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Membrane fouling can have a significant impact on the cost, design, and operationof full-scale facilities. To control biofouling, chloramination is one of the fewdisinfectant practices available that does not cause membrane deterioration formany thin-film composite membranes. Although chloramines have been shown tocontrol biological growth, one study showed that a nanofiltration membrane fed achloraminated water had the greatest amount of flux decline as compared to fourother membrane systems that were pretreated differently. Pyrolysis-GC/MS resultsshowed that the cake-layer from the chloraminated system differed chemically fromthe others. Specifically, the chloraminated system had elevated proteinaceousmaterial as opposed to polysaccharides. Two explanations may account for this.The first is that the microbial population was not allowed to flourish on themembrane due to chloramine's biocidal properties, preventing the production ofextracellular material rich in polysaccharides. The second explanation is thatthe chloramines, or free ammonia, chemically reacted with the organics in thecake layer, creating matter that produced prodigious amounts of protein-derivedfragments when pyrolyzed. Likewise, it has also been found that the use ofchloramines adversely affected nanofiltration flux. Therefore, since previouswork demonstrated that nanofiltration membranes fed chloraminated water hadgreater flux declines than other pretreatments, the intent of this work was toevaluate chloramination on nanofiltration fouling for systems fed Little MiamiAquifer water (LMAW) (Indian Hill Water Works, Ohio). Because this study wasconducted over an extended period of time, it was also able to evaluate seasonalwater quality changes on nanofiltration fouling. Includes 13 references, tables, figures.

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Edition: Vol. - No. Published: 05/01/2001 Number of Pages: 17File Size: 1 file , 270 KB