In situ oxidation reduction potential-driven bio-electrochemical system enhance antibiotics and nitrogen removal performance in constructed wetlands

Constructed wetlands (CWs) offer a promising approach for removing antibiotics from livestock wastewater; however, their effectiveness is often constrained by the availability of electron donors and acceptors, which is crucial for the degradation process. This study implanted single electrode in CW to enhance pollutants degradation through the utilization of in situ oxidation reduction potential (ORP). Results indicated that electrode implanted CW (E-CW) simulated the formation of electron flow, as evidenced by higher nitrogen (70.44 ± 8.41 %) and sulfamethoxazole (SMX) removal performance (89.88 ± 4.52 %) than that in CW. Attributed to the positive role of electrodes in mitigation SMX accumulation, especially in bottom anaerobic zone, antibiotic resistance genes performed lower concentration in E-CW. The implantation of electrode facilitated the assembly of a collaborative microbiome, characterized by an increased abundance of functional consortia proficient in SMX removal (e.g. Nakamurellaceae), nitrogen removal (e.g. Nitrosomonadaceae), and electroactive bacteria (e.g. Burkholderiaceae and Rhodocyclaceae). The present study demonstrates the efficacy and mechanism of an in situ ORP-driven single-electrode bioelectrochemical system for enhanced availability of electron donors and acceptors, thereby offering new avenues for the optimization of CW purification capabilities.