Banca de DEFESA: GABRIELA TUONO MARTINS XAVIER
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : GABRIELA TUONO MARTINS XAVIER
DATE: 27/07/2023
TIME: 09:00
LOCAL: https://conferenciaweb.rnp.br/webconf/wagner-27
TITLE:
Synthesis, characterization and application of PVDF membrane incorporated with modified bentonite for phosphorus removal
PAGES: 167
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:
Eutrophication is an environmentally significant problem lately, resulting from the excessive accumulation of nutrients, such as phosphorus and nitrogen, in water bodies. Due to the essential role of phosphorus in plant growth and its vital importance to all living organisms, the removal and recovery of this element in concentrated environments have been the focus of extensive research. That is because besides the environmental problems associated with its excess P is a non-renewable natural resource. In this context, this project aimed to obtain a mixed matrix membrane incorporated with bentonite modified with Fe(III) to enhance the P adsorption mechanism from aqueous solutions. For this purpose, a low-cost, national, and natural clay with a maximum adsorption capacity of 5.8 mg P/g was used, supported by polyvinylidene fluoride (PVDF), a widely used polymer in the fabrication of ultrafiltration membranes. The mixed matrix membranes obtained in this study showed increased thermal resistance, porosity, surface area, and permeability compared to the pristine membrane. The membranes with the incorporation of adsorbent exhibited resistance to the pressure required for continuous filtration processes. Batch adsorption tests demonstrated that the maximum adsorption capacity (Q) of the 1.5:1.2:10 (NT- 25Fe:PVDF:DMF) membrane was 1.40 mg P/g, with equilibrium being reached after 360 minutes of contact. It was also observed that the pseudo-second-order (kinetic) and Langmuir (isotherm) models best fit the obtained data, confirming that adsorption occurs through chemisorption, forming an inner-sphere complex between iron ions and the P species. Continuous flow adsorption tests demonstrated that the membrane has regenerative capacity in three consecutive cycles, recovering over 60% of the adsorbed P. Additionally, an increase in pressure had little effect on the adsorption capacity of the material, which achieved the removal of up to 50% of the P present in continuous flow. Q (mg P/m²) was higher at pH values of 3.0 and 7.0, while it increased with gradual increments in the initial P concentration and the amount of adsorbent present in the polymeric matrix. Simultaneous filtration of organic matter, in the form of humic acid, resulted in surface fouling of the material, leading to a decrease in the flux rate and P removal by the material. Lastly, the elaboration and development of this study were based on the growing need and interest within the scientific community to search for alternative materials, methods, and technologies to minimize the environmental impacts caused by P excess. In this perspective, the developed membrane showed a capacity for P removal under different experimental conditions, demonstrating a potential for application in different matrices and processes.
COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1601156 - WAGNER ALVES CARVALHO
Membro Titular - Examinador(a) Interno ao Programa - 1814655 - LUCIA HELENA GOMES COELHO
Membro Titular - Examinador(a) Externo à Instituição - GLÁUCIA PANTANO - UFPR
Membro Titular - Examinador(a) Externo à Instituição - SANDRA ANDREA CRUZ - UFSCAR
Membro Titular - Examinador(a) Externo à Instituição - ROBERTA CERASI URBAN - UFSCAR
Membro Suplente - Examinador(a) Interno ao Programa - 1933328 - HELOISA FRANCA MALTEZ
Membro Suplente - Examinador(a) Externo ao Programa - 2604737 - EVERALDO CARLOS VENANCIO
Membro Suplente - Examinador(a) Externo à Instituição - CAIO MARCIO PARANHOS DA SILVA - UFSCAR