Microbial community with the ability to biodegradation perchlorate in a bio-electrochemical reactor

¹ Hunan Research Academy of Environmental Science, Hunan Provincial Key Laboratory of Water Pollution Control Technology, Changsha 410004, China
² College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
³ College of Life Sciences and Chemistry, Hunan University of Technology, Zhuzhou 412007, P. R. China
⁴ Hunan Research Academy of Environmental Science Technology Consulting Co., Ltd, Changsha 410004, China

^* Corresponding author: heli95@hnu.edu.cn; fuguangyi107@aliyun.com

Abstract

In this study, the sediments from the Liuyang River (Hunan Province, China) were used as an inoculum to bio-reduction perchlorate in a bio-electrochemical reactor (BER). The efficient degradation of perchlorate was found in the BER by utilizing the hydrogen as electron donor. When the current intensity was 10 mA and HRT was 72 h, the removal rate of perchlorate (initial concentration was 5 mg/L) reached 84.13% and a removal flux of 178.68 mg/m2·d was achieved. High-throughput sequencing analysis confirmed that the biofilm in the reactor had been successfully acclimated, and the system could achieve perchlorate reduction effectively. Firmicutes and Bacteroidetes were the dominant phyla during inoculation phase, and Actinobacteriria, Proteobacteria, and Tenericutes also constituted a low proportion in the biofilm. Bacilli and Clostridia were dominant at class-level both in inoculum and biofilm, with the relative abundance about 56%-72% and 17%-23%, respectively. These results confirmed that the biofilm in the BER system had been successfully formed, and the BER system could biodegradation perchlorate effectively.