Banca de DEFESA: JOYCE SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JOYCE SILVA
DATE: 17/01/2023
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:
KEY WORDS:

Electrospinning, removal, polyacrylonitrile, polypyrrole, glyphosate.

PAGES: 100
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Population growth with the consequent increasing demand for food supplies led to a search for new agricultural techniques, including the use of pesticides. In its various formulations, glyphosate is the most widely used pesticide worldwide, despite the risks it poses to human and animal health and the environment. Among the technologies used for the removal of these substances, adsorption appears as an efficient and lowcost alternative. The objective of the present work was to prepare polyacrylonitrile (PAN) membranes coated with the conductive polymer polypyrrole (PPi), through in situ chemical polymerization, which would be efficient in removing the pesticide glyphosate dispersed in aqueous media. These membranes were characterized using SEM, FTIR, UV-vis techniques, point of zero charge and contact angle measurements, and mechanical tensile testing. Then, we carried out studies of the adsorption mechanisms, by placing the membranes in an aqueous medium containing glyphosate. With that, the adsorption isotherms were analyzed, and the corresponding kinetic and thermodynamic studies were carried out. The best removal results were obtained at pH 4.0, when an adsorption capacity (q e ) of approximately 47 mg/g was reached, with the equilibrium of the process being reached in 90 minutes. The adsorption process fitted better to the Langmuir isotherm and pseudo-second-order models, which indicates that it is controlled by the chemisorption mechanism, or monolayer adsorption, and is favored with decreasing temperature. The results obtained suggest that the PAN/PPi composite membrane is an efficient active agent to be used in protocols for the removal of glyphosate.

COMMITTEE MEMBERS:
Presidente - 1130294 - CELSO PINTO DE MELO
Interno - 1806089 - EDUARDO HENRIQUE LAGO FALCAO
Externo ao Programa - 1810494 - KLEBER GONCALVES BEZERRA ALVES - null