• Resources Recycling
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• v.7 no.5
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• pp.13-18
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• 1998

This study was carried out to understand the properties of the E.A.F. steel-making dusts for stabilization processing. The properties are related to mincral composition, shape, particle size, magnetism, density, porosity and leaching characteristic. the dust particles, the size of which ranges from sub-micron to tens-micron, were mainly spherical like balls that were agglomerated each other: the large particles were generally Fe-rich and the small particles were spherical like balls that were agglomerated each other: the large particles were franklinite (ZnFe$_{2}O_{4}$), magnetite (Fe$_{3}O_{4}$) and zincite (ZnO) by XRD analysis. When the dusts were sieved by a wet process, the particle fraction over 200 mesh had 1.5 wt.% with magnetite and quartz. The particles in the size range of 200-500 mesh consisted of magnetite, franklinite. The 82 wt.% of the steel-making dusts were occupied by the particles finer than 500 mesh and contained franklinite and zincite as main mineralogical compositions. When the dusts of around 78% porosity compressed under the load of approximately 1 KPa, the porosity decreased to 68% and to 535 under around 13 KPa. When the E.A.F. dusts were leached according to the Korea standard leaching procedure on the waster, the heavy metals exceeding the leaching criteria were cadmium, lead and mercury.

• Journal of the Mineralogical Society of Korea
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• v.24 no.2
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• pp.63-71
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• 2011

The mineral phases precipitated in the swamp built for the treatment of the mine drainage of the Dalsung Mine were investigated to reveal the mineralogical changes from schwertmannite to goethite and related behavior of heavy metals. Our XRD results show that most schwertmannite were transformed to goethite except the small portions of the samples in the uppermost part. No significant morphological changes were observed in the samples during mineral transformation by SEM, indicating that this transformation process occurred not from dissolution-precipitation process, but in solid state. Among heavy metals sorbed or coprecipitated in the mineral phases, Pb and Cu concentrations were relatively higher compared with their concentrations in the mine drainage. The relative concentrations of other heavy metals show similar values. The heavy metal concentration in the minerals do not show noticeable differences from uppermost schwertmannite to lower goethite samples, indicating the transformation process without any leaching or additional sorption of heavy metals in the solid state.

• Resources Recycling
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• v.16 no.2 s.76
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• pp.32-39
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• 2007

The measurement of physicochemical properties of ASR incineration ash has been carried dot and the preparation of light-weight material has also been performed using ASR ash for recycling point of view as building or construction materials. For this aim, chemical composition, particle size distribution, and heavy metal leachability were examined for 2 bottom ashes and 4 fly ashes obtained from the domestic ASR incinerator. In the present work, attempt has been made to prepare the lightweight material using boiler ash as a raw material, which is prepared by forming the mixture of boiler ash, lightweisht filler and inorganic binder and followed by calcination at elevated temperature. As a result, the content of Cu in bottom ash was as high as about 3wt% so that the recovery of Cu from ash was required. The major compound of SDR #5 and Bag filter #6 was found to be $CaCl_2{\cdot}Ca(OH)_2{\cdot}H_2O\;and\;CaCl_2{\cdot}4H_2O$, respectively. It is thought that heavy metal teachability of lightweight material prepared with boiler ash was significantly decreased due to the encapsulation or stabilization of heavy metal compounds.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.47-53
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• 1996

This study was carried out to estimate the amount and the characteristics of sewage sludge disposed of in the Nanjido sludge landfill site. Boring test was conducted to estimated the landfill volume and to get sludge samples to be analyzed. Total analysis and leaching test were performed to find the characteristics of sewage sludge. The Nanjido sludge landfill site had the surface area of $50,000m^2$ and the average depth of 15m. The estimated sludge volume was 600,000ton. Sewage sludge in Nanjido sludge landfill site was very stable. Results of total analysis of heavy metals indicated that the sludge could be classified as a non-hazardous waste according to the California state regulation. The sludge also could be used as compost based on compost quality criteria of foreign countries. Results of Korea Extraction Procedure showed that sewage sludge in Nanjido sludge landfill site was not a hazardous waste.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.857-861
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• 2010

Recently photochemical smog has become a serious urban air pollution. And VOC is the major pollutant for it. With the advance of industrialization and urbanization, MSWI fly ash and sewage sludge and melting slag were generated. It is necessary to de-toxificate ashes, because they contain many toxic constituents and probably lead to contaminate the environment. The objective of this research was to prepare multi-functional brick which is able to remove VOCs in ambient air. The bricks were made of MSWI fly ash, sewage sludge and slag. The benzene adsorption experiment by brick was acted to evaluate its adsorptivity. And also photocatalyst material was coated to enhance its adsorptivity and the endurance on the brick. According to the result, the benzene showed 74~96%. The removal efficiency was increased and the breakpoint time was lengthened by coating a brick.

• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.15-23
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• 2010

Dry sieving, wet sieving and photoscattering analyzer were tested as particle size analyzing methods for sediments from rivers and lakes of Han river, Nakdong river, Youngsan river, and Kumgang river area. Dry sieving showed a big error due to coagulating effect over drying process and this phenomena was severe for lake sediment. Wet sieving and PSA showed an accurate results though wet sieving needs more labor and complicate processes. Freeze-dry or freeze-dry after oxidation of organics with hydrogen peroxide showed improved results but gave lower portion of fine particles in comparing with wet sieving. Heavy metal contents and extractable metal contents were investigated for the sediments and high heavy metal content and extractable amount were obtained from fine particles as expected. Using of proper particle size analyzing method is important and the sediment management should be focused on the fine particles.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.481-481
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• 2016

하천퇴적물은 물의 순환과정에서 유역으로부터 유입되는 물질에 따라 조성이 변하게 된다. 특히 입자가 작은 토양과 유기성 물질들은 물순환과정에 이동성이 크게 나타나며, 인간에 의해 개발된 지역은 자연상태에 비해 이동하는 물질이 많이 나타나곤 한다. 본 연구에서는 하천에 건설된 보에 대한 퇴적물 조사를 실시함으로서 향후 수질관리에 필요한 기초 자료를 수집하고자 하였다. 본고에서는 금강과 낙동강에 건설된 보의 주요지점에 대한 퇴적물 조사를 실시하고 수질영향을 평가하였다. 조사는 홍수기전과 홍수기후로 구분하여 2회에 걸쳐 실시하였으며 물리적 성상과 화학적 항목에 대한 분석을 실시하였다. 입도분석 결과 금강 주요 10개 지점의 퇴적물 조성은 Sand, Silt와 Clay 성분이 혼합되어 있는 것으로 분석되었으며, 삼각좌표 분류법에 의한 토성은 대부분의 지점이 실트질양토(SiL)로 평가되었다. 완전연소가능량은 0.35~1.37로 전 지점에서 하천 호소 퇴적물 오염평가 기준의 유기물 함량기준 13%보다 높지 않은 것으로 나타났으며 홍수기 전 후에도 거의 유사하였다. 금강에서는 중금속뿐만 아니라 유기물 및 영양염류도 기준보다 낮게 나타났으며, 모든 항목에서 환경부예규인 하천 호소퇴적물 오염평가 기준보다 낮게 평가되었다. 하상 퇴적물이 수질에 미치는 영향을 평가하는 용출실험에서도 유기물 및 중금속 모두 수질에 미치는 영향은 거의 없는 것으로 평가되었다. 낙동강 주요 26지점의 입도분석 결과 퇴적물 조성은 대부분 Sand로 구성되어 삼각좌표 분류법에 의한 토성은 사토(S)로 평가되었다. 홍수기 전 후에 조사한 결과 완전연소가능량은 0.27~2.85으로 전 지점에서 하천 호소 퇴적물 오염평가 기준의 유기물 함량 기준보다 낮았으며 홍수기 전 후에도 거의 유사하였다. 화학적 성상 분석 결과 모든 항목에서 환경부예규인 하천 호소퇴적물 오염평가 기준보다 낮게 평가되었으며, 용출실험에서도 유기물 및 중금속 모두 수질에 영향을 거의 미치지 않는 것으로 평가되었다. 이번 조사는 4대강 건설 후 하상이 안정화 되지 않은 상태로 인해 지점간 특별한 경향성은 확인할 수 없었으며 보다 정확한 결과 도출을 위해서는 장기적인 조사를 통해 평가해야 할 것으로 판단되었다.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.51-59
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• 2021

In this study we analyzed the elution rates of 11 metals from 82 metallic kitchen utensils purchased in the market. The elution frequency of the 11 types of metals was iron > aluminum > chromium, nickel > zinc > copper > lead > arsenic > antimony > stannum > cadmium. For metallic kitchen utensils, the elution rate of heavy metals was 7.3-93.9%, and the average elution concentration was 0.001-13.473 mg/L. The average elution concentration of heavy metals was ranged between none-detected (N. D.) to 30.473 mg/L for non-coated kitchen utensils and 0.000-10.005 mg/L for coated kitchen utensils. The average elution concentration of metals from domestic kitchen utensils ranged from 0.001-25.145 mg/L, and from 0.000-33.518 mg/L for imported kitchen utensils. In particular, aluminum was found to be high in domestic kitchen utensils while iron was high in imported kitchen utensils. The average elution concentration of heavy metals was N.D.-2.670 mg/L for stainless steel, N.D.- 31.575 mg/L for aluminum, and N.D.-307.737 mg/L for iron. The amount of transition to food after cooking was investigated.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1239-1244
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• 2010

중금속 및 유류 오염토양 정화를 위해 효율적인 토양세척법과 공정 선정을 목적으로 최적의 오염정화 설계인자를 제시하기 위한 실험적 연구를 수행하였다. 실험분석 항목은 구리, 납, 아연을 포함하는 중금속항목과 총석유계탄화수소(TPH)인 유류항목에 대해 흡광광도법(absorptiometric analysis), 기체 크로마토그래피(gas chromatography)법을 이용하여 단계별로 분석하였다. 실험방법은 최적 세척용매 결정시험, 최적 세척시간 도출시험, 최적 진탕비(S/W ratio) 결정시험 등을 통해 얻어진 결과를 토대로 계면활성제 첨가량별 중금속 용출영향 분석시험 순으로 실시하였다. 실험결과 세척용매인 염산 0.1mole, 체류시간 1시간, 진탕비 1:3 조건에서 오염물질의 저감효과가 우수하게 나타났으며, 이들 조건을 적용하였을 때 1%의 계면활성제를 세척용매에 첨가하였을 경우 추가적인 오염물질의 농도 저감효과가 있는 것으로 분석되었다.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.293-301
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• 2005

We conducted several different leaching experiments for assessing the potential environmental risk when utilizing recycled concrete for stabilizing bridge pier. The methods include continuous batch leaching test (DIN 38414-S4), availability test (NEN 7341), pH-stat test (CEN/TC 292/WG6) and tank diffusion test (NEN 7345). The concentration ranges vary depending on the testing method. Nearly all the trace elements were low, some elements recording under detection limit. The maximum concentrations for trace elements leached throughout the whole tests are (as mg/L); Cd (0.029), Cu (0.437), Pb (0.14), Ni, Zn (0.95), Hg (0.005). Although the testing methods we used in this study are much more rigorous than other commonly adapted method including TCLP and domestic testing method for solid waste, the trace elemental concentrations are under the criteria for hazardous material set by the TCLP and domestic method. The result seems to suggest that applying the recycled concrete on stream water will be accepatable practice as for as trace elements are concerned. However, the influence of inorganics such as Ca, Mg, Ni and $SO_4^{2-}$ on aquatic ecology should be further examined.