Bioelectrochemical single reactor for reductive and oxidative removal of trichloroethylene from contaminated groundwater

Chlorinated aliphatic hydrocarbons such as trichloroethylene (TCE) are persistent groundwater contaminants due to improper disposal and low biodegradability. This work presents an innovative bioelectrochemical system for the integrated reductive/oxidative removal of TCE from contaminated water, implemented in a single tubular reactor. Unlike previous approaches relying on sequential reactor configurations, this study optimizes a three-electrode setup that enables both anaerobic and aerobic dechlorination processes to occur simultaneously within the same unit. The system features a mixed metal oxide (MMO) anode that facilitates oxygen evolution and supports oxidative degradation, and a graphite cathode for TCE reduction under anaerobic conditions. The reactor's configuration promotes the coexistence of both anaerobic and aerobic microbial communities, enabling complete dechlorination of TCE and minimization of toxic by-products RESULTS After characterizing the system from a fluid-dynamic point of view, continuous-flow galvanostatic runs at +15, +30, and +20 mA achieved removal efficiencies above 97%. By-product profiles confirmed the progression toward full mineralization. The most effective performance was obtained at +30 mA, with a removal rate of 38.6 μmol/L d−1. Coulombic efficiency and energy consumption were also evaluated, highlighting the feasibility of low-energy operation. CONCLUSION This single-reactor strategy represents a significant advancement in the design of compact and efficient systems for in situ groundwater remediation, reducing operational complexity while enhancing treatment performance. © 2026 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).