Softening was proposed as a pretreatment for ultrafiltration, which reduces foulants prior to membrane processes. The objectives of this research were to understand the nature of the fouling mechanisms for ultrafiltration when used for waters that either require softening or have been softened, and to use that understanding to determine promising options for the use of softening as a pretreatment before ultrafiltration (UF). Several characteristics of softening, including extent of softening, precipitation kinetics, and hydrophobicity of membrane materials, were investigated as independent variables. Because of softening, both the organic matter concentration and the particle concentration of feed water to ultrafiltration were reduced, thus reducing the degree of fouling. The slow kinetics of softening had little effect on membrane fouling although precipitation directly occurred on the membrane surface in the system during the operation. Detailed images of the membrane surface obtained by scanning electron microscopy confirmed substantial amounts of the precipitates on the surface. In contrast, the hydrophobicity of the membrane material showed a significant effect on the flux decline behavior. Overall, the integrated water treatment of softening and ultrafiltration is shown to be a promising option for hard waters.
Skip Nav Destination
Article navigation
Research Article|
December 01 2003
Effects of characteristics of softening as a pretreatment for ultrafiltration Available to Purchase
J.H. Kweon;
1Department of Civil Engineering, The University of Texas at Austin, Austin, TX 78712, USA
E-mail: [email protected]
Search for other works by this author on:
D.F. Lawler
D.F. Lawler
1Department of Civil Engineering, The University of Texas at Austin, Austin, TX 78712, USA
Search for other works by this author on:
Water Supply (2003) 3 (5-6): 429–435.
Citation
J.H. Kweon, D.F. Lawler; Effects of characteristics of softening as a pretreatment for ultrafiltration. Water Supply 1 December 2003; 3 (5-6): 429–435. doi: https://doi.org/10.2166/ws.2003.0199
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