• 자원리싸이클링
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• 제6권3호
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• pp.22-27
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• 1997

방사성 금속폐기물을 재활용하므로써 방사성 폐기물의 처분부피를 감축할 수 있을 뿐만 아니라, 자원활용의 극대화를 꾀할 수 있으며, 또한 방사성 폐기물의 감량으로 환경에 미치는 위해도를 최소화시킬 수 있다. 방사성 금속폐기물의 재활용은 여러 단계를 복잡한 공정을 거치면서 이루어지지만, 오염 방사능 물질을 제거하는 표면제염 공정이 핵심이며, 그 오염 특성 및 폐기물에 따라 물리적, 화학적 그리고 전기화학적 방법이 활용된다. 본 연구에서는 이러한 관점에서 표면제염기술의 특성을 고찰하였으며, 실제 방사성 금속폐기물을 이용해 SC 화학제염법 및 전해제염법으로 시험한 결과, 거의 자연 방사능 수준까지 제염시킬 수 있었다.

• 한국환경과학회지
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• 제13권5호
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• pp.479-488
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• 2004

Five sediment cores from the tidal flat of artificial Lake Shihwa are analyzed in terms of sedimentology and geochemistry to evaluate the heavy metal contamination and redox condition of surficial sediment following the Shihwa seawall construction. The variability of concentrations of various elements depends on the depositional environment, and reflects the various redox conditions and sediment provenances. The amounts of Ti and Al and their ratio of Ti/ Al with respect to Li clearly indicate that there is an anthropogenic contribution to the surficial sediment. The high concentrations of heavy metals suggest an anthropogenic contribution at ST. 34 and ST. 22. Concentrations of most elements (Cr, Cu, Zn and Pb) are higher near the Shihwa-Banwol industrial complex than in the central part of Lake Shihwa. Concentrations of heavy metal in surficial sediment near the Shihwa-Banwol industrial complex are two to eight times higher than in the center of Lake Shihwa. Enrichment factors (EF), which are normalized by the unpolluted shale, suggests a significant metallic contamination near the Shihwa-Banwol industrial complex (SBIC). The redox condition is divided into two anoxic and mixed oxi $c_oxic zones based on the carbon:sulfur (C/S) ratios of organic matter and elemental relationships. Correlations among geochemical elements Mn, U and Mo are significantly different from site to site, and may therefore be an indicator of the spatial redox condition. Controlling factors for switching anoxic/oxic conditions are thought to be water depth and the differences in industrial effluent supply. The variations of the Cu/Mn ratio in the sediments confirms above mentioned spatial differences of a redox condition in part, and therefore shows a location-dependence redox condition in sediments at four other sites. The redox condition of the surficial sediment characteristics of the Shihwa Lake are controlled by its geographic location and water depth.th.

• The Plant Pathology Journal
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• 제27권3호
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• pp.266-271
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• 2011

Physicochemical characteristics and heavy metal content of soils located along the drainage way of an abandoned mine at Busan, Korea ($35^{\circ}31'N$, $129^{\circ}22'E$) (contaminated soil; CS) and uncontaminated soils (50-70 m apart from the drainage way) (NS) were examined. Growth of tomato plants (Solanum lycopersicom cv. Rutgers) in CS and NS, development of the root-knot nematode (Meloidogyne incognita) as root-knot gall formation on tomato plants, and non-parasitic nematode populations in soil were also examined. Growth of tomato plants, root-knot gall formation, and non-parasitic nematode populations were significantly reduced in CS with higher As content, lower pH, higher electrical conductivity (EC), and lower available phosphate (av. $P_2O_5$) than in NS. None of the other physicochemical characters examined differed significantly between CS and NS (low and no significance) and were above or below the critical levels detrimental to plant growth and nematode development, suggesting that As may be the primary hazardous heavy metal in CS. The toxicity of As might be enhanced at low pH in CS because exchangeable forms of some heavy metals increase with the decrease of soil pH. The heavy metals, especially As, may have contributed to increasing EC and decreasing av. $P_2O_5$. Therefore, the effects of mine drainage contamination from the abandoned mine were derived primarily from contamination by heavy metals such as As. These may have been enhanced in toxicity (solubility) by the lowered pH, increased soil salinity (EC) and decreased av. $P_2O_5$. Our results suggest synergistic adverse effects on the plant and the nematode by decreasing osmotic potential and nutrient availability.

• 한국습지학회지
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• 제12권3호
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• pp.15-20
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• 2010

마산만유역의 창원시 수계에서 발생한 오염부하는 차집관로를 통하여 하수종말처리장으로 운반되거나 창원시 하천을 거쳐 봉암갯벌을 경유한 후 마산만으로 유입된다. 즉 마산만 하구 갯벌인 봉암갯벌은 도심에 위치하여 있고 민관산학의 협력으로 보존되어 생태학습장으로 이용되는 귀중한 갯벌이다. 특히 최근 몇 년 동안 조개류, 어류와 물새 등 다양한 생물이 관찰되고 있으며 우리나라 최초의 마산만특별관리해역 연안오염총량관리의 중심 지역에 해당한다. 1970년에 시작한 창원기계공업단지의 가동으로 마산만의 하구와 내만은 중금속으로 오염되었음이 보고되었다. 봉암갯벌의 저서생물의 서식지인 퇴적물에 존재하는 잔류성이 강한 주요 중금속 오염물질의 변화를 분석하였다. 아연, 구리, 납이 오염퇴적물 기준의 상위 기준 또는 심한 오염 기준을 초과하였고 인근 지점 별로도 95% 신뢰구간에서 차이를 보였다. 2006년과 2009년의 자료를 비교할 때 모든 중금속 농도가 점차 감소하고 있었다.

• 한국환경농학회지
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• 제26권3호
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• pp.204-209
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• 2007

Agricultural area in the vicinity of the ${\triangle}{\triangle}$ smelting factory in Kyeongbuk province, the third largest zinc smelting factory in the world, was contaminated by high concentration of heavy metals. However, the heavy metals source was not yet directly traced and thus, resulted to a conflict between the factory and residents within its vicinity. In order to determine the level of heavy metal contamination in the arable lands located at the north eastern part of the factory, soils were sampled systematically. To find out the major reason for the occurrence of this problem, waters and aerosols were sampled with constant intervals to the upward and downward direction from the factory and were analyzed to find out the heavy metal concentrations. Cadmium (Cd) and zinc (Zn) of the heavy metals were highly accumulated more than the Korean warning criteria (Cd 1.5, Zn 300 mg $kg^{-1}$) with mean values 1.7 and 407 mg $kg^{-1}$, respectively, at the surface soils (0-20 cm), and heavy metal concentration significantly decreased with increasing soil depth In addition, the concentration of both metals slightly decreased with increasing distance from the factory to the surface soils. Cadmium and Zn were detected in the upward stream water with low concentration and concentrations increased significantly in the downstream after passing across the factory. Aerosol samples also showed traces of Cd and Zn which could be attributed to the contamination of the water system and the surface soils. Conclusively, Cd and Zn emitted from the ${\triangle}{\triangle}$ smelting factory moved with the aerosol in the atmosphere and thus, contaminated the agricultural areas and the water system within it vicinity.

• Advances in environmental research
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• 제2권2호
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• pp.155-166
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• 2013

A preliminary investigation to establish the status of contamination of trace metals in the Western coast of Ghana was conducted prior to the commercial production of crude oil in the area. The study revealed the presence of heavy metals such as Pb (4.00-79.64 mg/kg), As (8.81-236 mg/kg), Cu (12.86-108.06 mg/kg), V (28.07-953.32 mg/kg), Zn (7.08-264.25 mg/kg), Cr (101.69-1366.62 mg/kg), Ni (42.41-451.43 mg/kg), Mn (16.77-1890.45mg/kg), Br (7.66-142.78 mg/kg), Ti (542.03-19960 mg/kg) and Fe (7472.88-97120 mg/kg) at six sites sampled along the coast. With the exception of Ti and Fe which showed no variation in metal concentration, the rest of the metals varied significantly among the sampled locations. Potential ecological risk of metals particularly of Co, As and Br which exhibited extreme enrichment of the sediments indicates considerable metal pollution in the studied areas. The degree of contamination is of particular concern especially to benthic biota that inhabit this environment for survival.

• 한국해양학회지:바다
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• 제24권1호
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• pp.64-78
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• 2019

2016~2017년 '국가해양생태계 종합조사(연안생태계)'에서 얻어진 495개의 퇴적물 중금속 자료를 이용하여 한반도 연안 퇴적물의 중금속 배경농도를 산정하고 오염도를 평가하였다. 퇴적물 입도를 나타내는 지시자로 Al, Cs, Li이 적절하였으며, 이 들과 중금속 농도 사이의 관계에서 이상치 제거 및 잔차 분석을 통하여 가장 낮은 기울기의 자료를 선택하여 중금속과 지시자 사이의 회귀 직선으로 배경농도를 표시하였다. 기존 연구에서의 배경농도와 본 연구의 결과는 비교적 잘 일치하였으며, 본 연구에서는 As 및 Cd에 대해 처음으로 제시하였고, 지시자로 Li을 사용한 배경농도 식을 처음으로 제시하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.123-128
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• 2013

Water quality and contamination of sediment is a growing concern in the Iksan stream of Korea. Heavy metal contamination and changes in the physicochemical properties of the stream were evaluated. Water and sediment samples were collected from six sites during the dry and rainy seasons; pH, DO, EC, ORP, turbidity, $PO_4$-P, $NO_3$-N and selected heavy metals (Cu, Pb, Ni, As, Zn, Cd, Hg) were measured. Results showed almost no change in pH between seasons. DO was highest at site 2 (~2.63 mg/L) in the dry season; EC (1,540 ms/m) was greatest at site 1 in both seasons. The ORP gradually increased from the dry to rainy season at most of the sites and was highest at site 5. Turbidity was highest at site 1 and gradually decreased from the dry to rainy season at all sites except site 3. $PO_4$-P ranged from a high of 1,193mg/L at site 1 to in the dry season to a low of ~1.2 mg/L at site 4. In contrast, $NO_3$-N was highest at site 3 in the rainy season (12,531 mg/L). Among the heavy metals measured, Cu and Zn concentrations were highest at all sediment sites. Cu and Zn are added to livestock feed to improve reproductive rates and can be carried to the stream with manure. Transport of sediment and heavy metals during the rainy season is the major source of stream contamination and it is important to continue monitoring and take necessary action in these areas.

• 한국재료학회지
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• 제28권4호
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• pp.208-213
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• 2018

Epitaxial ($11{\bar{2}}0$) a-plane GaN films were grown on a ($1{\bar{1}}02$) R-plane sapphire substrate with photoresist (PR) masks using metal organic chemical vapor deposition (MOCVD). The PR mask with striped patterns was prepared using an ex-situ lithography process, whereas carbonization and heat treatment of the PR mask were carried out using an in-situ MOCVD. The heat treatment of the PR mask was continuously conducted in ambient $H_2/NH_3$ mixture gas at $1140^{\circ}C$ after carbonization by the pyrolysis in ambient $H_2$ at $1100^{\circ}C$. As the time of the heat treatment progressed, the striped patterns of the carbonized PR mask shrank. The heat treatment of the carbonized PR mask facilitated epitaxial lateral overgrowth (ELO) of a-plane GaN films without carbon contamination on the R-plane sapphire substrate. Thhe surface morphology of a-plane GaN films was investigated by scanning electron microscopy and atomic force microscopy. The structural characteristics of a-plane GaN films on an R-plane sapphire substrate were evaluated by ${\omega}-2{\theta}$ high-resolution X-ray diffraction. The a-plane GaN films were characterized by X-ray photoelectron spectroscopy (XPS) to determine carbon contamination from carbonized PR masks in the GaN film bulk. After $Ar^+$ ion etching, XPS spectra indicated that carbon contamination exists only in the surface region. Finally, the heat treatment of carbonized PR masks was used to grow high-quality a-plane GaN films without carbon contamination. This approach showed the promising potential of the ELO process by using a PR mask.

• 자원환경지질
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• 제37권3호
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• pp.311-324
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• 2004

전라남도 보성강에 축조된 주암댐의 집수유역 내 하상퇴적물을 대상으로 중금속의 오염현황과 거동 특성을 알아보았다. 주암댐의 집수유역에는 많은 폐금속 및 탄광이 위치하고 있어 주암댐 호저퇴적물에 잠재적인 오염원으로 작용할 수 있다. 집수유역 내 하상퇴적물의 중금속 함량(Cr, Cu, Ni, Pb, Zn)은 매우 낮기 때문에 주암댐의 호저퇴적물에 영향을 줄 것으로 판단되지 않는다. 하지만 폐금속광산지역 내 하상퇴적물의 Pb 함량은 하류로 갈수록 증가하는 경향을 보여, Pb의 오염 확산이 우려된다. 폐금속광산의 환경을 고려한 강산성 조건의 용출실험결과, 하상퇴적물의 용출비로부터 결정된 중금속의 상대적 이동도는 Pb＞Zn=Cu＞Ni＞Cr으로서, Pb이 주암댐 호저퇴적물에 영향을 미치는 원소가 될 수 있음을 지시해준다. 한편 댐으로 유입한 퇴적물이 호저에 놓이게 되면(즉, 환원환경), Pb의 이동도가 비교적 높게 나타나 물-퇴적물 경계에서 Pb의 수중으로 재용출될 수 있다.