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

Abstract 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 °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 H2 production rate of 0.24 ± 0.005 m3(H2) m−3 d−1 and 0.21 ± 0.005 m3(H2) m−3 d−1 with ~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.