• 한국환경과학회지
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• 제29권1호
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• pp.55-68
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• 2020

The purpose of this study is to investigate the relationship of fine dust PM₁₀ and heavy metals in PM₁₀ in Asian dust flowing into Gwangju from 2013 to 2018. The migration pathways of Asian dust was analyzed by backward trajectory analysis using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model, and the change of heavy metal concentration and heavy metal content per 1 ㎍/㎥ of fine dust PM₁₀ in Gwangju area were analyzed. Also, the characteristics of the heavy metals were analyzed using the correlation between the heavy metals in PM₁₀. As a result of analyzing Asian dust entering the Gwangju region for 6 years, the average concentration of PM₁₀ measured in Asian dust was 148 ㎍/㎥, which was about 4.5 times higher than in non-Asian dust, 33 ㎍/㎥. A total of 13 Asian dust flowed into the Gwangju during 6 years, and high concentration of PM10 and heavy metals in that were analyzed in the C path flowing through the Gobi/Loess Plateau-Korean Peninsula. As a result of the correlation analysis, in case of Asian dust, there was a high correlation between soil components in heavy metals, so Asian dust seems to have a large external inflow. On the other hand, in case of non-Asian dust, the correlation between find dust PM₁₀ and artificial heavy metal components was high, indicating that the influence of industrial activities in Gwangju area was high.

• 한국수산과학회지
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• 제44권6호
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• pp.772-784
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• 2011

We measured grain size, organic matter, and metallic elements (Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As) in intertidal sediments collected from six islands in the western part of Jellanam Province in order to evaluate heavy metal contamination in the tidal flat sediments of coastal islands. The evaluation of metal contamination was carried out using geochemical assessment techniques such as sediment quality guidelines (SQGs), enrichment factor (EF), and geoaccumulation index ($I_{geo}$). Surface sediments were classified into four sedimentary facies: sand, gravelly muddy sand, slightly gravelly mud, and silt. The concentrations of heavy metals in intertidal sediments from Jaeun, Amtae, Biguem, and Docho islands showed good positive correlations with mean grain size and ignition loss, indicating that the concentrations of metallic elements in these sediments were dependent on grain size and the organic matter content. The concentrations of heavy metals in sediments from almost all of the stations were lower than two criterion values proposed by the National Oceanic and Atmospheric Administration (NOAA) in the United States. Based on the EF and $I_{geo}$ results, surface sediments were a little polluted for Cr and were moderately polluted for As. Our results suggest that more intensive studies are necessary in the future in order to determine the major source of As in intertidal sediment and to evaluate the As pollution level in macrobenthos.

• 자원환경지질
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• 제25권3호
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• pp.317-336
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• 1992

The garden soils, main road dusts, residential road dusts, and playground soils/dusts of Seoul, Geumsan, Onsan, and Taebaek areas were analyzed in order to investigate the level of heavy metal pollution by urbanization and industrialization. The soil pH is in the range of 5.48~8.40 and was generally neutral. The color of soils and dusts is mainly Raw Umber to dark greyish Raw Umber. Some samples from Taebaek city, a coal mining area, showed a deep black color due to contamination by coal dusts. Major minerals of the dusts and soils are quartz, feldspars, and micas, reflecting the composition of the parent rocks. However, pyrite was found as a major mineral in the samples of industrial road dusts of Onsan, a smelting area, and resicential road dusts of Taebaek. Thus, the high level of heavy metals in mining and smelting areas can be explained with the sulfide minerals. The mode of occurences of heavy metals in Seoul, a comprehensive urbanized area, were related to the metallic pollutants and organic materials through observation by scanning eletron microscopy. In main road and residential road dusts of Onsan area, Cd, Zn, and Cu were extremely high. Some industrial road and residential road dusts of Seoul area showed high Cu, Zn, and Pb contents, wereas some garden soils and residential road dusts of Taebaek area were high in As content. In general, the heavy metal contents in dust samples were two to three times higher than those in soil samples. Main road dust samples were the most reflective from the discriminant analysis of multi-element data. Cadmium, Sb, and Se in Onsan area, As in Taebaek area, Pb and Te in Seoul area were most characteristic in discriminating the studied areas. Therefore, Cd in smelting areas, As in coal mining areas, and Pb in metropolitan areas can be suggested as the characteristic elements of each pollution pattern. The dispersion of heavy metal elements in urban areas tends to orignate in main roads and deposit in garden soils through the atmosphere and residential roads. The heavy metal contamination in Seoul is characteristic in areas with high population, factory, road, and traffic decsities. Heavy metal contents are high in the vicinity of smelters in Onsan area and are decayed to background levels from one kilometer away from the smelters.

• 환경위생공학
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• 제24권3호
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• pp.28-36
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• 2009

We have closely examined the concentration change characteristics, emission amounts, and the material balance of hazardous air pollutants at both early and later stages of the prevention facilities. These results will be uses as the basic data when preparing for the regulatory and management plans for hazardous air pollutants. The results of the study on heavy metals illustrated that the content of heavy metals in sludge across five facilities were as follows: copper> zinc> chrome> nickel> cadmium> mercury. In terms of heavy metal content in swage sludge, the sludge in incinerating facilities other than the sludge in the D incinerating facility containing industrial water waste, was examined in order to satisfy the ocean contamination standard and fertilizer specifications. Most of the items were shown to have satisfied the emission tolerance standards in the latter part of the prevention facilities(The average elimination rate was over 90%). Therefore, it is concluded that swage sludge containing high-concentrate heavy metals needs to be incinerated rather than recycled as fertilizer.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.46-51
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• 2000

Environmental quality regulations are used to establish the maximum permissible concentrations of heavy metals before a site can be deemed to be polluted or contaminated. This paper compares the results obtained by 0.IN HCl extraction and acid extraction method(HNO$_3$+HClO$_4$.HCl). The leaching efficiency of 0.1N HCl extraction is directly proportional to the final pH of leachate, due to the different solubilities of the heavy metals at different pH values, The severe differences between 0.1N HCl-extractable and total metal contents result mainly from the buffering effect of carbonates, present in sediment. samples. Application of sequential extraction experiments to some sediments collected from gully pot in Seoul illustrates a much stronger scavenging effect by Fe and Mn-hydroxides, carbonates and organic phases. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be: Mn>Zn>>Co>Cd>>Cu>Pb>Cr>Fe, in spite of large differences in heavy metal content and localization. Changes in the physicochemical environments (such as acidification) caused by a traffic accident may result in the severe environmental pollution of heavy metals of surrounding area( surface water and rivers).

• 한국산림과학회지
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• 제82권3호
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• pp.271-282
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• 1993

조경수목(造景樹木)들의 대기오염물질(大氣汚染物質) 흡수(吸收), 정화능력(淨化能力)을 알아보기 위해 서울, 대전(大田) 등(等) 대도시(大都市) 지역과 광릉지역(光陸地域)을 선정하고 소나무, 잣나무, 은행나무, 튜립나무 및 양버즘나무 잎을 채취하여 유황함량(硫黃含量)과 중금속(重金屬) 함량(含量)을 측정 분석하였다. 조경수목(造景樹木)의 엽내(葉內) 유황함량(硫黃含量)은 서울 및 대전(大田)의 오염지역(汚染地域)의 수목(樹木)들이 비오염지역(非汚染地域)인 광릉지역(光陸地域) 수목(樹木)에 비하여 모두 높았으며, 활엽수(闊葉樹)가 침엽수(針葉樹)에서보다 2.6배(倍)나 더 높게 나타났다. 특히 은행나무(나자식물(裸子植物))와 양버즘나무(피자식물(被子植物))의 유황(硫黃) 흡수능(吸收能)이 높았다. 시기별(時期別)로는 은행나무, 양버즘나무 및 튜립나무에서 경시적(經時的)으로 유의적(有意的)인 증가(增加)를 하고 있었다. 엽내(葉內) Pb 함량(含量)은 오염지역(汚染地域)이 비오염지역(非汚染地域)에 비하여 잣나무, 소나무, 양버즘나무, 튜립나무 및 은행나무에서 각각(各各) 14.1, 10.6, 5.0, 4.2 및 3.9배(倍) 더 높게 나타났으며, 엽내(葉內) Zn의 함량(含量)은 오염지역(汚染地域)에서 각각(各各) 2.0, 1.4, 5.3, 8.8 및 3.6배(倍) 더 높게 나타났다. 오염지역(汚染地域)에서는 침엽수(針葉樹)의 경우 Pb의 흡수(吸收), 축적(蓄積)이 많았고 활엽수(闊葉樹)의 경우 Zn의 흡수(吸收), 축적(蓄積)이 더 많았다. 수종별(樹種別)로는 잣나무가 소나무보다 엽내(葉內) Pb, Zn, Cu의 함량(含量)이 높았으며, 엽령별(葉令別)로 1년생(年生)잎보다 2년생(年生)잎에서 더 높았고, 소나무, 잣나무, 튜립나무 및 양버즘나무에서는 전유황함량(全硫黃含量)과 중금속(重金屬)(Pb+Zn+Cu) 함량(含量)의 평균치간(平均値間)에 정(正)의 상관(相關)이 있었다.

• 대한금속재료학회지
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• 제49권1호
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• pp.73-78
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• 2011

Weldability, especially HAZ cold cracking, weld metal solidification cracking, and HAZ liquation cracking susceptibilities, of ASTM A356 CA6NM martensitic stainless steel casting was investigated and compared with that of 9-12% Cr ferritic steel castings. Irrespective of the Cr and Ni content in the castings, the HAZ maximum hardness increased with an increase of carbon content. CA6NM steel, which has the lowest carbon content, had the lowest HAZ hardness and showed no cold cracking in y-slit cracking tests. CA6NM steel, meanwhile, showed the largest weld metal solidification cracking susceptibility in varestraint tests because of its higher amount of impurity elements, phosphorus, and sulfur. All castings investigated had good high temperature ductility in hot ductility tests and showed little difference in liquation cracking susceptibility.

• 환경생물
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• 제20권4호
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• pp.360-365
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• 2002

경상북도내의 금속광산, 공장 및 공업, 일반폐기물, 공단주거지역 및 특수 용수사용지역 등 360곳의 토양을 2001년 3월부터 10월가지 채취하여 토양 오염도를 조사하였다. 토양 오염도는 중금속인 카드뮴, 구리, 비소, 수은, 납, 6가 크롬 및 시안의 7개 항목을 대상으로 하였으며, 그 중 각 항목에서 가장 오염도가 심한 5개 지점을 대상으로 토양내 곤충병원성 선충의 분포를 조사하였다. 토양내 선충은 누에를 이용하여 곤충병원성, 사물기생성 선충을 대상으로 하였으며, white trap을 설치하여 선충을 분리하였다. 카드뮴오염이 0.870ppm 이하인 지역에서 Rhabditida목 선충 2과가 확인되었으며, 비소에 오염된 토양에서는 0.745ppm이하에서 Rhabditidae과 선충이 확인되었다. 6가 크롬은 0.05ppm 이하인 토양에서 Cylindrocorpidae과 선충이 확인되었고, 납과 구리, 시안 오염 지역에서는 오염농도와 관계없이 Rhabditidae목 선충 2과가 검출되었다. 그러나, 시안에 오염된 토양과 토양오염우려기준을 초과한 토양에서는 선충이 검출되지 않았다. 이러한 결과는 오염지역내 선충의 분포 밀도는 매우 낮거나 존재하지 않는 것으로 확인되며 토양의 오염은 선충의 생존에 불리한 환경으로 작용하는 것으로 보인다.

• 한국환경과학회지
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• 제13권8호
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• pp.711-719
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• 2004

The effect of nickel (Ni) on growth and some tolerance strategies with regard to heavy metal tolerance mechanism was investigated in radish (Raphanus sativus) seedlings. The protective effect of histidine on nickel stress conditions was also monitored. The seedling growth decreased with an increase in metal concentrations. The inhibitory effect was more pronounced in the root elongation than in the shoot elongation. Increasing Ni supply showed a progressive increase of Ni concentrations in the roots and shoots. Ni content was higher in the shoots than in the roots. In the presence of nickel, radish exhibited an antioxidative defense mechanism, as evidenced by the elevated malondialdehyde(MDA), showing that nickel is an efficient inducer of lipid peroxidation. Exposure of radish to elevated concentrations of nickel was accompanied by an increase in the proline content. Supplemental histidine in the presence of Ni ameliorated metal-induced growth inhibition and lipid peroxidation. Combinations of Ni and histidine resulted in a significant decline in proline content compared with Ni stress alone, indicating that histidine may provide protection against the adverse effect of Ni stress. From the results it is suggested that histidine is an efficient chelator by complexing metal ion within the plant and may playa role in nickel tolerance implicated in metal detoxification.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.211-216
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• 2002

To investigate transition region in welded overlay relating to disbonding crack, the effect of vanadium addition on disbonding of Cr-Mo steels overlay welded with austenitic stainless steel was studied. V modified Cr-Mo steels have a higher resistance to disbonding than V free Cr-Mo steel. One reason is due to the fact that fine vanadium carbide precipated in base metal traps hydrogen and thus decreases the susceptibility to the disbonding. The second is related to the higher stability of the vanadium and stable carbides formed during PWHT, in which the carbon diffusion to the interface is lower than for V free Cr-Mo steel. Decreasing the carbon content at the interface of the weld overlay shows good resistance to the disbonding. Hence, it is important to control the carbon content at the interface of the weld overlay.