Bioelectrochemical system for bioremediation and energy generation

Abstract

Bioelectrochemical systems (BESs) are one of the rising technologies capable of converting chemical energy into electric energy and vice versa by achieving simultaneous wastewater bioremediation. The microorganisms involved in the process are the core of BESs as they catalyse the oxidation of organic matter present in wastewater to produce electrons. While the chemical energy present in wastewater is converted into electrical energy in a microbial fuel cell (MFC), the electrical energy is being used to produce chemicals in a microbial electrolysis cell (MEC). Similarly, appropriate use of ion exchange membranes makes MFC capable of desalinating saline water and also facilitates recovery of nutrients from wastewater. The BESs have also proved its efficiency in utilising the solar energy for application in photosynthetic MFC employing microalgae as well as higher plants. Moreover, wastewater bioremediation in MFCs has extended its applicability in treating diverse waste streams starting from industrial and domestic to wastewater containing dye, organo-chloride, nitrate, ammonia, etc. Most remarkable advancement in BES research started with the recovery of value-added products including heavy metals, apart from generation of power. Even though innovative designs and low-cost efficient materials for electrodes, catalysts and proton exchange membranes (PEMs) for application in BESs have been developed, there are quite a few challenges of BESs that need to be addressed to take this technology forward. This chapter showers light on the microbial aspects of BES, with special focus on MFC, along with a thorough discussion on the recent developments in BES research emphasising its bottlenecks and challenges.