Influence of substrate COD on methane production in single-chambered microbial electrolysis cell

• Published in: Huanjing kexue Vol. 36; no. 3; p. 1021
• Main Authors: Teng, Wen-Kai, Liu, Guang-Li, Luo, Hai-Ping, Zhang, Ren-Duo, Fu, Shi-Yu
• Format: Journal Article
• Language: Chinese
• Published: China 01.03.2015
• Subjects: Bacteria; Bioelectric Energy Sources; Biological Oxygen Demand Analysis; Electrolysis; Methane - biosynthesis; Waste Disposal, Fluid - methods; Waste Water
• ISSN: 0250-3301
• DOI: 10.13227/j.hjkx.2015.03.035

The chemical oxygen demand (COD) of substrate can affect the microbial activity of both anode and cathode biofilm in the single-chamber methanogenic microbial electrolysis cell (MEC). In order to investigate the effect of COD on the performance of MEC, a single chamber MEC was constructed with biocathode. With the change of initial concentration of COD (700, 1 000 and 1 350 mg x L(-1)), the methane production rate, COD removal and energy efficiency in the MEC were examined under different applied voltages. The results showed that the methane production rate and COD removal increased with the increasing COD. With the applied voltage changing from 0.3 to 0.7 V, the methane production rate increased at the COD of 700 mg x L(-1), while it increased at first and then decreased at the COD of 1000 mg x L(-1) and 1350 mg x L(-1). A similar trend was observed for the COD removal. The cathode potential reached the minimum (- 0.694 ± 0.001) V as the applied voltage was 0.5 V, which therefore facilitated the growth of me