OBTAINING PHOTOATIVE HYBRID POROUS MEMBRANES FOR ENVIRONMENTAL REMEDIATION: CHITOSAN/PVAL/BENTONITE/TITANIA/CHLOROPHYLL

• Grant number: 22/07773-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2022
• End date: September 30, 2024
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Emerson Henrique de Faria
• Grantee: Hugo Fernando Meira dos Santos
• Host Institution: Pró-Reitoria Adjunta de Pesquisa e Pós-Graduação. Universidade de Franca (UNIFRAN). Franca , SP, Brazil

Abstract

Brazil is one of the world's leading consumers of pesticides, raising concerns about environmental contamination. The presence of these products in aquatic ecosystems is particularly alarming, with few documented records to date. This has spurred research into effective remediation methods to prevent environmental damage and treat affected areas. One herbicide of significant concern in this context is tebuthiuron, widely used in sugarcane plantations due to its long persistence in the soil, mobility, and potential harm to organisms.An approach to pollutant degradation that has garnered attention is photocatalysis, due to its efficiency and ability to be repeatedly applied, requiring only specific wavelengths of light energy. This project is based on the capture of light, essential for life on Earth, as in photosynthesis, to create a material that can mimic the capture of solar energy and use it in photocatalysis. This material consists of chlorophyll (an essential pigment for capturing solar energy), TiO2 (a widely used semiconductor), and bentonite (a clay mineral that enhances photocatalytic properties). The goal is to obtain a material capable of effectively degrading tebuthiuron, using a wide range of wavelengths of light without harming the environment.Furthermore, this material will be incorporated into a polymeric matrix, consisting of chitosan (a biopolymer derived from chitin) and polyvinyl alcohol (a polymer with excellent physicochemical properties). This will enable the formation of microspheres and films to enhance the material's applicability without compromising its properties.The results will be evaluated through various photocatalysis tests, considering efficiency at different wavelengths, quantifying adsorption for process separation, and assessing effectiveness in degrading terephthalic acid at concentrations similar to those found in environmental pollution. Material characterization will be conducted using X-ray diffraction, infrared and ultraviolet-visible absorption spectroscopy, thermal analyses, specific surface area measurement, cation exchange capacity, and scanning electron microscopy.