Simultaneous organic matter removal and disinfection of wastewater with enhanced power generation in microbial fuel cell

• Major breakthrough in MFC research is disinfection with hypochlorite catholyte.
• Simultaneous secondary treatment and disinfection can be achieved in MFCs.
• Power generation increases by increasing available chlorine dose from 0.67 to 3 g/L.
• At Cl2 dose of 3 g/L Coulombic efficiency of 26% and 6 fold more power is produced.
• Both the chambers of MFC were effectively used for pollutant removal.

Presence of pathogenic microorganism in anodic effluent of microbial fuel cell (MFC) makes it unfit for reuse. In this study, performance of dual chamber MFC was evaluated in terms of organic matter removal, power generation and disinfection in cathodic chamber. Anodic effluent was treated further in cathodic chamber for achieving disinfection with different doses of sodium hypochlorite (NaOCl) with available chlorine varying from 0.67, 1.32, 2, 3 and 4 g/L. Addition of different doses of NaOCl resulted in satisfactory disinfection along with removal of nitrogenous compounds. Power output of MFC improved up to 3 g/L of available chlorine (6.5 W/m3); however, further increase in chlorine concentration decreased the power. Voltammetric and impedance analysis showed higher and faster electron reduction and decrease in polarization resistance at 3 g/L dose. Higher organic matter removal from wastewater and complete elimination of microorganism, along with improved power output, demonstrates effectiveness of hypochlorite as catholyte.