Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
588308 | Process Safety and Environmental Protection | 2014 | 7 Pages |
The feasibility of using endpoint pH control to achieve stable partial nitritation (PN) in an SBR for landfill leachate treatment was investigated. By imposing a fixed-time anoxia followed by variable-time aeration in an SBR cycle, successful partial nitritation was maintained for 182 days at a nitrogen loading rate of 0.30–0.89 kg/m3/day. The effluent NO2−-N/NH4+-N ratio and the effluent NO3−-N concentration were 1.30 ± 0.22 and 16 ± 9 mg/L, respectively. High free ammonia (FA) and low dissolved oxygen (DO) concentrations were inhibition factors of nitrate formation. The termination of aeration at a suitable endpoint pH was the key to achieve an effluent NO2−-N/NH4+-N ratio close to the stoichiometric value. This endpoint pH control strategy represents practical potentials in the engineered application of combined PN–ANAMMOX processes.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (97 K)Download as PowerPoint slideHighlights► Endpoint pH control was reliable to achieve stable partial nitritation performance. ► An effluent NO2−-N/NH4+-N ratio close to 1.32 was achieved. ► High FA and low DO concentrations were the main causes for inhibition of nitrate formation. ► Nitrogen loss was observed in both the air-off and air-on phases, possibly due to denitrification.