Bioelectrochemical enhancement of methane production in low temperature anaerobic digestion at 10 °C. (1st August 2016)

• Record Type: Journal Article
• Authors: Liu, Dandan; Zhang, Lei; Chen, Si; Buisman, Cees; ter Heijne, Annemiek
• Is Part Of: Water research. Volume 99(2016)
• Page Start: 281
• Page End: 287
• Publication Date: 2016-08-01
• Subjects: Anaerobic digestion -- Bioelectrochemical system -- Low temperature -- Methane -- Methanogenic activity; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2016.04.020
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Anaerobic digestion at low temperature is an attractive technology especially in moderate climates, however, low temperature results in low microbial activity and low rates of methane formation. This study investigated if bioelectrochemical systems (BESs) can enhance methane production from organic matter in low-temperature anaerobic digestion (AD). A bioelectrochemical reactor was operated with granular activated carbon as electrodes at 10 °C. Our results showed that bioelectrochemical systems can enhance CH4 yield, accelerate CH4 production rate and increase acetate removal efficiency at 10 °C. The highest CH4 yield of 31 mg CH4 -COD/g VSS was achieved in the combined BES-AD system at a cathode potential of −0.90 V (Ag/AgCl), which was 5.3–6.6 times higher than that in the AD reactor at 10 °C. CH4 production rate achieved in the combined BES-AD system at 10 °C was only slightly lower than that in the AD reactor at 30 °C. The presence of an external circuit between the acetate-oxidizing bioanode and methane-producing cathode provided an alternative pathway from acetate via electrons to methane, potentially via hydrogen. This alternative pathway seems to result in higher CH4 production rates at low temperature compared with traditional methanogenesis from acetate. Integration of BES with AD could therefore be an attractive alternative strategy to enhance the performance of anaerobic digestion in cold areas. Graphical abstract: Highlights: BES enhances CH4 production in anaerobic digestion (AD) at 10 °C. BES provides an alternative route for CH4 production in AD at 10 °C. Performance of BES-enhanced AD at 10 °C is similar to AD at mesophilic condition. BES uses less energy to assist AD at 10 °C than heating up AD to mesophilic condition.