scholarly journals Enhancing Nitrogen Removal in Coking Wastewater Treatment by Activated Sludge Process: Comparison of Sodium Acetate, Methanol and Phenol as External Carbon Source for Denitrification

2014 ◽  
Vol 26 (1) ◽  
pp. 205-208 ◽  
Author(s):  
Xuewen Jin ◽  
Enchao Li ◽  
Shuguang Lu ◽  
Zhaofu Qiu ◽  
Qian Sui ◽  
...  
1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.


1998 ◽  
Vol 37 (12) ◽  
pp. 95-102 ◽  
Author(s):  
Pericles R. Barros ◽  
Bengt Carlsson

More stringent effluent and cost requirements are increasing the need for better control of wastewater treatment plants. In an activated sludge process, the nitrogen removal efficiency may be improved by adding an external carbon source. In this paper, automatic control of the nitrate level by regulating external carbon flow is discussed. More specifically, an iterative tuning procedure for the controller is outlined. Iterative controller design schemes aim at tuning high performance controllers of low complexity using closed loop data. The basic strategy used in this paper is an iterative pole placement controller design procedure. The suggested approach is compared with conventional design in a simulation study.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1315-1323 ◽  
Author(s):  
H. Aspegren ◽  
B. Andersson ◽  
U. Nyberg ◽  
J. la C. Jansen

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization. On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.


Author(s):  
A. Kuokkanen ◽  
K. Blomberg ◽  
A. Mikola ◽  
M. Heinonen

Abstract Nitrous oxide emissions can contribute significantly to the carbon footprint of municipal wastewater treatment plants even though emissions from conventional nitrogen removal processes are assumed to be moderate. An increased risk for high emissions can occur in connection with process disturbances and nitrite (NO2−) accumulation. This work describes the findings at a large municipal wastewater treatment plant where the levels of NO2− in the activated sludge process effluent were spontaneously and strongly increased on several activated sludge lines which was suspected to be due to shortcut nitrogen removal that stabilized for several months. The high NO2− levels were linked to a dramatic increase in nitrous oxide (N2O) emissions. As much as over 20% of the daily influent nitrogen load was emitted as N2O. These observations indicate that highly increased NO2− levels can occur in conventional activated sludge processes and result in high nitrous oxide emissions. They also raise questions concerning the risk of increased greenhouse gas (GHG) emissions of the nitritation-denitritation processes – although the uncontrolled nature of the event described here must be taken into consideration – and underline the importance of continuous monitoring and control of N2O emissions.


1998 ◽  
Vol 37 (9) ◽  
pp. 227-233 ◽  
Author(s):  
S. Hasselblad ◽  
S. Hallin

Efficient nitrogen removal in a pre-denitrifying activated sludge process strongly depends on the amount and nature of the carbon source in the wastewater. If denitrification has to be supported at periods, the response to a supplemental carbon source should be immediate and substantial. The aim of this work was to study how intermittent addition of ethanol affects process performance and the denitrifying capacity of the biomass in a pre-denitrifying activated sludge process. The investigated intermissions simulated a possible operational situation with a short stop of ethanol addition or a strategy with addition only at weekends. The long-term effect of intermittent addition was also studied. Experiments were performed in a pilot-scale activated sludge plant. Effluent nitrate was measured on-line and potential denitrification rates were determined with the acetylene inhibition technique. Once the bacteria were adapted to the external carbon source, the studied intermission of 24 hours as well as an intermission of six days showed no severe effect on denitrification capacity of the sludge. In order to maintain process stability with intermittent addition, the denitrifying bacteria had to sustain a high capacity at each stop. Five weeks of intermittent addition of ethanol did not change the level of nitrate reduction in the system during periods of ethanol addition. Denitrification potential was, however, negatively affected. The results suggest that it is possible to use an intermittent strategy when adding ethanol as an external carbon source in a pre-denitrifying system and for instance only support the denitrifying bacteria during weekends.


2013 ◽  
Vol 726-731 ◽  
pp. 2589-2593
Author(s):  
Tao Yang ◽  
Pei Ying Wu ◽  
Zhan Sheng Zhao ◽  
Hua Wei Xu ◽  
Gao Zhi Lv

Enriched domestication in SBR was used to improve the proportion of aerobic denitrifiers in activated sludge, and actual power plant wastewater was treated, which proved the existence of aerobic denitrification. But at the later stage, because of carbon deficiency, aerobic denitrifiers were inhibited and NO3--N accumulated. Sodium acetate used as external organic carbon source was added when reaction carried on 3.5 hours to improve the COD/NH4+-N ratio from 6.5 to 10, effluent NO3--N concentration was 3.6 mg\L, average removal efficiency of TN was 90%, which could improve the aerobic denitrification performance of whole system effectively.


2011 ◽  
Vol 143-144 ◽  
pp. 228-232
Author(s):  
Xiao Hua Wang ◽  
Zhu Guo Yu ◽  
Min Hu ◽  
Zeng Liang Yu

Activated sludge process is generally applied on biological wastewater treatment. The Activated sludge Model No.1 (ASM1) is a mathematical description of biochemical processes in the reactor for nitrogen and chemical oxygen demand removal. ASM1 model was used to simulate the concentrations of components in leaving water with single-stage completely mixed CSTR (continuously stirred tank reactor) assumed. According to the concentrations of components in entering water of published data, curve simulation results of SNH and SNo show that the nitrogen removal process follows the nitrification-denitrification principle. And the steady-state results of 10 kinds of selected components indicate the simulation of the components concentration of leaving water is relatively accurate,and the nitrogen removal effect is obvious. The simulation system can provide effective technical support for wastewater treatment of actual plant.


2000 ◽  
Vol 41 (9) ◽  
pp. 15-20 ◽  
Author(s):  
R.E. Adamski ◽  
V. DeSantis ◽  
A. Spangel ◽  
J. Pynn ◽  
L. Betty ◽  
...  

The Newtown Creek Water Pollution Control Plant (WPCP) is New York City's largest wastewater treatment plant. Wastewater treatment is provided by a high-rate activated sludge process without primary sedimentation. This process has achieved approximately 65 percent BOD5 and 75 percent TSS removal. As part of a revised facility plan, two alternative tracks were recommended for upgrading the plant to secondary treatment and providing nitrogen removal. One track would require demolishing most of the existing tankage and constructing new primary tanks followed by a step-feed biological nitrogen removal activated sludge process. The second track would preserve the existing high-rate activated sludge process and use biological filters to remove additional TSS, BOD5 and nitrogen. Alternatives have been investigated to enhance treatment at the Newtown Creek WPCP while the secondary treatment plant upgrading is being completed. This investigation demonstrated that simply converting the existing aeration tanks to step-feed operation could significantly improve TSS and BOD removals. These findings have led the City to consider a third track to meet secondary treatment requirements, (but with no nitrogen removal), consisting of modifying the existing plant to step-feed and adding additional step-feed aeration/sedimentation capacity. This track offers significant cost savings over Track 1 and Track 2.


Sign in / Sign up

Export Citation Format

Share Document