Full Description

Utilities that treat water containing high concentrationsof arsenic (As) face the challenge of preventingAs mobilization from residuals. Sometreatment plants prepare residuals for disposal to alandfill by placing them in a lagoon and allowing thesolids to dry naturally over months or even years.Other utilities use mechanical dewatering to removewater from residuals. In either case, the As in dryingponds must be immobilized to protect public healthand prevent recontamination of water sources withAs through leakage or infiltration. Furthermore,before residuals can be disposed of in a landfill, theymust meet individual state requirements. This studyprovides insight into the mechanisms of As immobilization,specifically the mechanism by which calcium(Ca) prevents As release. Bench-scale lagoon testswere conducted on residuals from treatment plants.Results indicated that many parameters contribute tosoluble As mobilization, but Ca in the form of limemay prove to be an effective method that water supplierscan use to immobilize As in ferric and alumresiduals. Includes 15 references, tables, figures.

Product Details

Edition: Vol. 95 - No. 6 Published: 06/01/2003 Number of Pages: 11File Size: 1 file , 320 KB