• 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 Soil and Groundwater Environment
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• v.15 no.3
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• pp.52-60
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• 2010

The stone-dust is an unavoidable by-product of aggregate production, which is produced about 0.8~1.0 million $m^3$ annually. The stone-dust is currently regarded as a hazard material on environment because it is classified as an industrial waste in the Waste Management Law of Korea. At present, the stone-dust is considered as a environmentally hazardous material, and is classified as an industrial waste according to the Waste Management Law of Korea. In this study, we assessed the heavy-metal contamination of the stone-dust on surrounding environments by various leaching tests. Leaching experiments (such as Korea Standard Leaching Procedure (KSLP), Soil Environment Preservation Act of Korea (SEPAK), Toxicity Characteristic Leaching Procedure (TCLP), and Synthetic Precipitation Leaching Procedure (SPLP)) show that very low heavy metals (As, Cd, Cu, Pb, Zn, Hg) and CN are leached out, or much less than each regulatory thresholds. The resuts of the leaching test with time in acidic solution (initial pH 5 and 3) indicate that pH-buffering minerals are present in the stone-dust. These results suggest that the stone-dust can not potentially affect adverse impact on surrounding environments such as surface water, groundwater and soil etc..

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.72-83
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• 2024

Most of the slags generated from steel-making industry in Korea are recycled into media-contact aggregates such as fill and cover materials. For their use as media-contact aggregates, the slags must meet not only the waste quality criteria, but also the Daphnia magna acute toxicity test criteria. In this study, Korean Leaching Test ES 06150.e (Korea), Japanese Leaching Test JIS K 0058-1(Japan), Detuch Leaching Test DIN 19529 (Germany), Toxicity Characteristic Leaching Procedure (USA) were conducted for batch leaching test of slags from 6 Korean steel-making companies. In addition, Korean Standard up-flow percolation test (ES 06151.1) mimicking field conditions was conducted to assess the impact of the slag leachate on the surrounding environment indirectly. Heavy metals such as Cr⁶⁺ and Zn²⁺ were detected from both extractant and leachate samples, but all of them did not exceed waste quality criteria of each country. However, Daphnia magna acute toxicity tests using the leachate samples from up-flow percolation test with slag alone and slag/natural soil conditions exceeded ecotoxicity standard (TU=2) due to their high pH (11.3-12.5). After neutralizing the pH of the slag leachate to 6.5~8.5, the Daphnia magna mortality and immobilization were reduced to satisfy ecotoxicity standard. As the reducing pH of slag leachate would be extremely difficult, appropriate recycling management considering the physicochemical characteristics of he slags should be stuided further.

• 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 Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.1-5
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• 2011

Arsenic is one of the most abundant contaminant found in waste mine tailings and soil around refinery, Because of its carcinogenic property, the countries like United States of America and Europe have made stringent regulations which govern the concentration of arsenic in soil. The study focuses on solidification/stabilization for removal of arsenic from soil. Cement was used to solidify/stabilize the abandoned soil primarily contaminated with arsenic (up to 68.92 mg/kg) in and around refinery. Solidified/stabilized (s/s) forms in the range of cement contents 5-30 wt % were evaluated to determine the optimal binder content. Revised Korean standard leaching tests (KSLT), toxicity characteristic leaching procedures (TCLP), Old Korea standard leaching test and revised Korea standard leaching test were used for chemical characterization of the S/S forms. The addition of 10 % cement remarkably reduced the leachability of arsenic in contaminated soil. The concentration of As in leachate of TCLP, KSLT, and old KSLT for soil are below the standard. However that in leachate of revised KSLT is above the standard. Because of extraction fluid used in revised KSLT is very strong acid. It is arsenic in s/s with binder should be exhaustingly leached. Therefore S/S process would not be available for As treatment in soil in Korea.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.427-437
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• 2013

Generation rate of construction wastes in Korea has occupied preponderantly in recent years. To understand chemical properties of recycled concrete aggregate (RCA), RCA samples were tested for their leaching characteristics. Leaching tests were conducted according to Korean Standard Leaching Test (KLT) and Toxicity Characteristics Leaching Procedure (TCLP) respectively. The RCA samples were characterized using X-ray fluorescence (XRF). Alkalinity of the leachate was determined using a pH meter titration method. The XRF analysis result shows that the calcium oxide (CaO) content in the RCA sample is 25.3~50.4 %. When the RCA sample was mixed with water in a batch reactor, pH in the solution was rapidly increased, and 70% of the total pH change was found in 1 hour. The TCLP showed slightly higher efficiency for leaching heavy metals than the KLT. The leaching efficiency was also higher as the particle size of RCA sample was smaller. The leaching test results suggest that RCA can be generally classified as nonhazardous waste.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.255-260
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• 2010

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.

• International Journal of Concrete Structures and Materials
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• v.7 no.2
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• pp.111-117
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• 2013

Heavy oil fly ash (HOFA) is a byproduct generated by the burning of heavy fuel oil. Chemical analysis showed that HOFA is mainly composed of unburned carbon with a significant amount of heavy metals. Due to toxicity, management of this waste poses a challenge to the industry personal. The present study investigates the possible use of HOFA as a black pigment or admixture in cement mortar aiming to produce ornamental brick. In order to investigate the change of cement mortar strength when HOFA is added, the standard compressive strength test with 50 mm cubes was performed. The results showed that the addition of 2-5 % of HOFA in cement mortar does not affect its strength. The leaching behavior of trace elements within HOFA and HOFA mixed mortar were investigated through laboratory batch leaching experiments. The results confirmed that HOFA can be utilized as a black pigment in ornamental brick, which is environmentally safe and provides good balance between color and brick properties.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.276-284
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• 2022

In this study, performance evaluation and rheological characteristics were analyzed for recycling the fine powder of nuclear power plant dismantled waste concrete as a solidifying agent for radioactive waste disposal. The radioactive concrete fine powder was used to prepare a simulated sample, and the test specimen was prepared using Di-water, CoCl₂, and 1 mol CsCl aqueous solution as mixing water. Regardless of the aggregate mixing ratio and the type of mixing water, it satisfies the performance standard of 3.45 MPa for compressive strength at 28 days of age. All specimens satisfied the criteria for submersion strength, and the thermal cycle compressive strength satisfies the criteria for all specimens except Plain-50. As a result of evaluating the rheological properties of the solidifying agent, it was found that the increase in the aggregate mixing rate decreased the yield stress and plastic viscosity. The leaching index for cobalt and cesium of all specimens was 6 or higher, which satisfies the standard. In order to secure the stable performance of the solidifying agent, it is considered effective to use 40 % or less of the aggregate component in the solidifying agent.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.453-458
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• 2001

This study was performed to reuse the dyeing wastewater sludge treated by Fenton process through the solidification/stabilization technique. To solidify the dyeing sludge the industrial by-products such as blast furnace slag, fly ash and waste sand with cement were used. The laboratory scale and pilot scale test were conducted at room temperature to make construction brick which has high compressive strength and low leaching of heavy metals. The experimental results showed that blast furnace slag and fly ash could be used instead of cement and the products satisfied the regulation of Korean Standards. The blast furnace slag increased the compressive strength and the optimum ratio of slag/dyeing sludge on dry basis was found 0.4. The solidifying agent of SB series could increase rapidly the compressive strength and the optimum ratio of solidifying agent/sludge on dry basis was 0.26 at which the strength was two times compared with non-added condition. The portion of waste and industrial by-products in matrix was over 80%. From the pilot test the optimum pressure in molding was 100kg/$\textrm{cm}^2$ at which the compressive strength was over 100kg/$\textrm{cm}^2$. And the strength increased continuously to 160kg/$\textrm{cm}^2$ until 120 days curing time due to pozzolanic reaction. When SB-20 as a solidifying agent was used, the unconfined compressive strength of dyeing sludge could be obtained 110kg/$\textrm{cm}^2$ which satisfied the regulation of cement brick in Korea Standard(KS).