied: solid and wet, having commercial molybdenum molybdate [(NH₄) ₆ [Mo₇O₂₄]4H₂O] and cobalt nitrate [Co(NO₃)₂.6H₂O] as the starting material. The doped precursors were characterized and the products of the thermal treatment (oxides) and the carbo-reduction reaction (carbides) were evaluated according to morphological (SEM), compositional (FRX) and crystallographic (XRD) aspects. It was verified that the dopant’s addition via solid state methodology presented itself, in both cases, as a more robust route; producing materials with smaller crystal sizes (~ 30nm to the carbide) and with higher dopant retention (δ ~ 10%) than the wet method (dp ~ 50nm and δ ~ 40%). A study of the conditions for obtaining Mo₂C with and without addition of dopant was performed using interval reactions. In the kinetic evaluation, Avrami’s nucleation and growth models were tested, as well as those proposed by Levenspiel of Shrinking Core. It was verified that the reaction proceeds according to MoO₂àMoà Mo₂C and that the model that best represents the actual behavior of the gas-solid reaction is that of Avrami with grain growth rate of M = 85.4 and dimensional parameter N = 0.34.

Changes in the climate resulted from the burning of fossil fuels claims to an urgent modification in the energy matrix. Biodiesel is one of the alternatives proposing the replacement of mineral diesel. The aim of this work is the study of biodiesel production from oiticica oil by a methylic transesterification through homogeneous catalysis (NaOH and KOH). Oiticica has a high oil content in its almond (> 60%). Oiticica seeds were selected and classified according to the year (2015 and 2017), harvest and the degree of maturation (green - V, dry - SS, mature - M and green without epicarp - SV). Oil was extracted by mechanical pressing (continuous and discontinuous). The chemical composition of oiticica oil and biodiesel was determined by Gas Chromatography coupled to Mass Spectroscopy (GC-MS). The synthesis study was carried out under various reaction conditions: temperature (between 32 and 80 °C), reaction time (2 to 5 h), oil/alcohol molar ratio (1:6 - 1:20), and mass percentage of catalyst (0.5 to 2.0%). The most favorable conditions were obtained with molar ratio of 1:9 (O: A), 32 °C, 1% KOH/MeOH catalyst and 4 h for green oiticica oil without epicarp of the second harvest of 2017 (OSV2). The best physico-chemical results obtained from the biodiesel syntheses showed: 0.34 mg KOH/g (acid number), 922.6 kg/m3 (density) and 8.647 mm2/s (kinematic viscosity). The conversion of the esters was determined by thermogravimetric analysis (TG/DTG) and by TGA-FTIR (thermogravimetric analysis coupled with infrared spectrophotometry) by spectra the presence of esters only for B100. Under optimized conditions, the maximum purity was 96.1%, in 4 h 15 min, with 1.27% of the KOH/MeOH catalyst at 32 °C. The oxidative stability of B100 was 0.43 h, indicating a short time to maintain in storage due to susceptibility to biodiesel oxidation. The formulated blends (B10 to B50) showed an acid value above the limit only for B50. For density and kinematic viscosity, all results were within the range specified by the ANP. The flash point for B100 (183 ° C) and B10 (58 ° C) was well above the specified limit, which demonstrates the energy potential of these biofuels. It was concluded that the reactive conditions studied were feasible for the production of oiticica biodiesel. It was also indicated the mixture with other biodiesels due to the viscosity and the use of antioxidants, in order to improve the thermooxidative stability of the biodiesel of oiticica.

Sulfur is one of the main contaminants of petroleum-based fuels and is present mainly in oils from mature fields, like most Brazilian onshore fields. The issue of sulfur in the form of SOx originated in burning of these fuels, such as diesel, affects air quality and bring health risks. Sulphur, when present in large quantities, also promotes corrosion of engines, reducing your lifespan. In 2013, ANP has adopted the new specifications for diesel oil (resolution 50/2013), becoming mandatory for nationwide marketing of diesel oil A (without addition of biodiesel) and B (with addition of biodiesel) with a maximum sulfur content of 500 ppm. Removal of sulfur is therefore of interest to the petrochemical industry. Oxidative desulfurization followed by solvent extraction is one of the most promissing techniques for sulfur heretocycles removal such as dibenzothiphene (DBT) and dimethyldibenzothiophene (DMDBT). In this context the present work studied the application of oxidative desulfurization of diesel (1200 ppm of sulfur), followed by liquid-liquid extraction using non-ionic surfactants. Were obtained the parameters related to liquid-liquid extraction and to the oxidation reaction using hydrogen peroxide (H₂O₂) and acetic acid (CH₃COOH) as a catalyst. The reactional parameters such as temperature, time, concentrations of peroxide and acid and the use of a catalyst on the reaction were evaluated using a 2^6-2 fractional factorial design. Sulfur concentration were reduced from 1200 ppm to 220 ppm after one oxidative desulfurization step and one liquid-liquid extraction step using Ultranex NP110. Under the same conditions for a model fuel containing 1200 ppm of DBT in n-dodecane the concentration were reduced to below 3 ppm. Therefore, the oxidation and subsequent extraction with surfactant have proven to be effective in desulfurization of diesel.

The growing interest of the bioprocess industry for the purified recombinant antigens is mainly due they can be used as a tool for the vaccines production. However, the application of these antigens requires a quite higher degree of purity thus techniques that could reduce the downstream processing cost it would be important. The Expanded Bed Adsorption (EBA) has been shown as a good alternative since it is simple, and combines the clarification, concentration and purification at only step. This study aims investigating the recovery and purification of the 503 antigen from Leishmania i. chagasi expressed in E. coli as well as the simultaneous removal of the endotoxin using EBA coupled to IMAC. First, the best method for the cellular disruption for obtaining the higher antigen content was assayed. The methods studied used were assayed by means of factoral planning using Lysozyme, beads, urea as well as EDTA. Next, adsorption tests in batch were used in order to investigate the use of five metal ions (Cu²⁺, Ni²⁺, Zn²⁺, Co²⁺, Fe³⁺) at concentration of 0.1 M, 0.5 M and 0.8 M coupled to the Streamline chelating resin in the adsorption capacity of the 503 antigen. The metal showing the best adsorption capacity was chosen for the EBA experiments. EBA experiments were carried out using a column of 2.6 cm in diameter (30 cm height), coupled to a peristaltic pump. Results showed that higher quantity for the total protein as well as the 503 antigen was obtained ureia at 8.0 M. Also, the best batch adsorption was shown by the Cu²⁺ metal showing 503 antigen adsorption capacity of 0.102; 0.128 and 0.111 mg/mL of adsorbent for concentrations of 0.1, 0.5 and 0.8 M, respectively. Also, EBA protocol using Streamline chelating coupled copper eluted witht 0.6 M of imidazole was able to recovery only 4.0 % 503 antigen.