Full Description

The analysis of total organic halogen (TOX) in drinking water indicates that asubstantial amount of the TOX cannot be accounted for by known specific disinfectionbyproducts (DBPs). The primary aim of the research was to characterize thehydrophobicity and molecular size distribution of the unknown halogenated DBPs usingXAD resins and ultrafiltration membranes. The impact of membrane rejection on the sizeanalysis of unknown TOX was also investigated using chlorinated fulvic acid. Sixfinished waters from different locations and treatment processes were collected andfractionated into various hydrophobicity and molecular size groups. The results indicatethat most unknown TOX is in the size range between 0.5 kDa and 10 kDa, but it can havea wide spectrum of hydrophobicites. Ultrafiltration membranes were shown to reject asignificant fraction of DBPs with molecular weight (MW) lower than the membranecutoffs. Flushing with deionized water was effective in removing these low MWcompounds from the ultrafiltration cell. A significant reduction in the size distribution ofunknown TOX resulted when low MW DBPs are flushed out of the cell (comparing withclassic parallel ultrafiltration). Coagulation of fulvic acid can significantly reduce the sizedistribution of UTOX formed by chlorine. Includes 22 references, tables, figures.

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Edition: Vol. - No. Published: 11/01/2006 Number of Pages: 19File Size: 1 file , 390 KB