This paper presents guidelines for the selection and use of polyaluminum chloride (PACl) coagulants and alum in terms of raw water quality and treatment method. The concentration of natural organic matter (NOM) was found to be the most important parameter affecting coagulant dose. The nature of the NOM, as measured by the specific ultraviolet absorbance (SUVA), was useful for predicting the degree of NOM removal expected. Raw water turbidity and NOM did not influence the type of coagulant that was most effective. Raw water alkalinity, as it relates to the pH of coagulation, was found to be very important for choosing one coagulant type over another. PACl basicity should be matched to raw water alkalinity, so that coagulation pH is as close as possible to the pH of minimum solubility of the coagulant. The solids separation process used for treatment was also found to be important for coagulant selection. Raw waters coagulated with PACls containing sulfate were found to have the best settling characteristics, but showed the highest headloss rates in direct filtration applications. Dissolved air flotation (DAF) performance was relatively insensitive to coagulant type.
Skip Nav Destination
Article navigation
March 2006
This article was originally published in
Journal of Water Supply: Research and Technology-Aqua
Article Contents
Research Article|
March 01 2006
Selection of alum and polyaluminum coagulants: principles and applications
David J. Pernitsky;
1CH2M HILL, 800 6th Avenue SW, Suite 1500, Calgary, AB, T2P 3G3,Canada
Tel.: +1 403 237 9300 Fax: +1 403 237 7715; E-mail: [email protected]
Search for other works by this author on:
James K. Edzwald
James K. Edzwald
2Civil and Environmental Engineering, 18 Marston Hall,University of Massachusetts, Amherst, MA 01003, USA
Search for other works by this author on:
Journal of Water Supply: Research and Technology-Aqua (2006) 55 (2): 121–141.
Article history
Received:
January 03 2005
Accepted:
October 04 2005
Citation
David J. Pernitsky, James K. Edzwald; Selection of alum and polyaluminum coagulants: principles and applications. Journal of Water Supply: Research and Technology-Aqua 1 March 2006; 55 (2): 121–141. doi: https://doi.org/10.2166/aqua.2006.062
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
eBook
Pay-Per-View Access
$38.00