A hybrid bioelectrochemical system for concurrent bioenergy and biohydrogen production

The growing global demand for sustainable energy solutions and effective waste management strategies has increased interest in bioelectrochemical systems (BESs) capable of simultaneously treating waste and producing clean energy. This study presents the development and performance evaluation of a novel, membraneless, cost-effective hybrid BES integrating microbial electrolysis cell (MEC) and microbial fuel cell (MFC) technologies for simultaneous hydrogen (H2) and bioelectricity production from urea-rich cow manure waste streams. Experiments were conducted using synthetic mixtures containing varying urea concentrations (5 g and 10 g), with and without cow manure, to assess their effects on system performance. The results showed that H2 production and bioelectricity generation increased with higher urea concentrations and the addition of cow manure. The highest H2 yield exceeded 1000 ppm within 50 min for the 10 g urea-cow manure solution. Similarly, maximum voltage output reached 165 mV after 233 min. These enhancements were attributed to the synergistic effects of urea as a nitrogen source and the rich microbial community in cow manure. Overall, this study highlights the potential of integrated BESs for sustainable energy recovery, waste valorization, and environmental protection.