Enhancing biohydrogen production from sugar industry wastewater using Ni, Ni-Co and Ni-Co-P electrodeposits as cathodes in microbial electrolysis cells

Microbial electrolysis cell (MEC) can be utilized for the simultaneous treatment of actual industry wastewater and biohydrogen production. However, efficient and cost-effective cathode, working at ambient conditions and neutral pH, are required to make the MEC as a sustainable technology. In this study, MEC with electrodeposited cathodes (co-deposits of Ni, Ni-Co and Ni-Co-P) were utilized to evaluate the treatment efficiency and hydrogen recovery of sugar industry wastewater. MECs operation was carried out at 30 +/- 2 degrees C temperature in batch mode at an applied voltage of 0.6 V in neutral pH with sugar industry effluent (COD 4850 +/- 50 mg L-1, BOD 1950 +/- 20 mg L-1) and activated sludge as a source of microorganism. The Ni-Co-P electrodeposit on both cases achieved the maximum H-2 production rate of 0.24 +/- 0.005 m(3)(H2) m(-3) d(-1) and 0.21 +/- 0.005 m(3)(H2) m(-3) d(-1) with similar to 50 % treatment efficiency for a 500 ml effluent in 7 days' batch cycles. It was also found that fabricated cathodes can treat real wastewater efficiently with considerable energy recovery than previously reported literature. This study showed the potentiality of the real-time industrial effluents treatment and biohydrogen production near to ambient atmospheric conditions that emphasizes the waste to energy bio-electrochemical system.