Eight USA soils were used for this study. The purpose of this study is to illustrate the characteristics of metals in the soil based on the sequential extraction with increasing pH. Extracts were analyzed for metals by ICP-MS and for dissolved organic carbon(DOC). As the pH increasing, the DOC extracted in each increment initially decreased and reached the minimum at pH 3 and then increased substantially at higher pH values. According to the pH increasing, the extraction of Ca, Cu, and Zn were illustrated as L type. It was found that there were strong correlation between the extracted Fe and DOC(r=0.64～0.97).

Electrokinetic technique was considered in removing arsenic from the abandoned mining tails. In order to estimate the removal characteristics of arsenic, the sequential extraction analysis and desorption experiment were carried out prior to the application of electrokientic process. The result of sequential extraction analysis indicated that the water soluble and exchangeable fraction, easily leachable to ground water, were very low as much as about 2.5% and the fraction except residual (38.3%), possibly extractable under very acidic or alkalic environment, was about 59%. In the result of desorption test using four different kinds of electrolytes, the mixture of citric acid and sodium dodecyl sulfate (SDS) showed the highest desorption efficiency as much as 77.3%. The removal efficiencies of arsenic from mining tailings by electrokinetic process under the different electrolyte environments were slightly low and resulted in the following order: citric acid + SDS (18.6%) > 0.1 NHNO3 (8.1%) > HAc (7.4%) > Distilled water(6.6%). Also, arsenic in soil matrix was moved favorably in the direction of anodic rather than cathodic region, which is opposite trend with cationic metal ions generally existing in soil, because anionic form of arsenic is dominated in acidic soil caused by the movement of acid front form anode.

Oxidative TCE decomposition over TiO2-supported single and complex metal oxide catalysts has been conducted using a continuous flow type fixed-bed reactor system. Different types of commercial TiO2 were used for obtaining the supported catalysts via an incipient wetness technique. Among a variety of titanias and metal oxides used, a DT51D TiO2 and CrOx would be the respective promising support and active ingredient for the oxidative TCE decomposition. The TiO2-based CrOx catalyst gave a significant dependence of the catalytic activity in TCE oxidation reaction on the metal loadings. The use of high CrOx contents for preparing CrOx/TiO2 catalysts might produce Cr2O3 crystallites on the surface of TiO2, thereby decreasing catalytic performance in the oxidative decomposition at low reaction temperatures. Supported CrOx-based bimetallic oxide systems offered a very useful approach to lower the CrOx amounts without any loss in their catalytic activity for the catalytic TCE oxidation and to minimize the formation of Cl-containing organic products in the course of the catalytic reaction.

To obtain the safety evaluation of the ginseng, residues of heavy metals in culture environment of ginseng on Punggi and Sangju, Kyeongbuk are surveyed. The concentration for component of ginseng on Punggi and Sangju were 14.12 mg/kg and 15.74 mg/kg, respectively. The concentration for general component such as crude fiber, ash, crude lipid, crude protein, carbohydrate, of ginseng were coincided between Punggi and Sangju. The concentration for As, Pb, Cd, and Hg in soil on Punggi were 14.24 ppb, 43.13 ppb, 8.73 ppb and 0.82 ppb, respectively. The concentration for As, Pb, Cd, and Hg in soil on Sangju were 19.20 ppb, 54.82 ppb, 15.90 ppb and 1.04, respectively. Residual heavy metals are not polluted in the soil with culture ginseng on Punggi and Sangju. The concentration for As, Pb, Cd, and Hg with ginseng on Punggi were 29.30ppb, 21.78 ppb, 1.32 ppb and 2.72 ppb, respectively. The concentration for As, Pb, Cd, and Hg with ginseng on Sangju were 3.22 ppb, 24.43 ppb, 1.44 ppb and 4.74 ppb, respectively. Also the detection concentration for As, Pb, Cd, and Hg in ginseng were also lower than the Korea Food & Drug Administration advisory level for heavy metal in herbal medicines. Residual heavy metals are not polluted in the ginseng on Punggi and Sangju at Kyeongbuk, Korea.

Type 304 stainless steel 시편에 느슨하게 붙어있는 분말에 대한 초음파 제염 거동을 조사하였다. 매질을 물, PFC 및 의 음이온 계면활성제를 함유한 PFC 용액으로 변화시킴에 따라 제염계수는 20, 50 및 200으로 증가하였다. 제염계수에 차이가 생기는 이유를 초음파 매질의 표면장력 및 양으로 하전된 산화물 표면과 음이온 계면활성제 사이의 상호작용에 기인한 것으로 설명할 수 있었다. 음이온 계면활성제를 함유한 PFC 용액 내에서 분말로 오염된 평면 시편, 파이프 시편, 틈새 시편 및 용접 시편에 대한 초음파 제염 효과를 관찰하였다. 연구된 모든 시편에 대해, 대부분의 오염물이 완벽하게 제거되는 것으로 나타났다. 길이가 6cm인 파이프 시편에 대해서는 오염물의 가 제거되었다.