A high-rate and stable nitrogen removal from reject water in a full-scale two-stage AMX ® system

• Published in: Water science and technology Vol. 83; no. 3; pp. 652 - 663
• Main Authors: Jung, Minki, Oh, Taeseok, Rhu, Daehwan, Liberzon, Jon, Kang, S Joh, Daigger, Glen T, Kim, Sungpyo
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01-02-2021
• Subjects: air-lift granulation reactor; Ammonia; Ammonium; Ammonium Compounds; anaerobic ammonium oxidation; Biofilms; Bioreactors; Chemical oxygen demand; Commercialization; Denitrification; Granulation; high nitrogen loading rate; Influents; Load distribution; Load fluctuation; Loading rate; Moving beds; Nitrogen; Nitrogen removal; Oxidation; Oxidation-Reduction; Reactors; reject water; Removal; side-stream treatment; Sludge; Solid suspensions; Suspended particulate matter; Total suspended solids; two-stage amx® system; Waste Water; Water
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2021.002

This paper reports long-term performance of a two-stage AMX
system with a capacity of 70 m
/d treating actual reject water. An air-lift granulation reactor performed partial nitritation (PN-AGR) at an average nitrogen loading rate (NLR) of 3.1 kgN/m
-d, producing an average effluent NO
-N/NH
-N ratio of 1.04. The average nitrogen removal rate of the system was 3.91 kgN/m
-d following an anaerobic ammonium oxidation (Anammox) stage moving bed biofilm reactor (A-MBBR). Although the total nitrogen concentrations in the reject water fluctuated seasonally, overall nitrogen removal efficiency (NRE) of the two-stage AMX
system was very stable at over 87%. The two-stage AMX
system, consisting of a PN-AGR followed by an A-MBBR, operated at a stable NLR of 1.86 kgN/m
-d (1.64 kgN/m
-d including the intermediate tank), which is 1.8 times higher (1.6 times including the intermediate tank) than other commercialized single-stage partial nitritation/Anammox (PN/A) processes (which operate at a NLR of about 1 kgN/m
-d). The PN-AGR was affected by high influent total suspended solids (TSS) loads, but was able to recover within a short period of 4 days, which confirmed that the two-stage PN/A process is resilient to TSS load fluctuations.