Experimental investigation and assessment of an integrated membraneless sustainable technology for hydrogen production and wastewater treatment

Bioelectrochemical systems offer a sustainable approach for wastewater treatment and resource recovery. Among these technologies, microbial electrolysis cells enable biohydrogen production while simultaneously treating wastewater. In this study, wastewater sludges are used as a feedstock, and a membraneless microbial electrolysis cell is experimentally investigated under a range of operational conditions to evaluate the effects of key parameters on treatment performance and biohydrogen production. The highest system performance is achieved at an applied voltage of 1.1 V, an electrode spacing of 2.5 cm, a stirring speed of 300 rpm, an operating temperature of 30 °C, an electrode surface area of 28 cm 2 , and the use of aluminum electrodes. Under these conditions, the system produces 1000 ppm of biohydrogen and achieves 51.93% COD removal. The system achieves overall energy and exergy efficiencies of 13.39% and 15.46%, respectively. The findings demonstrate that membraneless microbial electrolysis (ME) systems provide sustainable bioelectrochemical wastewater treatment with simultaneous hydrogen production. • Experimentally evaluated the performance of a membraneless MEC using wastewater sludge as feedstock. • Investigated the impact of key operational parameters on bioH 2 production in a membraneless MEC. • Achieved a maximum bioH 2 concentration of 1000 ppm under optimized conditions. • The system achieved efficiencies of 13.39% for energy, 15.46% for exergy, and 51.93% for COD removal. • Demonstrated the potential of membraneless MEC system for integrated waste-to-energy applications.