Banca de DEFESA: MARCONI SANDRO FRANCO DE OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARCONI SANDRO FRANCO DE OLIVEIRA
DATE: 29/12/2022
TIME: 09:00
LOCAL: Remota
TITLE:

VOLTAMETRIC DETERMINATION OF HEAVY METALS AND ORGANIC COMPOUNDS IN EMERGING POLLUTANTS USING VITREOUS CARBON AND BORON DOUPED DIAMOND ELECTRODES


KEY WORDS:

Produced water; Heavy metals; Electrochemical oxidation; electrodes


PAGES: 100
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:
In recent years, the oil, pharmaceutical and food industries have developed to meet a population expansion and, with that, the problem of environmental pollution has increased without precedent. Today, urban centers and the environment where these industries were installed present  pollution problems in their regions. Produced water is one of the main by-products of the oil industry and is characterized as an effluent of complex composition, formed by various organic and inorganic compounds. It represents about 70 % of the total wastewater generated during the life of the well, on which its characteristics and quantities produced also depend. Currently, in Brazil, millions of cubic meters of water effluents are discarded into the environment, as well as a considerable amount of oils and greases. Emerging contaminants (ECs), products of the pharmaceutical and food industry, are considered persistent pollutants and have been studied worldwide. Several aquatic matrices have low concentrations of these pollutants causing damage to human health and the ecosystem, which makes them need identification, quantification and alternative treatments capable of promoting their degradation. The present thesis aimed to investigate, through synthesized effluents and contaminated real samples, the application of analysis with voltammetric detection in a BDD electrode for the determination of ECs (Caffeine, paracetamol and methyl orange) in synthetic effluent and in unmodified glassy carbon (GCEn ) for heavy metals (Pb2+, Zn2+ and Cd2+) in a real sample of produced petroleum water. For comparison purposes, the analytical methods of absorption spectroscopy in the UV-vis region and high performance liquid chromatography (HPLC, High-Performance Liquid Chromatography) were used in the analysis of the samples as reference techniques. The present study evaluated the efficiency of electrochemical oxidation (EO) in the degradation of caffeine, paracetamol and methyl orange. In addition, the energy consumption of all processes applied was verified, in this study, presented a low operating cost, thus enabling the application of the EO process for the treatment of effluents. The results obtained were strong, as complete removal of ECs was achieved in all applied processes. To reliably quantify the analytes in the sample, before and after the oxidative treatment, Differential Pulse Voltammetry (DPV) analysis was performed on a BDD electrode, together with HPLC and UV-vis in the characterization of ECs. The result obtained by the electrochemical method was statistically in agreement with the spectrophotometric and HPLC methods. The calibration curves ranged linearly from 3.88 to 19.20 mg L−1 for caffeine, for example. Detection limits were 3.43, 0.84 and 0.46 mg L−1 for caffeine, acetaminophen and methyl orange, respectively. The unmodified glassy carbon electrode (GCEn) was used as an electrochemical detection platform to determine traces of lead, cadmium and zinc ions in samples of produced water from petroleum by differential pulse redissolution voltammetry (DPSV). The calibration curves ranged linearly from 0,.05 to 1,.19 mg L−1 for the metals Pb2+, Zn2+ and Cd2+. The detection limits were 0,.164537 mg L−1 for Pb2+, 0,.14257 mg L−1 for Zn2+ and 0,.133594 mg L−1 for Cd2+. The detection limits were 0,14 mg L−1 for Zn2+, 0,12 mg L−1 for Cd2+ and 0,12 mg L−1 for Pb2+ for simultaneous analysis. The unmodified glassy carbon electrode has been successfully applied in the analysis of trace metals in water produced from contaminated petroleum. The comparison of the electroanalysis results with those of UV-vis and HPLC, establishes and confirms a potentially applicable technique for the determination of caffeine, paracetamol and methyl orange analytes in synthetic effluents. And in general, the electrochemical method can be highlighted due to its low consumption of reagents, ease of operation, speed of analysis and excellent precision and accuracy, characteristics that lead to the use of this technique as another way of determining analytes in effluents.
In recent years, the oil, pharmaceutical and food industries have developed to meet a population expansion and, with that, the problem of environmental pollution has increased without precedent. Today, urban centers and the environment where these industries were installed present  pollution problems in their regions. Produced water is one of the main by-products of the oil industry and is characterized as an effluent of complex composition, formed by various organic and inorganic compounds. It represents about 70 % of the total wastewater generated during the life of the well, on which its characteristics and quantities produced also depend. Currently, in Brazil, millions of cubic meters of water effluents are discarded into the environment, as well as a considerable amount of oils and greases. Emerging contaminants (ECs), products of the pharmaceutical and food industry, are considered persistent pollutants and have been studied worldwide. Several aquatic matrices have low concentrations of these pollutants causing damage to human health and the ecosystem, which makes them need identification, quantification and alternative treatments capable of promoting their degradation. The present thesis aimed to investigate, through synthesized effluents and contaminated real samples, the application of analysis with voltammetric detection in a BDD electrode for the determination of ECs (Caffeine, paracetamol and methyl orange) in synthetic effluent and in unmodified glassy carbon (GCEn ) for heavy metals (Pb2+, Zn2+ and Cd2+) in a real sample of produced petroleum water. For comparison purposes, the analytical methods of absorption spectroscopy in the UV-vis region and high performance liquid chromatography (HPLC, High-Performance Liquid Chromatography) were used in the analysis of the samples as reference techniques. The present study evaluated the efficiency of electrochemical oxidation (EO) in the degradation of caffeine, paracetamol and methyl orange. In addition, the energy consumption of all processes applied was verified, in this study, presented a low operating cost, thus enabling the application of the EO process for the treatment of effluents. The results obtained were strong, as complete removal of ECs was achieved in all applied processes. To reliably quantify the analytes in the sample, before and after the oxidative treatment, Differential Pulse Voltammetry (DPV) analysis was performed on a BDD electrode, together with HPLC and UV-vis in the characterization of ECs. The result obtained by the electrochemical method was statistically in agreement with the spectrophotometric and HPLC methods. The calibration curves ranged linearly from 3.88 to 19.20 mg L−1 for caffeine, for example. Detection limits were 3.43, 0.84 and 0.46 mg L−1 for caffeine, acetaminophen and methyl orange, respectively. The unmodified glassy carbon electrode (GCEn) was used as an electrochemical detection platform to determine traces of lead, cadmium and zinc ions in samples of produced water from petroleum by differential pulse redissolution voltammetry (DPSV). The calibration curves ranged linearly from 0,.05 to 1,.19 mg L−1 for the metals Pb2+, Zn2+ and Cd2+. The detection limits were 0,.164537 mg L−1 for Pb2+, 0,.14257 mg L−1 for Zn2+ and 0,.133594 mg L−1 for Cd2+. The detection limits were 0,14 mg L−1 for Zn2+, 0,12 mg L−1 for Cd2+ and 0,12 mg L−1 for Pb2+ for simultaneous analysis. The unmodified glassy carbon electrode has been successfully applied in the analysis of trace metals in water produced from contaminated petroleum. The comparison of the electroanalysis results with those of UV-vis and HPLC, establishes and confirms a potentially applicable technique for the determination of caffeine, paracetamol and methyl orange analytes in synthetic effluents. And in general, the electrochemical method can be highlighted due to its low consumption of reagents, ease of operation, speed of analysis and excellent precision and accuracy, characteristics that lead to the use of this technique as another way of determining analytes in effluents.


COMMITTEE MEMBERS:
Presidente - 2275848 - ELISAMA VIEIRA DOS SANTOS
Interno - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Externa à Instituição - DANYELLE MEDEIROS DE ARAUJO - CNPq
Externo à Instituição - INALMAR DANTAS BARBOSA SEGUNDO - CNPq
Externa à Instituição - MAYRA KEROLLY SALES MONTEIRO - UFRN
Notícia cadastrada em: 22/12/2022 09:52
SIGAA | Superintendência de Tecnologia da Informação - (84) 3342 2210 | Copyright © 2006-2024 - UFRN - sigaa09-producao.info.ufrn.br.sigaa09-producao