Containing Heavy Metals Hazardous Solid Waste Pharmaceutical Stabilizing Treatment And Mechanistic Studies

Medicament stability is a new technique developed in recent years which deals with hazardous waste. Its process is first to add chemical medicaments to waste, then hazardous waste components react with chemical medicaments, so some insoluble compounds are formed to prevent hazardous components leaching from waste. In this paper, the optimum synthesizing process of macromolecule chelate complex is decided (pH:9~10; HTA/[S] = 1.2 (molar ratio); reaction temperate: 50癈; reaction time: 4h),and the substitute degree of chelate complex is 0.568.The influences of pH, quantity of chelate, initial concentration, contacting time and other metal ions coexisting on chelate adsorbing heavy metal are studied. The results indicate that the removal ratios of Cu2+ and Pb2+ are 99.46%, 97.95% respectively, but those of Cr3+and Cd2+ are lower, 89.62% and 75.12% respectively.The properties of waste forms containing chelate are tested. The results show, compared with sample without chelate, toxicity of leachate of waste forms reduces by 66.4%, and far lower than 1.5mg/L. After 28 days, the scalar of surface leaching rate reach 10"6. The compressive strength of waste forms decreases with chelate added, but is still more than SOMPa after 28 days, meeting all the conditions in general construction or landfill.The kinetic of absorbing heavy metals is also discussed. The results indicate that removal ratio of heavy metals in multi-stage adsorption process is more than that in single-stage adsorption process. At the same time IR is applied to study reaction mechanism qualitatively.