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Selection of coagulant using jar test and analytic hierarchy process: A case study of Mazandaran textile wastewater

  • Asadollahfardi, Gholamreza;Zangooei, Hossein;Motamedi, Vahid;Davoodi, Mostafa
    • Advances in environmental research
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    • v.7 no.1
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    • pp.1-11
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    • 2018
  • Textile factories are one of the industries which its wastewater treatment is a challenging issue, especially in developing countries and a conventional treatment cannot treat all its pollutants properly. Using chemical coagulants is a technique for physical and chemical primary treatment of the wastewater. We applied jar test for selection of suitable coagulant among the five coagulants including alum, calcium hydroxide, ferrous sulfate, ferrous chloride and barium chloride for the effluent of wastewater in Mazandran textile factory located in Mazandran Province, Iran. In addition, jar test, we also used analytic hierarchy process (AHP) method considering criteria which included coagulation cost, sensitivity to pH change, the amount of sludge generation and side effects for coagulation. The results of the jar test indicated that calcium hydroxide was proper among the coagulants which it removed 92.9% total suspended solid (TSS), 70% dye and 30% chemical oxygen demand. The AHP analysis presented that calcium hydroxide is more suitable than other coagulants considering five criteria.

The Experimental Study of Predicting Optimum Dosage of PAC Using Jar-Test Results (Jar-Test를 이용(利用)한 응집제(凝集劑) 주입율(注入率) 결정(決定)에 관한 실험연구(實驗硏究))

  • Kim, Hong Seog;Kim, Seong Heon
    • Journal of Korean Society of Water and Wastewater
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    • v.7 no.2
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    • pp.39-46
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    • 1993
  • In this experimental study, it is concerned to develop a simple equation using jar-test results in order to predict the optimum dosage of coagulant, PAC(polyaluminum chloride). Considering the relationships with the reactions of coagulation and flocculation, the four independent variables (e.g. turbidity, temperature, pH and alkalinity) are selected out of many parameters and they are put into calculations to develop an equation by means of multi-regression method. As the result, the dosing rate of PAC is proportional to turbidity, pH and alkalinity, but in inverse to temperature. And the developed equation is as follow, $$D_c=\frac{3.2{\cdot}T^{0.37}{\cdot}A^{0.04}{\cdot}P^{0.5}}{t^{0.1}},\;(R^2=0.9443)$$ And also, comparing between the estimated value from the equation and the real dosing rate in the plant, Kwangam and Tdukdo, during 1988~1991, it is represented an agreement having a relative error of 16.4%, 17.8%, respectively.

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The Method of Optimum Operation of Coagulant Dosage Facility (응집제 주입설비 최적 운영방안)

  • Jun, Uk-Pyo;Oh, Sueg-Young
    • 유체기계공업학회:학술대회논문집
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    • pp.275-281
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    • 2004
  • Generally Jar-Test is available to determine the coagulant dosage rate. Disadventages associated with Jar-Test are that regular samples have to be taken requiring manual intervention and the limitation to feedback control. To deal with this difficulty, determined optimized dosage rates of coagulant to Investigates the union operation method of the statistical equation which uses the multi-regression method and the SCD.

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The Method of Automathic Operation of Coagulant Dosage by the quality of water (수질에 따른 응집제 주입 자동운영 방안)

  • Jun, Uk-Pyo
    • 유체기계공업학회:학술대회논문집
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    • pp.278-283
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    • 2005
  • Generally Jar-Test is available to determine the coagulant dosage rate. Disadventages associated with Jar-Test are that regular samples have to be taken requiring manual intervention and the limitation to feedback control. To deal with this difficulty, determined optimized dosage rates of coagulant to investigates the union operation method of the statistical equation which uses the multi-regression method and the SCD.

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Experimental Study on the Pressure Characteristics in the Cupping Therapy (부항요법(附缸療法)의 압력특성에 관한 실험적 연구)

  • Kim, Yang-Joong;Kim, Do-Ho;Yeom, Seung-Chul;Lim, Byung-Chuel;Choi, Youn-Sung;Lee, Geon-Hui;Kim, Hyung-Soo;Lee, Jai-Kyoo;Lee, Geon-Mok
    • Journal of Acupuncture Research
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    • v.25 no.1
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    • pp.121-130
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    • 2008
  • Objectives : Cupping therapy is a stimulation therapy similar to acupuncture and moxibustion with effects that differ depending on the degree of stimulus. To make the strength of the skin objective in cupping therapy for this study, we measured negative pressure in the cupping jar and calculated the expansion rate of the skin. Subjects and Methods : In this study, we experimented with cupping therapy jars made for sale and used in clinics. We studied the pressure in the jars and the changes on the skin surface by measuring properties. We used commercial jars of four different volumes and diameters and tried to discover the properties on the size of the jar. Results : The results of experiment with the cupping therapy are as follows: 1. The lowest pressure in a jar was measured at $-600{\sim}610mmHg$, and the number of operating of vacuum pump for reaching lowest pressure was increased recording where the volume of the jar would be big, but the lowest pressure was not increased recording where the size of that would be big. 2. As the vacuum pump continued to operate, the pressure gradient in the jar got smaller which shows that the expansion rate of the skin was not linear. The pressure gradient shows different operational numbers on the vacuum pump near 0mmHg/operation unrelated to jar volume. 3. When negative pressure worked on the jar, air in the jar decreased. The percentage of air gradually reduced as the negative pressure acted in the jar. For example, the percentage of skin was 37-66% when the negative pressure, reatched -500mmHg. According to out results, different test areas generate different percentages of air in the jar, presumably related to skin elasticity. This phenomenon was most pronounced with the smallest jars. 4. At -500mmHg, the expansion rate of the skin was 1.57-1.9 on the abdomen, and $1.52{\sim}1.68$ on the back. The expansion rate of the skin appeared greater when the jar was relatively small, and it appeared smaller when the jar volume was relatively large relatively.

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Coagulation Control of High Turbid Water Samples Using a Streaming Current Control System (유동흐름 전류계를 이용한 정수장 고탁도 유입수 응집 제어 방법에 대한 연구)

  • Nam, Seung-Woo;Jo, Byung-Il;Kim, Won-Kyong;Zoh, Kyung-Duk
    • Journal of Environmental Health Sciences
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    • v.38 no.2
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    • pp.128-135
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    • 2012
  • Objectives: This study was aimed at determining the optimum coagulation dosage in a high turbid kaolin water sample using streaming current detection (SCD) as an alternative to the jar test. Methods: SCD is able to optimize coagulant dosing by titration of negatively charged particles. Kaolin particles were used to mimic highly turbid water ranging from 50 to 600 NTU, and polyaluminum chloride (PAC, 17%) was applied as a titrant and coagulant. The coagulation consisted of rapid stirring (5 min at 140 rpm), reduced stirring (20 min at 70 rpm), and settling (60 min). To confirm the coagulation effect, a jar test was also compared with the SCD titration results. Results: SCD titration of kaolin water samples showed that the dose of PAC increased as the pH rose. However, supernatant turbidity less than 1 NTU after coagulation was not achieved for high turbid water by SCD titration. Instead, a conversion factor was used to calculate the optimum PAC dosage for high turbid water by correlating a jar test result with that from an SCD titration. Using this approach, we were able to successfully achieve less than 1 NTU in treated water. Conclusions: For high turbid water influent in a water treatment plant, particularly during summer, the application of SCD control by applying a conversion factor can be more useful than a jar test due to the rapid calculation of coagulation dosage. Also, the interpolation of converted PAC dose could successfully achieve turbidity in the treated water of less than 1 NTU. This result indicates that an SCD system can be effectively used in a water treatment plant even for high turbid water during the rainy season.

The Effects of Mixer Geometry on Hydraulic Turbulence : Computational Modeling (3-D 전산유체를 이용한 급속혼화조 형상에 따른 난류 유동장 연구)

  • Park, No-Suk;Kim, Sung-Hoon;Park, Heekyung
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.7
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    • pp.1173-1182
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    • 2000
  • The rapid mixing process has been considered as an important step in water treatment. Since the coagulant dispersion into raw water by rapid mixer can influence on the flocculation and filtration efficiency, many researchers have developed various devices and mixing methodologies. Until now, they focused attention on only coagulant dose, pH. rotating velocity and G value but overlooked the real turbulent flow and mixer geometry in rapid mixer. Therefore this paper questions the significance of turbulent flows in rapid mixer and focuses on the analysis of turbulent fluid in various mixer geometry with CFD(Computational Fluid Dynamics). The results of the jar-tests using various geometries indicate that the turbidity removal rate in a circular jar without baffle is higher than that of a circular with baffle. And the turbidity removal rate in Hudson jar is also founded to be higher than in the circular jar with baffle. The CFD simulation of velocity fields in jar demonstrates that the differences of removal rates among the various geometries are largely due to the formation of the different turbulent fluids fields with different geometries.

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Optimal coagulant and its dosage for turbidity and total organic dissolved carbon removal (탁도와 총유기탄소 제거를 위한 최적응집제 및 투여량 선정 연구)

  • Park, Hanbai;Woo, Dal-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.2321-2327
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    • 2015
  • Three coagulants, alum sulfate(alum), poly aluminum chloride(PAC) and poly aluminum silicate chloride (PASC), were used to remove low to high turbidity and TOC in surface and ground blended water. Laboratory experiments and pilot plant experiments were carried out to evaluate the optimal coagulant and its dosage. To determine the optimized coagulant and its dosage, the turbidity, TOC and pH were measured. The experimental results showed the best removal performance using PASC. The optimal dosage of PASC between 3-20 NTU was found to be 15 mg/L in the jar test. In the pilot test, a 15 mg/L PASC dosage was applied and resulted in the efficient removal of turbidity and TOC between 3.6-27 NTU. The removal efficiency of PASC increased with increasing turbidity and TOC.

The development of algae removal system to minimize the damage of algae bloom on freshwater (담수조류의 대량번식에 따른 피해를 최소화하기 위한 녹조제거기 개발)

  • Han J.H.;Park W.S.;Kim J.H.;Lee Y.S.;Rho J.H.;Kim Y.K.;Yoon B.S.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.3 no.1
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    • pp.62-69
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    • 2000
  • The study was performed to apply the algae removal system to coagulation-filtration process for minimize the damage to screen interruption of water treatment plants and died of fish by algae bloom on freshwater. Sample used Nokdong river water and Alkalinity, turbidity, chlorophyll-a and pH measured using Jar test and drum filter for coagulation-filtration process to determine optimum coagulation condition. A jar test apparatus and laboratory reactor were used in this study. The highest removal efficiency was observed when condition of flocculation time, coagulant dosage, drum filter rpm and chlorophyll-a concentration were to be 5min, 5mg/ℓ, 3rpm and 90㎍/ℓ, respectively. The average removal efficiencies measured of chlorophyll-a and turbidity using Alum were 50~60% and 30~50%, respectively. PAC was more effective than Alum in removal chlorophyll-a about 20%.

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The Effect of Coagulant on Filtration Performance in Submerged MBR System (침지형 MBR 공정에서 응집제가 여과성능에 미치는 영향)

  • Kim Kwan-Yeop;Kim Ji-Hoon;Kim Young-Hoon;Kim Hyung-Soo
    • Membrane Journal
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    • v.16 no.3
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    • pp.182-187
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    • 2006
  • The purpose of this study was to investigate effect of coagulation on filtration performance of membrane in submerged MBR system and influence of continuous aeration to reduce fouling of membrane surface on coagulated floc. For this purpose, aeration tank sludge of MBR system was compared with jar-test sludge. The experimental results were analysed in terms of floc size and SRF (Specific resistance of Filtration). The more alum was added, the more content of floc below $10{\mu}m$ reduced and SRF decreased. But compared with jar-test results, it was found that effect of coagulation on MBR floc was reduced. Operation time of membrane in alum added MBR was longer than that in control MBR. But operation time was not proportional to alum dose. It was thought that the result was reason that floc below $10{\mu}m$ was not reduced sufficiently by shear force of continuous aeration. Moreover it was founded that if alum is added more than proper dose, it brings filtration resistance to increase.