• Journal of the Korean Society of Groundwater Environment
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• v.1 no.2
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• pp.85-89
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• 1994

Groundwater and soil contamination by the leak of leachates from the waste disposal site (WDS) is one of the serious environmental problems, and leachates are generally produced by the biogeochmical decomposition and/or precipitation in the WDS. At the Sindae-dong waste disposal site in Taejon, the average Cu, Pb and Zn concentrations in the surrounding soils are higher than those in other Korean soils but these are not high enough to cause any harmful effect to man through the crop plants. Copper, Pb and Zn are not detected in the groundwater samples but the pH of the sample is 5.6 which is not suitable for the drinking water. In contaminated soil samples, the heavy metal concentrations are higher in subsurface soil than in surface soil and it may be influenced by the leachates in groundwater. With the electric resistivity method, the water contains layers are found in contaminated soils and the resistivity values are considerably low because of the dispersion of plume by the leak of leachates. According to the distance from the leak point of leachate, resistivity values increased and heavy metal concentraions in soils decreased due to the reduction of plume.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.1
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• pp.1-7
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• 2000

In order to reduce the groundwater contamination around the Kimpo landfill in Korea by the leakage of the leachate within it, The method establishing 5 sets of Radial Collector Well Laterals(RCWLs) within the landfill, the method utilizing the wells dewatering the condensed water, the method establishing an interception wall to the 2nd layer at the circumference of the landfill and 22 sets of RCWLs within it, and the method establishing an interception wall to the 3rd layer and 40 sets of RCWLs were studied. Hydraulic parameters were measured for this study and then the groundwater flow and contaminant transport systems around the Kimpo landfill were analyzed with the MODFLOW and MT3D models. Conclusively, the method establishing an interception wall to the 2nd layer and 22 sets of RCWLs was evaluated as the most stable and economical option to reduce groundwater contamination concentration below drinking water standards.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.1
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• pp.39-45
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• 2008

As a waste management tool, the prohibition of landfilling of food waste has enforced since 2005. the composition of municipal solid waste (MSW) has changed dramatically. In this study, MSW generated from a small city collected once a year in 2004, 2005 and 2007, to qualify the characteristics of MSW before and after implementation of the tool. The prohibition of landfilling of food waste dramatically reduces food waste in MSW to 5.5 weight %, and on the other hand results to increase papers to 50.6 % and plastics to 22.6 %, The bulk density lowers to 50 %, which newly propose the necessity of volume reduction and incineration of MSW to ensure efficient transport and disposal. As water content of MSW reduces to 15.9 %, lower heat value of MSW after prohibition of landfilling of food waste increase to 3565.6 kcal/kg. Mitigation of bad smell and waste leachate with lower contaminants are recommendable as a kind of positive effects benefited by the tool.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.25-34
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• 1999

This geochemical study was carried out to find out the distribution of metals and cyanide in the soils around the Keum-Jung abandoned mine. Chemical analysis showed that extractable As contents in the soils near the mine exceeded 15mg/kg, Korean standard of soil contamination for farm land. The Results suggests that As contamination is due to input of tailings in the soils. According to total decomposition of tailings, As was highly concentrated in tailings. The water in a tailings impoundment was changed to acidic and contaminated by metals and sulfate which were released through oxidation of impoundment. Acid mine drainage from the tailings impoundment distribution channels directed to the paddy soils. The proper measures are required to prevent contamination of the soil and water in the vicinity of the Keum-Jung mine.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.4
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• pp.175-184
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• 1997

The Seokdae Waste Landfill is a middle-sized site used from June, 1987 to May, 1993. Many joints and faults are developed in andesitic rocks and rhyolitic rocks distributed at the landfill. The chemical analyses of leachates, streams and groundwaters sampled in July, 1996 and June, 1997 show that the concentrations of leachates and streams were decreased, and that the groundwater qualities became worse. The groundwater contamination is deeply extended to not only shallow groundwater but also bedrock-groundwater around the Seokdae Waste Landfill Area. The range of groundwater contamination by the leachates is about 500 m to the west and about 1 km to the south from the boundaries of the waste landfill. The development of monitoring wells and pumping wells, the construction of a leachate-treatment facilities, and the adjustment of the existing grout curtains are necessary for the control of water pollution at the Seokdae Waste Landfill Area.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.4
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• pp.303-310
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• 2000

This study is conducted in order to find more improved solidifying effects than the former converter slag solidification technology. The converter slag is used as a solidifying agent, and the quick lime and the gypsum are used as solidifying aids. Several tests are performed for the purpose of investigating the solidifying effects and the applicability of the solidified sludge as a daily or intermediate landfill cover. The unconfined uniaxial compressive strength, pH and leaching of heavy metal are investigated. In the case of using both quick lime and gypsum as solidifying aids, the compressive strength of specimen has significantly increased that of specimen which used quick lime only. The compressive strength of each specimen cured for 7 days which is mixed with quick lime and gypsum as mixing ratios 7:1, 5:1 and 3:1 are $0.59kg/cm^2$, $1.18kg/cm^2$, and $1.25kg/cm^2$, respectively. The results of all the leaching tests of specimen cured for 7 days show that the concentrations of leachate heavy metals(Cu, Pb, Cd and $Cr^{6+}$) are lower than the Korea toxic waste criteria. The microstructure analysis by SEM shows that needlelike crystals appear as the solidification proceed. The analysis of these crystals by EDS confirms that these main components are Ca. Si etc. Also, XRD analysis shows that the main solidification products are CSH and Ettringite; in addition, $Ca(OH)_2$ CAH are observed. When the added gypsum is used as a solidifying aid, more improved solidifying effects are obtained and the solidified sludge may be appropriately used as a daily or intermediate landfill cover.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.39-49
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• 2022

Bottom ash generated from thermal power plants is mainly disposed in landfills, from which metals may be leached by infiltrating water. To evaluate the effect of metals in leachate on soil and groundwater, we characterized bottom ash generated from burning cokes, bituminous coal, the mixture of bituminous coal and wood pellets, and charcoal powder. The bottom ash of charcoal powder had a relatively large particle size, and its wood texture was well-preserved from SEM observation. The bottom ash of charcoal powder and wood pellets had relatively high K concentration from total element analysis. The eluates of the bottom ash samples had appreciable concentrations of Ca, Al, Fe, SO₄, and NO₃, but they were not a significant throughout the batch test. Therefore, it is considered that there is low possibility of soil and groundwater contamination due to leaching of metal ions and anions from these bottom ash in landfills. To estimate the trend of various trace elements, long-term monitoring and additional analysis need to be performed while considering the site conditions, because they readily adsorb on soil and aquifer substances.

• Economic and Environmental Geology
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• v.28 no.3
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• pp.259-269
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• 1995

Column leaching tests were conducted using fresh and weathered pulverised fuel ash of some 17 and 40 years old from two major British power plants, with deionised water and simulated synthetic industrial leachate. The former was to see the leaching behaviour of weathered ash and the latter was to see if the formation of secondary products from water and PFA interaction and ameliorating effect in removing metals from industrial leachates. Fresh PFA liberates elevated concentrations of surface-enriched inorganics, including Ca, Na, K, B, $Cr_{total}$, Li Mo, Se and $SO^{2-}_4$. This might indicate their association with the surface of PFA particles. In the column leaching tests using weathered ash and deionised water, elements are not readily leached but are released more slowly, showing relatively constant concentrations. For the case of weathered ash, some readily soluble surface-enriched elements appears to have been liberated in their early stage of leaching and the liberation of glass associated elements are thought to be more important function in controlling the element concentration. The result from column leaching tests exceed for a number of elements when compared with various Water Standards and suggests the leachate from PFA disposal mound needs dilution to achieve target concentrations. PF A shows element retention effect for many elements, including B, Fe, Zn, Hg, Ni, Li and Mo, in the order of fresh Drax ash > weathered Drax ash > Weathered Meaford ash in retaining capacity. Geochemical modelling using a computer program WATEQ4F reveals some solubility controlling secondary solid products. These include $CaSO_4{\cdot}2H_2O$ for Ca, $Al(OH)_3$ for Al and $Fe(OH)_3$ for Fe.

• Journal of the Mineralogical Society of Korea
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• v.27 no.2
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• pp.97-105
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• 2014

Artificial precipitation ponds, consisting of three steps of oxidation pond, successive alkalinity producing system (SAPS) and swamp, were constructed for the treatment of the acid mine drainage from the Iwal coal mine. The efficacies of the passive treatment system in terms of neutralization of mine water and removal of dissolved ions were evaluated by the chemical analyses of the water samples. Mine water in the mine adits was acidic, showing the pH value of 2.28-2.42 but the value increased rapidly to 6.17-6.53 in the Oxidation pond. The purification efficiencies for the removal of Al and Fe were 100%, whereas those of $SO_4$, Mg, Ca, and Mn were relatively low of 50%, 40%, 24%, and 59%, respectively. These results indicate a need for application of additional remediation techniques in the passive treatment systems. The precipitates that formed at the bottom of the mine water channels were mainly schwertmannite ($Fe_8O_8(OH)_6SO_4$) and those in the leachate water were 2-line ferrihydrite ($Fe_2O_3{cdot}0.5H_2O$).

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.3-12
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• 2001

This study conducted to Investigate the movement of fertilized nutrients in a volcanic ash soil in Jeju using by the pressure-vacuum soil water sampler. The percolated water to measure the ion concentration of leachates was taken from a lysimeter at depths of 20, 40, 60, 80, 100 and 120 cm in the soil in where a corn and potato were cultivated as a preceding and succeeding crop, respectively. Fertilizers of N-$P_2$O$_{5}$-$K_2$O were applied at the rate of 36-30-30 kg $10a^{-1}$ for the corn and 28-22-24 kg $10a^{-1}$ for the potato prior to planting of both crops. The highest concentrations of Cl , $NO_3$-N, $Ca^{+2}$ and $K^+$ in percolates were showed at 20cm and 40cm in soil depth at one month after fertilizing, and then gradually moved and reduced into below soil depths. At 5.5 months after fertilization, the concentrations in all soil depths were similar with the value of before fertilization. At depth of 120cm, the concentration of NO$_3$-N and the other cations in leachate was highest 1 to 1.5 months after fertilization. pH in percolated water was negatively correlated with NO$_3$-N concentration while the concentration of $NO_3$-N showed positive correlation between Cl, $Ca^{+2}$ and $Mg^{+2}$ concentrations. This result indicated that those cations can be leached out by accompanied with $NO_3$-N.