Avaliação do potencial de adsorção de microplásticos após tratamentos oxidativos com O3 e O3/H2O2

Author(s)

Tiago Gomes de Aragão Belé

• Document type: Master's Dissertation
• Press: Limeira, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Tecnologia
• Defense date: 2020-07-29

Examining board members

Renato Falcão Dantas; Enelton Fagnani; Giovana da Silva Padilha

• Advisor: Joyce Cristale; Renato Falcão Dantas

Abstract

Microplastics (MPs) are small particles of plastics defined as having less than 5mm of size and considered nowadays as emerging contaminants. Due to their adsorption capacity, MPs can also act as contaminant carriers. When MPs pass through wastewater treatment plants equipped with advanced oxidation systems, MPs might be oxidized, changing their surface characteristics and adsorption behavior. This work evaluated if ozone (O3) and the association of O3 and hydrogen peroxide (H2O2) can shift the adsorption potential of three plastics present in water. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) MPs were characterized by X-ray Diffractometry (XRD), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analyses. To perform this study, the sorption of two pesticides, Chlorpyrifos (CPF) and dichlorvos (DDVP), onto PE, PP, and PS was analyzed using different kinetic and isotherm models. The sorption capacity follows the trend of PE > PP > PS. The second-order of the kinetic model described the sorption kinetics of DDVP and CPF, and the Freundlich and Henry isotherm models described the adsorption mechanism of DDVP and CPF, respectively. O3 and O3/H2O2 oxidation were able to modify the adsorption behavior by creating carbonyl and hydroxyl groups in MPs, thus, changing chemical interactions between adsorbate-adsorbent. This study demonstrated that MPs might have their adsorption behavior changed if submitted to oxidation processes used in wastewater treatment plants (AU)

• FAPESP's process: 18/15706-0 - Influence of secondary effluent composition on O3/H2O2 disinfection
• Grantee: Tiago Gomes de Aragão Belé
• Support Opportunities: Scholarships in Brazil - Master