Analyzing performance and microbial mechanisms in an incineration leachate treatment after waste separation: Integrated metagenomic and metaproteomic analyses

• Published in: The Science of the total environment 2024-11, Vol.951, p.175821, Article 175821
• Main Authors: Wang, Han, Ma, Xiaoqian, Ran, Xiaochuan, Wang, Tong, Zhou, Mingda, Liu, Chao, Li, Xiang, Wu, Min, Wang, Yayi
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Incineration leachate; Label free proteomics; Metagenomic; Two-stage A/O; Waste separation
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.175821

The absence of food waste after separation poses a significant challenge to incineration leachate treatment, as it decreases the C/N ratio and COD of leachate, greatly impacting the biological treatment process. A one-year in-situ study was systematically conducted in an incineration leachate treatment plant that experienced waste separation, focusing on the variations in carbon and nitrogen removal performance as well as the involved microbial mechanism of the “anaerobic digestion (AD) + two-stage A/O” process. Results indicated that the biodegradability of leachate significantly decreased over time, with COD concentration decreasing by 10 times and the average C/N ratio decreasing from 12.3 to 1.4. The AD process was maintained stable, achieving a COD removal efficiency exceeding 92 %. The nitrification process also remained stable; while the denitrification process was significantly affected, and a nine-fold increase in external glucose addition was required to achieve a nitrogen removal efficiency of 85 %. Metagenomic analysis indicated that comammox Nitrospira (contributing 90 % to ammonia monooxygenase) occupied the dominant position over Nitrosomonas for nitrification due to the low NH4+-N concentration in A/O tanks (92 %.•Nitrification remained stable, and comammox Nitrospira innovatively dominated.•Imbalance expressions within de