Operation of full-scale fluidized bed for denitrification

2000 ◽  
Vol 41 (9) ◽  
pp. 115-121 ◽  
Author(s):  
J. Bosander ◽  
Å.D. Westlund
Keyword(s):  
Carbon Source ◽  
Fluidized Bed ◽  
Total Nitrogen ◽  
Nitrate Nitrogen ◽  
Reduction Rate ◽  
Full Scale ◽  
Nitrogen Reduction ◽  
Start Up ◽  
Investment Cost ◽  
The Cost

The SYVAB company has extended the plant with a fluidized bed for post denitrification. The method was chosen mainly for two reasons. First, the relatively low investment cost and second, the flexibility in the process to adjust the discharged nitrogen according to the circumstances in the recipient. Start-up took place in April 1997 with an adaption period of four weeks. From mid September the same year the plant has been in full denitrifying operation. The average nitrate-nitrogen reduction rate has been 90% with 1.9 mg NO3–N in the outlet. Methanol is used as external carbon source. At the present purification rate the cost for total nitrogen reduction is 18 SEK (2.25 USD)/kg N.

Full-Scale Testing Postpones Total Nitrogen Reduction Expansion

2018 ◽  
Vol 2018 (5) ◽  
pp. 14-21
Author(s):  
Don Esping ◽  
David Green ◽  
Mark Allenwood
Keyword(s):  
Total Nitrogen ◽  
Full Scale ◽  
Nitrogen Reduction ◽  
Full Scale Testing

scholarly journals Study on Start-Up Process of SAGD by Solvent: Experiment Research and Process Design

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jun Sun ◽  
Yanping Sun ◽  
Chengsheng Wang ◽  
Hui Lin ◽  
Wenchao Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Physical Simulation ◽  
Low Cost ◽  
Reduction Rate ◽  
Injection Pressure ◽  
Viscosity Reduction ◽  
Cost Calculation ◽  
Core Flooding ◽  
Start Up ◽  
The Cost

Steam-assisted gravity drainage (SAGD) has been used to develop the “super heavy” oil reservoirs in Canada. The viscosity can reach more than 30,000 cp at 50°C. Moreover, owing to their continental deposit origin, the reservoirs have a low porosity and permeability. Because of these challenges, the conventional steam circulation start-up process takes 6 to 12 months before the well pair can be switched to production. Solvent has been used to start-up SAGD with success. But now, low price of oil and high cost of solvent make solvent-assisted start-up process limited. This paper applies experimental schemes, such as viscosity reduction rate evaluation, core flooding, and 3D physical simulation, tests solvent performance, optimizes process parameters, and designs process solutions. Apply numerical simulation to test solvent-assisted SAGD start-up effect and calculate the cost. This paper researches a unique low-cost solvent compare with xylene. The basic properties and core flood experiment show that the two solvents are similar with viscosity reduction rate, asphalt dissolution rate, and injection pressure, and the price of solvent is 18% lower. The 3D model experiment shows that the average start-up time is reduced by 15%, and steam injection volume is reduced by 21.4%. The numerical simulation results show that without solvent, it will take 180 d for start-up process, and with solvent, the time has reduced by 50% and takes 90 days. Cost calculation results show that the cost will reduce 18% by solvent compared to xylene. Moreover, the production rate has been improved in production stage. This paper applies a 3D physical model to simulate the solvent-assisted SAGD start-up process. Research conclusions show the start-up mechanism of solvent and the process of temperature change of steam chamber.

Full-Scale Testing Postpones Total Nitrogen Reduction Expansion

2018 ◽  
Vol 2018 (10) ◽  
pp. 3854-3859
Author(s):  
Don Esping ◽  
Mark Allenwood ◽  
Dave Green
Keyword(s):  
Total Nitrogen ◽  
Full Scale ◽  
Nitrogen Reduction ◽  
Full Scale Testing

A Study on the Start-up Period of Underground Infiltration System Treating Rural Domestic Sewage

2013 ◽  
Vol 774-776 ◽  
pp. 552-555
Author(s):  
Ming Fen Niu ◽  
Jian Wei ◽  
Jian Ma ◽  
Xin Chen
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Nitrate Nitrogen ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Domestic Sewage ◽  
Nitrogen And Phosphorus ◽  
Start Up ◽  
Better Than

This paper studied the removal effect of domestic sewage nitrogen and phosphorus during the start-up period of underground infiltration system. The experiment is conducted under the conditions of influent temperature 9~10°C, hydraulic loading 0.04m3·m-2·d-1, COD concentration 112.31~143.49mg / L, NH4+-N 20.93~27.26mg / L and TP 2.12~2.86mg / L. The experimental results showed the removal rate of COD, NH4+-N and TP was 80%, 98% and 95% respectively. In the start-up period, TN removal was not obviously for 34% removal rate. After treated the effluent nitrate nitrogen concentration was high, showing during the start-up period the nitrification was better than the denitrification. Lacking of carbon source and low temperature may account for this. To improve the conditions of the start-up period, promoting denitrification was the key to improve nitrogen removal rate by underground infiltration system.

scholarly journals Effects of Reduced Nitrogen with Bio-Organic Fertilizer on Soil Properties, Yield and Quality of Non-Heading Chinese Cabbage

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2196
Author(s):  
Yingbin Qi ◽  
Fangling Jiang ◽  
Rong Zhou ◽  
Ying Wu ◽  
Xilin Hou ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Chinese Cabbage ◽  
Rhizosphere Soil ◽  
Nitrate Nitrogen ◽  
Organic Fertilizer ◽  
Nitrogen Reduction ◽  
Yield And Quality ◽  
Reduced Nitrogen ◽  
Heading Chinese Cabbage

Fertilizer is extremely essential to increasing the yield of vegetables. However, excessively using fertilizers has had a negative impact on the yield and quality of vegetables as well as soil environment in recent years. Non-heading Chinese cabbage ‘yellow rose’ was applied to determine the influence of organic manure and inorganic fertilizer on the character of rhizosphere soil, the growth and quality of plants. There were five treatments: conventional fertilization (NF), a total nitrogen reduction of 20% (NF20), a total nitrogen reduction of 30% (NF30), a total nitrogen reduction of 20% with 100 kg·667 m−2 bio-organic fertilizer (BNF20) and a total nitrogen reduction of 30% with 200 kg·667 m−2 bio-organic fertilizer (BNF30). The results show that the content of nitrate nitrogen, organic matter in rhizosphere soil treated by BNF20 and BNF30, was significantly enhanced compared with NF. The yield, Vc and soluble protein of plants treated by BNF20 and BNF30 increased by 30.11%, 17.26%, 5.66% and 15.90%, 16.02%, 5.37%, respectively, compared with NF. On the contrary, the nitrate content significantly decreased in plants of BNF20 and BNF30 by 47.87% and 40.98% compared with NF. The significantly positive correlation was observed between nitrate nitrogen content in rhizosphere soil and the yield (p < 0.05). In conclusion, reduced nitrogen with bio-organic fertilizer can improve the yield and quality of ‘yellow rose’ cabbage by improving the quality of rhizosphere soil.

A seven year plan for upgrading the 200.000 p.e. treatment plant of Uppsala, Sweden

1994 ◽  
Vol 29 (12) ◽  
pp. 117-127
Author(s):  
Jan Erik Lind ◽  
Ernst Olof Swedling
Keyword(s):  
Cost Efficiency ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Working Environment ◽  
Regional Environment ◽  
Nitrogen Reduction ◽  
Total Investment ◽  
Close Cooperation ◽  
The Cost

The sewage treatment plant of Uppsala was originally built in 1946 and has since then been extended and upgraded several times up to 1972 when the last major upgrading was completed. In 1987 it was decided to renew the treatment plant for at least another 20-30 years of operation and to upgrade the biological process to include nitrogen reduction. A 7 year plan covering some 18 items with a total investment cost of approximately 120 MSEK was set in action during 1987. The aim was to raise the cost efficiency by introducing modern techniques, new machinery, a better working environment and a better understanding of the processes used. The need to keep the plant in operation during reconstruction work has caused difficulties, delays and unforseen costs but a close cooperation between all parties concerned (operators, contractors, engineers and the regional environment administration) has solved most of the problems. Experiences so far include an improved effluent quality, a better cost efficiency, a healthier and more engaged operating staff. A research team has been engaged to develop and introduce a nitrogen reduction scheme in the activated sludge process. This has been a challenging and fruitful experience.

Biomass Characterization in a Nitrification-Denitrification Biological Enhanced Phosphorus Removal (NDBEPR) Plant during Start-Up and Subsequent Periods of Good and Poor Phosphorus Removal

1994 ◽  
Vol 29 (7) ◽  
pp. 91-100 ◽  
Author(s):  
K. C. Lindrea ◽  
S. P. Pigdon ◽  
B. Boyd ◽  
G. A. Lockwood
Keyword(s):  
Phosphorus Removal ◽  
Poor Performance ◽  
Intracellular Distribution ◽  
Full Scale ◽  
Laboratory Scale ◽  
Plant Operation ◽  
The Poor ◽  
Start Up ◽  
Biomass Characterization

During commissioning and process stabilization of a NDBEPR plant at Bendigo intracellular distribution and movement of phosphorus, K+, Mg2+ and Ca2+ was followed to establish the nature of biomass development. The system was also monitored at the end of a period of breakdown of the BEPR process and during its return to phosphorus removal. Phosphorus (P) and Mg2+ distribution in the biomass were closely related during all phases of plant operation, and laboratory trials indicated that the poor performance of the full-scale plant was associated with seasonal reduction in influent Mg2+. Laboratory scale trials produced a similar effect when the influent Mg2+ was limited to concentrations much lower than those experienced in the full scale plant, but only after the Mg2+ and P reserves in the biomass were depleted. The distribution of P, K+, Mg2+ and Ca2+ in the biomass from the full scale plant was similar to that seen in the laboratory trials when cations in the feed were severely limited and recovery of the full scale plant also closely matched that of the laboratory scale system.

Nitrogen Reduction – Volume Demand

1992 ◽  
Vol 25 (4-5) ◽  
pp. 233-240
Author(s):  
T. Palmgren
Keyword(s):  
Suspended Solids ◽  
Age Factors ◽  
Reduction Rate ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Nitrogen Reduction ◽  
Solids Concentration ◽  
Yearly Average ◽  
Nitrification Process

Due to the slow growth of nitrification bacteria at low temperatures, nitrogen reduction normally requires long hydraulic retention time during winter. Important for the nitrification process is the aerated sludge age. Factors influencing the sludge age are aerated volume, mixed liquor suspended solids concentration, organic loading and sludge yield. In an existing plant you cannot easily expand the volume and the load is difficult to decrease. But the suspended solids concentration can be increased by running the biological step with the contact stabilisation process. At the Käppala Association sewage treatment plant in Lidingö just outside Stockholm, one of the six aeration tanks has been reconstructed for full scale nitrogen removal experiments. In this tank the old aeration system has been replaced with rubber membrane diffusers. Further more there are several zones separated by walls in the tank. The tank can thereby be run with great flexibility. By running it with the contact stabilisation process, the sludge age has been improved by a factor between 1.5 and 2 and thereby it succeeds in keeping the nitrification bacteria in the system even during snow melting. At temperatures of about 9 °C and hydraulic retention times of less than 3 hours in the contact zone there has been a nitrification degree of up to 50 to 60 %. The experiment was conducted with a stabilisation zone of up to half the total volume of the aeration tank. The main purpose for the experiments during the winter seasons was to improve nitrification. Keeping the nitrifiers in the system had been a crucial problem during previous years. When the nitrifiers were lost with an increased flow and decreased temperature the nitrification process didn't restart until the temperature was increased and the load decreased. Usually this didn't occur until the middle of the summer meaning a loss of nitrification for up to six months. In Sweden there is a goal set for 50 % nitrogen reduction for the plants in the Stockholm region. At Käppala we manage to keep 60 to 70 % nitrogen reduction during the warm season, that is from July to December. If we can keep up the nitrification the whole year we can achieve 50 % as a yearly average under normal conditions even though we can't keep the nitrogen reduction rate as high during the cold season.

scholarly journals Effect of Prior Oxidation on the Reduction Behavior of Magnetite-Based Iron Ore During Hydrogen-Induced Fluidized Bed Reduction

2021 ◽  
Author(s):  
Heng Zheng ◽  
Daniel Spreitzer ◽  
Thomas Wolfinger ◽  
Johannes Schenk ◽  
Runsheng Xu
Keyword(s):  
Fluidized Bed ◽  
Partial Oxidation ◽  
Iron Ore ◽  
Reduction Rate ◽  
Deep Oxidation ◽  
Initial Reaction ◽  
Oxidation Treatment ◽  
Rate Limiting Step ◽  
Rate Limiting ◽  
Prior Oxidation

AbstractMagnetite-based iron ore usually shows a high sticking tendency and a poor reducibility in the fluidized bed because of its dense structure. To enhance the fluidization and reduction behaviors of magnetite-based iron ore during hydrogen-induced fluidized bed reduction, the effect of a prior oxidation treatment is investigated. The results show that the untreated magnetite-based iron ore cannot be fluidized successfully in the tested temperature range between 600 °C and 800 °C. At 600 °C reduction temperature, the de-fluidization can be avoided by a prior oxidation treatment. At higher reduction temperatures, the fluidization behavior can be further improved by an addition of 0.5 wt pct MgO. Magnesiowüstite (FexMg1−xO) is formed, which decreases the contact chance of the sticky surface between particles. Regarding to the reduction rate, a prior partial oxidation is more beneficial compared to deep oxidation. The kinetic analysis shows that MgO could promote the initial reaction. The reaction rate limiting step is no longer diffusion but chemical reaction for prior partly oxidized samples. A prior partial oxidation combined with an addition of MgO is considered to be a promising pretreatment method for a successful processing of magnetite-based iron ore.

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