Assessment of the Fate of Nitrate in the Phreatic Zone of Urban Aquifers in Tropical Areas

• Grant number: 25/00814-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: May 31, 2025
• End date: May 30, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Resources
• Principal Investigator: Reginaldo Antonio Bertolo
• Grantee: Fernanda Souto Barreto
• Supervisor: Philippe Van Cappellen
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Waterloo, Canada
• Associated to the scholarship: 22/02681-4 - Hydrochemical and hydrodynamic assessment of nitrogen in the Bauru River Basin, BP.DD

Abstract

Nitrate contamination of urban aquifers resulting from leaking sewage networks, often poorly designed and/or maintained, is a significant environmental and public health concern. In Bauru City (São Paulo State, Brazil), the levels of this contaminant exceeding the drinking water standards (>10 mg/L N-NO3-) have been registered in the Bauru Aquifer System (BAS) over the past two decades, reflecting the impacts of the disorderly land use occupation and inadequate sanitation. BAS is an unconfined hydrogeological reservoir, and it is responsible for the water supply of private users. This internship project proposes a detailed multidisciplinary approach to the hydrogeochemical processes controlling the fate of nitrate and other nitrogen species in the subsurface, based on chemical and physicochemical analyses (major ions, nitrogen species, DOC, pH, EC, redox potential, temperature), environmental isotopes (¿15NNO3 and ¿18ONO3) of groundwater samples from the phreatic zone of the BAS and reactive transport modeling. These activities will be conducted at the University of Waterloo (Canada), a partner institution of the SACRE Thematic Project (Process Number 2020/15434-0). The results acquired during the internship abroad will improve the understanding of the aforementioned processes in porous media affected by anthropic sources and provide subsidies for simulating future scenarios, helping to propose strategies for groundwater protection.