Achieving superior nitrogen removal in an air-lifting internal circulating reactor for municipal wastewater treatment: Performance, kinetic analysis, and microbial pathways. (March 2023)

• Record Type: Journal Article
• Authors: Han, Yi; Lu, Xiejuan; Liu, Yang; Deng, Yangfan; Zan, Feixiang; Mao, Juan; Hao, Tianwei; Cao, Cheng; Wu, Xiaohui
• Is Part Of: Bioresource technology. Volume 371(2023)
• Publication Date: 2023-03
• Subjects: Internal circulating reactor -- Nitrogen removal -- Simultaneous nitrification and denitrification (SND) -- 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.2023.128599
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphic abstract: Highlights: Superior removal of COD, TN, and NH4 + -N could be achieved in the bioreactor. The high internal circulation ratio enhanced the resistance to the loading impact. The macro and micro gradient DO environment was beneficial for SND. SND was estimated to contribute to 68.7% of total nitrogen removal. Abstract: Anticipated growth in living standards has accentuated higher requirements for effluent quality from municipal wastewater treatment. In this study, an air-lifting internal circulating reactor with a high internal circulation ratio (36:1) was established to treat municipal wastewater with a long-term operation. In the bioreactor, the average effluent chemical oxygen demand, total nitrogen, and ammonium nitrogen could be 13.1, 5.7, and lower than 1 mg/L, respectively. Further analysis of nitrogen removal showed that traditional nitrification and denitrification, simultaneous nitrification and denitrification (SND), and nitrogen assimilation accounted for 27.4 %, 68.7 %, and 3.9 % respectively. The proportion of aerobic bacteria ( Saprospiraceae ) and facultative bacteria ( Comamonadaceae ) were significantly increased, indicating a higher capacity for organic degradation in the reactor. The relative abundance of denitrifying bacteria and bacterial groups with SND ( Comamonadaceae ) increased. These results suggested the air-lifting internal circulating reactor could be a viable and efficient option for superior nitrogen removal in wastewater treatment.