The origin and behavior of lead, cadmium and antimony in MSW incinerator

The Amendment to the Waste Disposal and Public Cleansing Law in Japan has introduced new regulation of waste requiring strict management. In this regulation, the fly ash generated in the Municipal Solid Waste (MSW) incinerator process was designated as specially controlled solid waste because of relatively high concentrations of lead and cadmium. Furthermore, antimony is a regulated constituent within the Basel Convention on the control of transboundary movements of hazardous wastes and their disposal and was designated a monitor item of environmental standards on water pollution. Thus, in order to understand where the problems lie, the behaviors of these heavy metals in the MSW incinerator was investigated. Also investigated were the kinds of products causing the fly ash to be contaminated. As a result, the amount of lead, cadmium and antimony in household waste was about 120, 3.5 and 7.6g/T, respectively. The major origins of Pb, Cd and Sb from household waste are small sealed lead batteries, nickel-cadmium batteries and flame-proofed products such as curtains and plastic covers. By incineration treatment, these metals shifted to the fly ash (EP ash); the transfer ratio of Pb, Cd and Sb was about 33, 92 and 45%, respectively. The observed results indicated that the partitioning of metals in the MSW incinerator showed the influence of the vapor pressure of the elements and their compounds. Clearly, to produce precise estimates of this behavior, it will be necessary to determine not only the concentration of the elements in the waste but also the compounds used and the changes these would undergo in the furnace. Finally, several measures which will be helpful in solving these problems are introduced to discuss the future direction of environmentally-friendly social systems.