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Because of byproducts from algal blooms (e.g., 2-methylisoborneol [MIB] and geosmin), many waterutilities struggle to provide aesthetically pleasing water.Most utilities choose to combat these taste and odorepisodes by dosing powdered activated carbon (PAC)at the beginning of their treatment process because it isrelatively inexpensive, easy to dose, and requires littlemaintenance. However, this practice can have severaldeficiencies, rendering it less effective for MIB removal.Few studies have been conducted on the use of commerciallyavailable granular activated carbon (GAC) asa cost-effective, plausible treatment technology forensuring that customers receive potable and palatablewater. No papers compare various commercially availablecarbons for their ability to adequately retain MIBonce the odor episode ceases. Thus, because GACavoids the problems cited with PAC addition, the purposeof this study was to compare the performance ofvarious activated carbons, both virgin and reactivated,to determine whether GAC offers a plausible strategyfor combating taste and odor episodes.Rapid small-scale column tests were used to comparevirgin, conventionally reactivated, and steampyrolysis-reactivated GACs for their performance inremoving MIB and for their ability to retain MIB whenthe odor episode subsided. Two clarified waters wereused to compare the differences in GAC performancefor MIB removal when in competition with differingconcentrations of total organic carbon. Although thevirgin wood-based GAC processed more bed volumesbefore initial breakthrough and before surpassing theodor threshold concentration than did the coal-basedvirgin GACs, its affinity for MIB when the odor episodesubsided was the weakest. However, the physicallyactivated and reactivated carbons had excellent affinitiesfor MIB after the odor episode concluded. Includes 29 references, tables, figures.

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Edition: Vol. 97 - No. 6 Published: 06/01/2005 Number of Pages: 12 File Size: 1 file , 320 KB