Effective Jan. 23, 2006, the maximum contaminant level
(MCL) for arsenic (As) will be reduced from 50 to 10 ug/L,
and removing As to meet the new MCL is anticipated to cost
US utilities $0.2-0.7 billion per year. These compliance costs will
be greatly reduced if innovative As-removal technologies are
proven and implemented. Using a jar-test protocol, this study
evaluated the performance of conventional coagulation/sedimentation,
microsand-ballasted coagulation, coagulation-assisted
microfiltration, and microsand-ballasted coagulation/microfiltration
to compare the relative effectiveness of innovative coagulation-
based treatment processes on As removal. The various technologies
were evaluated in waters that simulated a variety of
common surface water and groundwater conditions.
Microsand-ballasted coagulation provided promising As
removal in bench-scale tests of simulated waters; however, no
synergistic benefits were observed when it was used as a
pretreatment to microfiltration. Polymer was critically important
to the performance of the microsand-ballasted coagulation
process. Although coagulation/microfiltration typically provided
the best As removal at a given iron dose, microsand-ballasted
coagulation processes are likely to be a promising alternative
method of As treatment if their lower projected capital and
operating costs are proven valid. Utilities screening for least-cost
As-removal techniques to meet the new As MCL may
find this protocol useful in evaluating potential treatment
technologies. Includes 10 references, tables, figures.
| Edition : | Vol. 94 - No. 9 |
| File Size : | 1
file
, 260 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 09/01/2002 |
