• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.862-867
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• 2011

Pozzolanic-based stabilization/solidification (S/S) is an effective and economic remediation technology to immobilize heavy metals in contaminated soils. In this study, quick lime (CaO) was used to immobilize cadmium and zinc present in waste mine contaminated clayey sand soils. Addition of 5% quicklime to the contaminated soils effectively reduced heavy metal leachability after 2 bed volume operation below the drinking water regulatory limits. Lime addition was revealed to increase the immobilization for all heavy metals in tested pH ranges, so it could be an optimal choice for short-term remediation of heavy metal contaminated soil. The mass balances for these column tests show metal reduction of 92% for Cd and 87% for Zn of total resolved mass in case of 5% lime application.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.45-46
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• 2013

Stabilization characteristics of highly $N_2$-diluted $CH_4-O_2$ flame in an axially two-section porous inert medium were experimentally investigated for its application to the waste gas scrubber in semiconductor manufacturing processes. The flame behaviors were observed with respect to the fuel and $N_2$ flow rates and the equivalence ratios. As a result, four kinds of flame behaviors such as stable, flashback crossing the interface, blowout and sudden extinction were observed. It was also found that there exists two flame regime divided by a critical fuel flow rate. In addition, the flame stability was discussed based on the $N_2$ index which means the abatement capacity of our combustor in scrubbing the waste gas from the semiconductor processes.

• Journal of Wetlands Research
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• v.4 no.2
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• pp.23-41
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• 2002

In this paper, changes of the coliform bacteria were investigated when aquatic plant pond was used for separating algal particles from waste stabilization ponds(WSPs). Three different types of integrated natural systems were operated. It was found that there were no significant interferences for the disinfection efficiency of two integrated systems (WSPs coupled with water hyacinth ponds) used for treating domestic sewage and upgrading the secondary effluent as well. However, when constructed wetland (CW) was combined with the shallow algal ponds and used for the secondary effluent, it seriously interfered with the disinfection efficiency due to the regrowth and/or after-growth of the coliform bacteria, which can readily metabolize the amino acids and sugars leached from plants. In order to find out the primary disinfection parameters, several sets of the batch test were run. It was found that sunlight is the most predominant factor for the coliform decay. During the night, algal toxicity partly supports the decay but during the day, deteriorates it by attenuating the sunlight. The pH in the range of 4 to 10 did not affect the decay in the dark.

• Journal of environmental and Sanitary engineering
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• v.18 no.4
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• pp.36-44
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• 2003

The cement-based system among S/S(Solidification/Stabilization) is widely used to treat hazardous wastes. In this study, tannery sludge was solidified to evaluate the stabilization effects of using admixtures in the cement-based S/S. Fly ash as substitute also used to increase the strength of the S/S of hazardous waste. The compressive strength measurement and leaching experiment of chromium metal of solidified mortar were carried out to compare and evaluate the physical and chemical characteristics of solidified hazardous waste sludge. From the result of this study, there was increased of compressive strength by using AEW-3(early-hardening AE water reducing agent), and leaching concentration of chromium became low enough to satisfy the regulatory criteria. The successful solidification for the organic contaminant and heavy metal in hazardous waste should enable to treat by cement-based system using early-hardening AE water reducing admixture and fly ash as substituted cement.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.75-81
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• 1998

In most of studies on solidification/stabilization with waste, small columns have been used to examinate adsorption or leachate. However, these experiments using small apparatus have been limited to apply with the field. In this study, considering an application to the field, a large Lysimeter(100cm$\times$100cm$\times$100cm) used for the simulation. Then, the open dumping waste was mixed directly with bentonite to simulate the stabilization of waste, environmental aspects and several basic tests. As a result, the concentration of heavy metals and contaminated substances changed with bentonite rate. Most of contaminated substances were decreased in leaching with increased mixing rate of bentonite. Especially, the concentration of CODcr removed 25~30%. Also, the residual soil in dumping waste produced approximately 80% of total volume by 40$\times$40mm screen.

• 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

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.17-25
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• 1999

The feasibility of using waste lime, which is produced as a byproduct during the manufacture of sodium carbonate in Inchon, Korea. as a stabilization admixture with weathered granite soil was investigated. Laboratory tests were conducted to determine the chemical composition, pH, compaction characteristics, unconfined compression strength. X-ray diffraction analysis of waste lime and weathered granite soil admixtures. Based on the present tests, it appears that the admixtures are environmentally safe and can be used as landfill material.

• Resources Recycling
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• v.17 no.1
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• pp.3-11
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• 2008

The treatment of domestic municipal solid waste has inclined to incineration process instead of disposal in landfills. So, the amount of ash generated by incineration of municipal solid waste is gradually increased. The incineration ash divides into bottom ash and fly ash. The bottom ash which accounts for about 90% of the incineration ash consists of ceramics, glasses and metals. And it can be used as the recycling product by the stabilization process. For example, the bottom ash is used as secondary building material or for other similar purposes such as road sub-bases and noise barrier in USA, Europe and Japan. But, the stabilization-treatment technique of bottom ash sti11leaves much to be desired in Korea. Thus, the domestic study of recycling about bottom ash must be improved through investigation about the chemical property and technique of stabilization.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.7
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• pp.523-529
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• 2011

This study has been performed to examine the influence of the size of particles on the stabilization in the aerobic stabilization equipment connected with MBT system. The biodegradable waste inside the reactor (60% of food waste, 25% of paper waste, 2% of wood waste and 5% of compost) has been charged in same composition. The degree of stabilization was compared and analyzed after charging with adjustment of particle size in 5 mm, 10 mm, 20 mm, 50 mm, 100 mm and state of no separation. The experiment revealed that highest temperature beyond $65^{\circ}C$ was shown in the particle size of less than 50 mm in change of temperature and the highest temperature was about $50^{\circ}C$ in reactor of 100 mm and no separation. The proportionality between generated quantity of $CO_2$ and particle size was not observed, even the highest in generated quantity was shown in over 100 mm. The weight changes based on wet and dry conditions in the reaction process showed the 30% and 46% of reduction in the smallest particle size of 5 mm and it showed the trend of the lower reduction rate at the bigger particle size. The water soluble $COD_{Cr}$ and TOC showed the reduction rate of 60% in reactor of particle size in 100 mm and no separation while the reduction rate comparing to the initial stage of reaction in the reactor of less than 50 mm was 80%. Such result derived the conclusion of acceleration in the decomposing stabilization of biodegradable material due to the decomposing rate of organic substance as the particle size of biodegradable waste gets smaller. It is concluded as necessary to react in adjustment under 50 mm of particle size as much as possible.

• Environmental Engineering Research
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• v.23 no.2
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• pp.189-194
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• 2018

The traditional gold mining in Kulon Progo district, Special Region of Yogyakarta Province produced tailings containing mercury (Hg) from the gold amalgamation process. Mercury accumulated in tailings has 164.19 mg/kg - 383.21 mg/kg in total concentration. Stabilization/solidification (S/S) is one of the remediation technologies to reduce waste pollution. Portland cement is one of the additive materials in S/S that effective encapsulates heavy metal waste. The aim of this research is to know the optimum composition of tailings mixture with Portland cement in S/S process. This research used variation of tailings composition. Variation of Portland cement composition with tailing are 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80 and 10:90. The result of this study found that the optimum composition of Portland cement: tailings was 10:90, with compression test of $257ton/m^2$ and TCLP test was 0.0069 mg/L. The compression test results were in accordance to US EPA Standard quality of $35ton/m^2$. TCLP test results meet the standard of Indonesian Government Regulation No. 101 Year 2014 of 0.05 mg/L.