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1.
Hua Zhang Pin-Jing He Li-Ming Shao Xin-Jie Li 《Journal of Material Cycles and Waste Management》2008,10(1):7-13
With the increase in the number of municipal solid waste incineration (MSWI) plants constructed in China recently, great attention
has been paid to the heavy metal leaching toxicity of MSWI residues. In this study, the effects of various parameters, including
extractant, leaching time, liquid-to-solid ratio, leachate pH, and heavy metal content, on the release properties of Cd, Cr,
Cu, Ni, Pb, and Zn from MSWI bottom ash were investigated. Partial least-squares analysis was employed to highlight the interrelationships
between the factors and response variables. Both experimental research and geochemical modeling using Visual MINTEQ software
were conducted to study the pH-dependent leaching behavior of these metals in fresh and weathered bottom ash, considering
precipitation/dissolution and surface complexation reactions (adsorption by hydrous ferric oxide and amorphous aluminum oxide/hydroxide).
The results showed that leachate pH was the predominant factor influencing heavy metal leachability. The leaching of Cu, Pb,
and Zn was mainly controlled by precipitation/dissolution reactions, whereas surface complexation had some effect on the leaching
of Cr, Cd, and Ni for certain pH ranges. The modeling results aggreed well with the experimental results.
Part of this work was presented at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission
Control (i-CIPEC) 相似文献
2.
Metallic-phase lead in slag of municipal solid waste incineration ash and leaching characteristics 总被引:2,自引:0,他引:2
Metallic phases in slags and their influence on the leaching characteristics were investigated. The proportions of metallic
phase in four slags were 0.028%, 0.24%, 1.87%, and 3.05% by weight. The lead content was 10–248 mg/kg in bulk slag after metal
removal, while in the metallic phase it was 579–7390 mg/kg. Lead concentrations in the metallic phase were more than ten times
higher than in slags after metal removal. Lead was distributed in the metallic phase at 2.0%, 8.3%, 10.3%, and 47.4%. The
concentrations of all metallic elements in metallic phases were much higher than in bulk slag. Iron, copper, and nickel had
accumulated in magnetic metals, while aluminum and zinc were found in nonmagnetic metals. As regards chromium, manganese,
lead, and tin, the proportion of metallic phases depended on the slag samples. By removing metallic phases, both water and
pH 4 leachable lead decreased. The basic principles of melting residues containing lead are the separation of lead as a metal
in reductive melting, and the containment of lead ions into uniform glassy particles in oxidization melting. Melting slag
can be seen to contribute to environmental preservation by facilitating the recycling of materials through the separation
of metals from melting slag.
Received: February 21, 2000 / Accepted: July 27, 2000 相似文献