AWWA ACE65397

The most commonly used indices for determining the suitability of feedwater for reverse osmosis (RO)treatment are the silt density index (SDI) and the modified fouling index (MFI). Theseindices, especially SDI, are not considered to be a representative measure of theparticulate fouling potential of RO feedwater in all cases. In this study, a cross-flowsampler (CFS) has been developed to select the particles that are most likely to depositand cause fouling. Combined with the upstream CFS, the SDI/MFI was systematicallymeasured to detect the fouling potential of various feedwater with different pretreatmenttechniques. Results showed that the SDI and MFI values obtained with the CFS systemwere not proportional to standard SDI and MFI indices except when tight microfiltration/ultrafiltration (MF/UF)pretreatment was used. Because the CFS system was operated at similar hydrodynamicconditions as in a RO process, the SDI and MFI measurements obtained using the CFSsystem could serve to be a more appropriate method to measure fouling indices. As partof future work, the indices obtained after CFS system would be compared to flux declinebehavior of various source waters to determine the sensitivity in measurements and, hence,predict RO flux decline. Includes 10 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2007

Number of Pages:

46

File Size:

1 file , 520 KB