The University of Massachusetts Amherst
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Effect of pre-ozonation on organics removal by in-line direct filtration

TitleEffect of pre-ozonation on organics removal by in-line direct filtration
Publication TypeJournal Article
Year of Publication1993
AuthorsTobiason JE, Edzwald JK, Reckhow DA, Switzenbaum M.S.
JournalWater, Science & Technology
Start Page81
Date Published06/1993
Keywords2-methylisoborneol, assimilable organic carbon, direct filtration, disinfection by-products, dissolved organic carbon, pre-ozonation

A pilot-scale study of the effects of pre-ozonation on the performance of in-line direct filtration was carried out. Performance measures included filtered water turbidity, unit filter run volumes, and organics in filtered waters: DOC, UV254, AOC and DBPs. Continuous operation of four dual media GAC/sand filters with and without pre-ozonation and chlorinated backwash and a dual media anthracite/sand filter were compared to full-scale performance. Pre-ozonation frequently results in longer filter runs, causes a twofold increase in raw water AOC and has little effect on raw water DOC. GAC/sand filters consistently reduced the AOC in the ozone train to levels below that of the full-scale plant and also provided 25 % lower DOC levels as compared to anthracite/sand filters. The effect of ozone and filtration on chlorinated DBPs followed overall DOC removal while DBPs created by ozonation followed AOC removal trends.