• 한국토양비료학회지
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• 제47권6호
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• pp.391-397
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• 2014

Acid mine drainage occurrence is a serious environmental problem by mining industry; it usually contain high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of greatest concern. It causes mine impacted soil pollution with mining and smelting activities, fossil fuel combustion, and waste disposal. In the present study, three bacterial strains capable of producing urease were isolated by selective enrichment of heavy metal contaminated soils from a minei-mpacted area. All isolated bacterial strains were identified Sporosarcina pasteurii with more than 98% of similarity, therefore they were named Sporosarcina sp. KM-01, KM-07, and KM-12. The heavy metals detected from the collected mine soils containing bacterial isolates as Mn ($170.50mg\;kg^{-1}$), As ($114.05mg\;kg^{-1}$), Zn ($92.07mg\;kg^{-1}$), Cu ($62.44mg\;kg^{-1}$), and Pb ($40.29mg\;kg^{-1}$). The KM-01, KM-07, and KM-12 strains were shown to be able to precipitate calcium carbonate using urea as a energy source that was amended with calcium chloride. SEM-EDS analyses showed that calcium carbonate was successfully produced and increased with time. To confirm the calcium carbonate precipitation ability, urease activity and precipitate weight were also measured and compared. These results demonstrate that all isolated bacterial strains could potentially be used in the bioremediation of acidic soil contaminated by heavy metals by mining activity.

• Advances in environmental research
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• 제3권4호
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• pp.283-292
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• 2014

Iron precipitating organisms play a significant role in the formation of ferric hydroxide precipitate, which acts as strong adsorbent for toxic metal. In this respect four different iron precipitating cultures were isolated from Hutti gold mine surface winze water sample on citrate agar medium. The best isolate was screened out for metal removal study on the basis of fast visual iron precipitation. The selected isolate was identified as Enterobacter sp. based on routine biochemical tests and Biolog GN microplate results and as Enterobacter cloacae subsp. dissolvens by 16S rRNA gene sequence analysis (GenBank accession number EU429448). Influence of medium composition, medium initial pH, the influence of inoculum size, effect of various media and ferric ammonium citrate concentration were studied on metal removal in shake flask experiments. Under the optimized conditions studied, E. cloacae showed $94{\pm}2$, $95{\pm}2$ and $70{\pm}2%$ of cadmium, copper and mercury removal from a simulated waste in shake flask studies. In lab scale column reactor more than 85% of copper and mercury removal was achieved.

• 자원리싸이클링
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• 제21권1호
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• pp.3-16
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• 2012

도시광산 재자원화기술의 모듈과 한국의 비철제련 프로세스를 파악하기 위하여 재자원화기술의 전체상과 요소기술, 물리선별, 비철제련 프로세스 및 바람직한 도시광산 처리기술의 단위조작을 밝히고, LS-Nikko동제련(주)과 고려아연(주)의 리싸이클링 프로세스를 탐색하였다. 끝으로 일본의 대표적인 비철제련소인 DOWA Holdings 및 JX Holdings 리싸이클링 프로세스와 한국의 위 두 비철제련소의 리싸이클링 프로세스를 비교검토 하였다.

• 한국환경농학회지
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• 제32권4호
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• pp.245-251
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• 2013

BACKGROUND: The objectives of this study are to investigate the contamination levels of heavy metals in soil, ground water, and agricultural product near the abandoned Boeun and Sanggok mine areas in Korea and to assess the health risk for these local residents exposed to the toxic heavy metals based on analytical data. METHODS AND RESULTS: By the results of human health risk assessment for local residents around Boeun and Sanggok, human exposure to cadmium, copper, arsenic from soil and to lead, cadmium, and arsenic from rice grain were higher in Sanggok, but human exposure to zinc and arsenic from ground water was higher in Boeun. By the results of hazard index (HI) evaluation for arsenic, cadmium, copper, lead, and zinc, HI values in both areas were higher than 1.0. This result indicated that the toxicity hazard through the continuous exposure to lead, cadmium, arsenic from rice, ground water, and soil would be likely to occur to the residents in the areas. Cancer risk assessment for arsenic, risks from the rice were exposed to one to two out of 10,000 people in Boeun and one of 1,000 people in Sanggok. These results showed that the cancer risks of arsenic in both areas were 10~100 times greater than the acceptable cancer risk range of US EPA ($1{\times}10^{-6}{\sim}1{\times}10^{-5}$). CONCLUSION(S): Therefore, if these two local residents consume continuously with arsenic contaminated soil, ground water, and rice, the adverse health effects (carcinogenic potential) would be more increased.

• Horticulture, Environment, and Biotechnology : HEB
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• 제59권6호
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• pp.775-786
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• 2018

To test the hypothesis that humic acid (HA), anaerobically digested pig slurry filtrate (APS), and their combination would differently affect the chemical speciation and extractability of metals (cadmium, copper, and zinc) and their uptake by plants, we conducted a pot experiment using wormwood in two texturally contrasting soils (sandy loam and clay loam) collected from a field near an abandoned Cu mine. Four treatments were laid out: HA at $ 23.5g\;kg^{-1}$ (HA), APS at $330mL\;kg^{-1}$ (APS), HA at $ 23.5g\;kg^{-1}$ and APS at $330mL\;kg^{-1}$ (HA + APS), and a control. Each treatment affected the chemical speciation and mobility of the metals, and thereby resulting in variable patterns of plant biomass yield and metal uptake. The APS supported plant growth by increasing nutrient availability. HA supported or hindered plant growth by impacting the soil's water and nutrient retention capacity and aeration, in a soil texture-dependent manner, while consistently enhancing the immobilization of heavy metals. Temporal increases in whole-plant dry matter yield and metal accumulation suggested that the plants were capable of metal hyperaccumulation. The results were discussed in terms of the mobility of metals and plant growth and corroborated by the $^{15}N$ recovery of soil- and plant-N pools under H and HS treatments. Therefore, for effective phytoremediation of polluted soils, an appropriate combination of plant growth promoters (APS) and chelating agents (HA) should be predetermined at the site where chemical stabilization of pollutants is desired.

• 자원환경지질
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• 제42권5호
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• pp.445-455
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• 2009

미생물학적 황산염 환원은 황산염을 전자수용체로 이용하는 황산염 환원 박테리아에 의해 황산염이 황화이온으로 변환되는 과정이다. 형성된 황화이온은 주변의 용존 금속 이온과 결합하여 용해도가 낮은 금속 황화물로 침전된다. 이 연구에서는 비소와 중금속으로 오염된 송천 금은광산 일대 토양을 대상으로 하여 토착 박테리아에 의한 황산염 환원을 유도함으로써 독성 원소의 원위치 고정화 기술의 효율성을 평가하였다. 왕수 분해 결과, 대상 토양 내 비소, 구리, 납의 함량은 각각 1,311 mg/kg, 146 mg/kg, 294 mg/kg 등으로 나타나 특히 비소의 오염이 심각한 상태였다. 회분식 실험 결과, 미생물학적 황산염 환원에 의하여 pH 증가, 산화환원전위 감소, 황산염 함량 감소, 비소와 구리 함량 감소 등이 관찰되었다. 이 때 가장 높은 중금속 침전 효율을 유도하는 탄소원과 황산염의 농도 범위는 각각 0.2~0.5%, 100~200 mg/L로 나타났다. 미생물학적 또는 화학적으로 황화물 침전을 유도하게 고안된 컬럼 실험 수행 결과, 비소와 구리는 두 컬럼에서 모두 98% 이상 제거되었다. 그러나 산소를 다량 포함한 용액을 주입한 후, 화학적으로 황화물 침전을 유도한 컬럼에서는 즉각적인 비소와 구리의 재용출 현상이 나타났으나, 미생물학적 황산염 환원을 유도한 컬럼에서는 침전물이 30일 이상 장기간 안정성을 보였다. 미생물학적 컬럼 내에 형성된 검은색 침전물을 분석한 결과 FeS와 CuS로 나타났으며 비소는 대부분 철 황화물에 흡착되어 있는 것으로 확인되었다.

• 한국광물학회지
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• 제23권3호
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• pp.243-250
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• 2010

인도네시아 잠비산 복합 동광석을 대상으로 고품위 동 정광생산을 위한 부유선별 연구를 수행하였다. 본 연구에 사용된 시료는 대부분 탄산염인 공작석으로 이루어져 있으나, 일부 황화동이 존재하여 자연부유도가 높은 황화동을 먼저 부유선별에 의해 회수한 다음, 침강산물로부터 산화동 회수를 위한 공정을 적용하였다. 먼저 황화동 부유선별에서는 잔세이트(xanthate) 계열의 포수제인 AP-211과 AP-242를 1 : 1의 비율로 300 g/t 첨가하고, 광액 pH 6인 조건에서 Cu 품위와 회수율이 각각 57.7%와 9.5%인 동 정광을 얻었다. 그리고 침전된 산물을 대상으로 지방산 포수제인 올레인산을 300 g/t, 기포제 첨가량 50 g/t, 광액 pH 8.0, 그리고 정선횟수 2회인 조건에서 Cu의 품위와 회수율이 각각 30.8%와 92.1%인 결과를 얻었다. 회수된 황화동 및 산화동 정광을 합산한 결과 최종적으로 Cu의 품위와 회수율이 36.1%와 92.7%인 결과를 얻었다.

• 생명과학회지
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• 제15권5호
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• pp.826-833
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• 2005

식물 비생육지 토양의 깊이별 중금속 함량은 S1지점의 경우 1996년 오염토양 개선사업으로 S1지점 바로 위에다 남은 광미를 복토함으로써 광미 중금속이 강우에 의해 용탈되어 토양에 축적되기 때문에 오염되고 있는 것으로 판단되었고 S2지점은 오염토양 개선사업의 효과로서 표토에서 Zn과 Pb가 토양오염 우려기준을 초과하지 않았으며 Pb의 경우 $30\∼50cm$에서 토양오염 우려기준을 초과한 것은 광맥의 영향 때문이며 구리의 경우는 광산의 채광물로서 오염 정도가 심각하였다. 생육지 토양의 중금속 함량은 같은 표고상에 위치한 광산 위 지점(SP1, SP2, SP3)에서 볼 때 SP1지점에서는 Zn의 함량이 537.5 mg/kg로 가장 높았고, SP3지점에서는 Cu와 Pb의 함량이 가장 높았는데 이는 폐광산에 복토 사업을 했더라도 아직 토양 복원이 완전히 이루어지지 않아 강우와 풍화에 의한 광미의 영향 때문인 것으로 생각되며 SP2지점은 다른 지점보다 지대가 높아 광미의 영향을 적게 받는 것으로 생각된다. 식물체내의 중금속 함량은 차즈기>쑥>억새>살갈퀴 순으로 조사되었고 식물에 의한 연간 중금속 제거율 역시 차즈기가 가장 좋은 것으로 조사되었다. 특히 차즈기는 다량의 중금속이 축적되어 있고 중금속 오염 지역에 내성이 있는 지표종으로 생각될 수 있으며 본 식물의 중금속 축적 능력에 대한 더 많은 연구가 진행되어야 할 것으로 생각된다.

• 자원환경지질
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• 제33권2호
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• pp.91-100
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• 2000

It has been more than ten years since Dukun mine was abandoned. Tailings of waste deposits and slime dumps in the abandoned Dukum mine have been left to be deserted for fifty years. The results of fifty years of neglecting are nothing short of major environmental problems. Slime dumps have been exposed to air and water in the mine over ten years and then soil profile has been formed well. Soil in the upper layer (A horizon) is the light gray color due to the leaching of cations. Soil in the lower layer (A2 horizon, 0.2∼0.3m)is tinted with reddish brown and yellowish brown color due to the development of iron oxides and iron hydroxides. Soil in the lower part of B horizon of (1.0∼3.0m) with the growth of copper and zinc oxides exposes to the bluish green, light blue, and dark gray. Ranging from 3m to 8m in depth, 85 samples were taken from 22 sampling sites with 50m intervals located on the slime dump area with hand auger and trench (open cut). As tailings was distributed, heavy metal elements extracted by the process of surface water and ground water move and disperse in to the hydrosphere. Waste dumps were distributed in and around the mine and water draining from those dumps be a potential source of contamination. Soils, thus, can be dispersed into downslope and downstream through wind and water by clastic movement. These materials may be deposited in another horizon if the water is withdrawn, or if the materials are precipitated as a result of differences in pH, or other conditions in deeper horizons. These were primarily associated with acid mine drainage. The characteristics and rate of release of acid mine drainage are influenced by various chemical and biological reactions at the source of acid generations. Prolonged extration of heavy metal elements has a detrimental effect on the agricultural land and residental area. Twenty soil samples were collected from the agricultural land in the area (0∼30 cm). Seventeen samples were also taken from the sediment in the stream running alongside the dumps. The dispersion patterns of heavy metal elements are as follows: The content of As ranged 2∼6 ppm in a horizon, 20∼125 ppm in B horizon with large amount of clay mineral is concentrated and the content of Cd ranged 1∼2 ppm in A horizon, 4∼22 ppm in B horizon. Like Cd, the content of As, Cu, Zn, Pb in B horizon is higher than that in A horizon (approximately 5∼100 times). When soil formation proceeds in stages, it is necessary to investicate the B horizon with the concentration of heavy metal and preventive measures will have to established.

• 자원환경지질
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• 제29권1호
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• pp.45-55
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• 1996

Although the Dongjin Au-Ag-Cu mine had been abandoned since about forty years ago, the results of this study on the dispersion patterns and contamination level of heavy metals in the hydrologic system flowing via the waste rump show that the environmental impacts from the mine wastes are still significant. The stream water in the vicinity of the waste rump is severely acidified (pH 3.8 to 4.4) and highly enriched in various dissolved heavy metals. The heavy metal contents of the stream water and stream sediments are systematically attenuated with increasing distance from the mine area. However, it is worth to note that continuous attenuation of heavy metal contents in both media were reenriched in downstream area more than 800 m apart from the mine because it can be acted as a secondary source of heavy metal pollution. The heavy metals, especially Cd, Cu and Zn of polluted downstream sediments mainly occur in Fe-Mn oxides and organic materials, which indicates that these elements are the main pollutants from the waste rump of the Dongjin mine. The heavy metal contents of crops, such as sesame, perilla, red Pepper and brown rice, collected from the polluted farm land in the downstream area are lower than those of land plants from stream sides, but significantly higher in Cd, Cr, Cu and Zn than those from the unpolluted farm land. Especially, almost all of the crops in polluted farm land have been severly contaminated by Cd (>0.4 ppm). On the other hand, the heavy metal contents of the crops collected from refreshed farm land by means of a soil addition method shows significantly lowered level comparing with those of polluted area, which indicates that a soil addition method was effective for the refreshment of polluted farm land by toxic metallic pollutants. Wormwoods from this area showed very high contents in a11 the heavy metals even in unpolluted area (Cd > 1 ppm, Cr > 1 ppm, Cu > 11 ppm, Pb> 4 ppm, Zn > 55 ppm), indicating that a special caution must be payed when one takes ingest them.