Browse > Article

The Predilution Effect of Al-based Liquid Coagulants for the Optimal Efficacy  

Heo, Jae-Yong (Department of Chemical and Bio Engineering, Kyungwon University)
Lee, Sang-Wha (Department of Chemical and Bio Engineering, Kyungwon University)
Publication Information
Applied Chemistry for Engineering / v.17, no.1, 2006 , pp. 37-43 More about this Journal
Abstract
The coagulation efficacy of Al-based coagulants (such as Alum, PACS, and PACC) was investigated to ascertain removal efficiencies of turbidity and phosphate with variation of solution pH, coagulant dosages, and pre-dilution ratios. The efficacy of Al-based coagulants was maximized in the pH range of 6~9. Under the initial condition of pH 8, $10mg/L\;{PO_4}^{3-}$, and 20 NTU, Al-based coagulants exhibited a similar efficacy in the removal of turbidity, whereas the removal efficiency of phosphate was clearly dependent on the basicity of coagulants: Alum (0%) > PACS (45~50%) > PACC (70%). At high initial turbidity of 100 NTU, polymeric coagulants, such as PACS and PACC, exhibited a higher removal efficiency of turbidity compared to Alum. In comparison to direct injection of coagulants at low initial turbidity (20 NTU), 500~2000 times pre-diluted Alum, exhibited reduced coagulation efficacy; however, removal efficiencies of turbidity and phosphate increased with the increase of retention time. Pres-diluted PACC exhibited the enhanced coagulation efficacy followed by silght decrease of the removal efficiencies with increase of the retention time. At high initial turbidity of 100 NTU, pre-diluted Alum and PACC exhibited higher removal efficiencies of turbidity and phosphate.
Keywords
Al-based; coagulants; predilution; phosphate; turbidity;
Citations & Related Records
연도 인용수 순위
  • Reference
1 S. W. Lee, K. S. Lee, S. J. Haam, and J. W. Kwak, J. Korean Ind. Eng. Chem., 16, 74 (2005)
2 S. W. Lee, K. S. Lee, and J. W. Kwak, J. of KSWQ, 18, 19 (2002)
3 K. Kemira, Handbook on Water Treatment, Helsingborg, Sweden (1993)
4 R. D. Letterman, J. E. Quon, and R. S. Gemmell, J. AWWA, 65 716 (1973)   DOI
5 J. S. Kim and J. H. Choi, J. Korean Ind. Eng. Chem., 9, 330 (1998)
6 J. W. Kwak, Physico-Chemical Principle and Practice of Water Treatment, Ji-Sam, Seoul (1998)
7 J. W. Kwak, Environmental Technology, 18, 293 (1997)   DOI
8 S. J. Randtke, J. AWWA, 80, 40 (1988)
9 M. Rossini, J. G. Garrido, and M. Galluzzo, Waf. Res., 33, 1817 (1999)
10 L. Gillberg, Influence of the Basicity of Polyaluminium Chlorides When Cleaning Municipal Wastewater, Chemical Water and Wastewater treatment III, 39 (1994)
11 S. H. Kim, J. of KSEE, 18, 603 (1996)
12 K. Y. Kang, H. S. Jung, and J. K. Cheon, J. Korean Ind. Eng. Chem., 15, 523 (2004)
13 R. J. Francois, Wat. Res., 21, 523 (1987)
14 A. Amirtharajah and K. J. Mills, J. AWWA, 74, 210 (1982)   DOI