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Updated: Jun 21, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
High-rate nitrogen removal from livestock manure digester liquor by combined partial nitritation-anammox process
Sen Qiao1, Taichi Yamamoto, Motoki Misaka
1Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. qs_cyj@yahoo.com.cn
Abstract:
In this study, combination of a partial nitritation reactor, using immobilized polyethylene glycol (PEG) gel carriers, and a continuous stirred granular anammox reactor was investigated for nitrogen removal from livestock manure digester liquor. Successful nitrite accumulation in the partial nitritation reactor was observed as the nitrite production rate reached 2.1 kg-N/m(3)/day under aerobic nitrogen loading rate of 3.8 kg-N/m(3)/day. Simultaneously, relatively high free ammonia concentrations (average 50 mg-NH(3)/l) depressed the activity of nitrite oxidizing bacteria with nitrate concentration never exceeding 3% of TN concentration in the effluent of the partial nitritation reactor (maximum 35.2 mg/l). High nitrogen removal rates were achieved in the granular anammox reactor with the highest removal rate being 3.12 kg-N/m(3)/day under anaerobic nitrogen loading rate of 4.1 kg-N/m(3)/day. Recalcitrant organic compounds in the digester liquor did not impair anammox reaction and the SS accumulation in the granular anammox reactor was minimal. The results of this study demonstrated that partial nitritation-anammox combination has the potential to successfully remove nitrogen from livestock manure digester liquor.
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