Enhancing the CH4 yield of anaerobic digestion via endogenous CO2 fixation by exogenous H2

• Published in: Chemosphere (Oxford) Vol. 140; pp. 34 - 39
• Main Authors: Hu, Yuansheng, Hao, Xiaodi, Zhao, Dan, Fu, Kunming
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2015
• Subjects: Anaerobic digestion; Anaerobiosis; Carbon capture and storage; Carbon dioxide; Carbon Dioxide - metabolism; Carbon fixation; Digestion; Fixation; Hydrogen; Hydrogen - metabolism; Iron; Iron corrosion; Methane; Methane - metabolism; Phosphorus removal; Sewage; Waste activated sludge; Waste Disposal, Fluid - methods; Wastes; Waste activated sludge; Iron corrosion; Carbon fixation; Hydrogen; Anaerobic digestion
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2014.10.022

•H2 can be generated from anaerobic iron corrosion in anaerobic digestion (AD).•The generated H2 can be utilized for converting CO2 to CH4.•With CO2 fixation, enhancement up to 61% in the CH4 yield is achieved.•The added iron can also achieve phosphorus removal from the AD supernatant. A large amount (25–60%) of degraded organics is converted directly to CO2 during anaerobic digestion (AD) process, which substantially lowers the energy (methane, CH4) yield. In this study, endogenous CO2 fixation by H2 from in-situ iron corrosion was explored to enhancing the CH4 yield. The results demonstrated that a substantial enhancement (up to 61%) in the CH4 yield could be achieved with both nano-scale zero-valent iron (NZVI) and waste iron scraps (WIS) being the added iron. Additionally, the added iron could also achieve effective phosphorus removal from the AD supernatant.