AWWA WQTC65966

In this study, the fouling behavior of nanofiltration (NF) and reverse osmosis(RO) membranes during filtration of feed water containing both inorganic colloidalmaterials and dissolved organic matter (DOM) was investigated. Fouling experimentswere systematically performed in a cross-flow filtration system with both NF and ROmembranes to determine how interactions between DOM compounds and colloidalmaterials affect the fouling process and hence membrane permeate flux. Two organicmacromolecules of distinct adsorptive properties, dextran and bovine serum albumin(BSA), were used as model DOM compounds. In all cases, flux decline in combinedfouling by feed waters containing both inorganic colloidal materials and DOM wassignificantly higher than the additive sum of contributions from individual foulants. Twodifferent mechanisms causing the observed synergistic effect in combined fouling wereidentified: hindered back diffusion and macromolecule mediated colloidal interaction.The controlling mechanism depends on the type of organic macromolecules. It was alsofound that the physical properties of the combined fouling layer and its impact onmembrane flux and salt rejection highly depend on the salt rejection of the membrane. Includes 8 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

10

File Size:

1 file , 180 KB