• Journal of Microbiology
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• v.39 no.2
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• pp.83-88
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• 2001

There is considerable interest in how microbiological processes can affect the behaviour of metal contaminants in natural and engineered environments and their potential for bioremediation. The extent to which microorganisms can affect metal contaminants is dependent on the identity and chemical form of the metal and the physical and chemical nature of the contaminated site or substance. In general terms, microbial processes which solubilize metals increase their bioavailability and potential toxicity, whereas those that immobilize them reduce bioavailability. The balance between mobilization and immobilization varies depending on the metal, the organisms, their environment and physico-chemical conditions.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.31-39
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• 1997

Between 40,000 and 60,000 liters of light oil were spilled when an underground pipe broke at a newly constructed landfill site in coastal area, Korea. Methods were presented to examine the subsurface distribution of the contaminants in hydrocarbon-contaminated soil. As results, large quantities of oil and grease were found to have migrated horizontally at the site. Oil and grease plume at concentrations of 38-88 mg/kg was formed horizontally through silty sand with gravel fill and the vertical movement of the contaminants was thought to be limited to groundwater level between 2 and 4 m corresponding to sea water level. Right after finding the leakage area, the early action of excavation and pumping out the mixture of groundwater and oil was taken and it was proved to be very effective for preventing further contamination. Two months after the leakage, oil and grease in sea water sample near contaminated area was not detectable.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.21-30
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• 1998

The purpose of this study is to assess contaminant transfer and environmental impacts to the surroundings by inadequate control of USTs. Several methodologies can be used to approach for the site assessment depending on the appearance of contaminants on the site and their types. In this case study, randomized and/or triangle matrix techniques were used. As a result, the composition of materials in tank station were appeared in several state. From 1 to 1.5m depth, the soil was composed of reclaimed soils. And 1.8-3.5m depth, silty sand was appeared and about 4m, weathered soil was appeared. Based on the preliminary and actual site investigation by DPT methodologies on the width and depth of the site with analysis of BTEX and TPH, the contamination was found in this tank station and already distributed near areas. Finally, it was found that the hydroflow differences during the season affects the area and depth of contamination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.234-240
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• 2016

We examined the diffusion of contaminants released from the southern coast around Fukushima, Japan, during the passage of typhoons using a three-dimensional numerical model (POM) to track diffusing radioactivity (RA) released from the nuclear power plant at Fukushima following the accident caused by the giant tsunami event in March 2011. Radioactive contaminants released during the passage of typhoons may have significantly affected not only Japanese but also Korean coastal waters. The model domain covered most of the northwestern Pacific including marginal seas such as the East/Japan Sea and the Yellow Sea. Several numerical experiments were conducted case studies focusing on the westward diffusion from the southern coast of Japan of contaminants derived from the source site (Fukushima) according to various attributes of the typhoons, such as intensity, track, etc. The model produced the following results 1) significant amounts of contaminants were transported in a westward direction by easterly winds favorable for generating a coastal air stream along the southern Japanese coast, 2) the contaminants reached as far as Osaka Bay with the passage of typhoons, forced by a 5-day positive sinusoidal form with a (right-) northward track east of Fukushima, and 3) the range of contamination was significant, extending to the interior of the East/Japan Sea around the Tsugaru Strait. The model suggests that contaminants and/or radioactivity released from Fukushima with the passage of typhoons can affect Korean waters including the northeastern East/Japan Sea around the Tsugaru Strait, especially when the typhoon tracks are favorable for generating a westward coastal air stream along the southern Japanese coast.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.10a
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• pp.89-110
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• 2003

The limitations of conventional soil and groundwater contamination remediation technologies have motivated a search for innovative technologies; particularly in situ technologies that do not require extraction of contaminants from the subsurface. All engineered in situ remediation systems require that the contaminant be mixed with a remedial compound. Horizontal flow treatment wells (HFTWs), an innovative technology that consists of a pair of dual-screened treatment wells, were used at a trichloroethylene (TCE) contaminated site to efficiently achieve this mixing of contaminant and remedial compound in order to effect in situ bioremediation (McCarty et al., 1998). In this paper, the potential of HFTWs to treat chlorinated aliphatic hydrocarbons (CAHs) as well as other soil and groundwater contaminants of concern, such as nitroaromatic compounds (NACs), perchlorate, and methyl-tert-butyl ether (MTBE), is examined. Through a combination of laboratory studies, model analyses, and field evaluations, the effectiveness of this innovative technology to manage these contaminants is investigated.

• Journal of Conservation Science
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• v.36 no.2
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• pp.73-81
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• 2020

Considering the difficulties associated with the creation of deterioration maps for stone cultural heritages, quantitative determination of chemical and biological contaminants in them is still challenging. Hyperspectral image analysis has been proposed to overcome this drawback. In this study, hyperspectral imaging was performed on Stone Buddhas Temple in Four Directions at Gulbulsa Temple Site(Treasure 121), and several surface contaminants were observed. Based on the color and shape, these chemical and biological contaminants were classified into ten categories. Additionally, a method for establishing each class as a reference image was suggested. Simultaneously, with the help of Spectral Angle Mapper algorithm, two classification methods were used to classify the surface contaminants. Method A focused on the region of interest, while method B involved the application of the spectral library prepared from the image. Comparison of the classified images with the reference image revealed that the accuracies and kappa coefficients of methods A and B were 52.07% and 63.61%, and 0.43 and 0.55, respectively. Additionally, misclassified pixels were distributed in the same contamination series.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.675-695
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• 2023

The tracksite of dinosaurs and pterosaurs in Sanbuk-dong of Gunsan is the largest early Cretaceous dinosaur footprint fossil site in Korea, and all the footprints are important evidence indicating that large ornithopod and theropod dinosaurs inhabited the Korean peninsula during the early Cretaceous. The Sanbuk-dong site was covered with waterproof sheet in an outdoor environment until the installation of a protective enclosure in 2021. As a result, various factors such as shear force, load reduction, temperature and humidity fluctuations, acid rain, salinity and microorganisms have complexly interacted in the substrate of fossils, exacerbating the damage to footprints. For 159 footprints in 12 trackways among the footprints found in the site, the damage types were classified in detail and the level of each damage was assessed. The damages were classified into 6 types through the classification of deterioration degree of individual footprints. As a result of ultrasonic physical property evaluation on the surface of the fossil site, most of these footprints are in the completely weathered (CW) stage. Furthermore, various weathering patterns were observed in the study area, and surface contaminants were analyzed along the stratigraphy. Although the patterns of freshness and contaminants varied at different points within the fossil site, the chemical compositions were similar. Based on the results, an efficient conservation management system for dinosaur footprint fossils was established, and a conservation treatment type for each footprint was proposed.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.417-422
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• 2005

The procedure of investigation and design of the soil contaminated with petroleum was introduced. Soil and water quality analyses were carried out to figure out the type of contaminants and the flume range according to the national regulation. In the investigation, it was verified that the soils in several dispersed locations were contaminated with petroleum. Therefore, in the design process, it was necessary to select a optimal remediation method after making the conception model of the site, and then the treatment method of incineration was selected.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.87-93
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• 2008

To assess effects of contaminants on fish in Nakdong river, feral yellowfin goby Acanthogobius flavimanus were caugt in two different sites and its hepatic monooxygenase enzyme, including cytochrome P450 (CYP), NADPH-cytochrome P450 reductase (P450R), NADH-cytochrome b5 reductase (b5R), ethoxyresorufin deethylase (EROD), glutathione S-transferase (GST) were quantitatively determined. Gonadosomatic index (GSI), hepatosomatic index (HSI) and three sex steroid hormone (17$\beta$-estradiol, E2; testosterone, T; 11-ketotestosterone, 11-KT) levels of the fish were also investigated. HSI of fish from polluted site (site 1) were significantly higher than that of unpolluted site (site 2), but GSI levels were significantly lower in polluted site. No significant differences in plasma 11-KT and T levels were observed in two sites surveyed. E2 level was, however, significantly (p<0.05) higher in female fish from site 1 than site 2. In addition, hepatic EROD activity and CYP level of site 1 fish were lower than those of site 2 fish, whereas relatively high levels of P450R, b5R and GST activities were found in site 1. The results imply that yellowfin goby, especially female fish in Nakdong river estuary are affected from contaminants disrupting sex steroid hormone system.

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.87-94
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• 2013

As sediment contamination problems have recently been raised in Korea, the need for technologies to remove contaminants in sediments has increased. Contaminated sediments in Korea has been annually dredged and treated using processes of coagulation/flocculation, sedimentation on barges, dewatered and dried at prepared site, and then disposed at a landfill site, which is very costly, and only a limited landfill space available in Korea. Contaminants in media containing a high percentage of silt and clay sized particles, typically, are strongly adsorbed on the particles and difficult to remove. Particle separation processes that separate the fine clay and silt particles from the coarser sand and gravel and concentrate the contaminants into a smaller volume of sediment that can be further treated of disposed of, are very effective in the post step processes. In this study are to test the feasibility of treating dredged sediments using a hydrocyclone process, and to estimate design parameters for a pilot scale test. A hydrocyclone was operated to separate larger particles from the sediments. It was found that the particle separation was greatly affected by the solid contents and inlet pressure in the hydrocyclone.