Recently, there has been increasing interest in the simultaneous management of wastewaters for the sustainable supply of clean energy, hydrogen (H 2 ), and water. In this regard, we designed and evaluated a co-integrated microbial electrolysis cell (MEC) and microbial fuel cell (MFC) hybrid system for simultaneous H 2 production, wastewater treatment, and energy production in a single chamber. The effects of applied voltage, wastewater to inoculum ratio, temperature, and initial pH on H 2 production performance of the MEC reactor are evaluated. Under improved conditions (applied voltage of 1.0 V, wastewater-to-activated sludge ratio of 1:2, temperature of 35 °C, and initial pH of 7.0), the highest H 2 production rate in the MEC system is found as 26.5 mL/L. day In the MFC reactor, the maximum voltage of 215 mV with a power density of 4.66 W/m 3 and a COD removal efficiency of 29.7 % is obtained at a temperature of 55 °C and cow manure to distilled water ratio of 2:1. Moreover, the co-integrated MEC-MFC system is operated under fed-batch operating mode and the H 2 production at each cycle is obtained as 3.27-3.42 mL/L. day following fresh wastewater feeding. Consequently, these results show that co-integrated MEC-MFC systems for self-sustaining production of H 2 and wastewater treatment become feasible, providing a potential route for converting organic-rich wastewater into H 2 and as a sustainable energy source with waste management. • A novel bioelectrochemical system is designed to boost H 2 and energy production. • It results in H 2 production rate of 26.5 mL/L. day and recovery of 32.9 % in MEC. • It obtains the highest energy production of 215 mV and 4.66 W/m 3 in MFC. • An integration of MFC-MEC promotes effective H 2 production in fed-batch mode. • It offers a self-driven approach to produce green H 2 from wastewater.
Goren et al. (Tue,) studied this question.