STABILIZATION AND LEACHABILITY TESTS OF MERCURY-CONTAINING WASTES

摘要

This paper summarizes the findings of our studies on mercury stabilization by sulfidetreatment. Primary stabilization variables such as stabilization pH and sulfide/mercurymolar ratio were investigated. Mercury stabilization effectiveness was evaluated usingthe Toxicity Characteristic Leaching Procedure (TCLP) and constant pH leaching tests.The influence of interfering ions on Hg immobilization was also tested. Theexperimental results indicate that the most effective mercury stabilization occurs at pH 6combined with a sulfide/mercury molar ratio of 1. The mercury stabilization efficiencyreached 99%, even in the presence of interferents. The constant pH leaching resultsindicate that sulfide- treated mercury wastes produce significantly higher mercuryconcentrations in high pH (pH >10) leachants relative to others. Nevertheless, themercury stabilization efficiency was still as high as 99%, even with exposure of thewastes to high pH leachants. Therefore, it is concluded that sulfide-induced stabilizationis an effective way to stabilize mercury-containing wastes.