AWWA WQTC69361

AWWA WQTC69361 Evaluation of Alternative Taste and Odor Removal Technologies through Bench Scale Testing for Full Scale Application
Conference Proceeding by American Water Works Association, 11/01/2008

Slabaugh, Rebecca; Jousset, Stephane; Sullivan, Laurie; Burch, Richard; Dahl, David; Heeke, Bruce

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This powerpoint presentation begins by presenting study objectives that includeevaluating the following technologies for the removal oftaste and odor (T Granular Activated Carbon (GAC) Rapid Small-Scale ColumnTesting;Ultraviolet Advanced Oxidation Process (UV AOP); and,Ozonation Advanced Oxidation Process (Ozone/Hsub2/subOsub2/sub). Pac testing matrix produced the following conclusions: calgon WPH carbon performed best;chlorine will reduce PAC performance by at least 10-20%;moving chlorination downstream of PAC application willimprove MIB removal downstream of clarification,on top of filters andat clearwell entrance; and,a secondary treatment system is needed to achieve an MIBfinished water target level of 5 ng/L. UV AOP testing produced the following conclusions: UV AOP showed over a 99.999% (5 log) reduction in MIB;other water quality parameterswere not impacted (TTHM, HAA5, turbidity, alkalinity, and iron);use of UV AOP resulted in a small increase in AOC concentration;UV AOPs need to be located downstream of filtration; and,quenching of peroxide residual is necessary. Ozonation AOP testing produced the following conclusions: AOC levels increase as ozone doses increase, andwould require biological filtration using granular media;ozone alone can reduce MIB to very low levels;ozone should be located upstream of filtrationin order to remove AOC; and,would expect about 5% improved performancewith peroxide. Granular Activated Carbon (GAC) Rapid Small-Scale ColumnTesting (RSSCT) produced the following conclusions: Calgon F400 performed best;modifying current filters for use as GAC filter adsorbers wouldnot be practical because TOC pre-loading greatly impacts theability to remove MIB, and at least two change-outs of GAC wouldbe needed per year, with one change-out happening rightbefore Tpost-filter contactors, operated seasonally, would providerequired taste and odor removalused in combination with PAC, EBCT = 7 min andwithout PAC, EBCT = 15 min; and,operated for 90 days of the year when taste and odorevents are expected to occur. Includes tables, figures.