Influence of Applied Voltage for Bioelectrochemical Anaerobic Digestion of Sewage Sludge

Kim, Dong-Hyun; Song, Young-Chae; Qing, Feng; Kim, Dong-Hyun; Song, Young-Chae; Qing, Feng

doi:2015.37.9.542

The Korean text of this paper can be translated into multiple languages on the website of http://jksee.or.kr through Google Translator.

J Korean Soc Environ Eng > Volume 37(9); 2015 > Article

Original Paper

J Korean Soc Environ Eng 2015;37(9): 542-549. doi: https://doi.org/10.4491/KSEE.2015.37.9.542

하수슬러지의 생물전기화학 혐기성소화에 대한 인가전압의 영향

김동현, 송영채, 풍경

한국해양대학교 환경공학과

Influence of Applied Voltage for Bioelectrochemical Anaerobic Digestion of Sewage Sludge

Dong-Hyun Kim, Young-Chae Song, Feng Qing

Department of Environmental Engineering, Korea Maritime and Ocean University

Corresponding author

Young-Chae Song ,Tel: 051-410-4417, Fax: 051-410-4415, Email: soyc@kmou.ac.kr

Received: September 22, 2015; Revised: September 28, 2015; Accepted: September 28, 2015. Published online: September 30, 2015.

ABSTRACT

The bioelectrochemical anaerobic digestion for sewage sludge was attempted at different applied voltages ranged from 0.2 V to 0.4 V. At 0.3 V of the applied voltage, pH and VFAs were at 7.32 and 760 mg COD/L, respectively, which were quite stable. The methane production rate was 1.32 L CH₄/L.d, and the methane content in biogas was 73.8%, indicating that the performance of the bioelectrochemical anaerobic digestion could be considerably improved by applying a low voltage. At 0.4 V of the applied voltage, however, the contents of the minor VFA components including formic acid and propionic acid were increased. The methane production rate was reduced to 1.24 L CH₄/L.d and the biogas methane content was also reduced to 72.4%. At 0.2 V of the applied voltage, the pH was decreased to 6.3, and VFAs was accumulated to 5,684 mg COD/L. The contents of propionic acid and butyric acid in the VFAs were considerably increased, The performances in terms of the methane production rate and the biogas methane content were deteriorated. The poor performance of the bioelectrochemical reactor at 0.2 V of the applied voltage was ascribed to the thermodynamic potential lack for the driving of the carbon dioxide reduction into methane at cathode.

Key Words: Anaerobic, Bioelectrochemical, Applied Voltage, Sewage Sludge