단일 및 다단계 세척이 중금속 오염토양의 토양세척 효율에 미치는 영향

초록

This research was performed to estimate the effect of one or multi step extraction on soil washing efficiency of heavy metals-contaminated soil. The contaminated soil was obtained from the site near smelting factory. The soil was highly contaminated in approximately 15,000 mg/kg by Pb. 0.05 M EDTA and 0.1 M citrate solutions were selected for soil washing of the contaminated soil. After 1 hr-5 step extraction, Pb removal efficiencies of contaminated soil were 84.44% in EDTA and 70.42% in citrate solution, respectively. For EDTA soil washing, Cu removal efficiency in 1 hr-5 step extraction increased to 57%, while it was 35% in 12 hr-one step. For citrate soil washing, Pb removal efficiency in 1 hr-5 step extraction greatly increased to 70.4%, compared to 44.5% of 12 hr-one step. Multi step extraction efficiency was shown more distinctly in citrate than EDTA. After 0.05 M EDTA soil washing, TCLP results for Pb permitted EPA regulatory level in both 12 hr-one step and 1 hr-5step extraction. However, TCLP result for Pb did not permit EPA regulatory level in 12 hr-one step extraction using 0.1 M citrate. Danger Indices after EDTA soil washing were more decreased than citrate.

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