Application of CANON process for nitrogen removal from anaerobically pretreated husbandry wastewater

• Published in: International biodeterioration & biodegradation Vol. 136; pp. 15 - 23
• Main Authors: Huynh, Tuong Vy, Nguyen, Phuoc Dan, Phan, The Nhat, Luong, Duy Ha, Truong, Thi Thanh Van, Huynh, Khanh An, Furukawa, Kenji
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.01.2019; Elsevier BV
• Subjects: Aeration; Alkalinity; Ammonia; Anaerobic processes; Anaerobically pretreated husbandry wastewater; Anammox; Animal husbandry; AOB; CANON; Chemical oxygen demand; Continuously stirred tank reactors; Dissolved oxygen; Heterotrophs; Hydraulics; Nitrogen; Nitrogen removal; Organic chemistry; Oxidation; Reactors; Wastewater; Wastewater treatment; Water treatment; Anaerobically pretreated husbandry wastewater; Nitrogen removal; CANON; Anammox; AOB
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2018.09.010

In this study, the removal of nitrogen from anaerobically pretreated husbandry wastewater using a continuous stirred tank reactor of a completely autotrophic nitrogen removal over nitrite (CANON) process coupled with a simple aeration setup was investigated. The reactor was operated with anaerobically pretreated husbandry wastewater at hydraulic retention times (HRTs) of 16, 8, and 6 h with stepwise increased in average nitrogen loading rates (NLRs) of 0.47, 0.95, and 1.16 kg N m−3 d−1. The highest and stable nitrogen removal was obtained at HRT of 8 h (NLR of 0.95 kg N m−3 d−1). The key operating conditions were intermittent aeration for maintaining low dissolved oxygen concentrations (0.1–0.2 mg l−1) and alkalinity adjustment for obtaining pH values of 7.6–7.8. The effluent quality met Vietnamese husbandry wastewater standard for total nitrogen (<150 mg l−1 N). High chemical oxygen demand (COD) concentration (>400 mg l−1) in the feed wastewater reduced ammonia oxidizing bacteria (AOB) activity. At shorter HRT (6 h), the washout of fine bioflocs containing aerobic heterotrophs and AOB occurred, while the reddish anammox granules still remained in the reactor. [Display omitted] •A completely autotrophic nitrogen removal over nitrite (CANON) process was efficiently applied for nitrogen removal from anaerobically pretreated husbandry wastewater.•Anammox bacteria fully grew from the seed anaerobic heterotrophic granules.•Stratification of ammonia-oxidizing bacteria (AOB) in bioflocs and anammox bacteria in granules occurred in a continuous stirred tank reactor (CSTR).