Evaluating the effects of nitrogen loading rate and substrate inhibitions on partial nitrification with FISH analysis

2012 ◽  
Vol 65 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Liang Zhang ◽  
Shujun Zhang ◽  
Xiaoyu Han ◽  
Yiping Gan ◽  
Chengcheng Wu ◽  
...  
Keyword(s):  
Loading Rate ◽  
Substrate Inhibition ◽  
Nitrogen Loading ◽  
Partial Nitrification ◽  
Fish Analysis ◽  
Free Nitrous Acid ◽  
Reject Water ◽  
Denitrification Reactor ◽  
The Stability ◽  
The Impact

The effects of free ammonia (FA) or free nitrous acid (FNA) on partial nitrification (PN) has been well investigated. Nevertheless, little information was known about the combined effects of nitrogen loading rate (NLR) and substrate inhibition, as well as the impact on the community structure of nitrifiers. In this work, real reject water was treated in a pre-denitrification reactor. PN was achieved by gradually increasing NLR, and it was successfully maintained when average FA and FNA were within 0.8–3.2 mg NH3-N/L and 0.003–0.067 mg HNO2-N/L, respectively. When NLR was reduced, PN was slightly affected due to the FA declination. As FNA inhibition was also eliminated by adding alkalinity into the influent, PN was completely destroyed quickly. FISH results indicated the deterioration of the PN was mainly attributed to the recovery of NOB when inhibition effects were limited. It concluded the increase of NLR benefited the partial nitrification. However, the stability of the nitrite path way was more dependent on selective substrate inhibition effects, especially the FNA inhibition. These findings would be important for further treatment of actual reject water.

Nitrogen removal from reject water with primary sludge as denitrification carbon source

2010 ◽  
Vol 61 (12) ◽  
pp. 2965-2972 ◽  
Author(s):  
L. Zhang ◽  
S. J. Zhang ◽  
J. Zhou ◽  
S. Y. Wang ◽  
Y. P. Gan ◽  
...  
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Suspended Solid ◽  
Nitrogen Loading ◽  
Solid Retention Time ◽  
Primary Sludge ◽  
Reject Water ◽  
Denitrification Reactor

A novel system was used for nitrogen removal from reject water. This system includes one anoxic/oxic reactor for nitrification and a special reactor for denitrification in which primary sludge was added intermittently as electron donor. In denitrification reactor, sludge fermentation and denitrification reaction took place simultaneously and promoted each other. It was found that effluent recycle could improve nitrogen removal efficiency due to reclaiming of alkalinity. Under steady state conditions, the average solid retention time (SRT) in denitrification reactor was 12–15 d, a total nitrogen loading rate was 0.2 kg N/(m3 day) and TN removal efficiency was more than 90% without extra carbon source addition. Primary sludge was degraded so that volatile suspended solid (VSS) decreased by 50%. Further investigation showed that ORP could be taken as a control parameter for sludge addition.

scholarly journals Discrepant membrane fouling of partial nitrification and anammox membrane bioreactor operated at the same nitrogen loading rate

2016 ◽  
Vol 214 ◽  
pp. 729-736 ◽  
Author(s):  
Zhao Niu ◽  
Zuotao Zhang ◽  
Sitong Liu ◽  
Taro Miyoshi ◽  
Hideo Matsuyama ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Loading Rate ◽  
Nitrogen Loading ◽  
Partial Nitrification

scholarly journals CONTROL STRATEGIES OF NITRITE ACCUMULATION IN A SUBMERGED BIOFILTER

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
BURHANETTIN GURBUZ
Keyword(s):  
Dissolved Oxygen ◽  
Key Words ◽  
Removal Efficiency ◽  
Constant Temperature ◽  
Loading Rate ◽  
Control Strategies ◽  
Nitrogen Loading ◽  
Partial Nitrification ◽  
Nitrite Accumulation ◽  
N Removal

Short-cut nitrification under various Nitrogen Loading Rate (NLR), dissolved oxygen (DO) concentrations and pHs at a constant temperature of 25 ±1 0C was investigated in a submerged biofilter reactor. The lowest NO2-N/NOx-N ratio was observed when the NLR was up to 160 g/m3·day. Further increase the NLRresulted in incomplete oxidation of ammonium and the effluent NH4-N and NO2-N concentration increased. Although the highest NO2-N/NOx-N ratio of 0.61 was achieved, the NH4-N removal efficiency was drastically dropped to 48% at the NLR of 294 g NH4-N/m3.day. The highest NO2-N/NOx-N ratio of 0.68 was achieved at the pH of 9.0 and 1.0 mg O2/l. However, NN4-N removal efficiency and the NO2-N/NOx-N ratio were sharply dropped to 33% and 0.55 by getting the NLR to 381 g NH4-N/m3⋅day at the DO concentrations of 2.0 mg/l. Key words: partial nitrification, NO2-N/NOx-N ratio.

Anammox process for nitrogen removal from anaerobically digested fish canning effluents

2006 ◽  
Vol 53 (12) ◽  
pp. 265-274 ◽  
Author(s):  
A. Dapena-Mora ◽  
J.L. Campos ◽  
A. Mosquera-Corral ◽  
R. Méndez
Keyword(s):  
Nitrogen Removal ◽  
Bacterial Population ◽  
Loading Rate ◽  
Population Distribution ◽  
Nitrogen Loading ◽  
Fish Analysis ◽  
Organic Carbon Content ◽  
High Nitrogen ◽  
N Concentration ◽  
Anammox Process

The Anammox process was used to treat the effluent generated in an anaerobic digester which treated the wastewater from a fish cannery once previously processed in a Sharon reactor. The effluents generated from the anaerobic digestion are characterised by their high ammonium content (700–1,000 g NH+4-N m−3), organic carbon content (1,000–1,300 g TOC m−3) and salinity up to 8,000–10,000 g NaCl m−3. In the Sharon reactor, approximately 50% of the NH+4-N was oxidised to NO−2-N via partial nitrification. The effluent of the Sharon step was fed to the Anammox reactor which treated an averaged nitrogen loading rate of 500 g N m−3· d−1. The system reached an averaged nitrogen removal efficiency of 68%, mainly limited due to the nonstoichiometric relation, for the Anammox process, between the ammonium and nitrite added in the feeding. The Anammox reactor bacterial population distribution, followed by FISH analysis and batch activity assays, did not change significantly despite the continuous entrance to the system of aerobic ammonium oxidisers coming from the Sharon reactor. Most of the bacteria corresponded to the Anammox population and the rest with slight variable shares to the ammonia oxidisers. The Anammox reactor showed an unexpected robustness despite the continuous variations in the influent composition regarding ammonium and nitrite concentrations. Only in the period when NO−2-N concentration was higher than the NH+4-N concentration did the process destabilise and it took 14 days until the nitrogen removal percentage decreased to 34% with concentrations in the effluent of 340 g NH+4-N m−3 and 440 g NO−2-N m−3, respectively. Based on these results, it seems that the Sharon–Anammox system can be applied for the treatment of industrial wastewaters with high nitrogen load and salt concentration with an appropriate control of the NO−2-N/NH+4-N ratio.

Characteristics of Nitrous Oxide Emissions from Partial Nitrification Process Treating High Ammonium Wastewater

2014 ◽  
Vol 1073-1076 ◽  
pp. 844-848
Author(s):  
Ming Chuan Zhang ◽  
Xuan Gong ◽  
Xin Yang Xu
Keyword(s):  
Nitrous Oxide ◽  
Loading Rate ◽  
Granular Sludge ◽  
Nitrogen Loading ◽  
Partial Nitrification ◽  
Nitrous Oxide Emissions ◽  
Aerobic Granular Sludge ◽  
Intermittent Aeration ◽  
Nitrification Process ◽  
Biological Nitrogen

Nitrous oxide is a greenhouse gas, and biological nitrogen removal leads to nitrous oxide generation and emissions. In this study, the emission of nitrous oxide from partial nitrification process was investigated in two intermittently aerated SBRs (IASBRs). Activated sludge floc and aerobic granular sludge were feed into two IASBRs, respectively. In the steady state, partial nitrification was successfully achieved under intermittent aeration control strategy. Nitrous oxide emissions were 6.5% and 8.9% of the total influent nitrogen loading rate in IASBR1 and IASBR2, respectively. Nitrous oxide was mainly generated in non-aeration periods, but aeration period contributed to 91.8% and 90.6% of nitrous oxide emissions in two IASBRs, respectively. PHB can be used as the carbon source for heterotrophic denitrification, causing more nitrous oxide generated in IASBR2 which was seeded with aerobic granular sludge.

scholarly journals A Bayesian Approach to Infer Nitrogen Loading Rates from Crop and Landuse Types Surrounding Private Wells in the Central Valley, California

2017 ◽  
Author(s):  
Katherine M. Ransom ◽  
Andrew M. Bell ◽  
Quinn E. Barber ◽  
George Kourakos ◽  
Thomas Harter
Keyword(s):  
Loading Rate ◽  
Probability Distributions ◽  
Central Valley ◽  
Nitrogen Loading ◽  
Bayesian Regression ◽  
Nitrate Contamination ◽  
Agricultural Crop ◽  
Loading Rates ◽  
The Impact ◽  
Private Wells

Abstract. Nitrate contamination of alluvial aquifers in agricultural areas is a typical and major problem around the world. Nitrogen applied to crops, in the form of synthetic fertilizers or manure, in excess of plant uptake, largely leaches to groundwater in the form of nitrate, which is stable and highly mobile in oxygen-rich groundwaters. Increased awareness of the impact that excess nitrogen has had on groundwater and major health concerns about nitrate are prompting new regulations for farmers, e.g., in Europe and California, USA. This study is focused in the Central Valley, California, USA, an intensively farmed region with high agricultural crop diversity. Though nitrogen loading rates for several crop and landuse types in the Central Valley have been estimated or measured in a handful of studies, nitrogen loading rates for specific crop or landuse types and their impact to groundwater quality remain largely unknown. Knowledge of crop or other landuse specific groundwater nitrate impact may aid future regulatory decisions. Nitrogen loading rates for specific crop or landuse types are expected to vary depending on individual landuse practices; and interactions with hydrogeologic parameters that may promote or inhibit nitrate leaching. In this study, we developed a novel Bayesian regression model that allowed us to estimate crop or other landuse-specific groundwater nitrogen loading rate probability distributions from surveys of private wells, each of which is likely impacted by more than one landuse. We used recent nitrate measurements from 2149 wells in the Central Valley. We estimated nitrogen loading rate distributions for 15 crop and landuse groups. These were shown to compare favorably with prior mass-balance estimates of loading rates based on agronomic estimates of nitrogen loading.

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

IMPACT OF GOVERNMENT DEBT ON FINANCIAL SECURITY OF UKRAINE

2017 ◽  
Author(s):  
Olena Pikaliuk ◽  
◽  
Dmitry Kovalenko ◽  
Keyword(s):  
Economic Development ◽  
Public Debt ◽  
Positive Impact ◽  
The State ◽  
Financial Security ◽  
State Budget ◽  
The Public ◽  
Debt Security ◽  
The Stability ◽  
The Impact

One of the main criteria for economic development is the size of the public debt and its dynamics. The article considers the impact of public debt on the financial security of Ukraine. The views of scientists on the essence of public debt and financial security of the state are substantiated. An analysis of the dynamics and structure of public debt of Ukraine for 2014-2019. It is proved that one of the main criteria for economic development is the size of public debt and its dynamics. State budget deficit, attracting and using loans to cover it have led to the formation and significant growth of public debt in Ukraine. The volume of public debt indicates an increase in the debt security of the state, which is a component of financial security. Therefore, the issue of the impact of public debt on the financial security of Ukraine is becoming increasingly relevant. The constant growth and large amounts of debt make it necessary to study it, which will have a positive impact on economic processes that will ensure the stability of the financial system and enhance its security.

Influence of internal and external risks on sustainability of financial system of Аltai krai

2018 ◽  
Vol 35 (4) ◽  
pp. 133-136
Author(s):  
R. N. Ibragimov
Keyword(s):  
Sustainable Development ◽  
Financial Stability ◽  
Management Strategy ◽  
Financial System ◽  
Risk Management Strategy ◽  
The Sustainable Development ◽  
The Stability ◽  
The Impact

The article examines the impact of internal and external risks on the stability of the financial system of the Altai Territory. Classification of internal and external risks of decline, affecting the sustainable development of the financial system, is presented. A risk management strategy is proposed that will allow monitoring of risks, thereby these measures will help reduce the loss of financial stability and ensure the long-term development of the economy of the region.

Sign in / Sign up

Export Citation Format

Share Document