Simultaneous treatment of lipid rich ghee industry wastewater and power production in algal biocathode based microbial fuel cell

Abstract

ABSTRACT Microbial fuel cells have been constantly explored as robust technology for complex industrial wastewater treatment. The partial treatment of wastewater in anode chamber of MFC discourages its ability to thrive as stand-alone treatment process and further necessitates secondary treatment, prior to disposal. In our study, we have evaluated sequential treatment of ghee industry wastewater in the anode (primary) and later in microalgae-based biocathode chamber (secondary) to improve the treatment efficiency of bioelectrochemical system. The wastewater collected from ghee manufacturing unit was biochemically treated in the anode chamber after primary sedimentation and at the end of each batch, the anode effluent was transferred to a transient beaker and was used as a source for microalgal growth in cathode chamber without any modification. On comparison with conventional anaerobic treatment, microbial fuel cell could render higher COD removal with lower batch time. The highest power density and current density of 13.7 mW m−2 and 53.5 mA m−2 was produced with abiotic cathode. Though the power production was low in photo-bioelectrochemical system (3.33 mW m−2, 13.45 mA m−2) compared to abiotic cathode the treatment efficiency improved to 96%. Further, the photo-bioelectrochemical reactors enabled eco-friendly and efficient wastewater treatment with considerable power production.