Optimizing start-up strategies for the two-inflow nitritation/anammox process: Influence on biofilm microbial community composition

• Published in: Water science and technology 2024-03, Vol.89 (6), p.1583-1594
• Main Authors: Zulkarnaini, Zulkarnaini, Matsuura, Norihisa, Kanazawa, Sui, Honda, Ryo, Yamamoto-Ikemoto, Ryoko
• Format: Article
• Language: English
• Subjects: biofilm; candidatus brocadia; habitat segregation; nitrosomonadaceae; one-stage nitritation/anammox process
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2024.065

Low-energy nitrogen removal from ammonium-rich wastewater is crucial in preserving the water environment. A one-stage nitritation/anammox process with two inflows treating ammonium-containing wastewater, supplied from inside and outside the wound filter, is expected to stably remove nitrogen. Laboratory-scale reactors were operated using different start-up strategies; the first involved adding nitritation inoculum after anammox biomass formation in the filter, which presented a relatively low nitrogen removal rate (0.171 kg N/m · d), at a nitrogen loading rate of 1.0 kg N/m · d. Conversely, the second involved the gradual cultivation of anammox and nitritation microorganisms, which increased the nitrogen removal rate (0.276 kg N/m · d). Furthermore, anammox (Candidatus Brocadia) and nitritation bacteria (Nitrosomonadaceae) coexisted in the biofilm formed on the filter surface. The abundance of nitritation bacteria (10.5%) in the reactor biofilm using the second start-up strategy was higher than that using the first (3.7%). Thus, the two-inflow nitritation/anammox process effectively induced habitat segregation using a suitable start-up strategy.