PROCESS FOR THE RECOVERY OF HEAVY METALS SUCH AS LEAD FROM METAL CONTAMINATED SOIL

摘要

A process for the decontamination of a metal contaminated soil aggregate so asto obtain a product comprising a treated soil component having a metal contentlower than that of the metal contaminated soil aggregate, the metalcontaminated soil aggregate comprising at least one metal selected from thegroup comprising Pb, Hg, Cu, Cd, Zn, Ag, Ni, Co, Ga and Cr, the contaminatedsoil aggregate comprising a classified soil fraction representing soilparticles having a size of from 0.15 mm and smaller, comprising: providing aninitial aqueous soil slurry comprising the contaminated soil aggregate,admixing at least one water soluble dialkyldithiocarbamate with the initialsoil slurry so as to obtain a product aqueous soil slurry comprising one ormore water insoluble metal-dialkyldithiocarbamate complexes, and separatingone or more of the insoluble metal-dialkylthiocarbamate complexes from theproduct aqueous soil slurry so as to obtain a treated product aqueous slurrycomprising a treated soil component having a metal content lower than that ofthe metal contaminated soil aggregate, wherein the metal moiety of the one ormore water insoluble metal-dialkyldithiocarbamate complexes is a member of thegroup comprising Pb, Hg, Cu, Cd, Zn, Ag, Ni, Co, Ga and Cr.