Effects of partial capping in the contaminants mobilization and microbial degradation in a closed waste deposit

Abstract

The physicochemical and microbiological evaluation of areas impacted by waste deposits is essential for the understanding of the involved attenuation and transport processes, contributing to the prevision of the necessity of intervention measures, as well as for the verification of their effectiveness. In Brasil and in tropical and subtropical conditions, studies concerning the characterization of waste deposits contaminant plumes are still scarce, which leads to management activities not properly adapted to the local conditions. Therefore, this research project aims at conducting an integrated and comparative assessment of the conditions in the saturated and non-saturated zones in a closed dumpsite area in São Carlos city, São Paulo state, situated in a Guarani Aquifer recharge zone, before and after its partial capping is implemented. Groundwater and solid residues samples will be collected, followed by physicochemical and microbiological analysis (DNA extraction, PCR-DGGE, 16R rRNA sequencing), before and after the impermeabilization. Geophysical surveys will be conducted complementarily, aiming at helping in the evaluation of contaminants mobilization in both scenarios. With this study, the goal is to relate the microbial community with the pollutants present in the residues massif and with the possible ongoing degradation processes, and, thus, predict the natural attenuation processes and the effects and benefits of the adoption of capping in unplanned waste deposits. The results may contribute with a better management of contaminated areas, providing a tool for the identification of natural attenuation and helping in the proposal of intervention and remediation measures. This doctorate project is part of the FAPESP thematic project " Water availability and quality threats in a Guarani Aquifer System outcrop zone", FAPESP grant 2015/03806-1. (AU)