유동흐름 전류계를 이용한 정수장 고탁도 유입수 응집 제어 방법에 대한 연구
Coagulation Control of High Turbid Water Samples Using a Streaming Current Control System
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초록
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.
Abstract
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.
참고문헌 (28)
- Yang ZH, "Optimization of flocculation conditions for kaolin suspension using the composite flocculant of MBFGA1 and PAC by response surface methodology", Bioresour. Technol, 100(18), pp.4233~4239 (2009)
- Campbell A, "The potential role of aluminium in Alzheimer's disease", Nephrol Dial Transplant, 17(suppl 2), pp.17~20 (2002)
- Xia S, "Ultrafiltration of surface water with coagulation pretreatment by streaming current control", Desalination, 204(1-3), pp.351~358 (2007)
- Wu GD, "Effects of data normalization and inherent-factor on decision of optimal coagulant dosage in water treatment by artificial neural network", Expert Syst Appl, 37(7), pp.4974~4983 (2010)
- Khayet M, "Modelling and optimization of coagulation of highly concentrated industrial grade leather dye by response surface methodology", Chem Eng J, 167(1), pp.77~83 (2011)
- Lin JL, "Effect of Al(III) speciation on coagulation of highly turbid water", Chemosphere, 72(2), pp.189~196 (2008)
- "The Martin hubbe's streaming current definitions and concepts"[URL]
- "The Martin hubbe's plane of shear definitions and concepts"[URL]
- Kweon JH, "Evaluation of coagulation and PAC adsorption pretreatments on membrane filtration for a surface water in Korea: A pilot study", DESALINATION, 249(1), pp.212~216 (2009), ELSEVIER SCIENCE BV
- Di bernardo D., "Performance of two-stage filtration system for treating high turbidity water", J Water Supply Res Technol-Aqua, 55(7-8), pp.499~515 (2006)
- Zong D, "Variation of streaming current along water treatment process", Environ Sci Technol, 11, pp.86~88 (2008)
- Dentel SK, "Evaluation of the streaming current detector-I. use in jar tests", Water Res, 23(4), pp.413~421 (1989)
- Dentel SK, "Evaluation of the streaming current detector-II. continuous flow tests", Water Res, 23(4), pp.423~430 (1989)
- Henneberry YK, "Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts", Sci Total Environ, 409(3), pp.631~637 (2011)
- Chen J, "Dependency of polyelectrolyte complex stoichiometry on the order of addition. 1. effect of salt concentration during streaming current titrations with strong poly-acid and poly-base", Colloids Surf A, 223(1-3), pp.215~230 (2003)
- Song ZX, "Research on predictive control of coagulant dosage based on neural network", IEEE, 1, pp.217~221 (2011)
- Bachand PAM, "Treatment with chemical coagulants at different dosing levels changes ecotoxicity of stormwater from the Tahoe basin, California, USA", J Environ Sci Health, Part A, 45(2), pp.137~154 (2010)
- Zaucha M, "Zeta potential of particle bilayers on mica: a streaming potential study", J Colloid Interface Sci (2011)
- 채선하, "SCD에 의한 혼화공정의 모니터링 및 자동제어", 상하수도학회지, 15(6), pp.542~550 (2001), 대한상하수도학회
- Lee BB, "Optimizing the coagulant dose to control membrane fouling in combined coagulation", ultrafiltration systems for textile wastewater reclamation, 2009, pp.155(1-2), 101~107
- 이환, "정수처리에서 pH 저감에 의한 응집효율향상에 관한 연구", 한국환경보건학회지, 29(2), pp.1~6 (2003), 한국환경보건학회
- Kim JK, "A removal of heavy metals through conventional water treatment processes", Kor J Environ Health Sci, 20(4), pp.36~44 (1994)
- Trinh TK, "Response surface methodological approach to optimize the coagulation-flocculation process in drinking water treatment", Chem Eng Res Des, 89(7), pp.1126~1135 (2011)
- Gregory J, "Hydrolyzing metal salts as coagulants", Pure Appl Chem, 73(12), pp.2017~2026 (2001)
- Zembala M, "Streaming potential measurements related to fibrinogen adsorption onto silica capillaries", Colloids Surf B, 3(1), pp.119~129 (1994)
- Shin JY, "Stoichiometry of coagulation revisited", Environ Sci Technol, 42(7), pp.2582~2589 (2008)
- Tadros T., "Interparticle interactions in concentrated suspensions and their bulk (Rheological) properties", Adv Colloid Interface Sci, 168(1-2), pp.263~277 (2011)
- Walker CA, "The streaming current detector: a quantitative model", J. Colloid Interface Sci, 182(1), pp.71~81 (1996)