폐기물 소각시설 비산재의 함량-용출 상관관계 도출을 통한 수은화합물 안정도 평가

This study provides the correlation between mercury (Hg) content and leachate concentration of fly ash (FA) from waste incinerators: a municipal solid waste incinerator (MSWI) and a medical waste incinerator (MWI). In addition, the stability and leaching characteristics of Hg were estimated to develop stabilization treatment technology for hazardous waste having the leachate Hg concentration as 0.005 mg-Hg/L based on the waste management law in Korea. As a result of a sequential extraction procedure consists of five-steps, FA (MSWI) and FA (MWI) contained mainly unstable mercury compounds with high solubility or sensitive to changes in pH. The major constituents were found to be Ca, Fe and Si by the x-ray fluorescence analysis. The high alkalinity ([Ca]/[Si]) could affect the conversion of Hg compounds to amphoteric ions, then could contribute to the increasing of F3 fraction from the sequential extraction procedure. Fe could affect oxidation of Hg and increasing the production of HgO. These factors could affect the increase in mobility of Hg compounds in fly ash; spraying lime (Ca(OH2) in air pollution control devices also could affect the high mobility of Hg compounds. Therefore, the development of control technology (e.g. stabilization) of discharged fly ash by considering the chemical properties and stability.