Enhancing hydrogen production and wastewater treatment through an integrated bio-electrochemical system combining dark fermentation and galvanic cells

Traditional bio-electrochemical and microbial electrolysis systems often have low Power Density (PD) dependence on external energy inputs, which restrictions their scalability for energy recovery, waste water treatment and restricted Hydrogen (H₂) yields. To address these issues, the study introduces a novel Integrated Bio-Electrochemical System (IBES) that combines the galvanic cell with dark fermentation with the help of internal strength provided by spontaneous redox reactions. As a response, results indicates that the system was now capable of producing H₂ and removing pollutants without the need for external energy. To optimize the performance, four configurations were evaluated The IBES achieved a H₂ yield of 75.5–78.8 N LH₂/kg TOC, which is three times higher than dark fermentation alone, along with 94 % ammonium (NH₄⁺) removal at a Chemical Oxygen Demand (COD) concentration of 10,000 mg/L and a maximum COD reduction of 78 %. The system also produced a peak power density of 62.7 mW/m³.These outcomes demonstrate IBESs potential as an independent, energy efficient solution for combined wastewater treatment and renewable H₂ generation.