Banca de QUALIFICAÇÃO: ERNANI DIAS DA SILVA FILHO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ERNANI DIAS DA SILVA FILHO
DATE: 15/06/2023
TIME: 14:00
LOCAL: Auditório do Química III
TITLE:

Sorption of emerging contaminants in magnetic composites and chitosan particles in aqueous media: synthesis, characterization and thermodynamic modeling.

KEY WORDS:

water pollution, textile industry, medication disposal, drug adsorption, dyes

PAGES: 150
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Polímeros e Colóides
SUMMARY:

The pollution of water resources caused by the textile industry and the improper disposal of medicines are serious environmental problems that require immediate attention. Dyes used in the textile industry are highly soluble in water, contaminating water resources and making removal difficult. On the other hand, improper disposal of medicines can contaminate soil and water, representing a significant risk to public health and the environment. These emerging contaminants are being detected at increasing levels in the environment and which still do not have regulations or established control standards. It is crucial that the population is aware of the risks associated with the inappropriate disposal of medicines and that they take steps for their safe and responsible disposal, and through programs to collect expired or unused medications. In this context, this thesis proposes the study of the sorption of drugs in magnetic composites, as well as the study of the thermal degradation of these composites, and the development of a numerical method applied to the adsorption of dyes, acid blue 260 and methyl orange in cross-linked chitosan to simultaneously identify the concentration of these dyes in aqueous solutions. For that, techniques include thermogravimetric analysis, molecular absorption spectroscopy in the ultraviolet and visible region, infrared absorption spectroscopy, X-ray diffraction, and adsorption equilibrium studies. The drug study revealed that sorption occurred in multiple layers, reaching saturation with concentrations of 0.2 mmol of drug per gram of compound for HTCCl in both positive and negative magnetic composites, The anionic drug was adsorbed with similar intensity in both composites, its saturation for the negatively charged composite being achieved at a value of about 0.05 mmol per gram of composite. The Gibbs free energy of adsorption was estimated under dilute solution conditions, ranging from ‒17 to 3 kJ/mol. Analysis of the thermal degradation kinetics using the isoconversional approach showed that magnetite reduced the apparent activation energy, with values of up to 400 kJ/mol for the degradation of the organic phase. The method developed and applied to dyes, showed a more effective sorption for AA that could be characterized by determining different isothermal parameters, estimation of the Gibbs free energy of adsorption as well as competitive sorption by itself.

COMMITTEE MEMBERS:
Externo ao Programa - 1753094 - ALCIDES DE OLIVEIRA WANDERLEY NETO - nullPresidente - 1198847 - JOSE LUIS CARDOZO FONSECA
Interna - 1149440 - ROSANGELA DE CARVALHO BALABAN