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Showing 1 to 16 of 16 for “"Nitrite accumulation"”.
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The Investigation of Nitrite Accumulation and Biological Phosphorus Removal in an Intermittently Aerated Process Combining Shortcut Nitrogen Removal and Sidestream Biological Phosphorus Removal
… bio-P became more unstable and there was high nitrite accumulation in the B-stage effluent for 106 days with concentrations ranging from 1.1-5.9 mg/L NO2. The nitrite accumulation was not due to NOB out-selection, confirmed by AOB and NOB maximum activity tests. It was determined that the …
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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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The effect of ammonial loading, solids retention time and operating temperature on the biological nitrification and denitrification of high ammonia landfill leachate
… and approximately 170 mg NO.--N/L. Aerobic nitrite accumulation was observed and was likely a factor in a parallel decrease in the COD:NOx ratio from approximately 6:1 to 4:1. At the leachate ammonia level of 1500 mg N/L, "free" ammonia levels in the anoxic reactor were estimated to have …
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Effects of phosphoroamides on transformations of urea nitrogen in soil
… urea hydrolysis, nitrification, denitrification, nitrite accumulation, mineralization of organic N, and gaseous loss of urea N as NH(,3) in soils treated with urea. The phosphoroamides used were N-(diaminophosphinyl)-cyclohexylamine (DPCA), N-benzyl-N-methyl phosphoric triamide, diethyl phosphoric …
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Evaluation of Glycerol and Waste Alcohol as Supplemental Carbon Sources for Denitrification
… they both exhibited significant and consistent nitrite accumulation during the entire experiment. Based on reactor restart, nitrite accumulation was evident and significant within two days after startup and consistent for all further operation. Rapid nitrate to nitrite reduction coincident with …
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Development of High Efficiency Partial Nitrification as a First Step of Nitrite Shunt Process using Ammonium-Oxidizing Bacteria (AOB)
… from wastewater using two processes either nitrite shunt or deammonification. In this research, a complete partial nitrification as a first step of the Nitrite Shunt process has been developed under a high nitrogen loading rate (NLR) using a novel strategy to control the DO depending on …
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Evaluation of an Industrial Byproduct Glycol Mixture as a Carbon Source for Denitrification
… the lowest yield of 0.21 mg VSS/mg COD. Small nitrite accumulation was observed in the low dosage glycol reactor (COD=185"•15 mg/L), but effluent quality was not influenced. Excess glycol in the reactor caused deteriorated performance. The high dosage glycol reactor (COD=345"•20 mg/L) performed …
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Comparison of Aeration Strategies for Optimization of Nitrogen Removal in an Adsorption/Bio-oxidation (A/B) Process with an Emphasis on Ammonia vs. NOx (AvN) control
… a high particulate COD fraction. A high effluent nitrite accumulation ratio (NAR = NO2-/(NO2-+NO3-)) was seen during this period (46 ± 15%) accompanied by the out-selection of Nitrospira. Feeding effluent from AvN control to an Anammox MBBR improved removal efficiency. Increased soluble COD …
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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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Microbial Dynamics and Mechanistic Insights into a Hydrogenotrophic Denitrifying Microbial Consortium
… challenges associated with this process, such as nitrite accumulation, long-lag phases and relatively slower denitrification rates, require further elucidation. Notably, the impact of microbial interactions within hydrogenotrophic denitrifying consortia on these behaviors has yet to be …
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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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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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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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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 …
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A quantitative proteomics study of the additive effect of inflammatory cytokines and injurious compression on cartilage damage
… incorporation rates on day 6 post treatment, and nitrite accumulation in media in 5 days post treatment Results and Discussion: TNF-[alpha]+injury and IL-[beta] +injury treatment conditions show a very high correlation with each other. Most cytosolic, ER lumen and nuclear protein levels are highly …
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Deammonification Process Kinetics and Inhibition Evaluation
… process that oxidizes half of the ammonia to nitrite (nitritation) in a separate reactor such as in the SHARON process, or in the same reactor such as in the DEaMmONification (DEMON) process. Despite intensive laboratory research for the last 10 years to fully understand these processes, there …