Theoretical analysis and enhanced nitrogen removal performance of step-feed SBR

2008 ◽  
Vol 58 (4) ◽  
pp. 795-802 ◽  
Author(s):  
Jianhua Guo ◽  
Yongzhen Peng ◽  
Qing Yang ◽  
Shuying Wang ◽  
Ying Chen ◽  
...  
Keyword(s):  
Carbon Source ◽  
Theoretical Analysis ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
High Efficiency ◽  
Flow Mode ◽  
External Carbon Source ◽  
Influent Flow

To achieve high nitrification and denitrification rates, step-feed SBR with multiple aerobic and anoxic phases was adopted to study nitrogen removal performance. Theoretical analysis of step-feed SBR was presented first, from which feeding steps and C/N ratio had significant influences on nitrogen removal performance. Total nitrogen removal efficiency would increase with increasing of feeding steps, while the increasing extent was not distinct with feeding steps above 4. At a given feeding step, nitrogen removal efficiency would also increase with increasing of C/N ratio. Experimental work was conducted in a lab-scale SBR to investigate practical effects of these critical factors, using real municipal wastewater. The results showed when C/N ratio was appropriately decreasing influent flow mode could achieve enhanced nitrogen removal with less adding of external carbon source, compared with equal influent flow mode. Three-step equal influent flow mode was recommended to treat common municipal wastewater in view of operation complexity. Non steady-state experiments over about three months confirmed step-feed SBR was an enhanced nitrogen removal process with high efficiency. Total nitrogen in the effluent was under 2 mg/L, the average removal efficiency achieved for TN was over 97% just adding a little external carbon source, and good sludge settleability was obtained.

Advanced nitrogen removal via nitrite from municipal wastewater in a pilot-plant sequencing batch reactor

2009 ◽  
Vol 59 (12) ◽  
pp. 2371-2377 ◽  
Author(s):  
Q. Yang ◽  
X. H. Liu ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
H. W. Sun ◽  
...  
Keyword(s):  
Carbon Source ◽  
Process Control ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Pilot Plant ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Nitrite Accumulation ◽  
Advanced Nitrogen Removal

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.

Effects of influent COD/N ratio and internal recycle ratio on nitrogen removal efficiency in the KNR process

2006 ◽  
Vol 53 (9) ◽  
pp. 265-270 ◽  
Author(s):  
C.W. Suh ◽  
S.H. Lee ◽  
H.S. Jeong ◽  
J.C. Kwon ◽  
H.S. Shin
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Denitrification Rate ◽  
Optimal Operating ◽  
Operating Condition ◽  
Optimal Operating Condition ◽  
External Carbon Source ◽  
Recycle Ratio ◽  
Removal Efficiencies

In this study, with the KNR® process that has many advantages, the nitrogen removal efficiency of KNR was experimentally investigated at various COD/N ratios of influent conditions. The optimal operating condition of internal recycle ratio was evaluated. The TN removal efficiencies were 59.1, 72.5 and 75.9% at the COD/N ratios of 3, 5 and 7, respectively. These high removal efficiencies resulted from high denitrification rate in UMBR with high microorganism concentration. Furthermore, specific endogenous denitrification at MLVSS of 10.3 g/L that is similar to MLVSS in UMBR was over two times higher than that at MLVSS of 2.06 g/L. This result suggests that endogenous denitrification rate in UMBR is so high that the requirement of an external carbon source can be saved. As the internal recycle ratio increased from 100 to 400%, the TN removal efficiency also improved from 69.5 to 82.9%, and the optimal internal recycle ratio was 300%.

Enhanced denitrification with methanol at WWTP Zürich-Werdhölzli

1996 ◽  
Vol 33 (12) ◽  
pp. 117-126 ◽  
Author(s):  
I. Purtschert ◽  
H. Siegrist ◽  
W. Gujer
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Yield Coefficient ◽  
Adaptation Period ◽  
Municipal Wastewater Treatment

In coordination with the EU-guidelines the large wastewater treatment plants in Switzerland have to be extended with enhanced nitrogen removal. Due to the existing plant configuration, the low COD/N ratio and dilute wastewater, denitrification supported by an external carbon source instead of extending the plant may be an interesting and cost effective solution for municipal wastewater treatment. At the wastewater treatment plant Zürich-Werdhölzli different experiments were performed with methanol addition to predenitrification from March to July 1994. The aim of this work was to evaluate the use of methanol as an alternative to plant extension to achieve a higher nitrogen removal efficiency. Therefore, two parallel denitrifying lanes were investigated, one served for methanol addition experiments and the other as a control. The effect of oxygen input into the anoxic zone due to influent, return sludge and mixing was investigated, too. The results show that nitrogen removal efficiency can be substantially increased as compared to the reference lane. The adaptation period for methanol degradation was only a few days and the process was relatively stable. Based on total nitrogen in the inflow, the average denitrification was 55% with methanol addition and 35% without methanol. The yield coefficient YCOD was 0.4 g CODX g−1 CODMe. Due to the small net growth rate of the methanol degraders the denitrification capacity is relatively low and nitrate peak loads cannot be fully denitrified. Hence, methanol as a carbon source requires more or less constant dosing. To prevent nitrate limitation, methanol addition should be controlled by the anoxic nitrate concentrations.

The Analysis of Nitrogen Removal Performance for Eco-Ceramic Concrete Biofilm Reactors

2011 ◽  
Vol 418-420 ◽  
pp. 1002-1007
Author(s):  
Ming Yan Shi ◽  
Hai Liang Zheng ◽  
Jia Yu Liu ◽  
Can Qiang Xiao
Keyword(s):  
Water Temperature ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
High Efficiency ◽  
Dry Weight ◽  
Unit Mass ◽  
Removal Rates ◽  
Biofilm Reactors ◽  
Good Ability

In order to achieve high efficiency of biofilm and removing nitrogen with low consumption, people have developed a new eco-ceramic concrete filler, used for the denitrification in treating municipal wastewater. When the water temperature is 25 ~ 30°C, the pH of influent is 7.0 ~ 7.5, the concentration of DO is 2.5 ~ 3.0mg /L, and the removal rates of COD, ammonia and total nitrogen are 78.6 ~ 91.8%, 83.4 ~93.6% and 63.4 ~ 73.8 % respectively. The removal of the pollutants mainly concentrates on the front and center of the reactor. We can also draw a conclusion from the experiment that, SOUR, the dry weight of biofilm and the thickness of biofilm present a pattern of diminishing along the corridor. The average decreasing ratio of each filler are 0.81%, 1.3% and 1.05%, respectively. And the activity of per unit mass of biofilm has increased along the corridor, and the end of it is 51.5% more than the front, which indicates that the system has good ability of resistance.

scholarly journals Nitrogen Removal by HN-AD Bacteria Immobilized on Modified Absorbent Stone

2020 ◽  
Vol 34 (3) ◽  
pp. 193-207
Author(s):  
Wen Zhang ◽  
Zhen Zhang ◽  
Sufeng Wang
Keyword(s):  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Ammonia Nitrogen ◽  
Aerobic Denitrification ◽  
Immobilized Microorganisms ◽  
The Cost

How to simplify the nitrogen removal process, reduce the cost and improve the efficiency has become an urgent problem to be solved. In this research, the isolated HNAD (heterotrophic nitrification and aerobic denitrification) bacteria were used to remove<br /> the nitrogen in wastewater. Modified absorbent stone was used as high-efficiency and<br /> low-cost immobilized material. The modification effect was determined by the changes<br /> in mechanical strength, Zeta potential, pore structure, micrographs and biomass. The<br /> practicability of the modified carrier was further proved by experiments of environmental effect and reuse. The modified carrier had excellent performance. By comparing the<br /> degradation effects of immobilized microorganism and free microorganism, it was proved<br /> that the immobilized microorganisms have broad application prospects and strong adaptability to environmental factors. Under the optimum conditions (temperature of 30 oC,<br /> pH of 7, dissolved oxygen of 3.5 mg L–1), the removal efficiency of ammonia nitrogen<br /> reached 100 % in 40 hours, the removal efficiency of total nitrogen reached 60.11 % in<br /> 50 hours, and the removal rate of total nitrogen was 2.404 mg-NL–1 h–1 by immobilized<br /> microorganisms with the treatment of simulated nitrogen-containing wastewater. This<br /> research provides new material for the immobilization of HN-AD bacteria and a new way for nitrogen removal.

scholarly journals Application of Internal Carbon Source from Sewage Sludge: A Vital Measure to Improve Nitrogen Removal Efficiency of Low C/N Wastewater

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2338
Author(s):  
Huacai Wang ◽  
Cancan Jiang ◽  
Xu Wang ◽  
Shengjun Xu ◽  
Xuliang Zhuang
Keyword(s):  
Organic Matter ◽  
Sewage Sludge ◽  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
High Efficiency ◽  
Operating Cost ◽  
Sewage Treatment ◽  
Low Carbon ◽  
Nitrogen And Phosphorus

Biological nitrogen removal from wastewater is widely used all over the world on account of high efficiency and relatively low cost. However, nitrogen removal efficiency is not optimized when the organic matter has inadequate effect for the lack of a sufficient carbon source in influent. Although addition of an external carbon source (e.g., methanol and acetic acid) could solve the insufficient carbon source problem, it raises the operating cost of wastewater treatment plants (WWTPs). On the other hand, large amounts of sludge are produced during biological sewage treatment, which contain high concentrations of organic matter. This paper reviews the emerging technologies to obtain an internal organic carbon resource from sewage sludge and their application on improving nitrogen removal of low carbon/nitrogen wastewater of WWTPs. These are methods that could solve the insufficient carbon problem and excess sludge crisis simultaneously. The recovery of nitrogen and phosphorus from treated sludge before recycling as an internal carbon source should also be emphasized, and the energy and time consumed to treat sludge should be reduced in practical application.

Theoretical analysis on nitrogen removal of the step-feed anoxic-oxic activated sludge process and its application for the optimal operation

1996 ◽  
Vol 34 (1-2) ◽  
pp. 459-466 ◽  
Author(s):  
Shigeo Fujii
Keyword(s):  
Theoretical Analysis ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Optimal Operation ◽  
Activated Sludge Process ◽  
R Value ◽  
Total Nitrogen Removal ◽  
Reaction Patterns

The nitrogen removal efficiency of the step-feed anoxic-oxic activated sludge process, which has two anoxic tanks and two oxic tanks, was theoretically discussed on the basis of the stoichiometry of denitrification and nitrification reactions. As the first step, effluent NH4-N and NO3-N concentrations were formulated with four parameters; 1) a, equivalent ratio of alkalinity to ammonia in influent, 2) b, that of substrate to ammonia, 3) r, step ratio of influent to the second anoxic tank and 4) R, return (+ recycle) sludge ratio. This calculus was done for the possible sixteen (=24) cases which show different reaction patterns in four tanks, and 12 cases out of 16 were found to be available. The effects of step ratio, r were examined in its range of 0 - 1 at a fixed R value, and it was found that the increase of r alters the outcome in a different way depending on the ranges of a and b. Consequently, zoning of a-b coordinates was successfully made, and the optimal r value for maximum total nitrogen removal was obtained in each zone. In addition, the optimal volume allocation of the four tanks was discussed and the ratios were formulated for each zone.

Enhancing denitrification efficiency for nitrogen removal using waste sludge alkaline fermentation liquid as external carbon source

2018 ◽  
Vol 26 (5) ◽  
pp. 4633-4644 ◽  
Author(s):  
Mengyu Shao ◽  
Liang Guo ◽  
Zonglian She ◽  
Mengchun Gao ◽  
Yangguo Zhao ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Waste Sludge ◽  
External Carbon Source ◽  
Fermentation Liquid

Intermittent feeding of wastewater in combination with alternating aeration for complete denitrification and control of filaments

2010 ◽  
Vol 61 (9) ◽  
pp. 2259-2266 ◽  
Author(s):  
Styliani Kantartzi ◽  
Paraschos Melidis ◽  
Alexander Aivasidis
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Anoxic Conditions ◽  
Total Nitrogen Removal

In the present study, a laboratory scale system, consisting of a primary settling tank, a continuous stirred tank reactor and a clarifier were constructed and operated, using wastewater from the municipal wastewater treatment plant in Xanthi, Greece. The system operated under intermittent aeration in aerobic/anoxic conditions and feeding of the wastewater once in every cycle. The unit was inoculated with sludge, which originated from the recirculation stream of the local wastewater treatment plant. The wastewater was processed with hydraulic retention time (HRT) of 12 h, in which various experimental states were studied regarding the combination of aerobic and anoxic intervals. The wastewater was fed in limited time once in every cycle of aerobic/anoxic conditions at the beginning of the anoxic period. The two states that exhibited highest performance in nitrification and total nitrogen removal were, then, repeated with HRT of 10 h. The results show that, regarding the nitrification stage and the organic load removal, the intermittent system achieved optimum efficiency, with an overall removal of biological oxygen demand (BOD5) and ammonium nitrogen in the range of 93–96% and 91–95% respectively. As far as the total nitrogen removal is concerned, and if the stage of the denitrification is taken into account, the performance of the intermittent system surpassed other methods, as it is shown by the total Kjeldahl nitrogen (TKN) removal efficiency of 85–87%. These operating conditions suppressed the growth of filamentous organisms, a fact reflected at the SVI values, which were lower than 150 ml/g.

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