Operation and Performance of a New Activated Sludge Process: The Contact Stabilization Extended Aeration Hybrid

1982 ◽  
Vol 14 (1-2) ◽  
pp. 367-380
Author(s):  
B H Paepcke ◽  
P H Jones

In this study the operation and performance of a contact stabilization process operating under the extended aeration mode is examined. Data was obtained during a detailed plant study carried out at a full scale municipal wastewater treatment plant. This new hybrid activated sludge process has good process stability like the conventional extended aeration process, but achieves this with a significantly smaller aeration tank volume and therefore lower cost.

1997 ◽  
Vol 35 (10) ◽  
pp. 53-61 ◽  
Author(s):  
F. Coen ◽  
B. Vanderhaegen ◽  
I. Boonen ◽  
P. A. Vanrolleghem ◽  
P. Van Meenen

Dynamic simulation can be used to improve the design and performance of the activated sludge process. This is illustrated by means of two case studies:The simulation of a full scale industrial plant treating nitrogen-rich wastewater by an intensive nitrification-denitrification process. By means of simulation the most important operational cost (dosage of an external carbon source) was optimised and a control strategy was proposed.The simulation of a municipal wastewater treatment plant with the extension of nitrogen removal. Based on simulation the feasibility of the redesign was evaluated. In both cases the wastewater composition was characterised and the biological model (the activated sludge IAWQ-model No. 1) calibrated. By means of respirometry and standard laboratory analyses it was possible to estimate the COD fractions of the wastewater and the parameters for heterotrophic and autotrophic growth of biomass.


2014 ◽  
Vol 955-959 ◽  
pp. 2080-2082
Author(s):  
Hong Mei Liu ◽  
Gang Zhu ◽  
Ke Zhao ◽  
Zhuang Liu

The inertial effect applied to activated sludge process, the practice shows that in energy efficiency and reduce the hydraulic retention time it is obvious than not using the inertial effect. In cold winter areas to ensure water quality can meet the first grade A standard of "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant" (GB18918-2002)


2013 ◽  
Vol 845 ◽  
pp. 538-542 ◽  
Author(s):  
Muhammad Sani Gaya ◽  
Norhaliza Abdul Wahab ◽  
Yahya M. Sam ◽  
Sharatul Izah Samsuddin

Activated sludge process is the most efficient technique used for municipal wastewater treatment plants. However, a pH value outside the limit of 6-9 could inhibit the activities of microorganisms responsible for treating the wastewater, and low pH value may cause damage to the treatment system. Therefore, prediction of pH value is essential for smooth and trouble-free operation of the process. This paper presents an adaptive neuro-fuzzy inference system (ANFIS) model for effluent pH quality prediction in the process. For comparison, artificial neural network is used. The model validation is achieved through use of full-scale data from the domestic wastewater treatment plant in Kuala Lumpur, Malaysia. Simulation results indicate that the ANFIS model predictions were highly accurate having the root mean square error (RMSE) of 0.18250, mean absolute percentage deviation (MAPD) of 9.482% and the correlation coefficient (R) of 0.72706. The proposed model is efficient and valuable tool for the activated sludge wastewater treatment process.


2013 ◽  
Vol 1 (1) ◽  
pp. 47-53

Samples were taken from Metamorphosis/Attica combined treatment plant for municipal wastewater and septage, which treats about 12000 m3 d-1 of municipal wastewater and 8000 m3 d-1 of septage, and analyzed for solids, COD, ammonia, nitrate, orthophosphate, polyphosphate and total phosphorus. Ammonia is almost completely eliminated within the plant. Orthophosphates show a removal of about 28%, while total phosphorus is removed by about 15%. The mean value of the ratio (phosphorus eliminated)/(COD eliminated) in mg g-1 is 8. Assuming suspended-growth nitrification and denitrification kinetics as proposed in literature, the percentage of nitrifiers in the activated sludge population is estimated at 1.1%. Assuming that phosphorus removal in the aeration tank is proportional to cell formation, which in turn is proportional to substrate elimination, the phosphorus content of the activated sludge is estimated at 0.031 gP (gVSS)-1.


2001 ◽  
Vol 43 (1) ◽  
pp. 155-164 ◽  
Author(s):  
E. Plaza ◽  
J. Trela ◽  
B. Hultman

Seeding of nitrifying bacteria into the activated sludge process was studied both theoretically and experimentally. A simple model was developed for prediction of the effects of seeding of nitrifying bacteria from a separate stage into the activated sludge process. The purpose of seeding is to improve the treatment results and the process stability as well as to decrease the volume requirements of the process. Pilot plant studies were carried out at the Uppsala municipal wastewater treatment plant in order to evaluate the effects of seeding. One line was supplied with supernatant from dewatering of digested sludge and the nitrification process gave an activated sludge with a high fraction of nitrifying bacteria, suitable for seeding. The other line was supplied with pre-precipitated wastewater and with the excess sludge from the line treating the supernatant. The experimental results showed that nitrification could be obtained at sludge ages that would otherwise preclude nitrification. Performance relationships for the system developed, based on laboratory and on-line measurements were studied and are presented. The studies show that seeding may decrease the necessary volume needs for a stable nitrification process and that the effects could be predicted by use of a simple model.


1996 ◽  
Vol 33 (12) ◽  
pp. 89-98 ◽  
Author(s):  
Xu Shulan ◽  
Bengt Hultman

Simulation models of the activated sludge process are believed to be a useful tool for process optimization and trouble-shooting at today's treatment plant. However, the application of the models is limited at most treatment plants due to lack of advanced input of parameter values required by the model. Simplification of the procedures of wastewater characterization was investigated. Characterization work was reduced to two oxygen utilization measurements and two COD analyses. Model calibration is demonstrated with experimental data from Kungsängen municipal wastewater treatment plant in Uppsala, Sweden.


2005 ◽  
Vol 52 (4) ◽  
pp. 27-37 ◽  
Author(s):  
Y.S. Cao ◽  
K.H. Teo ◽  
W.A. Yuen ◽  
W.Y. Long ◽  
B. Seah

The paper describes and analyses the performance of anoxic selectors in upgrading activated sludge process in a municipal wastewater treatment plant under tropical climate, where poor sludge settleability is a problem due to elevated temperature. Site monitoring and laboratory experiment were conducted to study the denitrification, sludge settleability, kinetics, mass balance, pH and alkalinity variation in the system. The sludge settleability measured in Sludge Volume Index (SVI) was observed to improve with the increasing degree of denitrification in the anoxic selector. Under well-developed stable state, an average SVI value of 136 ml/g was achieved, which was significantly lower than the value of 250 ml/g before the application of anoxic selector. The specific reaction rates for denitrification and nitrification at 30°C were 0.06 mg NO3-N/mg MLSS day and 0.08 mg NH4-N/mg MLSS day, respectively. The overall efficiencies of nitrification and denitrification were 86 percent and 55.4 percent, respectively, with an alkalinity recovery ratio of 15.4 percent. 32 percent of total COD removed was used up as electron donor in the denitrification process. However, due to absence of the internal Mixed Liquor Recirculation (MLR), a higher degree of denitrification occurred in the secondary sedimentation tank than in the anoxic zone. Issues for further studies are also discussed.


1998 ◽  
Vol 38 (3) ◽  
pp. 167-172
Author(s):  
Jin Duanyao ◽  
Wang Baozhen ◽  
Wang Lin

The Zhen'an Wastewater Treatment Plant in Foshan City, Guangdong Province, China is a newly built large municipal wastewater treatment plant in south China, situated in the southeast of the famous ancient Foshan City, has a treatment capacity of 100,000 m3/d, serves an area of 32 km2 and 220,000 P. E., occupies 7 ha area with a total investment of 220 million RMB (about 26.5 million U.S dollar), which was put into operation in December 1995. As it is difficult to design and operate the wastewater treatment plant because of the low organic concentration of its influent, the simplified A/O activated sludge process without primary treatment for simultaneous removal of phosphorus and ammonia nitrogen was employed to design the plant, by which, the wastewater is treated very well, with higher effluent quality than the traditional activated sludge process, while the capital and O/M costs are lower than the latter.


2003 ◽  
Vol 47 (12) ◽  
pp. 285-292 ◽  
Author(s):  
C.-K. Chen ◽  
S.-L. Lo

This study combines a two-phase biological treatment system of activated sludge/contact aeration process by adding biological contact filters into the rear sector of the activated sludge aeration tank of the slaughterhouse wastewater treatment plant. This system keeps the advantages of complete mixing of substrates and microorganisms and flexible operation of the activated sludge process, and increased biological phase, less sludge, process stability and good settleability of sludge of the contact aeration process. This system could avoid the defects of sludge bulking, increased sludge production and difficult operation of the activated sludge process, and system clogging and rigid operation of the contact aeration process. Because suspended microorganisms are flowing into the contact aeration system, which then degrade or suspend within the biological contact filters after being adsorbed by the fixed biological film, on which partial bio-solids will act as seeding microorganisms. Suspended microorganisms and the dropped biological film will settled in the secondary settling tank, then reflux into the activated sludge aeration tank. The partial dropped biological film will decompose in the activated sludge aeration tank to achieve the function of decreasing sludge. Large specific gravity and good settling ability of biofilm sludge will provide better effluent quality. It has been proven through a practical experiment at a slaughterhouse wastewater treatment plant in Taiwan, that the activated sludge process effluent COD value of 150-200 mg/L and SS value of 80-100 mg/L were decreased to around 40 mg/L and 22 mg/L, respectively, after changing its system to the two-phase biological treatment system of activated sludge/contact aeration process.


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