Modified microbial fuel cell for Cr(VI) reduction and simultaneous bio-electricity production

A treatment approach to simulated Cr(VI)-contaminated water was investigated using modified microbial fuel cell (MFC) technology. Two different synthetic Cr(VI)-containing water (5 and 10 mg L (1)) was used as catholyte and anaerobic microorganisms as anodic biocatalyst. 5 mg L (1) of chromium was reduced to below detectable limits while, 10 mg L (1) was reduced to 2 mg L (1) during 456 h reaction in the MFC systems investigated. The MFC system with 5 mg L (1) of chromium exhibited a maximum power density of 92.65 mW m (2) and a voltage of 0.35 V. A power density of 75.08 mW m (2) and voltage of 0.103 V was obtained by 10 mg L (1) chromium containing cell. This work verifies the possibility of current production and simultaneous cathodic Cr(VI) reduction. The results demonstrated for the first time that Cr(VI) can be bio-electrochemically reduced in a modified MFC economically, by the help of a mixed consortium, under largely autotrophic conditions. The main advantage with this system is that it uses an uncomplicated and economical salt bridge in the place of costly membranes like Nafion and an abiotic cathode. (C) 2016 Elsevier Ltd. All rights reserved.