• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.2
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• pp.84-92
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• 2010

This research was conducted to investigate physico-chemical characteristics of municipal solid waste (MSW) generated from T City, Gangwon-do and leaching characteristics of the incineration ash. From the results, bulk density of MSW in T city was $231kg/m^3$. Combustible and incombustible components were in 94.0% and 6.0%, respectively. Food waste and papers in combustible component occupied 32.3% and 41.2%. Water, volatile solids, and ash content were 41.3%, 50.5%, and 8.2%. C, H, O, N, S, and Cl showed 51.4%, 6.3%, 26.7%, 1.1%, 0.2%, 0.5%, respectively. Low heating value (2,704 kcal/kg) of T city was similar to 2,764 kcal/kg of Chuncheon and was 1,000 kcal/kg higher than 1,467~1,584 kcal/kg of the past Kuro-gu and Koyang city. The specification of leaching characteristics of the incineration ash were within the Korean regulation standard.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.53-60
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• 1998

The influence of venting on the leaching characteristics of pure gasoline and gasoline contaminated soil was studied. The change of leaching characteristics by venting of contaminated soil column could be characterized by two distinct trends : 1) the leaching concentration in TPH-GRO rapidly decreased with evaporation until the evaporation loss became 75% of the original volume. Afterwards, it gradually decreased. 2) the leaching concentrations of individual components showed initial increase followed by gradual decrease. In general, the relative increase of leaching concentration and the venting time to reach the maximum increased with the molecular weight of the components. It should be noted that the decrease of gasoline concentration in the vented air occurs faster than that in the leaching solution. This indicates that, after removing most of the gasoline by evaporation, the focus of the risk assessment for the residual contaminants should be on the groundwater contamination rather than air pollution.

• Journal of Environmental Science International
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• v.27 no.7
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• pp.561-575
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• 2018

Agricultural soils around springwaters heavily affected by pesticide run-off and around wells considering the regional characteristics were collected at 24 stations in Jeju Island, and the physicochemical properties and adsorption and leaching characteristics of four nonionic pesticides (diazinon, fenitrothion, alachlor, and metalaxyl) were investigated. The values of the major soil factors affecting the adsorption and leaching of pesticides, namely, soil pH($H_2O$), organic matter content, and cation exchange capacity (CEC), were in the range of 4.64 ~ 8.30, 0.9 ~ 13.1% and 12.7 ~ 31.7 meq/100 g, respectively. The Freundlich constant, $K_F$ value, which gives a measure of the adsorption capacity, decreased in the order of fenitrothion > diazinon > alachlor > metalaxyl, which was identical to their lower water solubility. Among the collected soils, the $K_F$ value was very highly correlated with organic matter content ($r^2=0.800{\sim}0.876$) and CEC ($r^2=0.715{\sim}0.825$) and showed a high correlation with clay content ($r^2=0.473{\sim}0.575$) and soil pH($H_2O$) ($r^2=0.401{\sim}0.452$). The leaching of pesticides in the soil column showed a reverse relationhip with their adsorption in soils, i.e., the pesticides leached more quickly for the soils with lower values of organic matter content and CEC among the soils and for the pesticides with higher water solubility.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.234-239
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• 2015

Various leaching tests were applied to the soil affected by accidental leakage of HF in an industrial area in Korea. Three different leaching methods including pH-stat, continuous batch leaching, and column tests were adopted to assess leaching characteristics and mobility of fluorine(F) in soil and the potential risks to ecosystem. Both natural and spiked samples were used for the leaching tests. F concentrations in the batch tests increased by leaching rapidly in the early stage of leaching and then maintained rather constant levels. Column leaching test also show similar result to that of the batch test. pH also controlled the leaching behavior of the soil. With increasing pH, more F was released in the pH-stat test. This is mainly due to the competition and exchange with hydroxyl ions, as pH increase to the alkaline range. Most of the F released by the accident seem to have removed in the very early stage of leaching, whereas some natural proportion from soil minerals are thought to have been released very slowly. Therefore, little F released during the accident remained, based on the results of this study on the samples after two years of the accident. We could conclude that soil contaminated by external effects such as chemical accidents should be managed immediately, especially with F.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.213-217
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• 2008

The objective of this research is to investigate the leaching characteristics of unregulated heavy metals such as Ni, Zn, Ba, Be, Sb, Se, V in specified waste. 108 waste samples which were taken from the representative facilities emitting hazardous substances, were analyzed. The rate of leaching of heavy metal was measured using an official test method. From the results, wastewater treatment sludge and dust contained much Ni, and Zn was detected in all samples. Dust and waste catalyst producted from petroleum-refining process tended to reveal V in high concentration. Ba, Be, Sb, Se showed low concentration, but require additional analyses of waste generated at different industries.

• Environmental Analysis Health and Toxicology
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• v.22 no.4
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• pp.339-348
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• 2007

A laboratory experiment was conducted to study the characteristics of leaching of Cr, Cu, and As from chromated topper arsenate (CCA)-treated wood. The wood species tested was hemlock spruce ($10\;cm\;{\times}\;10\;cm\;{\times}\;10\;cm\;tube$). The leaching experiment was conducted over 60 days using I L of leachants whose pHs were adjusted to 2.0, 3.7, and 1.6, respectively with nitric acid, and also using lake water, according to the OECD guideline. Each leachate was analyzed for Cr and Cu using flame-AAS, and for As using vapor generation-AAS. Three metals were loathed at the highest levels at pH 2.0 but almost at similar levels at the other conditions. Cumulative quantifies over 60 days of a leaching period were in order of As>Cu>Cr. As was predicted to leach with an increase in flux over a 10 year period, while Cr and Cu fluxes were predicted to decrease with time. This result suggest that arsenic can pose a health risk to humans over a long period of time, when CCA-treated wood is used for building facilities (e.g., playgrounds, residential purposes, etc.) with which humans frequently contact.

• 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.

• Analytical Science and Technology
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• v.11 no.5
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• pp.394-399
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• 1998

This study was carried out to characterize the chemical composition and leaching properties of heavy metals in coal fly ash, which was generated from Korean electrical power utilities in several million tons per year. Comparion with respect to the leachability of heavy metals between the Korea standard leaching test (KSLT) and the American Environment Protection Agency (EPA) method 1311 (TCLP: Toxicity Chracteristic Leaching Procedure) was performed. The concentration of Ag, As, Ba, Cd, Cr, Cu, Pb, Se, Hg in the leacheate was determined by ICP-MS. The analytical result showed a significant difference of the leachability according to the characteristics of the leaching solution except Se, suggesting the necessity of improvement in the leaching test method that is currently implemented in Korea.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.372-378
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• 2003

This study investigates the fractional composition and the leaching characteristics of heavy metals in polluted soils due to mining activities. The fractionated composition of heavy metals is classified into five fractions, adsorbed, carbonate, reducible, organic and residual fraction. The status of humic substances in mine wastes of most sites are polyhumic except tailing from Sangdong mine. According to the sequential extraction procedures (SEPs), leaching probabilities of Cd in coal wastes and tailing are relatively low due to high percentage of residual fraction. 46.4% of Ni in tailings from Sangdong mine is probably leached under oxidized environment, and 39.4% of Cu in these tailings is readily extracted under strongly oxidized environment by organic fraction. According to leaching condition of pH 3.0 and pH 5.6, the amount of heavy metals leached out of coal wastes and tailing increases to 1/2 hours. At pH 3.0 and pH 5.6, concentration of Ni in tailing increases up three times of the initial value. Heavy metals released from coal wastes and tailing were not influenced significantly by leaching time.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.3
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• pp.83-91
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• 2011

This study aimed to investigate the engineering and environmental characteristics of phosphogypsum-cement-soil mixtures composed of phosphogypsum, soil, and a small amount of cement was analysed on the basis of the unconfined compression test, the tensile strength test, the freezing and thawing test, the wetting and drying test, SEM and EDS analysis, XRD analysis and Leaching test. The specimens were manufactured with soil, cement and phosphogypsum. The cement contents was 10 %, and the phosphogypsum contents was 10, 20, 30, and 40 % by the weight of total dry soil. Each specimen was manufactured after curing at constant temperature and humidity room for 3, 7 and 28 days, after which the engineering characteristics of phosphogypsum-cement-soil mixtures were investigated using the unconfined compression test, the tensile strength test, the freezing and thawing test, the wetting and drying test. The basic data were presented for the application of phosphogypsum-cement-soil mixtures as construction materials. To investigate the environmental characteristics, leaching test was performed and the leaching test results were far below than of regulatory requirement of Waste Management Act in Korea. Therefore the results show that phosphogypsum is environmentally safe and can be used as construction materials in environmental aspect.