Optimization of nitrogen removal from piggery waste by nitrite nitrification

2002 ◽  
Vol 45 (12) ◽  
pp. 89-96 ◽  
Author(s):  
Y. Eum ◽  
E. Choi
Keyword(s):  
Nitrogen Removal ◽  
Volume Ratio ◽  
Ph Control ◽  
Nitrogen Loading ◽  
Optimum Operating ◽  
Optimum Operating Condition ◽  
Nitrogen Loads ◽  
Study Results ◽  
Waste Characteristics ◽  
Nitrification And Denitrification

The piggery waste characteristics greatly vary with types of manure collections and the amount of water used. If solids are separated well, the waste strength will be greatly reduced resulting in lower TCOD/TKN ratio of 4 (average). If solids are separated by a mechanical scraper, some solids will remain and the waste strength will be increased with a TCOD/TKN ratio of 7. This study was conducted to find an optimum operating condition for nitrogen removal with these two ratios. Nitrite nitrification was targeted because it could be a short cut process for savings in oxygen for nitrification and carbon requirements for denitrification. The study results indicated that nitrogen loading rate and pH were the most important factors to be considered for stable nitrite nitrification. The applicable nitrogen loads were estimated to be 0.3 to 2.0 kgTKN/oxic m3/d for high TCOD/TKN ratio without pH control. With higher pH > 8, NO2N/NOxN ratios in oxic stages even with lower nitrogen loads were increased. The SBR with low TCOD/TKN ratio less than 4 required additional alkalinity. For a complete denitrification, the influent TCOD/TKN ratio must exceed 6 with oxic/total reactor volume ratio of 0.5. Nitrite nitrification and denitrification could save about 35% in tank volume and 50% in carbon requirement, respectively. However, 9.5% oxygen saving could be expected during the operation with low TCOD/TKN ratio. The elevated temperature due to the heat released from COD removal also enhanced microbial activities for nitrification and denitrification as well as ammonia stripping. However, careful attention must be provided for the reactor temperature not to inhibit the nitrification process.

Strategy for nitrogen removal from piggery waste

2002 ◽  
Vol 46 (6-7) ◽  
pp. 347-354 ◽  
Author(s):  
E. Choi ◽  
Y. Eum
Keyword(s):  
Nitrogen Removal ◽  
Treatment Plant ◽  
Nitrogen Loading ◽  
Full Scale ◽  
Organic Load ◽  
Optimum Operating ◽  
Organic Loading Rate ◽  
Activated Carbon Adsorption ◽  
Optimum Operating Condition ◽  
Ammonia Stripping

This study was conducted with an influent containing about 20% solids, obtainable from scraper type separation resulting in about 40 g/L TCOD and 5.5 g/L TKN, to find an optimum operating condition for nitrogen removal. Both laboratory scale reactors and a full scale treatment plant removed 80 to 90% nitrogen by biological means up to 35°C with 10% by ammonia stripping. The full scale plant however was operated at 35 to 45°C, and at 45°C, 30% nitrogen was removed by biological means, 50% by ammonia stripping, 14% by chemical coagulation and 6% by activated carbon adsorption, respectively. Struvite formation could not be observed at 30°C or higher. Nitrite nitrification and denitrification could save about 35% in tank volume and 50% in carbon requirements at 25°C, respectively. For a complete denitrification with a proper temperature, the influent TCOD/TKN ratio must exceed 6 with oxic/total reactor volume ratio of 0.5. The influent TCOD level or organic load should be lower so as not to increase the reactor temperature above 35°C and avoid nitrification inhibition. The estimated optimum nitrogen loading rates were 0.15 for summer and 0.23 kgTKN/m3/d for winter, respectively. With a cooling facility, the nitrogen loads could be increased to 0.35 kgTKN/m3/d equivalent to an organic loading rate of 2.5 kgCOD/m3/d.

Pilot study for the potential application of a shortcut nitrification and denitrification process in landfill leachate treatment with MBR

2006 ◽  
Vol 6 (6) ◽  
pp. 147-154 ◽  
Author(s):  
K.J. An ◽  
J.W. Tan ◽  
L. Meng
Keyword(s):  
Pilot Study ◽  
Landfill Leachate ◽  
Ammonia Oxidation ◽  
Carbon Sources ◽  
Treatment Plant ◽  
Optimum Operating ◽  
Leachate Treatment ◽  
Optimum Operating Condition ◽  
Nitrification And Denitrification ◽  
Denitrification Process

An advanced nitrogen removal pilot study was performed in China's Xia Ping Landfill Leachate Treatment Plant to undertake shortcut nitrification and denitrification with the Membrane Bio-reactor (MBR) process. It was found that the MBR process used 25% less of the oxygen and 40% less of the external carbon sources, compared to the conventional nitrification and denitrification process. The key feature of the MBR process is that it provides an environment more favorable for ammonia oxidation bacterium (AOB) than for nitrite oxidation bacterium (NOB) through controlling loading, pH, temperature, dissolved oxygen concentration (DO), and NH3 inhibition. Optimum operating condition was examined through continuous running of the pilot MBR, and it was found that a minimum HRT of 4.3 days and maximum ammonia loading of 0.6 kg N- NH4+ m3.d with pH 7–8.5, temperature 25–30 °C, and DO at 2 mg/L is favorable to AOB. Kinetic study was conducted to identify the characteristic of the microorganisms in the system. Measured Ks and μA,max of MBR sludge was 19.65 mg NH4-N/L (Temperature 25 °C, pH 8.5) and 0.26 d−1, respectively.

High strength nitrogen removal from nightsoil and piggery wastes

2004 ◽  
Vol 49 (5-6) ◽  
pp. 97-104 ◽  
Author(s):  
E. Choi ◽  
Y. Eum ◽  
K.-I. Gil ◽  
S.-W. Oa
Keyword(s):  
Anaerobic Digestion ◽  
Nitrogen Removal ◽  
Biological Treatment ◽  
Waste Treatment ◽  
Combined Treatment ◽  
High Strength ◽  
Soluble Nitrogen ◽  
Nitrogen Loads ◽  
Reactor Temperature ◽  
Nitrification And Denitrification

Nightsoil and piggery wastes generally present high strength organics and nitrogen. This study evaluated the nitrogen removal characteristics with the existing and modified nightsoil and piggery waste treatment plants. The existing conventional plants showed 20 to 40% nitrogen removal, but the modification with SBR or MLE process could remove effectively both nitrogen and organics with the minimum COD/TN and alkalinity/TN ratios of 6 and 3.6, respectively. Nitrite nitrification and denitrification rates obtainable at higher nitrogen loads were faster than the rates of nitrate nitrification and denitrification resulting in less reactor volume requirement. However, the higher nitrogen loads increased the organic loads resulting in the reactor temperature inhibiting nitrification. Thus, a combined treatment with anaerobic digestion with the adjustment of influent bypass rates was proposed to reduce the reactor temperature and the external carbon requirement. The biological treatment could discharge about 1,100 mg/L soluble COD and 50 mg/L soluble nitrogen, respectively.

Specific organic and nutrient loads in stabilized sludge from municipal treatment plants

1996 ◽  
Vol 33 (12) ◽  
pp. 243-250 ◽  
Author(s):  
O. Nowak ◽  
A. Franz ◽  
K. Svardal ◽  
V. Müller
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Single Stage ◽  
Nutrient Loads ◽  
Activated Sludge Process ◽  
Waste Sludge ◽  
Sludge Stabilization ◽  
Nitrogen Loads ◽  
Theoretical Considerations ◽  
P Removal

By means of theoretical considerations and of statistical evaluations, specific organic and nitrogen loads in separately stabilized sludge have been found to be in the range of 16 to 20g VSS/PE/d and of 1.1 to 1.5 g N/PE/d respectively. About 0.6g P/PE/d are removed from the wastewater in activated sludge plants without chemical or enhanced biological P removal. By using the single-stage activated sludge process without primary sedimentation and without separate sludge stabilization, almost complete nitrogen removal can be achieved, but specific organic and nitrogen loads in the waste sludge are up to two times higher than in separately stabilized sludge.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

Nitrogen removal from livestock and poultry breeding wastewaters using a novel sequencing batch biofilm reactor

2010 ◽  
Vol 62 (11) ◽  
pp. 2599-2606 ◽  
Author(s):  
Hong Xiao ◽  
Ping Yang ◽  
Hong Peng ◽  
Yanzong Zhang ◽  
Shihuai Deng ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Heterotrophic Bacteria ◽  
Biofilm Reactor ◽  
N Accumulation ◽  
Sequencing Batch Biofilm Reactor ◽  
Poultry Breeding ◽  
Mode 2 ◽  
Do Concentration ◽  
Nitrification And Denitrification ◽  
Biological Nitrogen

A study was conducted regarding the biological nitrogen removal from the livestock and poultry breeding wastewater (LPBWs) using a novel sequencing batch biofilm reactor (SBBR). Nitrogen removal process was studied under three aeration strategies/modes, referred to as MODE 1, 2, and 3. The results showed that MODE 2 (one operation period: instant fill of LPBWs, 3.0 h aeration, 1.5 h non-aeration, 1.5 h aeration, 1.0 h non-aeration and rapid drain of treated LPBWs) performed the best in nitrogen removal. Under MODE 2, the removal efficiencies were as high as 96.1 and 92.1% for NH3-N and TN, respectively. Simultaneous nitrification and denitrification (SND), as well as shortcut nitrification and denitrification are likely to be the two main mechanisms for the nitrogen removal in this study. Nitrifying bateria were not inhibited by heterotrophic bacteria with C/N ratios ranging from 18.1 to 21.4 and DO concentration of 2.0 mg/l. Alternation between aeration and non-aeration played an important role in NO2−-N accumulation.

Into Mesh Lubrication of Spur Gears With Arbitrary Offset Oil Jet. Part 1: For Jet Velocity Less Than or Equal to Gear Velocity

1983 ◽  
Vol 105 (4) ◽  
pp. 713-718 ◽  
Author(s):  
L. S. Akin ◽  
D. P. Townsend
Keyword(s):  
Inclination Angle ◽  
Gear Tooth ◽  
Optimum Operating ◽  
Spur Gears ◽  
Optimum Operating Condition ◽  
Operating Condition ◽  
The Common ◽  
Jet Velocity ◽  
Oil Jet

An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth. The optimum operating condition for best lubrication and cooling is provided when the oil jet velocity is equal to the gear pitch line velocity with both sides of the gear tooth cooled. When the jet velocity is reduced from pitch line velocity the drive side of the pinion and the unloaded side of the gear is cooled. When the jet velocity is much lower than the pitch line velocity the impingement depth is very small and may completely miss the pinion.

Thermoeconomic Approach and Optimization of a Solar Thermal Power Plant

2012 ◽  
Vol 232 ◽  
pp. 609-613
Author(s):  
Ali Baghernejad ◽  
Mahmood Yaghoubi
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Production Costs ◽  
Solar Thermal ◽  
Optimum Operating ◽  
Production Plant ◽  
Optimum Operating Condition ◽  
Solar Thermal Power

In the present study, a specific and simple second law based exergoeconomic model with instant access to the production costs is introduced. The model is generalized for a case study of Shiraz solar thermal power plant with parabolic collectors for nominal power supply of 500 kW. Its applications include the evaluation of utility costs such as products or supplies of production plant, the energy costs between process operations of an energy converter such as production of an industry. Also attempt is made to minimize objective function including investment cost of the equipments and cost of exergy destruction for finding optimum operating condition for such plant.

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