The extent of heavy metal pollution in agricultural soils near the abandoned mine land site was investigated using their concentrations from the 47 sampling sites in B mine. Samples were prepared using 0.1N HCl -Korean Standard Methods- and then analysed for Cd, Cu, Pb, As and Cr by Inductively Coupled Plasma Spectrometer. In addition, soil and mine tailing samples were sequentially extracted to investigate the chemical speciation of heavy metals in them. The soils in the vicinity of mining area are highly contaminated by heavy metals ranging up to 5.96㎎ Cd/㎏, 253.3㎎ Cu/㎏, 76.7㎎ Pb/㎏, and 15.45㎎ As/㎏, according to the analysis of Korean Standard Methods. The heavy metal levels by the sequential extraction are much higher than its level by Korean Standard Methods, and little correlated with each other. Based on the results, it is suggested that the As pollution in agricultural soils near the AMLS should be dealt as of prior significance in establishing reclamation strategies for the area.

The pure compound chloromethanes; methyl chloride, methylene chloride, chloroform and carbon tetrachloride were used as a model of chlorocarbon system with Cl/H ratio to investigate thermal stability and hydrodechlorination process of carbon tetrachloride under excess hydrogen atmosphere. The parent thermal stability on basis of temperature required for 99% destruction at 1 second reaction time was evaluated as 875℃ for CH3Cl, 780℃ for CH2Cl2, 675℃ for CHCl3, and 635℃ for CCl4. Chloroform was thermally less stable than CCl4, at fairly low temperatures (<570℃). The decomposition of CCl4, became more sensitive to increasing temperature, and CCl4 was degraded easier than CHCl3 at above 570℃. The number and quantity of chlorinated products decreases with increasing temperature for the product distribution of CCl4 decomposition reaction system. Formation of non-chlorinated hydrocarbons such as CH4, C2H4 and C2H6 increased as the temperature rise and particularly small amount of methyl chloride was observed above 850℃ in CCl4/H2 reaction system. The less chlorinated products are more stable, with methyl chloride the most stable chlorocarbon in this reaction system.