Because of byproducts from algal blooms (e.g., 2-
methylisoborneol [MIB] and geosmin), many water
utilities struggle to provide aesthetically pleasing water.
Most utilities choose to combat these taste and odor
episodes by dosing powdered activated carbon (PAC)
at the beginning of their treatment process because it is
relatively inexpensive, easy to dose, and requires little
maintenance. However, this practice can have several
deficiencies, rendering it less effective for MIB removal.
Few studies have been conducted on the use of commercially
available granular activated carbon (GAC) as
a cost-effective, plausible treatment technology for
ensuring that customers receive potable and palatable
water. No papers compare various commercially available
carbons for their ability to adequately retain MIB
once the odor episode ceases. Thus, because GAC
avoids the problems cited with PAC addition, the purpose
of this study was to compare the performance of
various activated carbons, both virgin and reactivated,
to determine whether GAC offers a plausible strategy
for combating taste and odor episodes.
Rapid small-scale column tests were used to compare
virgin, conventionally reactivated, and steam
pyrolysis-reactivated GACs for their performance in
removing MIB and for their ability to retain MIB when
the odor episode subsided. Two clarified waters were
used to compare the differences in GAC performance
for MIB removal when in competition with differing
concentrations of total organic carbon. Although the
virgin wood-based GAC processed more bed volumes
before initial breakthrough and before surpassing the
odor threshold concentration than did the coal-based
virgin GACs, its affinity for MIB when the odor episode
subsided was the weakest. However, the physically
activated and reactivated carbons had excellent affinities
for MIB after the odor episode concluded. Includes 29 references, tables, figures.
| Edition : | Vol. 97 - No. 6 |
| File Size : | 1
file
, 320 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 12 |
| Published : | 06/01/2005 |
