• Economic and Environmental Geology
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• v.37 no.1
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• pp.87-98
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• 2004

Tailings and contaminated soils from Cheongyang mine and Seobo mine have been analysed by ICP-AES from 5-step sequential extraction method of multielement determination on extraction solutions at each step. As and Co within tailings and contaminated soils from Cheongyang mine and Seobo mine are mainly in the residual phase. In case of Cd, Cu and Zn, the most dominant fraction for tailings of Cheongyang mine is the oxidizable phase, while tailings of Seobo mine is dominated by the residual phase. In contaminated soils from Seobo mine, the predominant fraction for Cd, Cu and Zn is the Fe-Mn oxide phase. The exchangeable fraction of Pb in tailings from Cheongyang mine and Seobo mine is relatively high compared with those of other metals; whereas Pb fraction in contaminated soils from Seobo mine is largely associated with the residual fraction.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.358-363
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• 2005

A large amount of oyster-shell waste has been illegally disposed at oyster farm sites along the southern coast of Korea, which already created serious environmental problems. Therefore, the study was undertaken to increase the consumption of oyster shell meal as a soil amendment. The effects of oyster shell meal on dynamics of heavy metals and uptake of heavy metals by spring Chinese cabbage were evaluated in silt loam soil (in Gyeongsang National University, Jinju, Gyeongnam-do, Korea), where 0, 4, 8, 12 and 16 Mg $ha^{-1}$ oyster-shell meal fertilizer were added. Lime treatment (2 Mg $ha^{-1}$) was selected as a control. In the results of this study, cabbage yields were increased by increasing levels of oyster-shell meal fertilizer. With increasing levels of oyster-shell meal fertilizer, total heavy metals concentrations were not significant among treatments. However, 0.1N HCl extractable heavy metals concentration was significantly reduced due to increasing of soil pH. A lot of portion (ca. $80{\sim}90%$) heavy metals fraction of all fractions was residual phase in soil after harvesting. The contents of Cu, Mo, Zn in cabbage were slightly increased by increasing levels of oyster shell meal fertilizer. However, there were no toxic symptoms of heavy metals during cultivation. Conclusively, it was estimated that oyster shell fertilizer could be a good amendment to increase productivity of crop and reduce uptake of heavy metals by crop and mobility of heavy metals in soil.

• Journal of Soil and Groundwater Environment
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• v.15 no.5
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• pp.16-22
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• 2010

Heavy metals in soils exist in various forms dependent upon surrounding conditions. As the Janghang smelter area is of concern for its high elevated heavy metal concentrations, Korean government decided to remediate the area. Main objectives of this research were; to analyze heavy metal concentrations and their existing forms in the vicinity of the smelter; and to understand differences made by analysis techniques of heavy metals. Top soils of rice field, crop field, bare field, and forestry in the area were sampled and analyzed for their physicochemical characteristics. Concentrations of Cu, Cd, Pb, and As were analyzed with two pretreatment techniques adopted using 0.1 N HCl and aqua regia. To analyze existing forms of heavy metals, Tessier's schemes for sequential extraction technique were adopted. Exchangeable fraction and carbonate bound fraction of heavy metals may pose potential threat to environment and were in the order of Pb > As > Cu > Cd. If assessing mobile fraction of heavy metals by land uses, the order was forestry > bare land > crop field > rice field. When analyzed using Tessier's scheme, high ratio of residual fractions to total arsenic concentration should be considered for remediation design of the area.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.56-63
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• 2003

Fractional composition and mobility of sediments some heavy metals in Okdong stream are investigated. The fractional scheme for sediment heavy metal was made for five chemically defined heavy metal forms as adsorbed fraction, carbonate fraction, reducible fraction, organic fraction, and residual fraction (Tessier et at., 1979). The most abundant fraction of the sediment heavy metal is reducible and secondly abundant organic fraction. Adsorbed fraction is minor part of the total heavy metals. Mobilization of sediment heavy metals in stream Okdong is occur 19.8∼56.7% of total cadmium concentrate. The most abundant fraction of the sediment metal is organic fraction in Cu, Pb metals investigated. Labile fraction of sediment metals are 0.5%∼48.5% of total Zn, 2.6%∼48.1% of total Pb, 0.2∼36.9% of total Cu respectively, Most of labile fraction consists of reducible fraction for Cd, Zn, adsorbed fraction for Pb, reducible fraction for Cu, adsorbed fraction for Ni. The Mobilization of Zn and Cu is most likely to occur when oxygen depletes and that of Pb and Ni occurs when physical impact, oxygen depletion and pH reduction.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.226-230
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• 2007

The purpose of this study was to analyze harmful heavy metals and residual pepsticides in 30 kinds of oriental medical materials. This study was carried out on 32 samples with 30 kinds of Oriental medical materials. The GC-ECD(Varian, CP-3800) was used to analyze residual pepsticides. ICP-OES(Varian, Vista-MPX) was used to analyze lead, arsenic, cadmium. Mercury was analyzed by amalgamation method. Arsenic was detected less than 3(mg/kg) in 21 samples and was not detected 11 samples. Lead was detected less than 5(mg/kg) in 25 samples and was not detected 7 samples. Mercury was detected less than 0.2(mg/kg) in 12 samples and was not detected 20 samples. Cadmium was detected more than 0.3(mg/kg) in 3 samples was detected less than 0.3(mg/kg) in 17 samples and was not detected 12 samples. A few residual pepsticides was detected, but all residual pepsticides was safe.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.183-191
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• 1991

A study was conducted to determine the influence of soil chemical properties on the distribution and forms of cadmium (Cd), lead (Pb), copper(Cu) and Zinc(Zn) in paddy soils near zinc mines. A sequential extraction procedure was used to fractionate the heavy metals in soils into the designated from of water soluble, exchangeable, organically bound, oxide/carbonate, and sulfide/residual. The predominant form of Cd, Pb, Cu and Zn in the soils was found to be sulfide/residual form. Oxide/carbonate Cd and Pb and organically bound Cu were high, while exchangeable Pb and Cu were very low. Water soluble Cd, Pb and Cu were not detected in the soils. The percentages of the heavy metals content in exchangeable fractions were inversely correlated with those in sulfide/residual fractions in the soils. Exchangeable Cd and Zn and the oxide/carbonate Pb were shifting to the sulfide/residual form with soil depth and the chemical forms of Cu were not changed. Organically bound Cu was positively correlated with soil organic matter content but Cd, Pb and Zn were not. The percentages of Cd, Pb and Zn content in exchangeable forms decreased with soil pH, while those in oxide/carbonate and sulfide/residual forms increased with soil pH. The amounts of oxide/carbonate and sulfide/residual forms of pb were higher than those of Cd and Zn at same soil pH.

• Korean Journal of Metals and Materials
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• v.48 no.9
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• pp.807-812
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• 2010

In this paper, the Ultrasonic Nanocrystalline Surface Modification (UNSM) surface treatment process was used to induce compressive residual stress and nanocrystalline structure by severe plastic deformation on the UNSM-treated surface. The test results for AISI304 stainless steel demonstrated that the grain size was found to be 23 nm, the dislocation density was increased by $0.2085{\times}10^{18}\;m^{-2}$, and the volume fraction of martensite is defined as 27.6% from austenite so that the surface hardness of the surface is increased from 200 Hv up to 515 Hv. The initial tensile residual stress is changed from 300 MPa to a compressive residual stress of 500 MPa after UNSM treatment. In addition, UNSM was applied under five various conditions, and the results of those conditions were defined as a function of depth quantitative.

• Journal of Korean Home Economics Education Association
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• v.19 no.3
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• pp.119-131
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• 2007

This study was to investigate the recognition level of food safety from high school students(264 male, 276 female) in Chuncheon area using questionnaires. The results of the survey are summarized as follows : Regarding the general consciousness of the conditions of food safety, the proportion of the students who worry about it is higher, while 40.0% respond they are not concerned with it. The information pertinent to food safety was usually acquired from the mass media. As a fundamental reason responsible for the food safety accidents, they pointed out deficient sense of responsibility of the personnels who produce, distribute, and sell food products. As the most problematic materials threatening food safety, they pointed out heavy metals(24.8%), and subsequent responses were environmental hormones(24.4%), food additives(17.0%). The foods, for which they are most concerned about residual pesticides, were vegetables and fruits. High proportion of the students perceived that agricultural products are not safe from residual pesticides, and most of the students(92.4%) thought that residual pesticides are bad for their health. The examination on the food safety influenced by heavy metals reveals that 87.4% of the students thought the materials do influence food safety. As the food kind that is likely to be most polluted by heavy metals, they pointed out fishery products. The highest concern about processed food stuffs was the food additives. Most of the students thought that the containers of processed foods may be toxical. 25% of the students are more seriously considering food safety when they buy foods. High proportion of the students who responded they confirm safety-related matters at the time of food purchase thought much of food safety, while high proportion of those who didn't confirm those matters lay a great importance on the taste.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.177-178
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• 2015

Sediments play a major role in determining pollution pattern in aquatic systems and reflecting the pollutant deposition. In the present study analysis the depth effect of organic pollutants and heavy metals using slow release biostimulant ball (BSB) in coastal sediment. BSB size fixed at 3cm, depth varied from 0cm to 10cm depth and 1 and 3 month interval period was carried out for the study. The organic pollutants of chemical oxygen demand, total solids and volatile solids were significantly changed at the surface sediment (0cm)in 1 month and 3 month interval time using BSB. In contrast, sediment depth increase upto 10cm the reduction percentage decrease like to control. Vertical distribution of heavy metals are not consistent from the surface layer toward the bottom layers. Heavy metals fractions were significantly changes, the exchangeable fraction was reduced and other organic and residual fractions were stabilized percentage are increased. This finding concluded BSB is effective for reduce organic pollutants, heavy metals stabilization from the contaminated sediment.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.10a
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• pp.48-71
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• 1996

Rectangular frames of thin sheet metals are press formed during their manufacture. The multistage process includes blanking, stamping, bending, and trimming. After stamping the sheet is subjected to warping and twisting due to residual stresses. The twist is not desirable since it affects the subsequent assembly processes. Study has been performed to predict the twist.