Bioelectroventing: an electrochemical-assisted bioremediation strategy for cleaning-up atrazine-polluted soils

The absence of suitable terminal electron acceptors (TEA) in soil might limit the oxidative metabolism of environmental microbial populations. Bioelectroventing is a bioelectrochemical strategy that aims to enhance the biodegradation of a pollutant in the environment by overcoming the electron acceptor limitation and maximizing metabolic oxidation. Microbial electroremediating cells (MERCs) are devices that can perform such a bioelectroventing. We also report an overall profile of the C-14-ATR metabolites and C-14 mass balance in response to the different treatments. The objective of this work was to use MERC principles, under different configurations, to stimulate soil bacteria to achieve the complete biodegradation of the herbicide C-14-atrazine (ATR) to (CO2)-C-14 in soils. Our study concludes that using electrodes at a positive potential [+600mV (versus Ag/AgCl)] ATR mineralization was enhanced by 20-fold when compared to natural attenuation in electrode-free controls. Furthermore, ecotoxicological analysis of the soil after the bioelectroventing treatment revealed an effective clean-up in <20days. The impact of electrodes on soil bioremediation suggests a promising future for this emerging environmental technology.