PIRACICABA, CAPIVARI AND JUNDIAÍ RIVER BASIN UNDER THE IMPACT OF POLLUTANTS OF EMERGING CONCERN: AN ENVIRONMENTAL PERSISTENCE STUDY

• Grant number: 24/21523-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2025
• End date: February 28, 2026
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Antonio Carlos Silva Costa Teixeira
• Grantee: Leticia Dietrich
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 25/09729-0 - Environmental Fate of 2-Fluorobiphenyl and 1-Bromo-4-Fluorobenzene: Evaluating Pathways and the Transformation Products in Sunlit Surface Waters, BE.EP.MS

Abstract

Contaminants of emerging concern (ECs) are potentially toxic compounds that are difficult to remove by traditional effluent treatment processes, detected in rivers, lakes, reservoirs, seas, etc. Recently, 45 ECs were identified in the rivers of the Piracicaba, Capivari and Jundiaí (PCJ) basin, including bisphenol A (BPA), 1-bromo-4-fluorobenzene (p-BFB), 2-fluorbiphenyl, dichloroacetic acid, 2,2'-methylen-bis(4-methyl-6-tert-butylphenol) (DBMC) and perfluorooctanoic acid (PFOA), the result of intense industrial activity in the region. Considering the impacts on aquatic ecosystems and the multiple uses of water, it is crucial to understand and quantify the environmental persistence of these pollutants, which is influenced by physicochemical properties and abiotic and biotic phenomena. Photochemical processes induced by sunlight, such as direct and indirect photolysis, are fundamental for their removal from surface waters. Direct photolysis occurs when ECs absorb UV-visible radiation and degrade, while indirect photolysis occurs when pollutants are oxidized by photoproduced reactive intermediates (hydroxyl radicals, HO.; singlet oxygen, 1O2; triplet excited states of dissolved chromophoric organic matter, 3CDOM*), as well as carbonate radicals (CO3.-), generated by the absorption of sunlight by inorganic and organic compounds present in the waters. In this context, this Master's Research Project aims to investigate the environmental persistence of the aforementioned contaminants in the waters of the PCJ basin, based on the experimental determination of parameters related to direct and indirect photolysis. Together with local geographic-temporal data on the incidence of solar radiation and the physicochemical characteristics of the waters of the PCJ basin, these experimental parameters will be used in mathematical simulations to predict the half-life times of the contaminants studied and to understand water purification. In addition, based on quantitative structure-activity relationship (QSAR) models, the ecotoxicological impacts of the compounds and their degradation by-products will be evaluated.