Full Description

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 costUS utilities $0.2-0.7 billion per year. These compliance costs willbe greatly reduced if innovative As-removal technologies areproven and implemented. Using a jar-test protocol, this studyevaluated the performance of conventional coagulation/sedimentation,microsand-ballasted coagulation, coagulation-assistedmicrofiltration, and microsand-ballasted coagulation/microfiltrationto compare the relative effectiveness of innovative coagulation-based treatment processes on As removal. The various technologieswere evaluated in waters that simulated a variety ofcommon surface water and groundwater conditions.Microsand-ballasted coagulation provided promising Asremoval in bench-scale tests of simulated waters; however, nosynergistic benefits were observed when it was used as apretreatment to microfiltration. Polymer was critically importantto the performance of the microsand-ballasted coagulationprocess. Although coagulation/microfiltration typically providedthe best As removal at a given iron dose, microsand-ballastedcoagulation processes are likely to be a promising alternativemethod of As treatment if their lower projected capital andoperating costs are proven valid. Utilities screening for least-costAs-removal techniques to meet the new As MCL mayfind this protocol useful in evaluating potential treatmenttechnologies. Includes 10 references, tables, figures.

Product Details

Edition: Vol. 94 - No. 9 Published: 09/01/2002 Number of Pages: 10File Size: 1 file , 260 KB