Metabolic coupling of aerobic methane oxidation and short-cut nitrification and denitrification for anaerobic effluent treatment in photo-sequencing batch biofilm reactor

Xiao An; Siqi Chen; Jiachen Fu; Caiyun Yang; Yeyuan Xiao; Zhongbo Zhou

doi:10.1016/j.biortech.2024.131845

Metabolic coupling of aerobic methane oxidation and short-cut nitrification and denitrification for anaerobic effluent treatment in photo-sequencing batch biofilm reactor

Bioresour Technol. 2024 Nov 18:131845. doi: 10.1016/j.biortech.2024.131845. Online ahead of print.

Authors

Xiao An¹, Siqi Chen², Jiachen Fu³, Caiyun Yang⁴, Yeyuan Xiao⁵, Zhongbo Zhou⁶

Affiliations

¹ Department of Environmental Science and Engineering, College of Resources and Environment, Southwest University, Chongqing 400715, China. Electronic address: 2975820723@qq.com.
² Department of Environmental Science and Engineering, College of Resources and Environment, Southwest University, Chongqing 400715, China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing 400715, China. Electronic address: chensssiqi@163.com.
³ Department of Environmental Science and Engineering, College of Resources and Environment, Southwest University, Chongqing 400715, China. Electronic address: fjc1181411817@163.com.
⁴ Department of Environmental Science and Engineering, College of Resources and Environment, Southwest University, Chongqing 400715, China; Chongqing Key Lab for Innovative Application of Gene Technology, Chongqing 400715, China. Electronic address: yangcyice@163.com.
⁵ Department of Civil and Environmental Engineering, College of Engineering, Shantou University, Shantou, Guangdong 515063, China. Electronic address: yeyuanxiao@stu.edu.cn.
⁶ Department of Environmental Science and Engineering, College of Resources and Environment, Southwest University, Chongqing 400715, China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing 400715, China; Chongqing Key Lab for Innovative Application of Gene Technology, Chongqing 400715, China. Electronic address: zhouzhongbo-1986@163.com.

PMID: 39566691
DOI: 10.1016/j.biortech.2024.131845

Abstract

This study explored the use of algae to supply oxygen in situ as an alternative to mechanical aeration for anaerobic effluent treatment in a photo-sequencing batch biofilm reactor (PSBBR). By establishing alternating aerobic (dissolved oxygen (DO) > 2 mg /L)/anoxic conditions (<0.5 mg-DO/L) through a 6-h off/6-h on biogas sparging cycle and continuous illumination (1500-3000 lx), the PSBBR achieved a significant ammonia removal rate of 15-25 mg N L^-1d^-1. This system demonstrated robust partial nitrification and nitrite reduction activities, coupled with aerobic methane oxidation. Metagenomic analysis revealed the enrichment of key microbial groups, including Leptolyngbyaceae, Methylocystis, Nitrosomonas and Hyphomicrobium. The key functional genes of methane (mmo, mdh, gfa, frm and fdh) and nitrogen (amo, hao, narGHI, and napAB) metabolisms were identified, while notably lacking nitrite oxidation genes. In conclusion, this study provides a promising post-treatment approach for anaerobic effluent through integrating biogas utilization with efficient nitrogen removal.

Keywords: Anaerobic digestion; Methane oxidation; Partial nitrification; Photobioreactor; Wastewater treatment.