Achieving efficient nitrite accumulation in glycerol-driven partial denitrification system: Insights of influencing factors, shift of microbial community and metabolic function. (November 2020)

• Record Type: Journal Article
• Authors: Zhang, Teng; Cao, Jiashun; Zhang, Yilei; Fang, Fang; Feng, Qian; Luo, Jingyang
• Is Part Of: Bioresource technology. Volume 315(2020)
• Publication Date: 2020-11
• Subjects: Partial denitrification -- Nitrite accumulation -- Glycerol -- Saccharibacteria species -- Metabolic function; 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.2020.123844
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: High NO2 – -N was accumulated in glycerol-driven PD reactor at C/N of 4.5 and pH 6–9. NO2 – -N was stably accumulated in long-term operation with an average NTR of 80.1%. The denitrifying bacteria: Saccharibacteria (77.9%) was highly enriched. The glycerol accelerated the metabolic rate for NO2 – -N accumulation in PD reactor. The disparity of NAR and NIR as well as encoding genes caused NO2 – -N accumulation. Abstract: Partial denitrification (PD), which could provide sufficient nitrite for subsequent anaerobic ammonium oxidation, is a novel strategy for mainstream nitrogen removal. In this study, the performance of using glycerol as electron donor for nitrite accumulation in PD process was evaluated. Results showed that a C/N of 4.5 was effective for nitrite production (average nitrite accumulation rate: 34.32 mg N h −1 gMLVSS -1 ; average nitrate-to-nitrite transformation ratio (NTR): 91.1%) with pH ranging from 6.0 to 9.0. Also, a stable nitrite accumulation was achieved in long-term operation with the average NTR of 80.1%. Mechanism investigation found that the denitrifying bacteria Saccharibacteria (77.9%) was enriched in glycerol-driven reactors. Moreover, the enzymatic activity as well as the encoding genes ( i.e. narG, narH and napA ) involved in nitrate reduction were much higher than that for nitrite reduction ( i.e. nirK ), and this disparity was responsible for the efficient nitrite accumulation in glycerol-driven PD system.