In Furnace Capture of Heavy Metals by Sorbents during Simulated MSW Incineration

摘要

Heavy metal capture experiments were carried out in a tube furnace to investigate the effect of different sorbents and Si-Al ratios on the capture of Zn, Cu, Pb, Cd and Cr during simulated MSW incineration. The incineration bottom ash was digested by aqua regia and HCl/HNO_3/HF, then determined by ICP-AES. Experimental results indicate that HCl/HNO_3/HF is more suitable for the digestion of incineration bottom ash than aqua regia; the volatilization capacities of the five metals during simulated MSW incineration at 1000°C follow the sequence of Pb > Cd > Cu > Cr > Zn; zeolite and limestone have a certain efficiency to capture Zn and Cr while kaolinite has no efficiency to capture all the five metals; the addition of kaolinite and zeolite can prevent the glass and brick powder from melting which can cause the package of heavy metals, but the addition of zeolite can promote Zn and Cr to form silicate, aluminate and aluminosilicate; the mixture of SiO_2 and Al_2O_3 is in favor of the adsorption of Cd and Cr, but against the adsorption of Pb and Cu compared with single SiO_2 or Al_2O_3.