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Showing 1 to 19 of 19 for “"Ammonia oxidizing bacteria (AOB)"”.
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Elucidating the Reactivity of Cytochrome P460: Maturation, Product Selectivity, and Substrate Scope
Ammonia oxidizing bacteria (AOB) have evolved a nitrogen-based metabolism in which they rely solely on the oxidation of ammonia as their energy for life. In contrast to carbon-based metabolisms, there is a large gap in our knowledge of nitrogen-based metabolisms. The primary energy producing step …
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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 …
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Nitrification process in integrated fixed-film activated sludge (IFFAS) system
The ammonia released from wastewater is a key factor in detrimental environment concerns such as eutrophication. Nitrogenous waste is most commonly removed from wastewater through biological means, typically involving the use of ammonia oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB), …
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Optimization of Biological Nitrogen Removal From Fermented Dairy Manure Using Low Levels of Dissolved Oxygen
… days and was designed to remove inorganic total ammonia nitrogen (TAN) from solids-separated dairy manure. An anaerobic fermenter, upstream of the N removal reactor, produced volatile fatty acids (VFAs), to be used as an electron donor to fuel denitrification, and TAN at a COD:N ratio of 18:1. …
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Using Oligonucleotide Probes to Characterize Nitrification in a Two-Stage Pilot Scale Biological Aerated Filter System
… two-stage (carbon oxidation stage one, ammonia oxidation stage two) fixed film biological aerated filter (BAF) process was operated on-site at a domestic wastewater treatment plant. Over the study period, hydraulic loadings to the system were varied, generating a range of organic and …
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Experimental testing and modeling of partial nitrification at different temperatures
… in a sequencing batch reactor (SBR) treating low ammonia wastewater (40 mg N/L) at low temperature (14oC); 4- investigating the effect of nickel on nitrification in a sequencing batch reactor (SBR) treating low ammonia wastewater (40 mg N/L) at low temperature (10 oC). First, a mathematical model …
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Microbial Regulation of Soil Greenhouse Gas Emissions in a Non-Bloat Legume Grazing System
… N cycling communities, and N2O sources. Ammonia oxidizing bacteria (AOB) were the most active nitrifiers following urine addition. Denitrifiers contributed the most N2O in urine amended soils and their dynamics varied. After urine deposition, nirS gene abundance and transcript increases …
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Mechanistic Understanding of the NOB Suppression by Free Ammonia Inhibition in Continuous Flow Aerobic Granulation Bioreactors
… mg N L-1 to verify that the upper range of total ammonia nitrogen (TAN) for domestic wastewater can supply 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 …
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Evaluation of Nitrification Inhibition Using Bench-Scale Rate Measurements, Profile Sampling, and Process Simulation Modeling
… are characterized 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, …
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Characterizing biological nitrification inhibition using native Nitrosomonas europaea: mechanism studies and maize cultivar screening
… process called nitrification. In this process, ammonia-oxidizing bacteria (AOB), such as Nitrosomonas europaea, oxidize NH₄⁺ and ammonia (NH₃) to nitrite (NO₂⁻), which is further converted to nitrate (NO₃⁻) by nitrite-oxidizing microorganisms and eventually reduced to di-nitrogen (N₂) via …
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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 …
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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
… PCR (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 …
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Characterizing Kinetic Shifts in Nitrifying, Denitrifying, and Phosphorus Removing Biomass Adapting to Low DO
… Oxygen Kinetics test, was able to estimate the ammonia oxidizing bacteria (AOB) oxygen half-saturation coefficient, ammonia maximum removal rate, denitrifier oxygen inhibition coefficient, total inorganic nitrogen (TIN) maximum removal rate, PAO oxygen half-saturation coefficient, phosphorus …
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Elucidating Factors that Impact the Removal of Organic Microconstituents by Ammonia Oxidizing and Heterotrophic Bacteria
… were performed with inactivated biomass samples (ammonia oxidizing bacteria (AOB), laboratory enriched heterotrophic cultures free of active nitrifiers with low (Ox⁻) or high (Ox⁺) oxygenase activity, and a nitrifying activated sludge (NAS) from a full-scale wastewater treatment plant) to …
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Development of Kinetic Parameterization Methods for Nitrifying Bacteria using Respirometry
… oxygen 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 …
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Mathematical Modeling of Carbon Removal in the A-Stage Activated Sludge System
… 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 (< 0.25 d) can produce high effluent substrates (SB and CB), and elevated COD:N ratios consistent with NOB …
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Evaluation Of Nitrification Kinetics For A 2.0 MGD IFAS Process Demonstration
… the study, 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 …
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Microbial diversity and activity in temperate forest and grassland ecosystems
… process. This PhD thesis aimed at studying ammonia oxidizing bacteria (AOB) community structure and richness as an integrated part of soil functioning. This research aimed at investigating the effect of aboveground plant diversity on ammonia oxidizing bacteria diversity and function in …
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Optimization of intermittent aeration for increased nitrogen removal efficiency and improved settling
… strategy 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 …