Achieving stable anammox process and revealing shift of bacteria during the start‐up in landfill leachate treatment

Abstract

Partial nitrification‐anammox (PN/A) is an energy‐efficient technology for nitrogen removal in landfill leachate treatment. Numerous studies have reported successful implementation of the PN/A process and its stable operation under laboratory conditions. One of the primary challenges in PN/A engineering applications is the mass of the seed sludge required for start‐up. This study examined the PN/A using a sequence batch reactor (SBR) inoculating a common mixture to treat landfill leachate. After 70 days of operation, the system successfully realized a one‐stage PN/A process and maintained a stable ammonium ()italicNH4+$$ \left({NH}_4^{+}\right) $$ removal efficiency of 97.65% ± 1%, where the effluent of NH4+$$ {NH}_4^{+} $$ and nitrate (NO3−$$ {NO}_3^{-} $$) were less than 4 ± 1.5 mg L−1 and 10 mg L−1. In addition, the relative abundances of Ca. Kuenenia and Ca. Brocadia, which are typical anaerobic ammonia‐oxidizing bacteria (AnAOB), increased from 0.08% to 3.99% (70 days) and 0.01% to 0.45%, respectively. The relative abundances of ammonia‐oxidizing bacteria (AOB) Nitrosomonas and Nitrosospira increased from 0.9% to 2.89% and 0.007% to 0.1% (70 days), respectively. Both AnAOB and AOB are important niches of the system. Practitioner Points The research realized PN/A rapidly by inoculating common mixture sludge. The experiment successfully enriched AnAOB from 0.09% to 3.89% within 70 days. The article revealing the ecological roles of AOB and AnAOB in the landfill leachate treatment.