Investigation and Evaluation of the Performance of Solidified Cellulose and Starch Xanthate Heavy Metal Sludges

摘要

This report presents the results of a laboratory investigation that evaluated the potential for metals to leach from cellulose and starch xanthate sludges and compares the results to the metal leaching characteristics of hydroxide precipitated sludge. Sludges were prepared using cellulose xanthate, starch xanthate, or calcium hydroxide to treat a synthetic waste solution containing four heavy metals (Cd, Cr, Ni, Hg) in a laboratory-scale study. Sludges were solidified with portland type I cement. Solidified and unsolidified sludges resulting from starch xanthate, cellulose xanthate, and hydroxide precipitation processes were tested for their physical and chemical characteristics. Physical tests performed on the solidified and unsolidified xanthate and hydroxide sludges included unconfined compressive strength and cone index tests. Chemical leaching characteristics of the unsolidified and solidified sludges were determined using the US Environmental Protection Agency's extraction procedure test and a serial batch extraction procedure.