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.