Response of partial nitritation and denitrification processes to high levels of free ammonia in a pilot mature landfill leachate treatment system: Stability and microbial community dynamics

• Published in: Bioresource technology 2023-11, Vol.387, p.129571-129571, Article 129571
• Main Authors: Li, Yonggan, Chen, Zhenguo, Zhang, Yangzhong, Wang, Zhiyu, Zhang, Chuchu, Deng, Zexi, Huang, Linxiang, Wang, Xiaojun, Fan, Junhao, Zhou, Songwei
• Format: Article
• Language: English
• Subjects: Ammonia-rich wastewater treatment; FA impact; Functional gene; Microbial community structure; Pilot plant
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2023.129571

[Display omitted] •PN and DN performance could maintain stability under high FA conditions.•Nitrosomonas exhibited strong tolerance to high levels of FA (1099.8 mg/L).•Microbial community dynamics of PN could make community resistant to the FA impact.•High levels of FA had scant impact on the microbial community and performance of DN. The high levels of free ammonia (FA) challenge the application of partial nitritation (PN) and denitrification (DN) in the treatment of ammonia-rich wastewater. This study explored the impact of high levels of FA on the PN and DN stability and microbial community dynamics. By reducing reflux and increasing influent load, the concentrations of FA in PN and DN reactors increased from 28.9 mg/L and 140.0 mg/L to 1099.8 mg/L and 868.4 mg/L, respectively. During this process, the performance of PN and DN remained stable. The microbial analysis revealed that the Nitrosomonas exhibited strong tolerance to high levels of FA, and its relative abundance was positively correlated with amoABC (R2 0.984) and hao (R2 0.999) genes. The increase in microbial diversity could enhance the resistance ability of PN against the FA impact. In contrast, high levels of FA had scant influence on the microbial community and performance of DN.