AWWA ACE68644

This powerpoint presentation begins by providing background information on the issue of algal toxins in surface water treated for potable consumption. The characterization of raw water is presented, along with treatability testing including Ozone and Ozone/Peroxide, UV and UV/Peroxide, GAC and PAC, Biologically Active Filtration, and NF and RO Membranes. Presentation summary includes the following: raw water toxin concentrations highly variable; activated carbon can provide about 50% removal at modest doses (10 mg/L PAC dose and 5-min EBCT GAC bed); ozone very effective (highly pH dependent); UV only effective at high doses (higher than typical water treatment dosages); Biological Treatment -- 30% removal, not a preferred mode of treatment; and, membrane treatment provided very effective treatment -- 95% removal under most circumstances. Includes figures.