An innovative and cost-effective method for hydrogen production from wastewater using a membraneless bioelectrolysis system

This study presents the development of a novel membraneless microbial electrolysis cell system for biohydrogen production using domestic anaerobic wastewater and sludge as the substrate and inoculum. The experimental design analyzed the effects of sludge/wastewater ratios ranging from 0.2 to 1.0, applied voltages between 1.0 V and 2.0 V, temperatures from 20°C to 60°C, and pH levels of 4, 7, and 10. Optimal conditions for biohydrogen production were identified as a sludge to wastewater ratio of 1.0, a voltage of 2.0 V, a temperature of 40°C, and a neutral pH, resulting in a peak biohydrogen yield of 862.792 mg/L. At the lowest sludge/wastewater ratio of 0.2, hydrogen production remained below 200 mg/L. Production increased to the range of 500 to 600 mg/L at a ratio of 0.6 and reached 800 mg/L at a ratio of 1.0. The impact of temperature was evident, with biohydrogen output rising from 300 mg/L at 20°C to 600 mg/L at 40°C, then stabilizing at higher temperatures. The applied voltage substantially affected hydrogen production, with yields below 400 mg/L at 1.0 V, increasing to 600 mg/L at 1.6 V, and reaching a maximum at 2.0 V. The highest biohydrogen production was achieved at neutral pH, while acidic and alkaline conditions reduced yields to below 200 mg/L. These findings underscore the importance of optimizing operational parameters to maximize biohydrogen production while effectively treating wastewater. The study also highlights the potential of integrating sustainable waste to energy technologies in wastewater management, advancing renewable energy production through process optimization. • Optimized membraneless MECs show promise for bioH2 production and wastewater treatment. • System optimized for bioH 2 using domestic wastewater and anaerobic sludge. • BioH 2 production reached a maximum at 2.0 V, while extreme pH conditions significantly reduced the yield. • Low sludge ratios resulted in bioH 2 production below 200 mg/L, while increasing ratios enhanced production above 800 mg/L. • BioH 2 production increased from 300 mg/L at 20 °C to 600 mg/L at 40 °C, stabilizing at higher temperatures.