Nitrogen Removal in Bio Electrochemical Systems

In recent years Bioelectrochemical systems (BESs) as a new approach represent an energy-efficient way for wastewater treatment, metal/nutrient recovery, and transformation of wastes to valuable products such as hydrogen. These unique characteristics of BESs are provided by a flexible platform for oxidation-reduction reactions. Although this process is still not fully developed but it can be nominated as a future trend of green energy and cleaner biochemical production pathway along with the waste remediation. Conversion of organic wastes into electricity and hydrogen/chemical products occurs in microbial fuel cells (MFCs) and microbial electrolysis cells (MECs), respectively. Different aspects of the process such as biological communities, physical configuration, and electrochemical conditions can affect a good performance of BES. In the present chapter review, the different fundamental mechanisms of BESs with emphasis on nitrogen removal have been reviewed. The behavior of affecting parameters on nitrogen and organic removal was discussed, including content pH, electrode material, level of supernatant concentration, the distance between electrodes and applied current, salinity and other operating conditions. Moreover, reported pathways and the theory of denitrification in BESs were described. Considering the finding, BES can be nominated as an alternative technology to the minimization of waste and a good way to generate electrical energy and valuable chemicals.

Keywords: Bioelectrochemical system, Denitrification, Electron donor, Electron acceptor, Microbial Fuel Cell, Nitrate, Nitrogen, Wastewater.