• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.149-161
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• 1999

In this study, to examine the applicability of the lime sludge as a landfill liner, 1) the geoechnical characteristics of sludge, 2) the characteristics of migrations of contaminants, and 3) the characteristic of leaching in the batch leaching test are investigated As a result, the hydraulic conductivity(K) of the lime sludge was found out to have 10 times lower hydraulic conductivity than the maximum allowable hydraulic conductivity of the liner Retardations of heavy metals(Cu, Pb) were found out to be higher than that of organic(phenol) due to the high pH(>11.0) of 4he lime sludge. As a result of the leaching test. the concentrations of Pb and Cu were found to be close to allowable limitation, so that they need to be kept in constant watch.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.21-31
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• 2003

IAEA, FT-04-020, and ANS 16.1, standard leaching test methods, were evaluated comparatively with their test results. Leaching index of Co-60 and Cs-137 for all waste forms were above 6.0. Their leaching behavior were contrary according to the type of matrix and leachant. Leachability of Co in cement waste form was higher in simulated seawater than demi. water, and higher in demi. water in paraffin waste form. Leachability of Cs was contrary to Cs. Cumulative fraction leached of Co was higher such as IAEA＞ANS＞FT in cement waste form.

• Nuclear Engineering and Technology
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• v.22 no.4
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• pp.315-325
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• 1990

The analytical repository source term (REPS) computer code is developed for the safety assessment of radioactive waste geologic repository. For reliable prediction of the leach rates for various radionuclides, degradation of concrete structures, corrosion rate of waste container, degree of corrosion on the container surface, and the characteristics of radionuclides are considered in this REPS code. For the validation of the radionuclide leach rates predicted by the REPS model, the calculated leach rates of Cs-137, Sr-85, and Co-60 are compared with two reported leaching test results. Cesium and strontium leach congruently, and the leaching test results of these species can be reproduced by the congruent leaching model included in the REPS model. In case of cobalt, the solid diffusion model is in good agreement with the leaching test results.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.1 no.1
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• pp.93-103
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• 2003

IAEA, FT-04-020, and ANS 16.1, standard leaching test methods, were evaluated comparatively with their test results. Leaching index of $^{60}$ Co and $^{137}$ Cs by ANS 16.1 method for waste forms of paraffin and cement were above 6.0. Their leaching behavior were depending on the type of matrix and leachant. Leachability of $^{60}$ Co for cement waste form was higher in simulated seawater than do-mineralized water, and was higher in de-mineralized water for paraffin waste form. leachability of $^{60}$ Co was contrary to $^{137}$ Cs. Cumulative fraction leached of $^{60}$ Co was higher in order or IAEA ＞ ANS ＞ FT in a cement waste form.

• Journal of the Korean GEO-environmental Society
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• v.11 no.6
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• pp.77-83
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• 2010

In this study, we tried to determine any detrimental effects on water quality when bottom ash obtained from a coal-fired power plant intended to be used as a fill material in construction sites. Physical-chemical properties of bottom ash were determined using proximate analysis, elemental analysis, XRD, and XRF. Classification of bottom ash as a waste material and soil contamination due to the use of bottom ash were performed by Korea waste standard leaching test and soil toxicity test, respectively. Results of leaching tests were compared to the regulations for water quality and groundwater quality and no harmful effects on water quality were found. Most of heavy metals in leachate were below detection limits but trace amount of $Cr^{6+}$ was found. However, concentration of $Cr^{6+}$ was below the regulation criteria. Column leaching tests indicated that concentrations of Pb and Zn were slightly higher than regulations but below regulations within 1 PVE, but concentrations of sulfate were 10 times higher than regulation and thus, the required time to reach regulation was almost 8 PVE.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.32-40
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• 2013

This study was objected to evaluate the potential impact on the groundwater environment of the coal bottom ash used as fill materials on the land surface. From four coal-fired power plants, bottom-ashes were collected and analyzed through sequential extraction and column leaching tests following the meteoric water mobility procedure. The column tests shown leaching heavy metals including Pb, As, B, Cu, Zn, Mn, Ni, Ba, Sr, Sb, V, Cr, Mo, and Hg. The relatively high concentrations of B, Sr, Ba, and V in leachate were attributed to both the higher concentrations in the bottom ash and the relatively higher portion of leachable state, sorbed state, of metals. Bottom-ash samples from the D-plant only show high leaching potential of sulfate ($SO_4$), probably originated from the coal-combustion process, called the Fluidized Bed Combustion. Consequently, to manage recycling bottom ashes as fill materials, an evaluation system should be implemented to test the leaching potentials of metals from the ashes considering the absolute amount of metals and their state of existence in ashes, and the coal-combustion process.

• Journal of Environmental Impact Assessment
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• v.16 no.1
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• pp.35-43
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• 2007

Vitrified aggregates obtained by using mine tailings were evaluated using various leaching methods to assess their environmental safety. The leaching tests in this study include continuous batch leaching, Dutch availability leaching, pH-stat and tank diffusion test as well as TCLP (Toxicity Characteristic Leaching Procedure), which is commonly adopted. Vitrification technique has successfully been applied treating some solid wastes containing high level of heavy metals, such as EAF (Electric Arc Furnace) dust and mine tailings. The potentially most leachable element among trace metals was As and theoretically about 7% of total concentrations in the aggregate can be released under extreme condition. Zinc was leached about 4% and the other trace metals including Cd, Cr and Pb were hardly released from the vitrified mine tailing aggregate.

• 연구논문집
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• s.31
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• pp.5-14
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• 2001

These days, interest in the leaching of hazardous heavy metals to consist of incinerator fly ash is increasing, because the heavy metals that leach from the incinerator fly ash pollute the soil and ground water. Therefore this study was undertaken to crystallize the fly ash and prevent the leaching of hazardous heavy metals from fly ash. The concentrations and the leaching concentration of hazardous heavy metals(Cd, Cr, Hg, Pb, Zn) in the law incinerator fly ash have been measured. The fly ash was melted with two kinds of flux($Na_2CO_3, CaCO_3$) and its add quantity(0, 1, 2, 3 wt%). The crystal structure of melting materials was analyzed by SEM(Scaning Electron Microscope) and X-RD(X-Ray Diffractometer). The leaching test of melting materials was undertaken. And the relation between crystallization of melting materials and flux and leaching concentration. These experiments indicate that the concentration and leaching concentration of heavy metals in incinerator fly ash was much higher than the regulatory standard for leachates in Korea and U.S.A and average concentration of heavy metals in soil. And the crystal structure was better.

• Journal of the Korean Chemical Society
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• v.11 no.1
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• pp.33-37
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• 1967

The influence of impurities contained in Marmatite ores on leaching of zinc was investigated. The zinc sulfide having the same crystal structure of natural Sphalerite was prepared by heating the zinc sulfide chemically precipitated, at $650^{\circ}C$ in nitrogen atmosphere. The activation energy of the sample was 25.8 kcal per mole in the leach test when oxygen partial pressure was 5 atm. and the value was exceedingly high compared to that obtained in Marmatite ores. Synthetic zinc sulfides added with small amount of each impurities were treated in same procedure. As a result, it was found that the leaching velocity was accelerated sharply when about 1 percent of $Cu^{++}$ was blended to the sample. Larger amount of iron has also same effect but the effect was minor compared to the copper. The other impurities indicated no appreciable catalytic action.

• Journal of the Korean Wood Science and Technology
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• v.25 no.4
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• pp.92-98
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• 1997

To make good use of chitosan forming complex with heavy metals in wood preservative treatment, woods impregnated with chitosan and copper sulfate were prepared. Amounts of leached copper, decay resistance, anti-mold efficacy, iron corrosion rates, moisture regain rates and degradation pattern in chitosan pre-treated and untreated wood were compared. After leaching test, amounts of leached copper from chitosan pre-treated wood had a much smaller than chitosan untreated wood, and good decay resistance was retained even after leaching test. From these results, it was proved that chitosan-copper complex formed in wood played and important role for decay durability. In chitosan pre-treated wood, damage values by test molds became remarkably smaller, but the growth of test molds was not perfectly inhibited. Distinct differences in iron corrosion rates between chitosan pre-treated and untreated woods was not recognized but chitosan pre-treated wood showed the lower moisture regain rates than chitosan untreated wood because of water insoluble chitosan membrane formed in wood. After leaching test, the tracheid walls in the wood treated with 2.0% copper sulfate only were eroded by the fungal attacks, but those in the wood pre-treated with chitosan remained almost intact.