Leaching transport of S-metolachlor and hexazinone in soils modified with aged microplastics

• Grant number: 25/11658-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2025
• End date: June 30, 2027
• Field of knowledge: Agronomical Sciences - Agronomy
• Principal Investigator: Kassio Ferreira Mendes
• Grantee: João Humberto dos Santos Rego Barbosa
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 24/08299-0 - TRACEABILITY OF MICROPLASTICS IN AGRICULTURAL SOILS AND INTERACTIONS WITH RESIDUAL HERBICIDES, AP.R

Abstract

This project will investigate the transport of the herbicides S-metolachlor and hexazinone in soils modified with aged microplastics, simulating leaching in the laboratory. Soil columns will be used to measure how these herbicides move vertically under a simulated rainfall regime of 200 mm in 48 hours. The herbicides will be applied to the top of the soil and, after the experiment, the columns will be sectioned into 5 cm layers to analyze the concentration of herbicides at different depths. The leachate will be collected and analyzed by high performance liquid chromatography (HPLC) to determine the presence of the herbicides. In addition, the herbicides retained in the soil will also be extracted and analyzed. The extraction method will be validated for parameters such as selectivity, linearity, limits of detection (LOD) and quantification (LQ), as well as precision and accuracy. The data will be statistically analyzed to identify differences in leaching between soils modified and not modified with aged microplastics. The aim of the study will be to evaluate the impact of the presence of aged microplastics on the transport and retention of the herbicides hexazinone and S-metolachlor in soils, helping to understand how these contaminants interact in environments with plastic waste.