Coaxial microbial electrolysis cell for cost-effective bioenergy production and wastewater treatment of potato industry effluent

BACKGROUND: The increase in energy and water demand due to industrialization and urbanization requires prioritized solutions for a sustainable future. Microbial electrolysis cells (MECs) have shown huge potential for biohydrogen production along with wastewater treatment. This study examined the effectiveness of employing nickel foam as an anode material for biohydrogen production from the widely available potato industry effluent. RESULTS: Hydrogen production rate increases exponentially with the increase in applied voltage. A maximum hydrogen production rate of 0.69 ± 0.02 m³ H₂ m⁻³ reactor volume d⁻¹ was achieved at 0.9 V with a maximum chemical oxygen demand removal efficiency of 97% at 0.8 V. The effluent of the 0.8 V cycle had the least salinity, low total dissolved solids, 84% reduced total hardness, highest effluent clarity (4.30 NTU, and negligible quantity of heavy metals. CONCLUSION: This study successfully produced biohydrogen from potato wastewater within 5 days of operation along with wastewater treatment of the substrate. The improved performance of the system can be attributed to the unique characteristics of nickel foam, such as high porosity, large surface area and excellent conductivity. The findings of this study have implications for the sustainable treatment of domestic and agro-industrial wastewater and the development of efficient and low-cost bio-electrochemical systems for renewable energy production.