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Zeolite biofilm aeration filter plays a pre‐nitritation role in autotrophic nitrogen removal from iron oxide red wastewater
Author(s) -
Feng Xinghui,
Wang Xiaojun,
Wang Ruixin,
Zheng Xuwen,
Zhong Zhong,
Chen Xiaozhen
Publication year - 2020
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.6505
Subject(s) - anammox , aeration , alkalinity , chemistry , wastewater , pulp and paper industry , ammonium , nitrite , sewage treatment , nitrogen , environmental engineering , denitrification , nitrate , environmental science , denitrifying bacteria , organic chemistry , engineering
BACKGROUND The completely autotrophic nitrogen removal over nitrite (CANON) system has excellent performance in treating ammonium‐rich wastewater and it depends on ammonia oxidizing bacteria (AOB) working together with anammox bacteria in a reactor. Higher ammonium nitrogen loading requires higher aeration to provide sufficient dissolved oxygen (DO) for nitritation, whereas high‐strength aeration in theCANON will destroy the sludge structure and inhibit the activity of anammox bacteria. The present study uses a stable pre‐nitritation system to reduce a part of nitritation and also decrease aeration intensity in the CANON. RESULTS Continuous aeration to maintain the DO concentration between 1.5 and 4.3 mg L –1 in the CANON achieved a stable nitrogen removal rate (1.22 kg N m –3 d –1 ) from iron oxide red wastewater with 400–1016 mg N L –1 after 183 days of operation. Using a mixed alkalinity donor [sodium carbonate (Na 2 CO 3 ) and bicarbonate (NaHCO 3 )] in the combined system can save ≈14.1–28.2% of the alkalinity cost compared with using NaHCO 3 only. CONCLUSIONS A zeolite biofilm aeration filter (ZBAF) used in a pre‐nitritation process can tolerate high DO concentration of ≤6.5 mg L –1 for nitritation and avoid all of the nitritation taking place in the CANON system. This can protect the sludge structure and anammox bacteria from high‐strength aeration erosion. © 2020 Society of Chemical Industry