nitrite oxidizing bacteria Articles
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Nitrous oxide formation during nitritation and nitrification of high-strength wastewater
The purpose of this study was to investigate the formation of nitrous oxide (N2O) in nitritation and nitrification under stable, comparable and not limiting conditions typical for treatment of high-strength wastewater. A laboratory-scale aerated chemostat was operated with reject water at different sludge retention times, achieving suppression of nitrate formation by wash-out of ...
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Low temperature biological phosphorus removal and partial nitrification in a pilot sequencing batch reactor system
Partial nitrification and biological phosphorus removal appear to hold promise of a cost-effective and sustainable biological nutrient removal process. Pilot sequencing batch reactors (SBRs) were operated under anaerobic/aerobic configuration for 8 months. It was found that biological phosphorus removal can be achieved in an SBR system, along with the partial nitrification process. Sufficient ...
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Partial nitrification in MBBRs for mainstream deammonification with thin biofilms and alternating feed supply
A new principle for mainstream nitrogen removal through nitritation followed by anammox was studied in a two-stage moving bed biofilm reactor (MBBR) configuration. The first stage was optimized for nitritation by using thin biofilms and a feed alternating between synthetic mainstream wastewater at 15°C and, for shorter periods, synthetic reject water at 30 °C. The exposure of the biofilm to ...
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Model-based evaluation of mechanisms and benefits of mainstream shortcut nitrogen removal processes
The main challenge in implementing shortcut nitrogen removal processes for mainstream wastewater treatment is the out-selection of nitrite oxidizing bacteria (NOB) to limit nitrate production. A model-based approach was utilized to simulate the impact of individual features of process control strategies to achieve NO−2-N shunt via NOB out-selection. Simulations were conducted using a ...
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Microbial characteristics of a CANON reactor during the start-up period seeding conventional activated sludge
An up-flow oxygen-controlled biofilm reactor filled with volcanic filter was used for a completely autotrophic nitrogen-removal over nitrite (CANON) process. The reactor was successfully established by seeding conventional activated sludge at ambient temperature without additional biomass inoculation. An average total nitrogen (TN) removal rate of 1.1 kg·(m3 d)−1 was achieved ...
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Differential sensitivity of nitrifying bacteria to silver nanoparticles in activated sludge
Nitrification is known to be one of the most sensitive processes affected when activated sludge (AS) is exposed to antimicrobial silver nanoparticles (AgNPs). However, the impact of AgNPs and their released silver ions (Ag+) on the abundance, activity and diversity of different nitrifying bacteria in wastewater treatment plants (WWTPs) is poorly understood. Herein we investigate the impacts of ...
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Energy efficient treatment of A-stage effluent: pilot-scale experiences with shortcut nitrogen removal
Energy autarky of sewage treatment plants, while reaching chemical oxygen demand (COD) and N discharge limits, can be achieved by means of shortcut N-removal. This study presents the results of a shortcut N-removal pilot, located at the biological two-‘stage (high/low rate) wastewater treatment plant of Breda, The Netherlands. The pilot treated real effluent of a high-rate activated sludge ...
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Long-term performance of side-stream deammonification in a continuous flow granular-activated sludge process for nitrogen removal from high ammonium wastewater
An innovative granular sludge deammonification system was incorporated into a conventional-activated sludge process. The process incorporated an internal baffle in the bioreactor for continuous separation of granular biomass from flocculent biomass, which allowed for controlling the solids retention time of flocculent sludge. The process was evaluated for ammonium removal from municipal ...
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Impact of carbon to nitrogen ratio and aeration regime on mainstream deammonification
While deammonification of high-strength wastewater in the sludge line of sewage treatment plants has become well established, the potential cost savings spur the development of this technology for mainstream applications. This study aimed at identifying the effect of aeration and organic carbon on the deammonification process. Two 10 L sequencing bath reactors with different aeration ...
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Achieving nitrogen removal via nitrite pathway from urban landfill leachate using the synergetic inhibition of free ammonia and free nitrous acid on nitrifying bacteria activity
In this study, a biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic–oxic (A/O) reactor was established for the advanced treatment of high ammonium urban landfill leachate. The inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on the nitrifying bacterial activity was used to achieve stable nitritation in the A/O reactor. The results ...
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Pilot scale studies on nitritation-anammox process for mainstream wastewater at low temperature
Process of partial nitritation-anammox for mainstream wastewater at low temperature was run in a pilot scale moving bed biofilm reactor (MBBR) system for about 300 days. The biofilm history in the reactor was about 3 years of growth at low temperature (down to 10 °C). The goal of the studies presented in this paper was to achieve effective partial nitritation-anammox process. Influence of ...
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Impact of inocula and growth mode on the molecular microbial ecology of anaerobic ammonia oxidation (anammox) bioreactor communities. Water Research
Abstract: The composition of distinctly inoculated granular anammox and biofilm-based completely autotrophic nitrogen removal over nitrite (CANON) bioreactors was investigated from startup through continuous long-term operation via denaturing gradient gel electrophoresis (DGGE) and sequencing. The granular anammox reactor was seeded with sludge from an operational anammox reactor in Strass, ...
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Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants
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 ...
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Effect of COD/N ratio on N2O production during nitrogen removal by aerobic granular sludge
N2O-production was investigated during nitrogen removal using aerobic granular sludge (AGS) technology. A pilot sequencing batch reactor (SBR) with AGS achieved an effluent in accordance with national discharge limits, although presented a nitrite accumulation rate of 95.79% with no simultaneous nitrification–denitrification. N2O production was 2.06 mg L−1 during the anoxic phase, with N2O ...
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Predicting N2O emissions from nitrifying and denitrifying biofilms: a modeling study
Wastewater treatment plants can be significant sources of nitrous oxide (N2O), a potent greenhouse gas. While our understanding of N2O emissions from suspended-growth processes has advanced significantly, less is known about emissions from biofilm processes. Biofilms may behave differently due to their substrate gradients and microbial stratification. In this study, we used mathematical ...
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The use of microsensors to study the role of the loading rate and surface velocity on the growth and the composition of nitrifying biofilms
The good composition and activity of biofilms are very important for successful operation and control of fixed-film biological reactors employed in liquid effluents treatment. During the last decade, microsensors have been applied to study microbial ecology. These sensors could provide information regarding the microbial activity concerning nitrification and denitrification that occur inside ...
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Optimization of a mainstream nitritation-denitritation process and anammox polishing
This paper deals with an almost 1-year long pilot study of a nitritation-denitritation process that was followed by anammox polishing. The pilot plant treated real municipal wastewater at ambient temperatures. The effluent of high-rate activated sludge process (hydraulic retention time, HRT = 30 min, solids retention time = 0.25 d) was fed to the pilot plant described in this ...
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The impact of influent total ammonium nitrogen concentration on nitrite-oxidizing bacteria inhibition in moving bed biofilm reactor
The application of nitrification–denitrification over nitrite (nitritation–denitritation) with municipal (i.e. diluted and cold (or low-temperature)) wastewater can substantially improve the energy balance of municipal wastewater treatment plants. For the accumulation of nitrite, it is crucial to inhibit nitrite-oxidizing bacteria (NOB) with simultaneous proliferation of ...
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Laboratory-scale investigation of integrated biological phosphorus removal and mainstream deammonification at the Terrence J. O`Brien Water Reclamation Plant. Proceedings WEFTEC.17
Abstract: In collaboration with the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), the environmental biotechnology research group at Northwestern University (NU) is conducting a laboratory-scale investigation of enhanced biological phosphorus removal (EBPR) integrated with mainstream deammonification using primary effluent as feed. The research presented here includes (1) A ...
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Anammox moving bed biofilm reactor pilot at the 26th Ward wastewater treatment plants in Brooklyn, New York: start-up, biofilm population diversity and performance optimization
New York City Environmental Protection in conjunction with City College of New York assessed the application of the anammox process in the reject water treatment using a moving bed biofilm reactor (MBBR) located at the 26th Ward wastewater treatment plant, in Brooklyn, NY. The single-stage nitritation/anammox MBBR was seeded with activated sludge and consequently was enriched with its own ...
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