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http://dx.doi.org/10.4491/KSEE.2015.37.6.325

Comparison of Al(III) and Fe(III) Coagulants for Improving Coagulation Effectiveness in Water Treatment  

Han, Seung woo (EFT R&D Center)
Kang, Lim seok (Department of Environmental Engineering, Pukyong National University)
Publication Information
Journal of Korean Society of Environmental Engineers / v.37, no.6, 2015 , pp. 325-331 More about this Journal
Abstract
The experimental results of the characteristics of aluminum based and ferric based coagulants for the Nakdong River water showed that the main hydrolysis species contained in alum and $FeCl_3$ are monomeric species of 98% and 93.3%, respectively. The PACl of r=1.2 produced by the addition of base contained 31.2% of polymeric Al species and the PACl of r=2.2 contained 85.0% of polymeric Al species, as showing more polymeric Al species with increasing r value. Coagulation tests using Al(III) and Fe(III) salts coagulants for the Nakdong River water showed that the coagulation effectiveness of turbidity and organic matter was high in the order of $FeCl_3$ > PACl (r=2.2) > PACl (r=1.2) > alum. $FeCl_3$ has showed better flocculation efficiency than Al(III) salts coagulants. In addition, in case of Al(III) coagulants, the Al(III) coagulants of higher basicity, which contained more polymeric Al species, resulted in better coagulation efficiency for both turbidity and organic matter removed. The optimum pH range for all of the coagulants investigated was around pH 7.0 under the experimental pH range of 4.0~9.5. Especially, the highest basicity PACl (r=2.2) and $FeCl_3$ were considered as more appropriate coagulants for the removal of turbidity in the case of raw water exhibiting higher pH.
Keywords
Coagulant; Basicity; Aluminum Salt; Ferric Salt; Coagulation Effectiveness;
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  • Reference
1 Letterman, R. D. and Driscoll, C. T., "Survey of residual aluminum in filtered water," J. Am. Water Works Assoc., 80(4), 154-158(1988).
2 MWH, Water treatment principles and design, 3rd ed., John Wiley & Sons, Inc., New Jersey(2012).
3 Van Benchoten, J. E. and Edzwald, J. K., "Chemical aspects of coagulation using aluminum salts," Water Res., 24(12), 1519-1526(1990).   DOI   ScienceOn
4 Crozes, G., White, P. and Marshall, M., "Enchanced coagulation: Its effect on NOM removal and chemical costs," J. Am. Water Works Assoc., 87(1), 78-89(1995).
5 Haarhoff, J. and Cleasby, J. L., "Comparing aluminum and iron coagulants for in-line filtration of cold water," J. Am. Water Works Assoc., 80(4), 168-175(1988).
6 Morris, N. and Knocke, W. R., "Temperature effects on the use of metal-ion coagulants for water treatment," J. Am. Water Works Assoc., 76(3), 74(1984).
7 Moon, S. D., Son, H. J., Yeom, H. S., Choi, J. T. and Jung, C. W., "Application of enhanced coagulation for Nakdong River water using aluminum and ferric salts coagulants," J. Korean Soc. Environ. Eng., 34(9), 590-596(2012).   DOI   ScienceOn
8 Lee, C. H., Lee, S. H. and Okada, M., "Removal algae and Cryptosporidium on drinking water treatment by polysilicatoiron coagulant," J. Korean Soc. Environ. Eng., 26(8), 876-882(2004).
9 Hwang-Bo, B. H., Kim, J. S., Han, S. W. and Kang, L. S., "Comparison of Al(III) and Fe(III) salt coagulants for improving water treatment process," J. Korean Soc. Environ. Eng., 20(7), 1005-1014(1998).
10 Nikolay, V., "Considerations for selection of seawater filtration pretreatment system," Desalination, 261(3), 354-364 (2010).   DOI   ScienceOn
11 Smith, R, M., "Relation Among Equilibrium and Nonequilibrium Aqueous Species of Aluminum Hydroxy Complexes, Nonequlibrium Systems in Natural Water Chemistry," (Gould, R. F. Ed.), A.C.S. Advances in Chemistry Series No. 106, American Chemical Society, Washington, D.C., pp. 250-279 (1971).
12 Bersillon, J. L., Hsu, P. H. and Fiessinger, F., "Characterization of Hydroxy-Aluminum Solutions," Soil Sci. Soc. Am. J., 51, 825-828(1988)
13 Parker, D. R. and Bertsch, P. M., "Identification and Quantification of the "$Al_{13}$" Tridecameric Polymeric Polycation Using Ferron," Environ. Sci. Technol., 26(5), 908-914(1992).   DOI
14 Murphy, P. J., Posner, A. M. and Quirk, J. P., "Chemistry of iron in soils. Ferric hydrolysis products," Australian J. Soil Res., 13, 189-201(1975).   DOI
15 APHA, AWWA and WEF, "Standard Method of the Examination of Water and Wastewater," 20th ed., APHA, AWWA and WEF(2005).
16 Lin, J. L., Chin, C. J., Huang, C. and Wang D., "Coagulation behavior of $Al_{13}$ aggregates," Water Res., 42(16), 4281-4290(2008).   DOI   ScienceOn
17 Bratby, J., "Coagulation and Flocculation in Water and Wastewater Treatment" 2nd. ed., IWA Publishing(2006).
18 Ministry of environment, "Standards and indication of water treatment agents," Notification No. 2013-188, pp. 7-14(2014).
19 Edzwald, J. K., "Coagulation in drinking water treatment: particles, organics and coagulants, Water Sci. Technol., 27, 21-35(1993).