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Showing 1 to 20 of 20 for “"nitrite oxidizing bacteria"”.
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Partial nitrification and oxygen transfer analysis utilizing hollow fiber membrane aeration
… ANAMMOX, anaerobically converts ammonium and nitrite to N<sub>2</sub> gas.y Because this system requires a 1:1.31 NH<sub>4</sub><sup>+</sup> : NO<sub>2</sub><sup>–</sup> ratio, a partial nitrification system is coupled with the ANAMMOX system to provide the necessary substrates.y A hollow …
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Effects of 2015 earthquake on biological stability of water in Nepal
… geobiochemical characteristics of water (Ammonia Oxidizing Archea and Bacteria, Nitrite Oxidizing Bacteria, Sulfate Reducing Bacteria), for example, Methylobacter, Nitrospira, Methylomonas, increased significantly right after the earthquake and decreased eight months later. This result indicated …
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Ammonia-monooxygenase-mediated cometabolic biotransformation and abiotic transformation of micropollutants
… To further elucidate roles played by ammonia-oxidizing bacteria (AOB), and nitrite-oxidizing bacteria (NOB) that grow dependently on AOB, we investigated the biotransformation capabilities of an NOB pure culture (Nitrobacter sp.), and an AOB (Nitrosomonas europaea)/NOB co-culture for fifteen …
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Evaluation Of Nitrification Kinetics For A 2.0 MGD IFAS Process Demonstration
… nitrification kinetics for both ammonia and nitrite oxidizing bacteria and plastic biofilm carrier biomass content were monitored on a near-weekly basis comparing the IFAS media, the IFAS process mixed liquor, and mixed liquor from the full-scale activated sludge process. Carrier biomass …
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Nitrification process in integrated fixed-film activated sludge (IFFAS) system
… means, typically involving the use of ammonia oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB), and denitrifying bacteria (DEN). This study looked at alternative nitrification processes, including anaerobic ammonia oxidiation (anammox) reactions that may be innately present in an …
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Mechanistic Understanding of the NOB Suppression by Free Ammonia Inhibition in Continuous Flow Aerobic Granulation Bioreactors
… an inhibitory level of free ammonia (FA) for nitrite oxidizing bacteria (NOB) suppression in CFRs at pH around 7.8. The ammonia oxidizing bacteria (AOB):NOB activity ratio was determined for a series of granule sizes to understand the impact of mass diffusion limitation on the FA inhibition of …
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Submerged-Membrane Bioreactor for the Treatment of NASA Wastewater
… was observed. An unexpected observation was nitrite accumulation, typically a transient species in wastewater treatment. Kinetic modeling suggests that nitrite accumulation results from inhibition of nitrite oxidizing bacteria due to a combination of free ammonia and nitrous acid.Organic …
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AN INVESTIGATION OF AQUATIC MACROPHYTE-BASED AQUATIC WASTEWATER TREATMENT SYSTEMS FOR TEMPERATE CLIMATES (ELODEA NUTTALLII, PHOTOSYNTHESIS, NUTRIENT BUDGET, ACTIVE TRANSPORT, NITRIFICATION)
… not rate-limiting to productivity. Ammonia- and nitrite-oxidizing bacteria were also present in high concentrations in the reactors, particularly in association with macrophyte and sediment samples (NH(,4)('+)-oxidizers, 10('8)(.)g dry wt('-1); NO(,2)('-)-oxidizers, 10('7)(.)g dry wt('-1)). E. …
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Micropollutants biotransformation by two nitrifying communities enriched from biofilm of a nitrification trickling tower
… effects. It has been hypothesized that ammonia-oxidizing bacteria (AOB) were responsible for micropollutants biotransformation, which contributes to the removal of micropollutants. Both inhibition studies and pure culture studies have been performed to test this hypothesis. By inhibiting ammonia …
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Evaluation of Digital PCR (dPCR) for the Quantification of Soil Nitrogen Turnover Bacteria in Wetland Mesocosms in Response to Season, Fertilization, and Plant Species Richness
… (QS3D dPCR) system was used to quantify ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), comammox, anammox, and denitrifiers. Principal component analysis (PCA) was used to identify dominant patterns in the microbial community and nitrogen species. Resampling-based analysis of …
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Development of Kinetic Parameterization Methods for Nitrifying Bacteria using Respirometry
… half-saturation coefficients for both ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) without the use of selective inhibitors. By eliminating the use of inhibitory substances, representative biomass characteristics were maintained throughout the tests. The developed …
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Bioaugmentation and Retention of Anammox Granules to a Mainstream Deammonification Bio-Oxidation Pilot with a Post Polishing Anoxic Partial Denitrification/Anammox Moving Bed Biofilm Reactor
… the overflow. B-Stage was operated to out-select nitrite oxidizing bacteria (NOB) by maintaining an ammonia residual (>2 mg NH4-N/L), a relatively high dissolved oxygen (DO) (>1.5 mg O2/L) concentration, an aggressive solids retention time (SRT) for NOB washout, and intermittent aeration for …
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Nutrient (Ammonium and Phosphate) Removal Using Aerobic Granulation at Pilot scale
… the functional diversity of the dominating bacteria in the AGS. Improper aeration pattern was identified as the main cause of preventing granulation at pilot scale. To maintain the aeration pattern and shearing activity regardless of the reactor scale, a scale-up factor (S) was developed …
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Application of Molecular Techniques to the Characterization of a Nitrifying Bioaugmentation Culture
… process whereby ammonia is converted first to nitrite by ammonia-oxidizing bacteria, and then the nitrite is subsequently converted to nitrate by nitrite-oxidizing bacteria. Ammonia and nitrite levels are closely monitored during treatment of wastewater due to their toxicity to other biological …
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Mathematical Modeling of Carbon Removal in the A-Stage Activated Sludge System
… was based on its suitability for a downstream nitrite shunt (i.e. nitritation/denitritation) process. In the downstream process the goal is to eliminate nitrite oxidizing bacteria (NOB) from the reactor while selecting for ammonia oxidizing bacteria (AOB). The results showed that a low SRT (< …
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Intensification of Biological Nutrient Removal Processes
… Shortcut nitrogen removal processes; including nitrite shunt, partial nitritation/anammox, and partial denitrification/anammox, as well as low-carbon biological phosphorus removal, were critically-evaluated in this study with an overall objective of intensification of existing infrastructure. At …
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Experimental testing and modeling of partial nitrification at different temperatures
… of pH, DO, total ammonium nitrogen (TAN), total nitrite nitrogen (TNN), and solids retention time (SRT) for successful shortcut nitrification. Second, to meet objective 2, a sequencing batch reactor (SBR) was operated at 35oC for over 4 months with dissolved oxygen (DO) and influent ammonia …
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Treatment of High-Strength Nitrogen Wasetewater With a Hollow-Fiber Membrane-Aerated Biofilm Reactor: A Comprehensive Evaluation
… metabolisms, partial nitrification to nitrite (nitritation) and anaerobic ammonium oxidation, was demonstrated in a single HFMBR. The system successfully treated a high-strength nitrogen wastewater intended to mimic a urine stream from such sources as extended space missions. For the …
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Evaluation of Nitrification Inhibition Using Bench-Scale Rate Measurements, Profile Sampling, and Process Simulation Modeling
… by sharp increases in effluent ammonia and nitrite with decreases in nitrate concentrations due to reduced growth rates in bacteria. The result is reduced overall total nitrogen (TN) removal. Continuous inhibition is evidenced by a previous engineering report by Hazen and Sawyer, P.C. …
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Optimization of intermittent aeration for increased nitrogen removal efficiency and improved settling
… based on set-points for reactor ammonia, nitrite and nitrate concentrations with the aim of maintaining equal effluent ammonia and nitrate + nitrite (NOx) concentrations was successfully employed. The goal was to inhibit nitrite-oxidizing bacteria (NOB) so the nitrification process stopped …