Electrochemical technologies and phytoremediation: Strategies for antibiotic waste removal, electricity generation, and water quality improvement

Abstract

This study evaluated the capacity of constructed wetlands combined with microbial fuel cells to remove antibiotics from wastewater. Two macrophyte species (Lemna gibba and Schoenoplectus tatora) and two types of electrodes (graphite and a bioelectrode derived from biochar produced from L. gibba biomass) were utilized. The experiments were conducted over three treatment cycles, measuring the removal of Ciprofloxacin (CIP) and Tetracycline (TET) in the influent and effluent sections of the wetland. Results showed that, in the influent, the second cycle exhibited more pronounced differences between treatments and time points for CIP and TET (p < 0.05), while cycles one and three showed similar results. In the effluent, high removal percentages were achieved across all three cycles, reaching 98.9% for CIP and 100.0% for TET. Additionally, physicochemical parameters such as pH, oxidation-reduction potential (ORP), and dissolved oxygen (DO) improved in all treatments, with initial and final values ranging from 4.7 to 7.2, -414.5 to -69.4 mV, and 0.3 to 3.2 mg/L, respectively. Regarding electricity production, the combination of Lemna gibba and the bioelectrode generated the highest output (0.067 mW) compared to other treatments. This study demonstrates that the system using a bioelectrode can effectively remove antibiotics from water within 60 minutes.