AI Article Synopsis
- The study examines how BTEX compounds (benzene, toluene, ethylbenzene, and xylene) contaminate soil and groundwater, focusing on their degradation in a Brazilian aquifer.
- By using compound-specific carbon stable isotope analysis (CSIA), researchers explored the biodegradation processes and formation of methane, revealing the movement and transformation of these contaminants in the environment.
- The findings enhanced the understanding of different oxygen conditions within the contamination zone, showing that both aerobic and anaerobic degradation processes are occurring.
Article Abstract
Release of benzene, toluene, ethylbenzene, and xylene (BTEX) as components of the light non-aqueous phase liquids (LNAPL) contaminates soil and groundwater. Assessing the mechanisms of degradation and mineralization of BTEX in groundwater helps understand the migration of the dissolved plume, enabling the reduction of risks to humans. Here, we studied the fate of ethylbezene, m,p-xylenes and o-xylenes and the accompanying formation of methane in a Cenozoic lateritic aquifer in Brazil by compound-specific carbon stable isotope analysis (CSIA), to gain insights into the complex dynamics of release and biodegradation of BTEX in the LNAPL source zone. The enrichment of ∂C in aromatic compounds dissolved in groundwater compared to the corresponding compounds in LNAPL indicate that CSIA can provide valuable information regarding biodegradation. The isotopic analysis of methane provides direct indication of oxidation mediated by aquifer oxygenation. The ∂C-CO values indicate methanogenesis prevailing at the border and aerobic biodegradation in the center of the LNAPL source zone. Importantly, the isotopic results allowed major improvements in the previously developed conceptual model, supporting the existence of oxic and anoxic environments within the LNAPL source zone.
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| http://dx.doi.org/10.1016/j.jconhyd.2020.103684 | DOI Listing |
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