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Showing 4 results for Stabilization
The Efficiency Comparison of Conventional Activated Sludge and Stabilization Pond Systems in Removal of Cysts and Parasitic Eggs (A case Study: Kermanshah and Gilangharb Wastewater Treatment Plants)
J Derayat, A Almasi, K Sharafi, H Meskini, A Dargahi,
Volume 4, Issue 2 (9-2011)
Abstract

Background and Objectives: Microbial quality, particularly parasitic characteristics in terms of effluent reuse in agriculture is one of the most important indices. The aim of this study is determination of removal efficiency of Kermanshah wastewater treatment(conventional activated sludge) and Gilangharb wastewater treatment plants (stabilization ponds) for cyst and parasitic eggs.
Material and Methods: In this study research samples were taken once in five days from both inlet and outlet of wastewater Plants within a period of five months. The identification and counting of cyst and parasitic eggs were carried out by Mac master slide according to Bailenger method.
Results: The findings shows that mean of parasitic eggs and protozoan cysts in effluent of Kermanshah wastewater treatment plant were 0.99±0.42 and 0.90±0.25 per liter respectively, indeed removal efficiency for parasitic eggs and cysts are %98.42±3 and %97.5±4.5 respectively, but, any parasitic eggs and protozoan cysts in Gilangharb wastewater treatment plant was not observed and removal efficiency of these tow parameters was %100. Ascaris lumbricoides eggs had most number in influent and effluent of both plants.
Conclusion: As results show, removal efficiency for cysts and parasitic eggs in both above mentioned are desirable, and the quality of effluent treatment plant of both the rate of nematode eggs Anglbrg index (number of nematode eggs: 1 " number per liter) is consistent.


The Compare Improvement of Ultrasonic  Treatment to Dewatering and Digestion in Aerobic  and Anaerobic Stabilization
Mahdi Kargar, Amir Hossein Mahvi,
Volume 5, Issue 1 (4-2012)
Abstract
A MicrosoftInternetExplorer4 Backgrounds and Objectives: Large quantities of sludge are produced in biological wastewater treatment. Because this sludge is highly rotten, it should be stabilized before its disposal. Aerobic and anaerobic digestion is widely considered as stabilization techniques. Because of high retention time and sludge dewatering difficulties, reduction in retention time, operation and maintenance should be given into consideration. Ultrasonic process increases the enzymatic activity, so decreases the hydrolysis time, a limiting factor in digestion process, and contributes to the decrease of the detention time. The objective of this investigation is to determine the effect of ultrasound in improving dewatering and stabilization of aerobic and anaerobic digested sludge. In addition, the impact of ultrasonic treatment on improvement of sludge dewatering and aerobic and anaerobic digestion is compared.
Materials and Methods: In this survey, samples of aerobic and anaerobic digestion were collected from local full-scale Garb Town and Tehran South wastewater treatment plant, respectively. The grab samples were collected for 4 month from July to October 2010. Total numbers of 20 samples were collected biweekly for each type of digestion. Each sample was sonicated for 15, 30, 60, and 90 min under 35 and 131 kHz frequencies separately. Total solids, volatile solids , pH, temperature , total COD, dissolved COD and settle able solids were measured. Ultrasound bath of the solution in a 300 mL glass reactor was performed as a bath reactor with power of 500 W.
Result: The results showed that the application of ultrasonic wave increased dissolved COD and temperature and decreased volatile solid, pH and settle able solids. Application of ultrasonic wave with frequency of 131 kHz decreased the VS and increased the dewatering of sludge more effective than the 35 kHz frequency and the highest performance was at 15 min of time and 131 kHz of frequency. Also sonication method showed better efficiency for anaerobic sludge samples compared to the aerobic sludge samples.                 
Conclusion: The results obtained showed that digestion and dewatering properties of sludge improved by ultrasonic application. Therefore it can be used as an alternative method for the sludge treatment.

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The Efficiency of Anaerobic Wastewater Stabilization  Pond in Removing Phenol from  Kermanshah  Oil Refinery Wastewater
Ali Almasi, Meghdad Pirsaheb, Abdollah Dargahi,
Volume 5, Issue 1 (4-2012)
Abstract
MicrosoftInternetExplorer4 Background and Objectives: Phenol is one of the aromatic compounds, which due to its high toxicity and its presence in the industrial effluents, should be removed and prevented it, to the receiving water resources. The natural biological plant has been accepted as one of the most feasible, eco-friendly and cost-effective options for the treatment of pollutants such as Phenol. The aim of this study is efficiency evaluation of the anaerobic stabilization pond performance in removing phenol and other organic compounds from Kermanshah oil refinery wastewater.
Materials and Methods: The method of study was experimental and analytical, a laboratory scale anaerobic stabilization pond, with dimensions of 1 × 1 × 0/2 m, using fiberglass sheet with a thickness of 6 mm was designed and built up. In this study The hydraulic retention time and hydraulic loading rate were expected 2 days and 95 liters per day respectively. Organic loading rate for anaerobic pond was 100 g/m3. After starting, seeding and biological stability, samples were taken. Initial phenol concentration was added about of 100 mg/l to pilot input, then the parameters such as NH3, PO4 and Phenol were measured by Varian spectrophotometer model UV-120-02 in the wavelength 425, 690, 500 nm respectively.  TCOD, SCOD, TBOD, SBOD, pH and ORP were measured according to the standard methods of water and wastewater.
Results: The results showed that the removal efficiency of NH3, PO4, phenol, TCOD, SCOD, TBOD, SBOD in the anaerobic pond were obtained 91.51%, 64.34%, 89.82% 74.99 % 73.34% 71.75%, 68.9% respectively.
Conclusion: The results showed that the ability for phenol and other organic compounds removal in anaerobic pond using petroleum refinery wastewater is higher than the other systems which are expensive and complex.

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Comparison of different inorganic amendments on decreasing of Cd, Pb, Ni, Cu, and Zn sorption by wastewater-irrigated plants
R Salmasi, A Behbahaninia, Ar Ostadrahimi,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Heavy metals fixation in-situ by using inorganic amendments is a method for immobilization of polluted soils. The goal of this research was to determine efficiency of five amendments for heavy metals fixation of waste-water-irrigated soils around Tabriz city.
Materials and Methods: Cadmium, Pb, Cu, Ni, and Zn- containing solutions were added to 0.5 gram of five amendments including calcite, hematite, zeolite, illite, and bentonite. 10 soil samples from around of Tabriz city were taken. After shaking the samples, the concentrations of the five elements were determined in the filtered solution by using atomic absorption instrument. Retention capacity percentages of these elements were calculated, and the best amendments were determined by using Dunkan method.
Results: There were differences of heavy metals retention between amendments. Calcite had the highest retention of Cd (91%), Ni (78%), and Zn (94.7%); hematite had the highest Cu (90.5%) and Pb (94.3%); and illite showed the lowest retention of the 5 elements. Calcite, zeolite, bentonite, and hematite had significant higher retention capacities of Cd, Ni, and Zn in compared to 10 the soil samples.
Conclusion: Among the studied amendments, retention capacities of calcite and hematite for the five elements were higher than the remaining ones for addition to the soil. These two amendments can cause low uptake and low accumulation of the elements in agricultural crops in polluted soils.
 

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