Third generation in bio-electrochemical system research - A systematic review on mechanisms for recovery of valuable by-products from wastewater

Bio-electrochemical system (BES) mainly focused on bio-energy generation in the form of methane and bio-hydrogen while treating wastewater in anodic chamber. The potential of BES to produce intermittent chemicals and high-value derivatives has been immensely explored since last decade by adopting modified reaction kinetics. This review article deals with the mechanism of recovery of resources and by-products during redox reactions in BES. The BES offers flexible platform for both oxidation and reduction processes. Development of BES for product synthesis via bio-electrochemical pathway has greatly extended the new horizon in bioenergy research. Microbial fuel cell and microbial electrolysis cell, the major two variants of BES, are useful to convert the energy present in wastewater to recover resources like bio-electricity, hydrogen, nutrients, heavy metals, minerals and industrial chemicals. Thus, after improving the performance of BES, widening the scope for products recovery by developing better understanding of the process and with efforts to reduce its production cost, it can become a sustainable technology for treatment of wastewater with added advantage of recovery of resources and bio-energy generation.