Simultaneous carbon and nitrogen removal by anaerobic ammonium oxidation and denitrification under different operating strategies

Anaerobic ammonium oxidation (anammox) has been proved to be a promising nitrogen removal method for treating ammonium-rich wastewater. However, because of the low-growth rate of anammox bacteria, maintenance of a sufficient amount of anammox biomass in reactor became a key factor in application. Gel immobilization is an efficient method to prevent biomass from being washed out and to promote hyper-concentrated cultures. This study focused on a nitrogen removal process by anammox enrichment culture immobilized in polyvinyl alcohol and sodium alginate (PVA-SA) gel beads. The rapid startup of reactor demonstrated that gel entrapment was supposed to be a highly effective technique for immobilizing anammox bacteria. The anammox bacteria present in the enrichment were identified to be Jettenia-like species (>98%). Moreover, the effect of hydraulic retention time (HRT), pH, and temperature on immobilized anammox processes were investigated. The effect of pH and temperature on the anammox process was evidently weakened in PVA-SA immobilized gel beads, however, the effect of HRT on the anammox reaction was enhanced. Therefore, a stable operated reactor could be obtained in an anaerobic sequencing batch reactor, which proved gel immobilization was an excellent method to maintain the biomass in anammox reactor for application.

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Enhancing Nitrogen Removal Performance in a Bioreactor Using Immobilized Anaerobic Ammonium Oxidation Sludge by Polyvinyl Alcohol-Sodium Alginate (PVA-SA)

Polish Journal of Environmental Studies ◽

10.15244/pjoes/75805 ◽

2018 ◽

Vol 27 (2) ◽

pp. 773-778 ◽

Cited By ~ 4

Author(s):

Yifeng Lu ◽

Lijuan Ma ◽

Yun Liang ◽

Bei Shan ◽

Junjun Chang

Keyword(s):

Polyvinyl Alcohol ◽

Sodium Alginate ◽

Nitrogen Removal ◽

Anaerobic Ammonium Oxidation ◽

Ammonium Oxidation

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Dominance ofCandidatus saccharibacteriain SBRs achieving partial denitrification: effects of sludge acclimating methods on microbial communities and nitrite accumulation

RSC Advances ◽

10.1039/c8ra09518c ◽

2019 ◽

Vol 9 (20) ◽

pp. 11263-11271 ◽

Cited By ~ 14

Author(s):

Wang Xiujie ◽

Wang Weiqi ◽

Zhang Jing ◽

Wang Siyu ◽

Li Jun

Keyword(s):

Energy Consumption ◽

Microbial Communities ◽

Nitrogen Removal ◽

Low Energy ◽

Anaerobic Ammonium Oxidation ◽

Nitrite Accumulation ◽

Ammonium Oxidation ◽

Low Energy Consumption

Partial denitrification (NO3−-N → NO2−-N) was combined with anaerobic ammonium oxidation (ANAMMOX) to achieve nitrogen removal with a low C/N ratio and low energy consumption.

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Nitrogen removal from sludge digester liquids by nitrification/denitrification or partial nitritation/anammox: environmental and economical considerations

Water Science & Technology ◽

10.2166/wst.2004.0599 ◽

2004 ◽

Vol 50 (10) ◽

pp. 19-26 ◽

Cited By ~ 115

Author(s):

C. Fux ◽

H. Siegrist

Keyword(s):

Nitrogen Removal ◽

Wastewater Treatment Plants ◽

Anaerobic Ammonium Oxidation ◽

Anaerobic Sludge ◽

Main Stream ◽

Ammonium Oxidation ◽

N2o Production ◽

Partial Nitritation ◽

Nitrogen Elimination ◽

Heterotrophic Denitrification

In wastewater treatment plants with anaerobic sludge digestion, 15–20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant significantly reduces the nitrogen load of the activated sludge system. Two biological applications are considered for nitrogen elimination: (i) classical autotrophic nitrification/heterotrophic denitrification and (ii) partial nitritation/autotrophic anaerobic ammonium oxidation (anammox). With both applications 85-90% nitrogen removal can be achieved, but there are considerable differences in terms of sustainability and costs. The final gaseous products for heterotrophic denitrification are generally not measured and are assumed to be nitrogen gas (N2). However, significant nitrous oxide (N2O) production can occur at elevated nitrite concentrations in the reactor. Denitrification via nitrite instead of nitrate has been promoted in recent years in order to reduce the oxygen and the organic carbon requirements. Obviously this “achievement” turns out to be rather disadvantageous from an overall environmental point of view. On the other hand no unfavorable intermediates are emitted during anaerobic ammonium oxidation. A cost estimate for both applications demonstrates that partial nitritation/anammox is also more economical than classical nitrification/denitrification. Therefore autotrophic nitrogen elimination should be used in future to treat ammonium-rich sludge liquors.

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Coupled anaerobic ammonium oxidation and hydrogenotrophic denitrification for simultaneous NH4-N and NO3-N removal

Water Science & Technology ◽

10.2166/wst.2018.459 ◽

2018 ◽

Vol 79 (5) ◽

pp. 975-984 ◽

Cited By ~ 4

Author(s):

Tatsuru Kamei ◽

Rawintra Eamrat ◽

Kenta Shinoda ◽

Yasuhiro Tanaka ◽

Futaba Kazama

Keyword(s):

Nitrogen Removal ◽

Inorganic Nitrogen ◽

Nitrate Removal ◽

Fixed Bed ◽

Anaerobic Ammonium Oxidation ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

N Removal ◽

Anammox Process

Abstract Nitrate removal during anaerobic ammonium oxidation (anammox) treatment is a concern for optimization of the anammox process. This study demonstrated the applicability and long-term stability of the coupled anammox and hydrogenotrophic denitrification (CAHD) process as an alternative method for nitrate removal. Laboratory-scale fixed bed anammox reactors (FBR) supplied with H2 to support denitrification were operated under two types of synthetic water. The FBRs showed simultaneous NH4-N and NO3-N removal, indicating that the CAHD process can support NO3-N removal during the anammox process. Intermittent H2 supply (e.g. 5 mL/min for a 1-L reactor, 14/6-min on/off cycle) helped maintain the CAHD process without deteriorating its performance under long-term operation and resulted in a nitrogen removal rate of 0.21 kg-N/m3/d and ammonium, nitrate, and dissolved inorganic nitrogen removal efficiencies of 73.4%, 80.4%, and 77%, respectively. The microbial community structure related to the CAHD process was not influenced by changes in influent water quality, and included the anammox bacteria ‘Candidatus Jettenia’ and a Sulfuritalea hydrogenivorans-like species as the dominant bacteria even after long-term reactor operation, suggesting that these bacteria are key to the CAHD process. These results indicate that the CAHD process is a promising method for enhancing the efficiency of anammox process.

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