Sustainable electro-bioremediation of multi-contaminated groundwater

Groundwater resources are threatened by a wide range of natural and anthropogenic pollutants, which restrict their potential for human consumption. The bioelectrochemical systems (BES) have received considerable attention as novel technologies for the remediation of contaminated groundwater due to their cost-effectiveness and minimal secondary pollution. The main objective of this study was to assess the application of BES for the remediation of multi-contaminated groundwater taken from the nitrate vulnerable zone of Arborea (Sardinia), focusing on process performance and practical feasibility. Initially, nitrate removal was evaluated in a two-chamber BES, focusing on the influence of hydraulic retention time on denitrification performance. Advanced cathode materials were further evaluated using carbon nanotube (CNT)-based membranes for denitrification. Subsequently, a three-chamber BES was developed to achieve simultaneous nitrate and salinity removal from real groundwater in compliance with drinking water standards, with integrated chlorine recovery. Then, the combined removal of nitrate, salinity, and trichloroethylene (TCE) was investigated in a three-chamber BES to address complex groundwater contamination. Finally, based on lab-scale experiments, a pilot-scale three-chamber BES was designed and implemented to evaluate its scale-up potential. The findings demonstrate the technical viability of BES for integrated groundwater treatment under real-world conditions.