Stable partial nitritation for low-strength wastewater at low temperature in an aerobic granular reactor
Partial nitritation for a low-strength wastewater at low temperature was stably achieved in an aerobic granular reactor. A bench-scale granular sludge bioreactor was operated in continuous mode treating an influent of 70 mg N-NH₄⁺ L⁻¹ to mimic pretreated municipal nitrogenous wastewater and the temp...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:166592 |
| Acceso en línea: | https://ddd.uab.cat/record/166592 https://dx.doi.org/urn:doi:10.1016/j.watres.2015.04.028 |
| Access Level: | acceso abierto |
| Palabra clave: | Mainstream NOB repression Partial nitritation Modeling |
| Sumario: | Partial nitritation for a low-strength wastewater at low temperature was stably achieved in an aerobic granular reactor. A bench-scale granular sludge bioreactor was operated in continuous mode treating an influent of 70 mg N-NH₄⁺ L⁻¹ to mimic pretreated municipal nitrogenous wastewater and the temperature was progressively decreased from 30 to 12.5ºC. A suitable effluent nitrite to ammonium concentrations ratio to a subsequent anammox reactor was maintained stable during 300 days at 12.5ºC. The average applied nitrogen loading rate at 12.5 ºC was 0.7 ± 0.3 g N L⁻¹ d⁻¹, with an effluent nitrate concentration of only 2.5 ± 0.7 mg N--NO₃ L⁻¹. The biomass fraction of nitrite-oxidizing bacteria (NOB) in the granular sludge decreased from 19% to only 1% in 6 months of reactor operation at 12.5ºC. Nitrobacter spp. where found as the dominant NOB population, whereas Nitrospira spp. were not detected. Simulations indicated that: (i) NOB would only be effectively repressed when their oxygen half-saturation coefficient was higher than that of ammonia-oxidizing bacteria; and (ii) a lower specific growth rate of NOB was maintained at any point in the biofilm (even at 12.5ºC) due to the bulk ammonium concentration imposed through the control strategy. |
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