• 한국환경과학회지
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• 제7권3호
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• pp.281-290
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• 1998

Thirty-eight sediment samples collected from the Youngsan River channel were analysed for Fe, Mn, Co, Cr, Cu, Nl, Zn and Pb to recognize the extent of contamination. Results showed that a wide range of contents was apparent far every metal over the study area. These differences have been mainly related to the textural variability of sediments. Exceptions to this were fecund in the contents of Cu, Zn, Pb and possibly Mn. The contents of Cu, Zn, Pb and Mn were particularly higher in the sediments loom the confluence of tributaries. Downstream profile of metal/Al ratios indicates that pollutant inputs from the Kwangju tributary are mainly responsible for enrichment of these metals in bed sediments of the Young-san River.

• 한국물환경학회지
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• 제24권4호
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• pp.407-414
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• 2008

This study was conducted to evaluate the heavy metal contamination in the soils of Maehyang-ri inland shooting range area. The texture of the Maehyang-ri inland shooting range soil was sandy. Extraction of heavy metals reached quasi-equilibrium within 6 hours using shaking with 0.1 N HCl. 95% and 94% of extraction efficiency was observed for Cu and Pb in the Maehyang-ri shooting range soils, respectively. And Cu and Pb contamination of level of the T-1 region soil was $114.4{\pm}5.7mg/kg$ and $362.3{\pm}20.5mg/kg$. This may be due to the effects of mineralogical factor, soil particle size and un-residual fractions such as exchangeable, carbonate, Fe-Mn oxide and organic+sulfide.

• Journal of Welding and Joining
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• 제10권3호
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• pp.1-12
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• 1992

A literature review was conducted to survey informations available on the welding metallurgy of aluminum alloys and its effect on fusion weldability, especially on solidification cracking and pore formation. Solidification cracking behavior of Al weld is a complicate matter as compared to other high alloys, where a relatively simple Fe-X(most detrimental elements S, P, B, Si, etc) binary diagram can be successfully applicable. Both additive and synergistic effects of elements should be considered together. A same element play a different role from system to system. Porosity, caused by hydrogen contamination of the weld is one of the most troublesome welding problems. The primary sources of hydrogen are believed to be an absorbed moisture on the filler metal or base metal and in the shielding gas. It is extremely important that reliable quality-control procedures be employed to eliminate all possible sources of hydrogen contamination. Selection of proper process and parameters is sometimes more important than controlling of alloying elements in order to make a defect-free weld.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3535-3541
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• 2014

Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N2 adsorption-desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible.

• 대한환경공학회지
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• 제27권6호
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• pp.626-634
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• 2005

본 연구에서는 강원도내 4개의 폐금속광산에서 발생되는 광미와 주변 토양의 중금속 오염현황 및 오염도를 평가하였다. 광미와 주변 토양의 오염정도는 총 중금속농도 기준으로 원동>제2연화>신예미${\fallingdotseq}$상동 순이었으며, 이들 광미는 배경토양 및 Kloke 값보다 각각 $1.2{\sim}78.2$와 $1.1{\sim}80.6$배가 높은 농도로서 주변 토양을 오염시키고 있었다. 광미내 대다수 중금속의 화합물형태는 잔류성이 대부분이었다. 비잔류형태 화합물에서는 상당부분이 환원성과 산화성이어서 장기간에 걸쳐 산화환경조건에 따라 중금속이 유출될 것으로 보이며 특히, 제2연화의 Cd은 교환성과 탄산염 화합물이 쉽게 유출되어 단기간에 주변 환경을 오염시킬 가능성이 클 것으로 판단된다. 우리나라 토양오염기준치의 초과여부 검토결과 많은 시료에서 토양환경보전법의 우려기준 및 대책기준 이상인 것으로 나타나 이에 대한 처리대책이 필요하였다. PI에 의한 오염도평가에서는 4개의 광산지역 모두 1.0 이상보다 훨씬 높아 오염정도가 심각하였으며 복원시 최우선 광산은 원동이었다. 또한, DI에 의한 복원수준정도 평가결과에서 원동광산은 단기간에 유출 가능한 교환성부터, 나머지 광산은 중 장기간에 걸쳐 유출되는 환원성부터 우선적으로 제거해야 할 것으로 나타났다.

• 한국토양비료학회지
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• 제44권2호
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• pp.297-302
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• 2011

Acid drainage generated by pyrite oxidation has caused the acidification of soil and surface water, the heavy metal contamination and the corrosion of structures in abandoned mine and construction sites. The applicability of Na-acetate (Na-OAc) buffer and/or Na-silicate solution was tested for suppressing pyrite oxidation by reacting pyrite containing rock and treating solution and by analyzing solution chemistry after the reaction. A finely ground Mesozoic andesite containing 10.99% of pyrite and four types of reacting solutions were used in the applicability test: 1) $H_2O_2$, 2) $H_2O_2$ and Na-silicate, 3) $H_2O_2$ and 0.01M Na-OAc buffer at pH 6.0, and 4) $H_2O_2$, Na-silicate and 0.01M Na-OAc buffer at pH 6.0. The pH in the solution after the reaction with the andesite sample and the solutions was decreased with increasing the initial $H_2O_2$ concentration but the concentrations of Fe and $SO_4^{2-}$ were increased 10 - 20 times. However, the pH of the solution after the reaction increased and the concentrations of Fe and $SO_4^{2-}$ decreased in the presence of Na-acetate buffer and with increasing Na-silicate concentration at the same $H_2O_2$ concentration. The solution chemistry indicates that Na-OAc buffer and Na-silicate suppress the oxidation of pyrite due to the formation of Fe-hydroxide and Fe-silicate complex and their coating on the pyrite surface. The effect of Na-OAc buffer and Na-silicate on reduction of pyrite oxidation was also confirmed with the surface examination of pyrite using scanning electron microscopy (SEM). The result of this study implies that the treatment of pyrite containing material with the Na-OAc buffer and Na-silicate solution reduces the generation of acid drainage.

• 한국분말재료학회지
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• 제25권1호
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• pp.30-35
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• 2018

The friction characteristics of Al-Fe alloy powders are investigated in order to develop an eco-friendly friction material to replace Cu fiber, a constituent of brake-pad friction materials. Irregularly shaped Al-Fe alloy powders, prepared by gas atomization, are more uniformly dispersed than conventional Cu fiber on the brake pad matrix. The wear rate of the friction material using Al-8Fe alloy powder is lower than that of the Cu fiber material. The change in friction coefficient according to the friction lap times is 7.2% for the Cu fiber, but within 3.8% for the Al-Fe alloy material, which also shows excellent judder characteristics. The Al-Fe alloy powders are uniformly distributed in the brake pad matrix and oxide films of Al and Fe are homogeneously formed at the friction interface between the disc and pad, thus exhibiting excellent friction and lubrication characteristics. The brake pad containing Al-Fe powders avoids contamination by Cu dust, which is generated during braking, by replacing the Cu fiber while maintaining the friction and lubrication performance.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권6호
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• pp.19-28
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• 2009

폐금속광산과 비위생매립지로 인하여 중금속으로 오염된 지하수를 처리하기 위해 FeS를 이용한 투과성반응벽체(Permeable Reactive Barriers; PRBs)를 이용한다면 효과적인 결과를 보일 것으로 예상되어 FeS를 PRB 매질로 사용하기 위한 연구를 수행하였다. 컬럼 실험에 앞서 반응 매질들의 중금속 제거 특성을 알바보고자 합성 나노 FeS, 원석 FeS, 경량기포콘크리트에 대하여 96시간까지 인공중금속오염지하수와 반응을 시키는 회분식 실험을 수행하였다. 3가지 매질 모두 pH 6 이상에서 평형을 이뤘으며, 합성 나노 FeS는 반응 1시간 이후부터 평형상태에 가까워졌다. 중금속 제거효율은 합성 나노 FeS가 반응 1시간에 As와 Ni를 제외한 모든 중금속 제거율이 99% 이상으로 다른 매질에 비하여 상대적으로 빠른 제거 속도와 높은 효율을 나타내었다. 컬럼실험 결과 합성 나노 FeS로 피복된 경량기포콘크리트로 충진된 컬럼은 회분식 실험과 같은 결과로 나타났으며, 원석 FeS로 충진된 컬럼에서는 초반에 Ni을 제외한 모든 중금속이 99%이상 제거되었으나 pH는 약 9.20에서 평형을 이루었다. 본 연구에서 나타난 결과를 종합하였을 때 다양한 중금속으로 오염되어 있는 지하수를 처리하기 위한 방법으로 별도의 pH 조절이 필요 없는 합성 나노 FeS로 피복된 경량기포콘크리트를 이용한 투과성반응벽체의 적용은 매우 효과적인 것으로 판단된다.

• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.155-163
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• 1999

Heavy metal accumulation in living organisms through food-wed can give serious damage on physiological responses for vital activities. The initiation of heavy metal supposed to begin from the bio-accumulation of plants. To establish basic data fur heavy metal contents in plants at the area without artificial contamination, both woody and herb plants at Mt. Kwang-Duk were studied. The content of heavy metals in various organs of plants were analyzed by ICP. The range of heavy metals in plants for Al, As, Cd, Co, Cr, Cu, Fe. Mn, Pb, Se and Zn were 1.019∼257.200ppm, O∼2.929ppm, 0∼0.079ppm, 0∼0.054ppm, 0.023∼3.007ppm, 0∼1.997ppm, 2.031∼148.500ppm, 1.069∼51.320ppm, O∼126.900ppm, 0.708∼4.927ppm and 0.846∼4.949ppm, respectively. The amount of heavy metals in plants are much less than that of soil except some species. In woody plants, it was detected that the metal contents of leaves were higher than that of stems especially in case of Al and Fe with statistical significance. There were significant differences between shoots and roots of herb plants in metal content of Al, Co and Fe. Those metals have more accumulated in roots comparing with shoots. Some species of plants had shown the difference tendency of heavy metal accumulation. Generally, most species had not exceeded over twice of mean value each other, and had various difference according to the kinds of heavy metals.

• 대한화학회지
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• 제55권6호
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• pp.1018-1023
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• 2011

Alzinc is a ursine situated in the Ghazaouet town western part of the republic of Algeria. The purpose of this study was to determine the degree of contamination which soil and plants are burdened with some heavy metals: Pb, Zn, Ni, Cu, Cd, Mn, Cr, Fe and As, then the accumulation of heavy metals in the soil and plant adjacent of area the alzinc ursine was detected and the interdependence of pollution among all three regions of the environment determined. This paper analyzes the heavy metal contents within a 2-years period in the soil and plants at the beginning of the vegetation period. The presence of Pb, Zn, Ni, Cu, Cd, Mn, Cr, Fe and As, in the samples were analyzed using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Measurements of heavy metal contents were performed at three locations in soil and vegetative parts of three-plant types (plant alimentary) period during summer. The plant samples from the immediate environment of the dumpsite were highly contaminated with Zn, Cd and Mn. Three plants species: grape, artichoke and pepper, particularly, grape met some of the conditions to be classified as accumulators for Zn, Cu, Cd and Fe, consequently, she revealed a health risk for human and livestock due to the spread of the metal pollution from waste dumpsites to agricultural areas.