Free Nitrous Acid-Guided Microbial Restructuring Enables Selective Enrichment of Candidatus Nitrosoglobus in Acidic Partial Nitritation Process

作者：Tianyi Zhang, Min Ye, Shen Cui, Tian Feng, Min Zheng, Yu-You Li · 发表于：Environmental Science & Technology · 年份：2025 · DOI：10.1021/acs.est.5c08500 · 被引用次数：5 · 研究领域：Wastewater Treatment and Nitrogen Removal、Microbial Fuel Cells and Bioremediation、Microbial Community Ecology and Physiology

High Resolution Image Download MS PowerPoint Slide Selective enrichment of the acid-tolerant ammonium-oxidizing bacteria (AOB) Candidatus ( Ca. ) Nitrosoglobus is critical for achieving stable partial nitritation (PN) under acidic conditions. This study explored the ecological mechanisms and operational strategies that enable Ca. Nitrosoglobus dominance in low-pH PN systems. Two parallel air-lift reactors were established using the same activated sludge, with one receiving free nitrous acid (FNA) pretreatment (FNA-PR) and the other operating without any pretreatment (wFNA-PR). The FNA-PR reactor exhibited robust nitrite accumulation and complete suppression of nitrite-oxidizing bacteria (NOB) while facilitating the replacement of Nitrosomonas by Ca. Nitrosoglobus . In contrast, the wFNA-PR reactor failed to enrich Ca. Nitrosoglobus, despite maintaining pH levels favorable for its growth. Batch activity assays and 16S rRNA analysis revealed that long-term FNA accumulation, rather than low pH alone, is the most important key driver of niche selection and microbial succession to Ca. Nitrosoglobus . Logistic modeling showed significant enhancement of AOB activity under acidic-FNA conditions (specific ammonium oxidation activity: 135.9 mg N g –1 VSS d –1 ) driven by Ca. Nitrosoglobus, while pH-driven systems led to the dominance of Nitrosospira and persistence of Nitrospira . These findings underscore the importance of sustained FNA accumulation and NOB suppression for targeted en...