Achieving robust mainstream nitritation by implementing light irradiation: long-term performance and microbial dynamics. (February 2023)

• Record Type: Journal Article
• Authors: Chu, Zhaorui; Huang, Dandan; Huang, Xiaoyu; He, Jianfeng; Chen, Lexin; Wang, Jinyin; Rong, Hongwei
• Is Part Of: Bioresource technology. Volume 369(2023)
• Publication Date: 2023-02
• Subjects: NOB suppression -- Nitrite shunt -- Partial nitritation/annamox -- Light irradiation -- Microbial community; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.128284
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Robust mainstream nitritation was successfully achieved using light irradiation. Light irradiation has positive impacts on denitrification activity. The enriched Rhodocyclaceae appears to be resistant to light irradiation. Light irradiation seems to be very effective for in-situ sludge reduction. Abstract: The effective inhibition of nitrite-oxidizing bacteria (NOB) is widely acknowledged to be a critical issue for mainstream short-cut biological nitrogen removal. This study demonstrated a stable mainstream nitritation by implementing light irradiation. A sequencing batch reactor with ultraviolet-A (UVA) irradiation was operated for 250 days, and a high nitrite accumulation ratio was achieved and stabilized at about 90 %. UVA irradiation also positively impacts denitrification activity, with total nitrogen removal up to 63 %. Microbial community analysis confirmed that the UVA effectively and stably decreased the abundance of Nitrospira (the only detected NOB) from 6.0 % to 0.1 %, while it showed no effect on Nitrosomonas . The enriched genus Rhodocyclaceae was the major contributor to the increase in denitrification activity in the light-induced nitritation system. The proposed UVA irradiation strategy has the potential to be integrated with an anoxic/aerobic (A/O) or integrated fixed-film activated sludge (IFAS) process for achieving mainstream short-cut biological nitrogen removal.