Achieving stable two-stage mainstream partial-nitrification/anammox (PN/A) operation via intermittent aeration. (April 2020)

• Record Type: Journal Article
• Authors: Chen, Yongzhi; Zhao, Zhichao; Liu, Hong; Ma, Yanhong; An, Fangjiao; Huang, Jianming; Shao, Zhaowei
• Is Part Of: Chemosphere. Volume 245(2020)
• Publication Date: 2020-04
• Subjects: Mainstream partial-nitrification/anammox (PN/A) -- Intermittent aeration -- Chemical oxygen demand (COD) -- Mixture ratio; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.125650
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The mainstream anammox process has attracted extensive attention recently. Compared to single-stage partial-nitrification/anammox (PN/A) system, two-stage PN/A process was more advantageous for achieving mainstream anammox. However, complex control strategy in partial-nitrification reactor (N-SBR) might not be feasible in practical application. The aim of this study was to provide an easy operation strategy to achieve two-stage PN/A process. Firstly, intermittent aeration was investigated to achieve 100% conversion of ammonium to nitrite in N-SBR. The effluent nitrite concentrations increased from 19.96 to 38.62 mg/L when intermittent aeration ratio (IAC) varied from 30 min/30 min–30 min/15 min. During 125 d's operation of N-SBR, stable partial nitrification performance was obtained through intermittent aeration, without coupling with low dissolve oxygen or short sludge retention time. Then, raw municipal wastewater was directly mixed with N-SBR effluent to provide suitable feed to anaerobic sequencing batch reactor (A-SBR).When the mixture ratio between the raw wastewater and the N-SBR effluent was 2.5, the effluent ammonium and total inorganic nitrogen (TIN) was only 0.97 and 2.52 mg N/L, respectively. Additionally, carbon-based pollutants was also removed in the proposed system without any pretreatment, which made the process easier to operate in practice. Highlights: Stable operation in a two-stage PN/A system was successfully achieved under an intermittent aeration strategy. There was no pretreatment of chemical oxygen demand (COD) in PN/A system. The system could achieve 96.62% total inorganic nitrogen (TIN) removal, and 59.57% of the nitrogen removal was via anammox.