논토양 안정화 현장 실증 시험을 통한 납, 구리의 용출 저감 및 벼로의 식물전이 특성 규명

Abstract

) and steel making slag as the immobilization amendments for Cu andPb contaminated farmland soils was investigated by batch tests, continuous column experiments and the pilot scalefeasibility study with 4 testing grounds at the contaminated site. From the results of batch experiment, the amend-ment with the mixture of 3% of limestone and 2% of steel making slag reduced more than 85% of Cu and Pbcompared with the soil without amendment. The acryl column (1 m in length and 15 cm in diameter) equippedwith valves, tubes and a sprinkler was used for the continuous column experiments. Without the amendment, the Pbconcentration of the leachate from the column maintained higher than 0.1 mg/L (groundwater tolerance limit). How-ever, the amendment with 3% limestone and 2% steel making slag reduced more than 60% of Pb leaching concen-tration within 1 year and the Pb concentration of leachate maintained below 0.04 mg/L. For the testing groundwithout the amendment, the Pb and Cu concentrations of soil water after 60 days incubation were 0.38 mg/L and0.69 mg/l, respectively, suggesting that the continuous leaching of Cu and Pb may occur from the site. For the test-ing ground amended with mixture of 3% of limestone + 2% of steel making slag, no water soluble Pb and Cu weredetected after 20 days incubation. For all testing grounds, the ratio of Pb and Cu transfer to plant showed as fol-lowing: root > leaves(including stem) > rice grain. The amendment with limestone and steel making slag reducedmore than 75% Pb and Cu transfer to plant comparing with no amendment. The results of this study showed thatthe amendment with mixture of limestone and steel making slag decreases not only the leaching of heavy metalsbut also the plant transfer from the soil.