Environmental remediation and generation of green electricity using constructed wetlands coupled with microbial fuel cell model system

Abstract

Antibiotic residues in wastewater are considered lethal to the crops and aquatic life. One of the promising way to treat this kind of wastewater is the use of constructed wetlands coupled with microbial fuel cell (CW-MFC). In this treatment, bacterial action and redox operation occurs at anaerobic anode and aerobic cathode respectively. Four different configurations of CW-MFCs was applied for comparison. This study focusses on the investigation of the removal of Co-trimoxazole (CMX), other co-existing pollutants and furthermore, the generation of green electricity with low hydraulic retention time (HRT) was studied. Results revealed that the effluent from configuration 1 (gravel based) had lower (CMX) concentration. This removal performance may be associated to greater electrode absorption capacity for (CMX). The removal efficiency was 92.58% at HRT of 3d and effluent concentration was 4 mg/L. On the other hand, CW-MFC1 exhibited the BOD removal (60.60%) regardless of the increasing effluent antibiotic concentration. Pure strain of Geobactor sulfereducens, adjusted with anaerobic sludge increased the bio-film growth. Maximum power density of 480.2 mW/m−3 observed for CW-MFC1. Electricity generation characteristic were also found to be effected with HRT.