• 자원환경지질
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• 제36권1호
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• pp.17-25
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• 2003

동명광산을 경유하는 수계의 pH는 5.9∼7.1의 변화를 보여 약산성 내지는 중성의 환경을 보인다. 하천수 중 중금속 원소함량의 분포는 자원소의 지구화학적 특성에 따라 다양한 분포 양상을 보이나 전반적으로 폐광산 주변에서 증가하는 경향을 보인다. 동명광산 지역의 광미, 폐석적치장토양, 농경지토양에 대한 성분분석 결과 농경지토양에는 중금속의 총 농토가 광미나 폐석적치장의 토양보다 훨씬 낮았을 뿐 아니라 총 중금속 농도 중 adsorbed, carbonate, reducible fraction들이 차지하는 비율이 낮아 이들이 농작물이나 주변 수계에 큰 영향을 미치지 못할 것으로 생각된다. 그러나 하천수중 중금속 원소함량 분포가 전반적으로 광산지역에서 증가하는 경향을 보이며, 광미나 폐석적치장 토양에서도 중금속의 총 농도가 매우 높았을 뿐 아니라 adsorbed, carbonate, reducible fractions들이 차지하는 비율이 농경지 보다 상대적으로 높았기 때문에 이들이 유실되거나 또는 산성우, 산성인 광산폐수의 유입 등으로 인해 화학적 환경변화가 발생할 경우 중금속 오염의 확산이 우려되므로 이에 대한 오염방지대책이 필요하다고 생각된다.

• 자원환경지질
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• 제30권4호
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• pp.341-352
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• 1997

Retention ponds have been dug along some of the motorways in France to minimize environmental pollution by keeping pollutants from spreading over the surrounding area. In order to study heavy metal pollution and diagenetic behaviour of sediments, eight core samples were collected from the bottom of a retention pond located along the A-71 motorway in Sologne. The metal concentrations in interstitial waters and extractable metal concentrations in sediment layers using sequential chemical extraction method were determined. The depth distributions of Pb, Zn and Cd concentrations in interstitial water and particulate sediments were studied, and distribution coefficients (KD) were also determined to investigate the environmental mobility of these elements. In addition. the index of geoaccumulation and the Fe-normalized enrichment factor were calculated to differentiate the natural accumulation from the anthropogenic pollution. The vertical concentration profiles of heavy metals in core sediments indicate that surface enrichments (0~2 cm) of Pb, Zn, Cd and organic carbon were always observed at each core sample, due to the early diagenesis. However, the major factor contributing to the accumulation of Cd at the sediment surface is attributed to the dissolution of Cd from polluted roadside soil during periods of rainstorms and its subsequent redeposition on the sediment surface after being carried to the retention pond. A comparison of the KD values indiactes that a decrease in the KD values for Pb and Zn was observed with depth while KD values for Cd increase. According to the KD values. the relative mobility of studied metals was determined as following: Mn>Zn>Cd>Pb, for the upper layer, and Mn>Cd>Zn>Pb, for the lower layers.

• Ocean and Polar Research
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• 제32권3호
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• pp.309-319
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• 2010

To assess community structure and diversity of archaea, a clone sequencing analysis based on an archaeal 16S rRNA gene was conducted at three sediment depths of the continental slope and Ulleung Basin in the East Sea. A total of 311 and 342 clones were sequenced at the slope and basin sites, respectively. Marine Group I, which is known as the ammonia oxidizers, appeared to predominate in the surface sediment of both sites (97.3% at slope, 88.5% at basin). In the anoxic subsurface sediment of the slope and basin, the predominant archaeal group differed noticeably. Marine Benthic Group B dominated in the subsurface sediment of the slope. Marine Benthic Group D and Miscellaneous Crenarchaeotal Group were the second largest archaeal group at 8-9 cm and 18-19 cm depth, respectively. Marine Benthic Group C of Crenarchaeota occupied the highest proportion by accounting for more than 60% of total clones in the subsurface sediments of the basin site. While archaeal groups that use metal oxide as an electron acceptor were relatively more abundant at the basin sites with manganese (Mn) oxide-enriched surface sediment, archaeal groups related to the sulfur cycle were more abundant in the sulfidogenic sediments of the slope. Overall results indicate that archaeal communities in the Ulleung Basin show clear spatial variation with depth and sites according to geochemical properties the sediment. Archaeal communities also seem to play a significant role in the biogeochemical carbon (C), nitrogen (N), sulfur (S), and metal cycles at each site.

• 한국분말재료학회지
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• 제20권3호
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• pp.180-185
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• 2013

The iron oxides nanoparticles and iron oxide with other compounds are of importance in fields including biomedicine, clinical and bio-sensing applications, corrosion resistance, and magnetic properties of materials, catalyst, and geochemical processes etc. In this work we describe the preparation and investigation of the properties of coated magnetic nanoparticles consisting of the iron oxide core and organic modification of the residue. These fine iron oxide nanoparticles were prepared in air environment by the co-precipitation method using of $Fe^{2+}$: $Fe^{3+}$ where chemical precipitation was achieved by adding ammonia aqueous solution with vigorous stirring. During the synthesis of nanoparticles with a narrow size distribution, the techniques of separation and powdering of nanoparticles into rather monodisperse fractions are observed. This is done using controlled precipitation of particles from surfactant stabilized solutions in the form organic components. It is desirable to maintain the particle size within pH range, temperature, solution ratio wherein the particle growth is held at a minimum. The iron oxide nanoparticles can be well dispersed in an aqueous solution were prepared by the mentioned co-precipitation method. Besides the iron oxide nanowires were prepared by using similar method. These iron oxide nanoparticles and nanowires have controlled average size and the obtained products were investigated by X-ray diffraction, FESEM and other methods.

• 자원환경지질
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• 제28권5호
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• pp.455-467
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• 1995

In order to investigate the dispersion patterns and speciations of Cu, Pb, Zn and Cd in soils, stream sediments and stream waters, geochemical studies of soil, stream sediment and stream water samples collected in the vicinity of the Shi-Heung Cu-Pb-Zn mine was carried out Cation exchange capacity measurement, size analysis, X-ray diffraction analysis and batch test were performed to select applicable soil for adsorption treatment The average content of Cu, Pb, Zn and Cd in soils collected from tailings and ore dressing plant is 1084 ppm, 2292 ppm, 3512 ppm and 29.2 ppm, respectively, and therefore, tailings and ore dressing plant site may be the major contamination sources in this study area. The mean content of Cu, Pb, Zn and Cd in stream sediments is extremely high up to 794 ppm, 1633 ppm, 2946 ppm and 25.2 ppm, respectively. Tailing particles and heavy metal ions are dispersed along the tributary system. Results from the sequential extraction analysis indicate; (1) most of Cu is bound to organic matters and sulphides, (2) fraction of Pb is mainly bound to Fe and Mn oxides. Most of Zn is largely bound to Fe and Mn oxides and residual fraction. Ion exchangeable fraction of Cd is relatively higher than those of Cu, Pb and Zn. Batch test on soils collected from the kaolinite and/or pyrophyllite mines and from the control areas was carried out to select an applicable soil samples for adsorption treatment The sample, S10, collected from the control area 2 (clay content 33.2%) shows the highest $K_d$ (distribution coefficient). Organic content in soils and several clay minerals shows relatively good correlation with $K_d$. It means that applicable soils for adsorption treatment of heavy metals show high organic and clay content.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.407-409
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• 2006

Geochemical analyses carried out on samples collected from cores on and near the southern smit of Hydrate Ridge have advanced understanding by providing a clear contrast of the two major modes of marine gas hydrate occurrence. High concentrations (15%-40% of pore space) of gas hydrate occurring at shallow depths (0-40 mbsf) on and near the southern summit are fed by gas migrating from depths of as much as 2km within the accretionary prism. This gas carries a characteristic minor component of C2-C5 thermogenic hydrocarbons that enable tracing of migration pathways and may stabilize the occurrence of some structure II gas hydrate. A structure II wet gas hydrate that is stable to greater depths and temperatures than structure I methane hydrate may account for the deeper, faint second bottom simulating reflection (BSR2) that occurs on the seaward side of the ridge. The wet gas is migrating In an ash/turbidite layer that intersects the base of gas hydrate stability on the seaward side of and directly beneath the southern summit of Hydrate Ridge. The high gas saturation (>65%) of the pore space within this layer could create a two-phase (gas + solid) system that would enable free gas to move vertically upward through the gas hydrate stability zone. Away from the summit of the ridge there is no apparent influx of the gas seeping from depth and sediments are characterized by the normal sequence of early diagenetic processes involving anaerobic oxidation of sedimentary organic matter, initially linked to the reduction of sulfate and later continued by means of carbonate reduction leading to the formation of microbial methane.

• 대한원격탐사학회지
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• 제10권2호
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• pp.37-48
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• 1994

In spatial information processing, particularly in non-renewable resource exploration, the spatial data sets, including remote sensing, geophysical and geochemical data, have to be geocoded onto a reference map and integrated for the final analysis and interpretation. Application of a computer based GIS(Geographical Information System of Geological Information System) at some point of the spatial data integration/fusion processing is now a logical and essential step. It should, however, be pointed out that the basic concepts of the GIS based spatial data fusion were developed with insufficient mathematical understanding of spatial characteristics or quantitative modeling framwork of the data. Furthermore many remote sensing and geological data sets, available for many exploration projects, are spatially incomplete in coverage and interduce spatially uneven information distribution. In addition, spectral information of many spatial data sets is often imprecise due to digital rescaling. Direct applications of GIS systems to spatial data fusion can therefore result in seriously erroneous final results. To resolve this problem, some of the important mathematical information representation techniques are briefly reviewed and discussed in this paper with condideration of spatial and spectral characteristics of the common remote sensing and exploration data. They include the basic probabilistic approach, the evidential belief function approach (Dempster-Shafer method) and the fuzzy logic approach. Even though the basic concepts of these three approaches are different, proper application of the techniques and careful interpretation of the final results are expected to yield acceptable conclusions in cach case. Actual tests with real data (Moon, 1990a; An etal., 1991, 1992, 1993) have shown that implementation and application of the methods discussed in this paper consistently provide more accurate final results than most direct applications of GIS techniques.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3268-3276
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• 2023

The practice of identifying the potential zones for mineral exploration in a speedy and low-cost method includes the use of satellite imagery analysis as a part of remote sensing techniques. It is challenging to explore the iron mineralization of a region through conventional methods which are a time-consuming process. The current study utilizes the Hyperion satellite imagery for mapping the iron mineralization and associated geological features in the Irikkur region, Kannur, Kerala. Along with the remote sensing results, the field study and laboratory-based analysis were conducted to retrieve the ground truth point and geochemical proportion to verify the iron ore mineralization. The MC simulation showed for shielding properties indicate an increase in the linear attenuation coefficient with raising the Fe₂O₃+SiO₂ concentrations in the investigated rocks where it is varied at 0.662 MeV in the range 0.190 cm^-1 - 0.222 cm^-1 with rising the Fe₂O₃+SiO₂ content from 57.86 wt% to 71.15 wt%. The analysis also revealed that when the γ-ray energy increased from 0.221 MeV to 2.506 MeV, sample 1 had the largest linear attenuation coefficient, ranging from 9.33 cm1 to 0.12 cm^-1. Charnockite rocks were found to have exceptional shielding qualities, making them an excellent natural choice for radiation shielding applications.

• 자원환경지질
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• 제56권5호
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• pp.501-514
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• 2023

산불은 연소 과정에서 다양한 오염물질을 배출하여 심각한 환경 문제를 초래할 수 있다. 최근 지구 온난화와 기후변화의 영향으로 전 세계적으로 산불의 규모와 빈도가 증가하여 환경에 미치는 영향 역시 급증할 것으로 예상된다. 한국은 산불 발생이 빈번한 동해안 지역에 원자력 발전소가 위치하고 있어, 중대 사고에 대비하여 산불 환경에서 방사성 핵종의 거동 특성에 대한 이해가 요구된다. 본 리뷰 논문에서는 산불이 지하수 토양 환경에 가져오는 변화와 오염 특성을 검토하고, 산불로 변화된 지하수 토양 환경에서의 방사성 핵종 거동을 고찰하였다. 특히, 변화된 지중환경의 여러 특성 중 방사성 핵종의 거동에 영향을 미칠 수 있는 요인들을 고려하였으며, 보다 구체적인 메커니즘 이해를 위해 산불이 초래하는 지하수 토양 환경 변화와 오염에 대한 연구의 필요성을 기술하였다.

• 한국지구과학회지
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• 제18권6호
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• pp.500-514
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• 1997

옥천습곡대 중앙부에 해당하는 문경지역예 분포하는 각섬암에 대하여 정밀한 산상, 조직 및 지화학적 성질을 조사하고, 지구조적 환경을 추적했다. 본역의 상내리층(옥천층군)과 석회암층(조선누층군)에 분포하는 각섬암은 변성된 조립현무암질 암상이며 주변암과 조화적로 분포함을 확인했다. 본 연구를 통하여 본 암석의 분포를 이전의 그것에 비해 크게 대선하였다. 상내리 지역을 중심으로 관찰한 암상을 최소한 4매 이상이다. 그 하나는 석회암층 내에 분포하며(Ls Sill, 두께 약 3 m), 나머지는 상내리층 내에 분포한다. 상내리층 내에 분포한 암상들을 하부로부터 각각 First Sill(두께 약 40 m), Second Sill(두께 약 100 m), Third Sill(두께 약 40 m)로 명명했다. 두꺼운 암상은 후기에 관입한 소규모의 암상을 포함하며, Third Sill은 2매의 주 암상과 2매의 소규모 암상으로 구성된다. 각 암상은 주변암과의 접촉부에서 세립질의 냉각대를 가지며, 내측으로 갈수록 입자의 크기가 증가한다. 두꺼운 암상은 다양한 암맥과 중심부에서 힌색의 단편을 가지며, 접촉부에서 중앙부로 감에 따라 화학적 성질도 규칙적으로 변한다. $SiO_2,\;Na_2O,\;K_2O,\;P_2O_5$는 증가하며, $TiO_2,\;FeO^*,\;Al_2O_3,\;CaO$는 감소하는 경향을 보인다. 각섬암의 산상과 화학적 특징을 고려하여, 초기에 관입한 마그마로 생각되는 대표적인 10개의 화학조성을 선택하여 그들의 주성분 및 부성분 변화를 조사하였다. 그들이 보여주는 조성변화는 단일 마그마의 분별결정작용으로 설명할 수 없다. 본 역의 각섬암에 관한 지질분포, 지화학적 특성 및 과거 연구자들의 자료는 각섬암의 원암(현무암질마그마)이 intracontinental rift 환경에서 암상형태로 관입하였음을 지시한다.