Light as a Novel Inhibitor of Nitrite-Oxidizing Bacteria (NOB) for the Mainstream Partial Nitrification of Wastewater Treatment

Conventional biological nutrient removal processes in municipal wastewater treatment plants are energy-consuming, with oxygen supply accounting for 45–75% of the energy expenditure. Many recent studies examined the implications of the anammox process in sidestream wastewater treatment to reduce energy consumption, however, the process did not successfully remove nitrogen in mainstream wastewater treatment with relatively low ammonia concentrations. In this study, blue light was applied as an inhibitor of nitrite-oxidizing bacteria (NOB) in a photo sequencing batch reactor (PSBR) containing raw wastewater. This simulated a biological nitrogen removal system for the investigation of its application potential in nitrite accumulation and nitrogen removal. It was found that blue light illumination effectively inhibited NOB rather than ammonia-oxidizing bacteria due to their different sensitivity to light, resulting in partial nitrification. It was also observed that the NOB inhibition rates were affected by other operational parameters like mixed liquor suspended solids (MLSS) concentration and sludge retention time (SRT). According to the obtained results, it was concluded that the process efficiency of partial nitrification and anammox (PN/A) could be significantly enhanced by blue light illumination with appropriate MLSS concentration and SRT conditions.

Download Full-text

Modelling the N2O Emissions in Municipal Wastewater Treatment Plants under Dynamic Conditions

10.29007/w6rq ◽

2018 ◽

Author(s):

Theoni Massara ◽

Borja Solis Duran ◽

Albert Guisasola ◽

Evina Katsou ◽

Juan Antonio Baeza

Keyword(s):

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Partial Nitrification ◽

Biological Nutrient Removal ◽

N2o Emissions ◽

Ammonia Oxidizing Bacteria ◽

N2o Production ◽

Dynamic Conditions ◽

Nitrifier Denitrification

Nitrous oxide (N2O), a greenhouse gas with a significant global warming potential, can be produced during the biological nutrient removal in wastewater treatment plants (WWTPs). N2O modelling under dynamic conditions is of vital importance for its mitigation. Following the activated sludge models (ASM) layout, an ASM-type model was developed considering three biological N2O production pathways for a municipal anaerobic/anoxic/aerobic (A2/O) WWTP performing chemical oxygen demand, nitrogen and phosphorus removal. Precisely, the N2O production pathways included were: nitrifier denitrification, hydroxylamine oxidation, and heterotrophic denitrification, with the first two linked to the ammonia oxidizing bacteria (AOB) activity. A stripping effectivity (SE) factor was used to mark the non-ideality of the stripping modelling. With the dissolved oxygen (DO) in the aerobic compartment ranging from 1.8 to 2.5 mg L-1, partial nitrification and high N2O production via nitrifier denitrification occurred. Therefore, low aeration strategies can effectively lead to a low overall carbon footprint only if complete nitrification is guaranteed. After suddenly increasing the influent ammonium load, the AOB had a greater growth compared to the NOB. N2O hotspot was again nitrifier denitrification. Especially under concurring partial nitrification and high stripping (i.e. combination of low DO and high SEs), the highest N2O emission factors were noted.

Download Full-text

Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants

Water Science & Technology ◽

10.2166/wst.2013.004 ◽

2013 ◽

Vol 67 (7) ◽

pp. 1481-1489 ◽

Cited By ~ 36

Author(s):

R. Barat ◽

J. Serralta ◽

M. V. Ruano ◽

E. Jiménez ◽

J. Ribes ◽

...

Keyword(s):

Wastewater Treatment ◽

Nitrogen Removal ◽

Nutrient Removal ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Operating Conditions ◽

Plant Performance ◽

Biological Nutrient Removal ◽

Nitrite Oxidizing Bacteria ◽

Removal Model

This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, apart from nitrite oxidizing bacteria two groups of ammonium oxidizing organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON (Single reactor system for High activity Ammonium Removal Over Nitrite) reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of wastewater treatment plant performance in wider environmental and operating conditions.

Download Full-text

Nitrogen removal by recycle water nitritation as an attractive alternative for retrofit technologies in municipal wastewater treatment plants

Water Science & Technology ◽

10.2166/wst.2004.0735 ◽

2004 ◽

Vol 49 (5-6) ◽

pp. 39-46 ◽

Cited By ~ 5

Author(s):

K.-I. Gil ◽

E. Choi

Keyword(s):

Wastewater Treatment ◽

Nitrogen Removal ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Biological Nutrient Removal ◽

Recycle Water ◽

Municipal Wastewater Treatment ◽

Effluent Quality ◽

Municipal Wastewater Treatment Plants ◽

Final Effluent

The recycle water from sludge processing in municipal wastewater treatment plants causes many serious problems in the efficiency and stability of the mainstream process. Thus, the design approach for recycle water is an important part of any biological nutrient removal system design when a retrofit technology is required for upgrading an existing plant. Moreover, the application of nitrogen removal from recycle water using the nitritation process has recently increased due to economic reasons associated with an effective carbon allocation as well as the minimization of aeration costs. However, for the actual application of recycle water nitritation, it has not been fully examined whether or not additional volume would be required in an existing plant. In this paper, the addition of recycle water nitritation to an existing plant was evaluated based on a volume analysis and estimation of final effluent quality. It was expected that using the reserve volume of the aeration tank in existing plants, recycle water nitritation could be applied to a plant without any enlargement. With the addition of recycle water nitritation, it was estimated that the final effluent quality would be improved and stabilized, especially in the winter season.

Download Full-text

Nitrification mainly driven by ammonia-oxidizing bacteria and nitrite-oxidizing bacteria in an anammox-inoculated wastewater treatment system

AMB Express ◽

10.1186/s13568-021-01321-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jing Lu ◽

Yiguo Hong ◽

Ying Wei ◽

Ji-Dong Gu ◽

Jiapeng Wu ◽

...

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Nitrogen Removal ◽

High Throughput Sequencing ◽

High Efficiency ◽

Ammonia Oxidation ◽

Ammonia Oxidizing Bacteria ◽

Ammonium Oxidation ◽

Strong Activity ◽

Nitrite Oxidizing Bacteria

AbstractAnaerobic ammonium oxidation (anammox) process has been acknowledged as an environmentally friendly and time-saving technique capable of achieving efficient nitrogen removal. However, the community of nitrification process in anammox-inoculated wastewater treatment plants (WWTPs) has not been elucidated. In this study, ammonia oxidation (AO) and nitrite oxidation (NO) rates were analyzed with the incubation of activated sludge from Xinfeng WWTPs (Taiwan, China), and the community composition of nitrification communities were investigated by high-throughput sequencing. Results showed that both AO and NO had strong activity in the activated sludge. The average rates of AO and NO in sample A were 6.51 µmol L−1 h−1 and 6.52 µmol L−1 h−1, respectively, while the rates in sample B were 14.48 µmol L−1 h−1 and 14.59 µmol L−1 h−1, respectively. The abundance of the nitrite-oxidizing bacteria (NOB) Nitrospira was 0.89–4.95 × 1011 copies/g in both samples A and B, the abundance of ammonia-oxidizing bacteria (AOB) was 1.01–9.74 × 109 copies/g. In contrast, the abundance of ammonia-oxidizing archaea (AOA) was much lower than AOB, only with 1.28–1.53 × 105 copies/g in samples A and B. The AOA community was dominated by Nitrosotenuis, Nitrosocosmicus, and Nitrososphaera, while the AOB community mainly consisted of Nitrosomonas and Nitrosococcus. The dominant species of Nitrospira were Candidatus Nitrospira defluvii, Candidatus Nitrospira Ecomare2 and Nitrospira inopinata. In summary, the strong nitrification activity was mainly catalyzed by AOB and Nitrospira, maintaining high efficiency in nitrogen removal in the anammox-inoculated WWTPs by providing the substrates required for denitrification and anammox processes.

Download Full-text

Partial Nitrification to Nitrite with Real-Time Aeration Duration Control in an SBR Treating Domestic Wastewater

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.1046 ◽

2011 ◽

Vol 356-360 ◽

pp. 1046-1049 ◽

Cited By ~ 1

Author(s):

Yu Chen ◽

Jun Li ◽

C .W Wang ◽

X.F Zhao ◽

B.H Zhao

Keyword(s):

Real Time ◽

Batch Reactor ◽

Domestic Wastewater ◽

Partial Nitrification ◽

Nitrite Accumulation ◽

Ammonia Oxidizing Bacteria ◽

Term Operation ◽

Nitrite Oxidizing Bacteria ◽

Low Strength

Sustainable partial nitrification to nitrite has been proven difficult in treating low strength nitrogenous wastewater. Real-time aeration duration control was used to achieve efficient partial nitrification to nitrite in a sequencing batch reactor (SBR) to treat low strength domestic wastewater. Above 95% nitrite accumulation ratio was maintained for long-term operation at normal condition. Partial nitrification established by controlling aeration duration showed good performance and robustness even though some time encountering long-term extended aeration. Process control enhanced the successful accumulation of ammonia oxidizing bacteria (AOB) and washout of nitrite oxidizing bacteria (NOB).

Download Full-text

Comparison of Nitrogen Removal Efficiencies and Microbial Communities of Full-Scale Anaerobic, Anoxic and Aerobic Processes in Municipal Wastewater Treatment Plants having Low and High COD/TN Ratios

10.21203/rs.3.rs-892521/v1 ◽

2021 ◽

Author(s):

Supaporn Phanwilai ◽

Pongsak Noophan ◽

Chi-Wang Li ◽

Kwang-Ho Choo

Keyword(s):

Wastewater Treatment ◽

Microbial Communities ◽

Removal Efficiency ◽

Nitrogen Removal ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Full Scale ◽

Biological Nutrient Removal ◽

Distribution Analysis ◽

Microbial Distribution

Abstract Full-scale anaerobic, anoxic and aerobic (A2O) process is used worldwide for biological nutrient removal (BNR). However, operation parameters for nitrogen removals and information of microbial communities related to nitrogen removal in full-scale A2O wastewater treatment plants (WWTPs) having low and high COD/TN ratios are not available. Based on the analysis of four full-scale A2O WWTPs, it is suggested that maintaining longer SRT of ≥ 30 day and DO of ≥ 0.9±0.2 mg-O2 L-1 is needed to improve nitrogen removal efficiency under low COD/TN ratio (≤ 3.7). On other hand, at high COD/TN ratio (≥ 4.2), DO level of ≥ 2.6 mg-O2 /L and typical SRT of 19‒ 25 days would be suggested. It was confirmed that phosphorus removal efficiency significantly improved under BOD/TP ratio of > 20 for A2O process in these full-scale WWTP. Microbial distribution analysis showed that ammonia-oxidizing archaea (AOA) was abundant under conditions of low DO level, longer SRT, high temperature and low COD/TN ratio (≤ 3.7). Nitrosomonas sp. are mostly found in aerobic tank of full-scale A2O WWTPs. However, abundances of Nitrosomonas sp. are proportional to DO and NH4+ concentrations for WWTPs with high COD/TN ratio. Nitrosospira sp. are only found under operating condition of longer SRT for WWTPs with low COD/TN ratio. Abundances of Nitrobacter sp. are proportional to DO concentration and temperature rather than abundance of Nitrospira sp. Predominance of nosZ-type denitrifiers were found at low COD/TN ratio. Abundance of denitrifiers by using nirS genes was over abundance of denitrifiers by using nirK genes at high COD/TN ratios WWTPs.

Download Full-text

Nitrogen Removal by a Nitritation-Anammox Bioreactor at Low Temperature

Applied and Environmental Microbiology ◽

10.1128/aem.03987-12 ◽

2013 ◽

Vol 79 (8) ◽

pp. 2807-2812 ◽

Cited By ~ 180

Author(s):

Ziye Hu ◽

Tommaso Lotti ◽

Merle de Kreuk ◽

Robbert Kleerebezem ◽

Mark van Loosdrecht ◽

...

Keyword(s):

Wastewater Treatment ◽

Low Temperature ◽

Nitrogen Removal ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Batch Reactor ◽

Cost Savings ◽

Anammox Bacteria ◽

Nitrite Accumulation ◽

Ammonium Oxidation

ABSTRACTCurrently, nitritation-anammox (anaerobic ammonium oxidation) bioreactors are designed to treat wastewaters with high ammonium concentrations at mesophilic temperatures (25 to 40°C). The implementation of this technology at ambient temperatures for nitrogen removal from municipal wastewater following carbon removal may lead to more-sustainable technology with energy and cost savings. However, the application of nitritation-anammox bioreactors at low temperatures (characteristic of municipal wastewaters except in tropical and subtropical regions) has not yet been explored. To this end, a laboratory-scale (5-liter) 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 pretreated 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 (N2O) 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 can be used as seeding sludge for wastewater treatment plants aimed at treating municipal wastewater that has a low temperature and low ammonium concentrations.

Download Full-text

Molecular assessment of ammonia- and nitrite-oxidizing bacteria in full-scale activated sludge wastewater treatment plants

Water Science & Technology ◽

10.2166/wst.2003.0460 ◽

2003 ◽

Vol 48 (8) ◽

pp. 119-126 ◽

Cited By ~ 24

Author(s):

K.G. Robinson ◽

H.M. Dionisi ◽

G. Harms ◽

A.C. Layton ◽

I.R. Gregory ◽

...

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

16S Rdna ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Amoa Gene ◽

Full Scale ◽

Ammonia Oxidizing Bacteria ◽

Copy Numbers ◽

Nitrite Oxidizing Bacteria

Nitrification was assessed in two full-scale wastewater treatment plants (WWTPs) over time using molecular methods. Both WWTPs employed a complete-mix suspended growth, aerobic activated sludge process (with biomass recycle) for combined carbon and nitrogen treatment. However, one facility treated primarily municipal wastewater while the other only industrial wastewater. Real time PCR assays were developed to determine copy numbers for total 16S rDNA (a measure of biomass content), the amoA gene (a measure of ammonia-oxidizers), and the Nitrospira 16S rDNA gene (a measure of nitrite-oxidizers) in mixed liquor samples. In both the municipal and industrial WWTP samples, total 16S rDNA values were approximately 2-9 × 1013 copies/L and Nitrospira 16S rDNA values were 2-4 × 1010 copies/L. amoA gene concentrations averaged 1.73 × 109 copies/L (municipal) and 1.06 × 1010 copies/L (industrial), however, assays for two distinct ammonia oxidizing bacteria were required.

Download Full-text