AWWA WKICO66062

This powerpoint presentation begins by introducing a case study of Cr(VI) at Glendale, California. The methods for analyzing contaminant removalprocesses are examined and include:XRF, XRD, SEM, chemical tests, XAFS, leachingprocedures. Treatment implications fromanalytical results included:low pH is necessary for maximizing Cr(VI) capacity onWBA resins (but not SBA resins) - protonation of aminegroup, less OH- competition, HCrO₄<sup>-M/sup> speciation; Cr(VI) is reduced to Cr(III) by the two WBA resins,perhaps after being adsorbed;Cr is not retained on the resins in the form of smallprecipitates - added stability;lack of crystalline solids suggests another electron donorperhaps part of the ion exchange functional groups or thebackbone of the resin material; other elements are simultaneously removed by the WBAresins, such as U, V, and Cu - may limit operational life.Disposal options for treatmentresiduals are listed, along with TCLP Results, CWET Results, and Total Uranium Results. Summary and Conclusions: mechanism of WBA resin treatment involvesreduction of Cr(VI) to Cr(III);no evidence of crystalline Cr(III) precipitates on theresins;WBA resins likely to be classified as non-hazardous waste byfederal standards and hazardous waste by California standards; and,uranium accumulation may limit useful operationallife of one resin rather than capacity. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/2008

Number of Pages:

30

File Size:

1 file , 1.2 MB