Characterization and phosphate stabilization of dusts from the vitrification of MSW combustion residues

摘要

The use soluble PO~3- _4 as a heavy metal chemical stabilization agent was evaluated for a evaluated for a dust generated from melting or vitrification of municipal solid waste combustion residues. Vitrification dusts contain high concentrations of volatile elements such as Cl, Na, K, S, Pb, and Zn. These elements are present in the dusts largely as simple salts (e.g. pbCl_2, ZnSO_4) which are highly leachable. At an experimental dose of 0.4 moles of soluble PO~3- _4 per kg of residue, the pH-dependent leaching (pH 5,7,9) showed that the treatment was able to reduce equilibrium concentrations by factors of 3 to 100 for many metals; particularly Cd, Cu, Pb and Zn.