논토양의 환원환경에서 비소 및 중금속의 용출특성과 제강슬래그의 처리효과

Abstract

There have been only a few studies focused on the stabilization of metal (loid)s in anaerobic soils such as paddy soils. In this study, laboratory-scalecolumn tests were conducted to artificially manipulate anoxic conditions in submerged paddy fields and we observed the release behavior of As, Cd, Pb,and Zn, as well as to examine the stabilization effect of steel refining slag (SRS) on the metal(loid)s. The leachate samples were collected and chemicalparameters were monitored during the test period. Results suggest that anoxic conditions were developed during submersion, and that As or heavy metals(particularly Cd) fractions bound to ferrous (Fe) /manganese (Mn) oxides were easily dissociated. Moreover, As is also reduced by itself to a trivalentform with higher mobility in the reducing environment of rice paddy soil. However, it was also shown that SRS significantly decreased the dissolutionof Zn, Pb, Cd, and As in the the leachates; their removal rates in the SRS-treated soil were 66 %, 45 %, 24 %, and 84 %, respectively, of those in the controlsoil.