Change of Ammonium Nitrogen Removal Rate and Nitrite Conversion Rate according to Change of Retention Time using Recycle Water

Rural runoff with abundant nutrients has become a great threat to aquatic environment. Hence, more and more attention has been focused on nutrients removal. In this study, an improved aerobic/anaerobic/aerobic three-stage water spinach constructed wetland (O-A-O-CW) was used to improve the removal of nitrogen and phosphorus of rural runoff. The removal rate of the target pollutants in O-A-O-CW was compared with the common matrix flow wetland as well as the no-plant wetland. The results showed that the O-A-O-CW significantly increased the chemical oxygen demand, total phosphorus, ammonium-nitrogen, nitrate, and total nitrogen removal rate, and the corresponding removal rate was 55.85%, 81.70%, 76.64%, 89.78%, and 67.68%, respectively. Moreover, the best hydraulic condition of the wetland, including hydraulic retention time and hydraulic loading, was determined, which were 2 days and 0.45 m3·m−2·day−1, respectively. Furthermore, the removal mechanism of the constructed wetland was thoroughly studied, which included the adsorption of nitrogen and phosphorus by the matrix and water spinach, and the nitrification and denitrification by the bacteria. The results demonstrated that the mechanisms of nitrogen removal in the new type wetland were principally by the nitrification and denitrification process. Additionally, adsorption and precipitation by the matrix are mainly responsible for phosphorus removal. These results suggested that the new O-A-O-CW can efficiently removal nutrients and enhance the water quality of the rural runoff.

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An Experimental Study on Compatible Solute Ectoine Dosing of High Salinity Wastewater

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.1907 ◽

2014 ◽

Vol 955-959 ◽

pp. 1907-1910

Author(s):

Su Chen ◽

Lei Chao ◽

Ning Chen ◽

Lin Shan Wang ◽

Xue Shao ◽

...

Keyword(s):

Nitrogen Removal ◽

Waste Treatment ◽

High Salinity ◽

Removal Rate ◽

Ammonia Nitrogen ◽

Ammonium Nitrogen ◽

Treatment Efficiency ◽

Removal Rates ◽

Cod Removal Rate ◽

Salinity Wastewater

When the reactor is added with ectoine of concentrations of 0, 0.1, 1 and 10 mmol/L, the impacts on brine waste treatment efficiency are investigated. The results show that the outflow COD and ammonia nitrogen removal rates are the highest, when the ectoine concentration is 0.1 mmol/L. The brine waste treatment efficiency under addition of ectoine of 1 and 10 mmol/L is even worse than that without ectoine addition. It can be preliminarily determined that the best ectoine dosage is in between 0.1-1.0 mmol/L. When ectoine concentrations added in reactors are 0.2, 0.5, 0.8 and 1.0 mmol/L, the results show that the average reactor outflow COD and ammonia nitrogen removal rates are increased compared with those of reactor without adding ectoine. But when ectoine of 1.0 mmol/L is added, the outflow COD and ammonia nitrogen removal rates decrease. When ectoine dosage is 0.5 mmol/L, the reactor outflow COD and ammonia nitrogen values are the lowest, the removal rates are the highest, the average COD removal rate is 74.46%, and the average ammonium nitrogen removal rate is 54.97%. Compared with reactor without adding ectoine, COD and ammonium nitrogen removal rates are increased by 13.16% and 26.81%. Therefore, the best dosage of ectoine is 0.5 mmol/L.

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Kinetic Modelling and Determination of Octyl Phenol Ethoxylate (OPE) and Bisphenol A (BPA) (used as plastic additives) Inhibition Constants for Nitrogen Conversion

Global NEST Journal ◽

10.30955/gnj.003591 ◽

2021 ◽

Keyword(s):

Kinetic Model ◽

Bisphenol A ◽

Nitrogen Removal ◽

Removal Rate ◽

Kinetic Modelling ◽

Ammonium Nitrogen ◽

Operating Conditions ◽

Optimum Operating ◽

Octyl Phenol ◽

Inhibition Constants

<p>Conversion of ammonia to nitrate is sensitive to a number of inhibitors. There is limited information on the nitrification inhibition coefficient and kinetic model in the current literature. Octyl Phenol Ethoxylate (OPE) and Bisphenol A (BPA) inhibition constants were found in nitrogen removal using an activated sludge system. Firstly, OPE and BPA free wastewater was used to determine the optimum operating conditions. The effect of OPE and BPA concentration on system performance was investigated. The ammonium removal rate was less affected by lower OPE and BPA concentrations. When the BPA and OPE concentrations were increased from 0 mg/L to 30 mg/L, the outlet ammonium nitrogen concentrations were increased respectively from 2.8 mg/L to 49.8 mg/L and from 2.6 mg/L to 20.40 mg/L. Due to the inhibition created by these compounds on Nitrobacter, nitrite nitrogen increased in the medium. As the OPE and BPA concentrations increased, the conversion rate of the ammonium nitrogen into nitrate decreased. Based on the experimental results, a kinetic model was developed, and the OPE and BPA inhibition constants (KOPE and KBPA) were found to be 40.7 mg/L and 11.76 mg/L, respectively. In nitrogen removal, BPA created a higher inhibition effect in comparison to OPE.</p>

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Kinetic study on nitrification of ammonium nitrogen-enriched synthetic wastewater using activated sludge

Water Science & Technology ◽

10.2166/wst.2020.080 ◽

2020 ◽

Vol 81 (1) ◽

pp. 62-70

Author(s):

Roumi Bhattacharya ◽

Debabrata Mazumder

Keyword(s):

Activated Sludge ◽

Nitrogen Removal ◽

Suspended Solids ◽

Removal Rate ◽

Nitrogen Concentration ◽

Ammonium Nitrogen ◽

Synthetic Wastewater ◽

Yield Coefficient ◽

Ammonium Oxidation ◽

Consecutive Reaction

Abstract Nitrification of ammonium nitrogen (NH4+-N)-bearing synthetic wastewater was performed in a batch-activated sludge reactor by varying the initial ammonium nitrogen concentration up to 400 mg/L at a pH of 8.1 ± 0.2 and temperature of 36 ± 2 °C for developing the process kinetics using acclimatised biomass. Maximum ammonium nitrogen removal efficiency of 98.3% was achieved with initial ammonium nitrogen and mixed liquor suspended solids concentration of 235 mg/L and 2,180 mg/L, respectively, at 48 h batch period. Based on the experimental results, kinetic constants for ammonia nitrogen removal following Monod's approach were obtained as maximum substrate removal rate coefficient = 0.057 per day, yield coefficient = 0.336 mg volatile suspended solids/mg ammonium nitrogen, half velocity constant = 12.95 mg NH4+-N/L and endogenous decay constant = 0.02 per day. Nitrification is a consecutive reaction with ammonium oxidation as the first step followed by nitrite oxidation. The overall rate of nitrite and nitrate formation was observed to be 1.44 per day and 0.34 per day, respectively.

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Study on Removing Ammonium Nitrogen from Wastewater Using Magnesium Hydroxide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.2550 ◽

2014 ◽

Vol 955-959 ◽

pp. 2550-2553 ◽

Cited By ~ 1

Author(s):

Yu Qi Wang ◽

Qi Zhang ◽

Luo Feng Liu ◽

Bi Jun Luo ◽

Dan Wu ◽

...

Keyword(s):

Reaction Time ◽

Nitrogen Removal ◽

Magnesium Hydroxide ◽

Removal Rate ◽

Ammonia Nitrogen ◽

Ammonium Nitrogen ◽

Molar Ratio ◽

Dihydrogen Phosphate ◽

Sodium Dihydrogen Phosphate ◽

Sodium Dihydrogen

Magnesium ammonium phosphate (MAP) precipitation has been studied by using magnesium hydroxide and sodium dihydrogen phosphate as precipitators for treating simulation wastewater in which the concentration of ammonia nitrogen is 10.00g/L. The effect of reaction time, pH and precipitator ratio on ammonium nitrogen removal rate has been investigated. The obtained optimum treatment conditions of MAP precipitation for treating ammonia nitrogen wastewater are as follows: reaction time is 4 hours, pH is 8.0, the molar ratio of sodium dihydrogen phosphate and ammonia nitrogen in wastewater, i.e. n (P):n (N), is 1.2, the molar ratio of magnesium hydroxide and sodium dihydrogen phosphate, i.e. n (Mg):n (P), is 1.4. Under these conditions, the ammonium nitrogen removal rate, by using MAP precipitation for treating simulation ammonia nitrogen wastewater, is 90.71%.

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Nitrogen removal of high strength wastewater via nitritation/denitritation using a sequencing batch reactor

Water Science & Technology ◽

10.2166/wst.2004.0601 ◽

2004 ◽

Vol 50 (10) ◽

pp. 27-33 ◽

Cited By ~ 28

Author(s):

E. Lai ◽

S. Senkpiel ◽

D. Solley ◽

J. Keller

Keyword(s):

Nitrogen Removal ◽

Sequencing Batch Reactor ◽

Removal Rate ◽

Batch Reactor ◽

High Strength ◽

Ph Control ◽

Pilot Scale ◽

Ammonium Nitrogen ◽

Experimental Results ◽

Short Period

The sequencing batch reactor (SBR) process concept was applied to achieve efficient ammonium removal via nitrite under both laboratory and pilot-scale conditions. Both sets of experimental results show that without pH control or carbon addition the nitritation process consistently converted approximately 50% of the ammonium from biosolids dewatering liquids to nitrite with hydraulic retention times (HRT) as short as 10 h. The results from the pilot-scale study also indicate that the selective oxidation of ammonium to nitrite is a reliable process as the accumulation of nitrate was never an issue during a 330-day trial. The SBR process concept was extended to achieve complete nitrogen removal through nitritation and denitritation in the laboratory scale. The experimental results indicate that a total reduction of 96-98% of the ammonium nitrogen from biosolids dewatering liquids (influent concentration typically 1,200 g m-3 ) was achieved with a short HRT of 1.1 d and a removal rate of 1.05 kgNm-3d-1. This process concept was tested at pilot scale where the nitritation process could be started up without temperature control in a short period of time. Nitrogen removal rates up to 1.2 kgNm-3d-1 at an HRT of 0.88 d have been obtained. COD to nitrogen ratios required in the pilot plant were consistently in the range 1.6-1.9 kgCOD kg-1N removed.

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Dynamics of Nitrifying Biofilm Growth in Biological Nitrogen Removal Process

Water Science & Technology ◽

10.2166/wst.1994.0365 ◽

1994 ◽

Vol 29 (7) ◽

pp. 377-380 ◽

Cited By ~ 6

Author(s):

Yu Liu ◽

Bernard Capdeville

Keyword(s):

Film Thickness ◽

Nitrogen Removal ◽

Removal Rate ◽

Biomass Accumulation ◽

Ammonium Nitrogen ◽

Specific Substrate ◽

Active Biomass ◽

Biofilm Growth ◽

Active Film ◽

Surface Removal

A conventional laboratory scale annular reactor was employed to investigate the dynamics of nitrifying biofilm growth. A dense and thin nitrifying biofilm was developed in this study. The results showed that the active growth of the nitrifying biofilm can be characterized best by the increase of the specific substrate removal rate until a maximum value, at which the maximum active film thickness and active biomass were attained. It was found that non active biomass accumulation directly resulted in the reduction in the specific ammonium nitrogen removal rate, however the ammonium nitrogen surface removal rate was not affected by the additional biomass accumulation. As a result, the credibility of the classic method using the substrate surface removal rate to estimate the maximum active film thickness was doubted. It was expected that thinner nitrifying biofilm ranging from 20 to 30µm has a higher specific nitrification rate to be 9.0mgNH4+-N/mgCOD-biomass/day.

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Nitrogen removal rates at a technical-scale pilot plant with the one-stage partial nitritation/Anammox process

Water Science & Technology ◽

10.2166/wst.2006.816 ◽

2006 ◽

Vol 54 (8) ◽

pp. 209-217 ◽

Cited By ~ 15

Author(s):

G. Cema ◽

B. Szatkowska ◽

E. Plaza ◽

J. Trela ◽

J. Surmacz-Górska

Keyword(s):

Nitrogen Removal ◽

Pilot Plant ◽

Removal Rate ◽

New Technology ◽

Anaerobic Bacteria ◽

Ammonium Nitrogen ◽

Anammox Bacteria ◽

Removal Rates ◽

Partial Nitritation ◽

Batch Tests

Traditional nitrification/denitrification is not suitable for nitrogen removal when wastewater contains high concentrations of ammonium nitrogen and low concentrations of biodegradable carbon. Recently, a deammonification process was developed and proposed as a new technology for treatment of such streams. This process relies on a stable interaction between aerobic bacteria Nitrosomonas, that accomplish partial nitritation and anaerobic bacteria Planctomycetales, which conduct the Anammox reaction. Simultaneous performance of these two processes can lead to a complete autotrophic nitrogen removal in one single reactor. The experiments where nitrogen was removed in one reactor were performed at a technical-scale moving-bed pilot plant, filled with Kaldnes rings and supplied with supernatant after dewatering of digested sludge. It was found that a nitrogen removal rate obtained at the pilot plant was 1.9 g m−2d−1. Parallel to the pilot plant run, a series of batch tests were carried out under anoxic and aerobic conditions. Within the batch tests, where the pilot plant's conditions were simulated, removal rates reached up to 3 g N m−2d−1. Moreover, the batch tests with inhibition of Nitrosomonas showed that only the Anammox bacteria (not anoxic removal by Nitrosomonas) are responsible for nitrogen removal.

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Nitrogen Removal Performance and Metabolic Pathways Analysis of a Novel Aerobic Denitrifying Halotolerant Pseudomonas balearica Strain RAD-17

Microorganisms ◽

10.3390/microorganisms8010072 ◽

2020 ◽

Vol 8 (1) ◽

pp. 72 ◽

Cited By ~ 6

Author(s):

Yunjie Ruan ◽

Mohammad J. Taherzadeh ◽

Dedong Kong ◽

Huifeng Lu ◽

Heping Zhao ◽

...

Keyword(s):

Nitrogen Removal ◽

Removal Rate ◽

Inorganic Nitrogen ◽

Ammonium Nitrogen ◽

Effluent Treatment ◽

Aerobic Denitrification ◽

Recirculating Aquaculture ◽

Pathways Analysis ◽

Total Ammonium ◽

Pseudomonas Balearica

An aerobic denitrification strain, Pseudomonas balearica RAD-17, was identified and showed efficient inorganic nitrogen removal ability. The average NO3−-N, NO2−-N, and total ammonium nitrogen (TAN) removal rate (>95% removal efficiency) in a batch test was 6.22 mg/(L∙h), 6.30 mg/(L∙h), and 1.56 mg/(L∙h), respectively. Meanwhile, optimal incubate conditions were obtained through single factor experiments. For nitrogen removal pathways, the transcriptional results proved that respiratory nitrate reductases encoded by napA, which was primarily performed in aerobic denitrification and cell assimilation, were conducted by gluS and gluD genes for ammonium metabolism. In addition, adding the strain RAD-17 into actual wastewater showed obvious higher denitrification performance than in the no inoculum group (84.22% vs. 22.54%), and the maximum cell abundance achieved 28.5 ± 4.5% in a ratio of total cell numbers. Overall, the efficient nitrogen removal performance plus strong environmental fitness makes the strain RAD-17 a potential alternative for RAS (recirculating aquaculture system) effluent treatment.

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The nitrogen removal potential of predenitrification systems in sensitive coastal areas

Water Science & Technology ◽

10.2166/wst.1995.0218 ◽

1995 ◽

Vol 32 (7) ◽

pp. 135-142

Author(s):

E. Görgün ◽

N. Artan ◽

D. Orhon ◽

R. Tasli

Keyword(s):

Water Quality ◽

Wastewater Treatment ◽

Nitrogen Removal ◽

Retention Time ◽

Treatment Process ◽

Hydraulic Retention Time ◽

Domestic Sewage ◽

Coastal Areas ◽

Careful Evaluation ◽

Denitrification Kinetics

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.

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