Wastewater treatment by microbial fuel cell coupled with peroxicoagulation process

Abstract

A microbial fuel cell is a rapidly growing, eco-friendly and green technology. As per this technology, the microorganisms are employed to convert the chemical energy stored in the biodegradable portion of organic matter into direct electric current by simultaneously treating the wastewater. In this study, dual-chambered H-type mediator-less and membrane-less microbial fuel cell was operated and was optimized using synthetic wastewater as a substrate. The influence of various factors such as cathodic electron acceptors, electrode configuration, electrode spacing on chemical oxygen demand removal and current output were investigated. The maximum current of 1.72 mA was obtained using synthetic wastewater with potassium permanganate as effective catholyte, electrode spacing of 2 cm from the salt bridge and surface area of 98 cm2. This study also investigated the effect of substrate in the optimized MFC by applying different real wastewaters (municipal wastewater, dairy wastewater, cassava wastewater) and found a superior performance by dairy wastewater with maximum current output of 5.23 mA and chemical oxygen demand removal of 94%. Electron microscopic observations revealed the development of biofilm on the electrode surface, which was responsible for biocatalytic activity in the microbial fuel cell during the operation. The current generated using microbial fuel cell was supplied to peroxicoagulation process and was used for the removal of rhodamine B dye. Decolorization of 98% achieved by the novel microbial fuel cell-coupled peroxicoagulation system. The novel microbial fuel cell-coupled peroxicoagulation is an energy-efficient as well as cost-effective technique.