부산대학교 도서관

Fly ash generated from municipal solid waste incinerator contains high concentrations of hazardous heavy metals. So it must be treated to inhibit their leaching for final disposal. In previous study, it was confirmed that cesium leaching was significantly suppressed after co-heating with aluminosilicates. Cesium was captured in amorphous phase and insolubilized. When this method was applied to municipal solid waste incineration fly ash, a decrease in lead leaching concentration was also confirmed. However, since lead forms hydroxide precipitates at high pH, it is not clear whether the reduction in leaching concentration is due to trapping by aluminosilicates or precipitation formation. The objective of this study was to clarify the chemical form of lead after co-heating with aluminosilicates. After heating of the mixture of aluminosilicates and fly ash and removing soluble lead, pH-dependence test was performed. As a result, the lead leaching concentration increased with decreasing pH, and there was no difference in the elution concentration with and without co-heating. Thus, decrease of leaching concentration of lead after co-heating with aluminosilicates is not capturing but just formation of hydroxides.