scholarly journals Determination of kinetic parameters in activated sludge process for domestic wastewater treatment plant

2007 ◽  
Vol 13 (4) ◽  
pp. 211-215 ◽  
Author(s):  
Ghasem Najafpour ◽  
Maedeh Sadeghpour ◽  
Zinatizadeh Lorestani
Keyword(s):  
Activated Sludge ◽  
Rate Constant ◽  
Large Scale ◽  
Oxygen Transfer Rate ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Cod Removal ◽  
Growth Rate Constant ◽  
Aeration Tank ◽  
Activated Sludge Process

The process was effectively used for the treatment of domestic wastewater known as the activated sludge process. To predict the biomass growth, the Monod rate equation was applied in a 30 liter(s) aerated and agitated vessel. The projected data for the kinetic model were used to estimate the large scale aeration tank for the efficient oxygen transfer rate. Food to microorganism ratio (F/M) and HRT were examined for the desired rate of COD removal. More than 52% yield of organic removal was obtained. Also, the endogenous decay coefficient of 0.06 d-1 was obtained. The growth rate constant (Ks) and rate constant (k) were determined as 85.5 mg/l and 1.71 d-1, respectively. 90% COD removal was achieved with the eight-day-old sludge.

Sensitivity of Effluent Variables in Activated Sludge Process

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
B Vivekanandan ◽  
K Jeyannathann ◽  
A. Seshagiri Rao
Keyword(s):  
Activated Sludge ◽  
Flow Rate ◽  
Oxygen Transfer Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Maximum Flow ◽  
Activated Sludge Process ◽  
Flow Conditions ◽  
Treated Effluent ◽  
Influent Flow

Abstract The quality of a treated effluent changes when there is a sudden variation in the influent flow to the wastewater treatment plant during dry, rain, and storm weather conditions. In this study, various influent flow conditions in an activated sludge process are considered that affect the sensitivity of effluent variables such as chemical oxygen demand (COD), biological oxygen demand (BOD), nitrate nitrogen (SNO), ammonical nitrogen (SNH), and total nitrogen (TN) with respect to varying internal recycle flow rate (Qa), sludge recycle flow rate (Qr), sludge wastage flow rate (Qw) and oxygen transfer rate co-efficient of aerobic tanks (KLa(3,4,5)). The analysis has been carried out based on benchmark simulation model no.1 (BSM 1) plant layout which comprises of two models namely activated sludge model no.1 (ASM 1) and simple one dimensional (Simple 1-D) Takacs model. Based on the present analysis, it is observed that the changes in influent flow rate have larger impact on the effluent variables. This variation can be subdued by introducing additional tanks to smoothen the perturbations or using internal recycle rate from the fifth tank in order to maintain the flow around the optimal influent flow rate. The sludge wastage rate has a greater impact on all effluent variables except nitrogenous variables during maximum flow conditions.

scholarly journals The effect of the sludge recycle ratio in an activated sludge system for the treatment of Amol's industrial park wastewater

2008 ◽  
Vol 14 (3) ◽  
pp. 173-180 ◽  
Author(s):  
Bahar Hosseini ◽  
Najafpour Darzi ◽  
Maedeh Sadeghpour ◽  
Mostafa Asadi
Keyword(s):  
Activated Sludge ◽  
Rate Constant ◽  
Continuous System ◽  
Cod Removal ◽  
Utilization Rate ◽  
Industrial Park ◽  
Aeration Tank ◽  
Recycle Ratio ◽  
Optimal Values ◽  
Constant Yield

An activated sludge aeration tank and a sedimentation basin were used to treat Amol's industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured. The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d-1, respectively. The hydraulic retention times (HRT) were in the range of 9 to 27 h. The sludge recycle ratios in the range from 0.3 to 1 were considered. The COD removal, SVI and DO were determined and the optimal values were obtained. It was observed that at HRT of 16 h and the sludge recycle ratio of 0.85, the COD removal and SVI were 95 and 85 %, respectively. The sludge recycle ratio greater than 0.85 had no significant effect on the COD removal.

scholarly journals Macroalgae and Activated Sludge Microbes in Treatment of Crepe Cotton Effluent

2019 ◽  
Vol 9 (2S2) ◽  
pp. 697-700
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Heat Insulation ◽  
Algal Species ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Cod Removal ◽  
Effluent Treatment ◽  
Textile Fabrics ◽  
Domestic Wastewater Treatment

Crepe cotton bandages (textile fabrics) are common household kit in the medical first aid boxes and are globally used in pharmaceutical and health care units to offer heat, insulation and support in many medical situations. Southern Tamilnadu comprises of more than 150 crepe bandage textile units and exports tonnes of crepe cottons. Many units are operated on continuous basis and therefore the amount of wastewater generated and its treatment is of critical importance. Unlike typical textile effluent, crepe cotton processing wastewater do not contain dyes, but significant proportions of caustic soda, soda ash, bleaching agents and COD. This paper discusses the effluent treatment of crepe cotton processing units using mixed cultures of macroalgae and activated sludge microbes. There are very few studies comparing the performance of activated sludge and macro algae in wastewater treatment. Fresh water macroalgae was collected from a nearby pond and activated sludge was collected from the aeration basin of domestic wastewater treatment plant. Crepe cotton processing effluent had significant concentrations of COD, TDS, TSS and was highly alkaline. The COD removal efficiency of about 73.8% and 99 % was obtained for macroalgae and activated sludge microbes respectively. COD removal was quick in activated sludge while macroalgae cultures took 144 h to remove 275 mg/L of COD. This study shows that activated sludge microbes are quick to adapt in uptake of organics from crepe cotton effluent when compared to macroalgal sp, further studies will provide insights on generating bioenergy from algal species grown in crepe cotton effluent for sustained plant operation.

Performance evaluation of various aerobic biological systems for the treatment of domestic wastewater at low temperatures

2008 ◽  
Vol 58 (4) ◽  
pp. 819-830 ◽  
Author(s):  
N. Sundaresan ◽  
L. Philip
Keyword(s):  
Performance Evaluation ◽  
Activated Sludge ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Biological Systems ◽  
Domestic Wastewater ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Activated Sludge Process ◽  
Cod Removal Efficiency

Studies were undertaken on the performance evaluation of three different types of aerobic reactors, namely, activated sludge process, fluidized bed reactor and submerged bed reactor. Initially synthetic wastewater was used for stabilizing the system and later domestic wastewater of IIT Madras was used as the feed for the biological systems. The hydraulic retention time was maintained as 24 h. The seed sludge was collected from IIT Madras sewage treatment plant. The inlet COD to the reactors with synthetic wastewater was 1,000±20 mg/L and with real wastewater, it was 150 to 350 mg/L. The performance of the reactors was evaluated based on the soluble COD and nitrogen removal efficiency. The pH, temperature, dissolved oxygen (DO) and mixed liquid suspended solid (MLSS) concentration were measured periodically. The reactors were acclimatized at 35°C in batch mode and changed to continuous mode at 30°C. After the systems attained its steady state at a particular temperature, the temperature was reduced from 35°C to 5°C stepwise, with each step of 5°C. The start-up time for submerged bed reactor was slightly more than fluidized and conventional activated sludge process. The COD removal efficiency of the three reactors was higher with synthetic wastewaters as compared to actual domestic wastewater. Submerged bed reactor was more robust and efficient as compared to activated sludge and fluidized bed reactors. The COD removal efficiency of the reactors was relatively good until the operating temperature was maintained at 15°C or above. At 10°C, submerged bed reactor was able to achieve 40% COD removal efficiency whereas; the fluidized bed and conventional ASP reactors were showing only 20% COD removal efficiency. At 5°C, almost all the systems failed. Submerged bed reactor showed around 20% COD removal efficiency. However, this reactor was able to regain its 90% of original efficiency, once the temperature was raised to 10°C. At higher temperatures, the nitrification efficiency of the reactors was above 80–90%. As the temperature reduced the nitrification efficiency has reduced drastically. In summary, submerged bed reactors seems to be a better option for treating domestic wastewaters at low temperature regions.

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
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Lower Cost ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Process Stability ◽  
Aeration Process ◽  
And Performance

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.

Treatment of Citric Acid Wastewater for High Quality Effluent on the Anaerobic-Aerobic Route

1993 ◽  
Vol 28 (2) ◽  
pp. 177-186 ◽  
Author(s):  
K. Svardal ◽  
K. Götzendorfer ◽  
O. Nowak ◽  
H. Kroiss
Keyword(s):  
Citric Acid ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Cod Removal ◽  
Aeration Tank ◽  
Aerobic Treatment ◽  
Equal Distribution ◽  
Anaerobic Reactor ◽  
High Calcium ◽  
High Ammonia

A large citric acid factory is situated close to a rather small river, so the discharge of its wastewater caused severe water quality problems. A highly concentrated stream holds more than 90% of the total COD-load, the lowly concentrated stream about 80% of the flow. Anaerobic pretreatment of the highly polluted stream and additional aerobic treatment of all wastewater reduces the total costs to less than one third in comparison to the aerobic treatment alone. The anaerobic treatment is linked with several problems like high sulphate, high ammonia and high calcium concentration leading to H2S and NH3 toxicity as well as calcium carbonate precipitation, about 3 times more than biomass growth. A special anaerobic reactor (EKJ-reactor) was designed to realize an equal distribution of the wastewater in the sludge bed and to prevent sludge and lime deposition. In 1986 the first stage of the full scale treatment plant for the high concentrated wastewater consisting of an equalization tank, an anaerobic reactor (10 000 m3) and a highly loaded activated sludge plant (2 000 m3) went into operation. In 1987 a second anaerobic reactor was built. In 1988 an additional activated sludge plant with simultaneous nitrification-denitrification (aeration tank volume 15 000 m3) for treatment of all the wastewater was designed in order to keep the effluent concentrations within the strict effluent limits. This plant went in operation in 1990. The anaerobic reactors have shown very good results throughout all the five years of operation. At a COD loading rate of 3 to 7kg/m3·d) a COD removal of almost 90% could be achieved. Because of the high COD removal rate of the anaerobic stage, nitrification occurred in the first post-treatment plant but only to nitrite due to high ammonia concentration and high pH. In the second activated sludge plant stable nitrification was obtained. The content of NH4-N as well as NO2-N in the effluent is generally less than 2 mg/l. Some highly concentrated wastewater is fed directly into the second stage in order to obtain rather complete denitrification. So the NO3-N-concentration in the effluent can be kept below 20 mg/l (85% nitrogen removal) mostly.

scholarly journals OPTIMALISASI IPAL GEDUNG ARIOBIMO DENGAN MODIFIKASI PROSES LUMPUR AKTIF DAN BIOFILTER

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Setiyono Setiyono
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Quality Standards ◽  
Activated Sludge Process ◽  
Treatment Technology ◽  
Process Modification ◽  
Domestic Wastewater Treatment

Ariobimo building, now has a domestic wastewater treatment plant which is equipped with the system re-use. At first, the process of wastewater treatment technology using activated sludge process, while the system re-use of wastewater using a combination of chemical-physical processes, namely the process of coagulation-flocculation followed by sedimentation, filtration and adsorption last with. Because this process is not optimal, then this WWTP outlet and the quality of its water re-use can not meet the expected quality standards. After the improvement of the existing activated sludge process, the quality of this WWTP outlet can meet the quality standards of waste discharges. While the process of coagulation-flocculation is replaced with biofilter process using  honey comb tube media, the quality of the effluent can meet water quality standards. Keywords :Domestic wastewater,process modification,  water reused. 

scholarly journals Treatment of slaughterhouse wastewater using an activated sludge/contact aeration process

2003 ◽  
Vol 47 (12) ◽  
pp. 285-292 ◽  
Author(s):  
C.-K. Chen ◽  
S.-L. Lo
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Two Phase ◽  
Slaughterhouse Wastewater ◽  
Aeration Process ◽  
Biological Treatment System

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.

Integration of membrane filtration into the activated sludge process in municipal wastewater treatment

1998 ◽  
Vol 38 (4-5) ◽  
pp. 429-436 ◽  
Author(s):  
N. Engelhardt ◽  
W. Firk ◽  
W. Warnken
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Membrane Filtration ◽  
Large Scale ◽  
Municipal Wastewater ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
New Process

Energy-efficient membrane modules for microfiltration are available to realize a new process engineering in municipal wastewater treatment. The microfiltration membrane ensures that all microorganisms are retained in the aeration tank. A content of mixed-liquor suspended solids of e.g. 15 gMLSS/l can easily be achieved in a large scale plant. Thus the aeration tank is considerably reduced in size. A secondary clarifier is no longer needed. A filtration and a disinfection can be dismissed. A pilot plant gives first knowledge on the application of the activated sludge process with submersed membrane filtration. Based on the tests' results and the knowledge gained during the operation of the pilot plant, a WWTP with membrane filtration for 3000 inhabitants is designed. The costs of investment and operation are estimated.

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