Article

Nitrogen Removal by a Nitritation-Anammox Bioreactor at Low Temperature

Department of Microbiology, IWWR, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands.
Applied and Environmental Microbiology (Impact Factor: 3.67). 02/2013; 79(8). DOI: 10.1128/AEM.03987-12
Source: PubMed

ABSTRACT

Currently, nitritation-anammox (anaerobic ammonium oxidation) bioreactors are designed to treat wastewaters with high ammonium concentration at mesophilic temperatures (25 - 40 °C). The implementation of this technology at ambient temperatures for nitrogen removal from municipal wastewater following carbon removal could lead to more sustainable technology with energy and cost savings. However the application of nitritation-anammox bioreactors at low temperature (characteristic of municipal wastewaters expect tropical and subtropical regions) is not yet explored. To this end, a laboratory-scale (5 l) nitritation-anammox sequencing batch reactor was adapted to 12 °C in 10 days and operated for more than 300 days to investigate the feasibility of nitrogen removal from synthetic pre-treated municipal wastewater by the combination of aerobic ammonium-oxidizing bacteria (AOB) and anammox. The activities of both anammox and AOB were high enough to remove more than 90 % of the supplied nitrogen. Multiple aspects, including the presence and activity of anammox, AOB, and aerobic nitrite oxidizers (NOB) and nitrous oxide (N(2)O) emission were monitored to evaluate the stability of the bioreactor at 12 °C. There was no nitrite accumulation throughout the operational period indicating that anammox bacteria were active at 12 °C and that AOB and anammox bacteria outcompeted NOB. Moreover, our results showed that sludge from wastewater treatment plants designed for treating high ammonium load wastewaters could be used as seeding sludge for wastewater treatment plants aimed at treating municipal wastewater that has low temperature and low ammonium concentrations.

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Available from: Mark Van Loosdrecht, Jun 19, 2014
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    • "Ammonium removal can be accomplished by biological reactions such as anaerobic ammonium oxidation (anammox), where anammox bacteria convert ammonium to N 2 with nitrite as a terminal electron acceptor under an oxygen-limited condition [17]. Nitritation by ammonium oxidizing bacteria (AOB) is required to oxidize part of ammonium to nitrite [18]. Thus, the cooperation of AOB and anammox bacteria is essential to achieve completely autotrophic nitrogen removal. "
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    ABSTRACT: Reverse flux of ammonium draw solute is a serious problem for applying forward osmosis (FO) in water/wastewater treatment. In this study, anaerobic ammonium oxidization (anammox) was synergistically linked to FO for removal of reverse-fluxed ammonium, thereby creating an osmotic anammox system. The feasibility of this system was demonstrated through both batch and continuous operation, and the anammox process was developed in two stages: sole anammox and nitritation-anammox. With addition of nitrite, the sole anammox process achieved an effluent ammonium concentration of 9.9±9.5mgNL-1. The nitritation-anammox maintained an ammonium concentration of 3.1±4.2mgNL-1, and increased the water flux to 2.46±0.24LMH (Lm-2h-1) compared with the sole anammox (1.90±0.14LMH). The nitritation-anammox process exhibited advantages over anammox process in assisting the FO with respect to water flux improvement and chemical savings. The osmotic anammox system can be linked to previously developed microbial electrolysis cells that recover ammonium from high-strength wastes as a draw solute for FO operation. The results encourage further investigation of this system for effects of organic residues, decreasing nitrate accumulation, understanding biofilm on the FO membrane, and long-term performance with actual waste.
    Full-text · Article · Aug 2015 · Journal of Membrane Science
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    • "For anammox capacity tests, activated sludge and biofilm were separately transferred to 2 L SBR reactors, which were continuously stirred after addition of nitrite and ammonium. Liquid samples were collected every 30 min for nitrogen compounds measurement (Hu et al., 2013). "
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    ABSTRACT: Nitritation-anammox process was successfully established in pilot- and full-scale integrated fixed-film activated sludge (IFAS) reactors. An average nitrogen removal efficiency of 80% was achieved under ammonium loading rate of 0.7-1.3kgN/(m(3)d) in the pilot-scale reactor (12m(3)). Moreover, molecular analysis showed that ammonium oxidizing bacteria (AOB) were more abundant in the activated sludge while anammox bacteria were primarily located in the biofilm. The segregation of AOB and anammox bacteria enhanced the nitrogen removal rate and operational stability. Furthermore, a full-scale IFAS reactor of 500m(3) was set-up to treat sludge dewatering liquors. An average nitrogen removal efficiency of 85% and a nitrogen removal rate of 0.48kgN/(m(3)d) were achieved after inoculation. It was noted that high influent suspended solids would seriously affect the performance of the IFAS system. Therefore, a pre-treatment was proposed to reduce suspended solid in the full-scale application. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Jul 2015 · Bioresource Technology
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    • "Therefore, the main challenge for applying anammox in the water line of a wastewater treatment plant (WWTP) is to achieve stable operation under temperature instability despite a lower anammox growth rate (Lotti et al., 2014). Although several studies have demonstrated that the anammox process still occurs at lower temperatures (Hendrickx et al., 2014; Hu et al., 2013; Yu et al., 2013), a stable anammox process could not be maintained at temperatures lower than 5 °C. "
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    ABSTRACT: In this study, the effects of realistic seasonal temperatures on the nitrogen removal performance of anaerobic ammonium oxidation (anammox) and the properties of the anammox granules were comparatively investigated for 330days. The results demonstrated that the nitrogen removal efficiency (NRE), nitrogen loading rate (NLR) and nitrogen removal rate (NRR) were decreased dramatically, as the temperature decreased from 31.2 to 2.5°C. However, the nitrogen removal performance recovered andante as the temperature increased gradually. After low temperature exposure, the settleability tended to worsen, and granules appeared to be more irregular with a smaller average granule diameter, and the extracellular polymeric substances (EPS) content increased slightly, while the specific anammox activity (SAA) decreased obviously. This realistic seasonal temperatures based research was an illation of the actual operation, and could be potentially implemented to maintain stability for the application of anammox technology. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Jun 2015 · Bioresource Technology
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