• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.665-674
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• 2000

A major source of the hazardous waste generated is from chemical industries producing plastics, herbicides, pesticides and chlorinated solvents. All of these processes produce a class if hazardous waste termed the chlorinated hydrocarbons(CHCs), either directly or from undesirable side reactions. In this study, we investigated the destruction characteristics of hazardous waste through incineration. A nonequilibrium combustion model was used to describe the effect of the chemical kinetics due to the flame inhibition characteristics of $CCl_4$ which was used as the surrogate of hazardous waste. A parametric screening studies was made in a dump incinerator proposed in this study. The dump incinerator showed high $CCl_4$ DRE(Destruction and Removal Efficiency) as 5 nines. $CCl_4$/CH$_4$ ratio appeared to be most important in the destruction of $CCl_4$ through incineration.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.394-398
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• 2004

This study was carried out to plan the prevention of the generation and discharge of acid mine drainage (AMD). Hydraulic characteristics were tested with the disk tension infiltrometer around the waste rock dump of the Imgi abandoned pyrophyllite mine in Busan, Korea. Because the waste rock dump of the Imgi mine have very low infiltration rate, most of rain was expected flowing into adjoined stream through the slope or plane as surface flow rather then throughflow or ground water. But slopes of the waste rock dump have many 'V' type erosion gullies and consist multi-layers. These gullies and multi-layers have coarse clastic particle layer which have very large hydraulic conductivity. So through these coarse clastic particle layers a large part of rain flow into ground. And also these layers could be played a function of aeration path, which induced oxidation of sulfide minerals and generation of AMD continuously.tinuously.

• Advances in environmental research
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• v.9 no.2
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• pp.97-107
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• 2020

The indiscriminate growth in global population poses a threat to the world in handling and disposal of Municipal solid waste. Rapid urban growth increases the production, consumption and generation of Municipal solid waste which leads to a drastic change in the environment. The methane produced from the Municipal Solid waste accounts for up to 11% global anthropogenic emissions, which is a major cause for global warming. This study reports the methane emission estimation using IPCC default, TNO, LandGEM, EPER and close flux chamber from open dump yards at Perungudi and Kodungaiyur in Chennai, India. The result reveals that the methane emission using close flux chamber was in the range of 8.8 Gg/yr-11.3 Gg/yr and 6.1Gg/yr to 9.1 Gg/yr at Kodungaiyur and Perungudi dump yard respectively. The per capita waste generation was estimated based on waste generation and population. The waste generation potential was projected using linear regression model for the period 2017-2050. The trend of CH₄ emission in the actual field measurement were increased every year, similarly the emission trend also increased in IPCC default method (mass balance approach), EPER Germany (zero order decay model) where as TNO and Land GEM (first order decay model) were decreased. The present study reveals that Kodungaiyur dump yard is more vulnerable to methane emission compared to Perungudi dump yard and has more potential in waste to energy conversion mechanisms than compare to Perungudi dump yard.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.57-66
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• 2015

A numerical analysis was performed of the seepage from and stability of a mine waste-dump slope in Imgi, Busan, considering rainfall intensity. The 40-45° slope angle of the waste dump is relatively steep, and the depth of the waste dump down to bedrock is 7-8 m. The groundwater level was 6.6 m below the surface. Various laboratory tests on samples obtained from the waste dump were performed to determine the input data for seepage and stability analyses of the waste-dump slope during rainfall. The results of seepage analysis for various rainfall intensities using the SEEP/W program show that the wetting front moved down with increasing rainfall duration. When the rainfall intensity was > 50 mm/ hour and the duration was > 24 hours, the waste dump became fully saturated because the wetting front reached the groundwater level. The results of slope stability analysis coupled with seepage analysis using the SLOPE/W program show that the safety factor of the slope decreased as the wetting front moved down due to rainfall infiltration. After continuous rainfall for 5-6 hours, the safety factor of the slope suddenly decreased but then recovered and converged. The sudden decrease was induced by an increase in pore-water pressure and a decrease in matric suction down to a certain depth as the wetting front approached the potential sliding surface.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.653-663
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• 2000

A lot of hazardous wastes are discharged as by-products of working process by industrial development. Hazardous wastes is physical characteristics of difficult destruction at hight temperature. Numerical simulation and combustion experiment performed of dump incinerator for hazardous waste incineration. For the numerical simulation, the SIMPLEST algorithm was used to ensure rapid converge A K-$\varepsilon$ model was incorporate for the enclosure of turbulence flow. Combustion model was used by ESCRS (extended simple chemically reacting system) model available of CHEMKIN thermodynamic data for the source term of species conservation equation or energy equation. Radiation model is used by six flux model. A parametric screening studies was carried out through numerical simulation and experiment. Residence time and concentration in the incinerator was strongly dependent on the parameters of mixture velocity, mixture equilibrium ratio, surrogate velocity and surrogate equilibrium ratio.

• Structural Engineering and Mechanics
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• v.89 no.3
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• pp.253-263
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• 2024

Slope stability is generally paid more attention to in slope protection works, especially for slope containing weak layers. Two indexes of safety factor and failure model are selected to perform slope stability. Moreover, the finite element limit analysis method comprehensively combines the advantage of the limit analysis method and the finite element method obtaining the upper and lower bounds of the safety factor and the failure mode under the slope stability limit state. In this study, taking a waste dump containing a weak layer as an engineering background, the finite element limit analysis method is adopted to explore the potential failure mode. Meanwhile, the sensitivity analysis of slope stability is performed on geometrical and geotechnical parameters of the waste dump. The results show that the failure mode of the waste dump slope is two wedges if the weak layer is located on the ground surface (Model A), while the slope can be observed as three wedges failure if the weak layer is below the ground surface (Model B). In addition, both failure modes are highly sensitive to the friction angle of the weak layer and the shear strength of waste disposal, and moderately sensitive to the heap height, the dip angle and cohesion of the weak layer, while the toe cutting has limited effect on the slope stability. Moreover, the sensitivity to the excavation of the ground depends on the location of the weak layer and failure mode.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.1
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• pp.1-8
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• 1996

Coastal waste dump in Pohang is composed of slags and sludge of POSCO. Hydraulic parameters in the coastal waste dump are very different from those in municipal landfills and general unconsolidated or fractured aquifers. In the waste dump pumping or slug tests are not adequate for the estimation of hydraulic parameters. Time-lag and amplitude of the tidal fluctuation of groundwater table are used to determine the hydraulic parameters. Groundwater table at the groundwater observation wells is about 40 cm higher than the sea level. The contributing factors of the groundwater-rise are estimated. Vertical profile of some chemical constituents in groundwater indicates the gradual transition of the fresh groundwater at the uppermost position to the sea water at the bottom.

• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.13-24
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• 2004

This study was carried out to plan the prevention of the generation and discharge of Acid Rock Drainage (ARD). The Acid Base Accounting(ABA) test was performed for geological materials such as pit wall, waste rock and stream sediments near the Imgi abandoned pyrophyllite mine in Busan, Korea. In addition, hydraulic characteristics were tested with the disk tension infiltrometer around the waste rock dump. Maximum Potential Acidity(MPA) of geological materials near the Imgi mine was 246.942kg $H_2SO_4/t$, and maximum Acid Neutralising Capacity(ANC) was 8.7kg $H_2SO_4/t$. These results indicate the pit wall and waste rock, except most of stream sediments are acid generating geological materials. These have salt and free hydrogen ion which resulted from oxidation of sulfides. Hence they could be convert rain water to acid rock drainage. Although the waste rock dump of the Imgi mine have very low infiltration rate, slopes of the waste rock dump have many "V" type erosion gullies and multi-layers. These gullies and multi-layers have coarse clastic particle layers which have very large hydraulic conductivity. Through this coarse clastic particle layer a large part of rain flow into ground. And also this layer could function as aeration path which induced oxidation of sulfide minerals and generation of ARD continuously.

• Advances in environmental research
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• v.5 no.1
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• pp.19-35
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• 2016

The phytoextraction of some toxic heavy metals from municipal waste dump soil by castor plant (Ricinus communis) was tested under natural and single or mixed chelant-assisted scenarios in pot microcosms. A sandy loam with total metal contents (mg/kg): Cd (84.5), Cu (114.5), Ni (70.3), Pb (57.8), and Zn (117.5), was sampled from an active dumpsite in Calabar, Nigeria and used for the study. Castor (small seed variety) was grown under natural phytoextraction or single/binary chelant (citric acid, oxalic acid, and EDTA) applications (5-20 mmol/kg soil) for 63 days. Castor exhibited no visual phytotoxic symptoms with typically sigmoid growth profiles at the applied chelant doses. Growth rates, however, decelerated with increase in chelant dose. Post-harvest biomass yields were higher under chelant application than for natural phytoextraction. Both root and shoot metal concentrations (mg/kg) increased quasilinearly and significantly ($p{\leq}0.05$) with increase in chelant dose, furnishing maximum levels as: Cd (55.6 and 20.9), Cu (89.5 and 58.4), Ni (49.8 and 19.6), Pb (32.1 and 12.1), and Zn (99.5 and 46.6). Ranges of translocation factors, root and shoot bioaccumulation factors were 0.21-3.49, 0.01-0.89 and 0.01-0.51, respectively. Overall, the binary chelant treatments were less toxic for R. communis growth and enhanced metal accumulation in shoots to a greater extent than the single chelant scenarios, but more so when EDTA was present in the binary combination. This suggests that the mixed chelants could be considered as alternative treatments for enhanced phytoextraction and revegetation of degraded waste dump soils.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.85-93
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• 2013

This study is conducted to evaluate the leaching of contaminants from mine tailing by natural water and finally to estimate the leaching and transportation of heavy metal contaminants by rainfall. In order to identify contaminated heavy metal of soil, 17 soil, 2 tailing and 2 waste dump and 2 control samples were taken at mine area and analyzed total metal contents. The leaching experiments were conducted using distilled water. Cu, Pb, Zn was extracted from the reddish mine tailing in a short period time, especially the extraction rate of Cu (45.0%) was highest. The contaminants were leached from the yellowish mine tailing within an hour and the leaching rate of Cd (42.0%) and Zn (17.2%) were relatively high. The reddish soil from the waste dump showed leaching of Cu (5.1%), Pb (4.0%) and Zn (3.3%), however the leaching rate was low except Mi (14.2%). From the yellowish soil sampled from the dumping site, the leaching of Cu (8.2%) and Ni (9.7%) was high while the leaching of Zn (0.2%) were relatively low.