Evaluation of Microbial electro-Fenton system performance in removal of tetracycline antibiotic from wastewater and renewable energy generation under the influence of different electrical circuit conditions

Microbial electro-Fenton system is a new and green technology that has the ability to removeresistant organic pollutants due to cathodic Fenton reactions along with the production ofrenewable electrical energy through the catabolic activity of microorganisms. The aim of this studywas to evaluate the performance of microbial electro-Fenton system in tetracycline antibioticremoval as a target contaminant from wastewater and energy generation under the influence ofdifferent electrical circuit conditions. In this study, a two-chambered microbial electron-Fentonsystem equipped with anode and cathode electrodes made of carbon felt, Nafion membrane with۲۰۰۰ mg/L substrate and anaerobic sludge as inoculum was operated in open, closed and shortcircuit conditions for ۲۴ hours. During the operation of the reactor, the effect of the type ofelectrical circuit on the cathodic removal efficiency of tetracycline and the production of electricalenergy was investigated. Electrical circuit conditions were introduced as important parameters ingenerating electricity and removing contaminants in the cathode. The findings of this study provedthat the efficiency of the microbial electro-Fenton system in tetracycline removal in short circuitconditions due to increased production of hydrogen peroxide at the cathode, increased comparedto open and closed circuit conditions and the removal efficiency of this pollutant in theseconditions reached ۹۹.۰۴%. In addition, the current density generation in short circuit conditionsimproved compared to closed circuit conditions and the voltage of ۲۶۰ mV, the power density of۹۳.۱۳ mW/m۲ in the current density of ۶۹۵ mA/m۲ were obtained in short circuit conditions. Theresults of this study showed that the microbial electro-Fenton system can be a suitable technologyfor clean and renewable electricity production and also simultaneous removal of various organicpollutants from the wastewater in different conditions of the electrical circuit.