| 초록 |
The soil sample obtained from shooting area contaminated with Pb, Cu, and Zn was investigated to determine the chemical forms of heavy metals with Tessier #x2019;s sequential extraction method, which is constituted of five fractions such as #x2018;exchangeable #x2019;, #x2018;bound to carbonate #x2019;, #x2018;bound to oxide #x2019;, #x2018;bound to organic matter #x2019;, and residual fractions. The amount of organic matter was measured by loss on ignition (LOI) and then the results of #x2018;bound to organic matter #x2019; and LOI were compared. The sequential extraction results show that 4.7%-45% of Pb, 6.2%-25.9% of Cu and 3.9%-15.3% of Zn belong to the #x2018;bound to organic matter #x2019; fraction, but LOI result shows that only 1.0%-2.8% of organic matter exists in the soil sample. In heavy medium separation tests, because Pb and Cu extracted in #x2018;bound to organic matter #x2019; and residual fractions were removed, the heavy metals in the fractions would exist as heavier forms. These results suggest that the part of heavy metal extracted in #x2018;bound to organic matter #x2019; fraction would result from the oxidation of metallic forms by hydrogen peroxide and nitric acid used in the fraction, and, consequently, that the #x2018;bound to organic matter #x2019; fraction should be investigated in detail to determine the removal method and treatment capacity when the Tessier #x2019;s sequential extraction method is used to examine heavy metal contaminants resulted from elemental metal like bullets. |
