• Korean Journal of Environment and Ecology
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• v.11 no.1
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• pp.126-132
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• 1997

Nanji-do is an island in Seoul, the area is 272ha, and in which gad was piled up waste discharged from Seoul metropolitan for 15 years(form March 1978 to March 1993). The volume of waste is 92, 000, 000m$^{2}$. The actual vegetation area of Nanji-do is 191ha, and the area of woody plant is 31ha. The rest area is covered by herbaceaus plant. In actual vegetation area of woody plant, Robinia pseudoacacia community and Salix pseudo-lasiogyne community are 83%. The soil pH is alkaline, though general soil pH is acid in Seoul. There is no relation with soil condition and actual vegetation. The result of this study, actual vegetation of Nanji-do don't help the establishment of vegetation restoration after soil stabilization construction. And so following a countermeasure is proposed. 1) Selection of adequate species by an experiment of planting pioneer species, native species, and dietary species 2) Establishment of an adequate planting plan and development of slope stabilization method by planting of native species 3) Establishment of a restoration plan of animal ecosystem by survey for animal ecosystem

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2001.04a
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• pp.46-52
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• 2001

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2006.04a
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• pp.94-97
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• 2006

• The Journal of Engineering Geology
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• v.5 no.3
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• pp.259-276
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• 1995

Electrical soundings and profilings were conducted for mapping the leachate in the region of Nanji - Do Landfill site. The results of electrical surveys conducted in the landfill area show that the basal leachate is formed at the height about 30 m above the mean sea level and that there is abundant floating leachate over the basal leachate. The surveys conducted around the landfill reveal that the groundwater which may be contaminated by the leachate from the landfill flows to the Han River. The top of the basement rock in this area has been severely affected by polluted groundwater. The layer which is thoroughly saturated with leachate in this region has the very low resistivity value below 10 ohm - m and this low resistivity value indicates that the groundwater and geology are severely contaminated by the leachate and wastes of the landfill.

• The Journal of Engineering Geology
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• v.17 no.1 s.50
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• pp.125-133
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• 2007

The environmental and geotechnical properties are investigated to the 8th landfill area made of only sewage sludge in Nanji-Do. To do this, the soils are sampled in this area, and leaching tests, heavy metal content tests, and so on are performed to research the environmental properties. As the result of heavy metal content tests, Pb, Zn, Cu, Ni, Cd and Cr were leached from the sewage sludge. Because the leaching concentration of Cu is more than the standard value of California state, Cu content have to bring down during the recycling of the sewage sludge. Meanwhile, a series of tests concerning specific gravity, liquid and plastic limits, compaction, permeability and shear strength is performed to research the geotechnical properties. The sewage sludge is consisted of sand, silt and clay, and is classified into non-organic silt or organic clay with 42.3% of plastic index. As the result of compaction test, it is expected that the compaction effect according to variation of water contents is low relatively because the dry unit weight is low and the curve of compaction forms flatness. Also, as the result of direct shear tests, the cohesion is $0.058kg/cm^2$, and the internal friction angle is $14^{\circ}$. Taking everything into consideration, the various problems are happening in case of recycling the sludge like the cover layer of landfill and so on because the compaction is bad, and the shear strength is low. Also, it is expected that the ground water pollution caused by leaching the heavy metal into the sludge. To do recycling the sewage sludge in this site, supplementary and treatment programs should be prepared.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.2
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• pp.95-100
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• 1996

Schlumberger electrical soundings and Coincident loop time-domain electromagnetic soundings were made on the Nanji-do landfill to investigate the nature of fills and the subsurface structure. The measured data were transformed into apparent resistivity values and then inverted in terms of 1-D resistivity models. At 6 points, both measurements were carried out to check the validity of the interpreted subsurface electrical structures. Interpreted layered models from each method show a good agreement. Obtained models show that a conductive zone exist below the shallow resistive zone. Conductive zone, which is considered to be influenced by decomposition of organic waste materials and infiltration of precipitation, is terminated by resistive zone which is considered as basement. Considering the fact that conductive zone extends to the basement and there exist no barrier layers such as clay layers, contaminant plumes are likely to flow into the groundwater directly.

• Journal of Korea Water Resources Association
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• v.30 no.1
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• pp.23-34
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• 1997

The Nanji-Do ladnfill is an ill-conditioned reclaimed land without pollution intercepting facilities, and has high ground water table and deep stratum. The purpose of this study is to analyze the solute transport in steady-state groundwater flow and to predict the solute dispersion in Nanji-Do landfill using HST-3D model. As results, the groundwater flows radially outward from the center of No. 1 and No. 2 landfills, and large amount of runoff is moved into Han River. The predicted relative concentration of total dissolved solute(TDS) at two years later was 0.25 in the weathering zone, 0.26 in the lower alluvium, and 0.28 in the upper alluvium. Thus, the further pollution to bottom rock and Han River was predicted by comparing the corresponding present values of 0.29, 0.32 and 0.35.

• Journal of Environmental Impact Assessment
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• v.4 no.2
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• pp.59-70
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• 1995

The solution-state of a reclaimed waste would be known to the method in using an analysis for seepage. But it is not the best method in the huge landfill reclaimed all kinds of the waste at random. Especially in case of the landfill called the Nan Gi-do located along the Han-river, it is difficult to judge the generative seepage to be flowed in to the Han-river. So to plan the effective stabilization on a landfill, it is very useful survey method using the Landsat TM image. Operating a heat-distribution analysis with the Landsat TM image, in case of a landfill not having definite data, we would assume the reclaimed sections of the waste to judge a solution-speed late comparatively such as a industry waste or a harmful waste through the heat change.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.12a
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• pp.97-101
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• 1996

Municipal and sanitary landfills can pose environmental problems due to leachate, landfill gas md unstable geotechnical properties. Most governmental bodies delay the correction of landfill problems or landfill replacement until a crises stage is reached. The replacement of a landfill is often made difficult due to costly regulatory controls, public opposition to siting and the high cost of closure for the previous landfill unit. Solutions to extending landfill life and capacity Involve waste minimization by recycling, refuse compaction and waste-to-energy incineration. Incineration can reduce the volume of refuse by 50-95%. The largest installed bases of municipal waste Incinerators are located in Japan and the U.S. The volume of waste contained in a landfill can be estimated by load count tabulations, weight-and-volume measurements or a material balance analysis based on the trash profile of user categories. for an existing landfill, core samples may be collected and analyzed for use in a material balance analysis. Newly generated refuse contains approximately 50% of the heating value of coal. However, landfill properties vary significantly due to the waste profile of the contributors and biodegradation due to time and weathering. The volume of the Nanji-do landfill

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.6
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• pp.553-556
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• 2006

A cis-1,2-dichloroethylene (cis-DCE)-degrading anaerobic bacterium, Clostridium sp. strain KYT-1, was isolated from a sediment sample collected from a landfill site in Nanji-do, Seoul, Korea. The KYT-1 strain is a gram-positive, endospore-forming, motile, rod-shaped anaerobic bacterium, of approximately $2.5{\sim}3.0\;{\mu}m$ in length. The degradation of cis-DCE is closely related with the growth of the KYT-1 strain, and it was stopped when the growth of the KYT-1 strain became constant. Although the pathway of cis-DCE degradation by strain KYT-1 remains to be further elucidated, no accumulation of the harmful intermediate, vinyl chloride (VC), was observed during anaerobic cis-DCE degradation. Strain KYT-1 proved able to degrade a variety of volatile organic compounds, including VC, isomers of DCE (1,1-dichloroethylene, trans-1,2-dichloroethylene, and cis-DCE), trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, and 1,1,2-trichloroethane. Strain KYT-1 degraded cis-DCE at a range of temperatures from $15\;to\;37^{\circ}C$, with an optimum at $30^{\circ}C$, and at a pH range of 5.5 to 8.5, with an optimum at 7.0.