• 대한환경공학회지
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• 제33권9호
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• pp.670-676
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• 2011

인위적 중금속 오염 토양은 중금속용액과 토양 간 흡착평형, 여과 또는 원심분리, 건조과정을 거쳐 완성되어 토양세척 및 토양독성 실험에 널리 이용되고 있다. 그러나 많은 문헌에서 실험에 사용한 오염토양이 건조과정 이후 충분한 세척을 마친 후 사용되었는지 불분명하다. 본 연구는 중금속 오염 토양 제조 과정에서 최종 세척과정이 중금속 오염 농도에 미치는 영향을 파악하고자 하였다. 3가지 대표적 중금속 오염 토양 제조방법(슬러리 건조법, 평형 후 건조법, 여과 후 건조법)에 의한 중금속(Cd, Pb) 오염 농도 차이를 파악하고 이후 최종 세척과정이 제조 중금속 오염 토양 농도에 미치는 영향을 분석하였다. 중금속용액과 토양을 흡착평형 시킨 후 건조과정만을 거쳐 제조한 오염토양 내 중금속은 이후 단순 세척과정에서 50% 이상 용탈되는 것으로 나타났다. 중금속용액과 토양 간 흡착평형을 거쳐 중금속 오염 토양을 제조한 경우 실험 전 충분한 세척을 거치지 않는다면 이후 토양세척 및 토양독성 실험 결과에 지대한 영향을 미칠 것으로 예상된다. 그러므로 제조오염토양을 이용한 실험에서는 초기 중금속 농도 결정 시점을 중금속 흡착 완료 단계가 아닌, 흡착 후 충분한 세척이 완료된 이후 초기 토양중금속 농도로 결정하는 것이 바람직하다.

• 한국토양비료학회지
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• 제44권4호
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• pp.591-596
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• 2011

The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.

• 환경영향평가
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• 제8권2호
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• pp.31-44
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• 1999

Atmospheric dry deposition flux and ambient particle mass size distribution were measured to evaluate the impact of atmospheric deposition around the Nanjido landfill sites. Wind direction affects greatly on the variation of mass flux and mass size distribution and made two times higher when the wind was blown from the road side. The effect of Nanjido landfill on the mass size distribution was significant comparing to simultaneously measured mass size distribution at the other sampling site. The results showed that the particle diameter bigger than $10{\mu}m$ explained the majority of atmospheric dry deposition flux. A survey was also carried out to investigate the contamination of soils in a completed Nanjido landfill. The chemical properties of the soil analyzed in the present study include pH, oxidation-reduction potential (ORP), anion and cation concentration, total organic carbon(TOC), and some-metal elements concentrations were analyzed. Microbial activity in the soils was also evaluated by measuring dehydrogenase activities. TOC in the soil contaminated with leachate was $467.0{\mu}g/g-dry$ soil, and the TOC in the soil, where Nanjido landfill gases were emitted from, was $675{\mu}g/g-dry$ soil. The highest microbial activity of $968.0{\sim}2147{\mu}g-TPF/g-dry$ soil day was found in the soil spouting Nanjido landfill gases. Compared with those in the uncontaminated soil, the concentrations of Cr, Cu and Ph in the contaminated soil were higher.

• Journal of Plant Biology
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• 제17권4호
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• pp.158-162
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• 1974

Some ecological attributes of perennial plants and Pb contamination were analyzed for study plots near an entrance of Nevade Test Site at Mercury Valley, Nye County, Nevada. The surface of the desert pavement soil was composed of stones (1 to 4cm diameter). The underside of each stone was coated with coarse and fine sand (about 90%). The profiles of soil were constituted with the A-horizon and C-horizon only. The soil pH at the plots ranges from 7.6 to 8.5, C/N was 13 and cation exchange capacity showed 15me/100g. Nine species and 42 number of individuals were found in all plots. Franseria dumosa and Larrea divaricata were dominant species. The discrete clumps of vegetation were consisted of 9 species of common perennials and these were covered about 25% on desert pavement, on the other words, bare area without vegetation was about 75%. The size and spacing of the plants was irregular. Community coefficient as comparison between shrub species in these study area and those in near the low elevation desert indicated a low degree of similarity. Density, cover and productivity in the study plots as compared with those in the nearest study areas in Mercury Valley showed a higher value. The soils in the studied area involved high heavy metal contents in the plant tissue was higher than those of its soil. The leavds of Lycium andersonii tended to accumulate more Zn and Mo than those of the other species. Larrea divaricata leaves accumulated very high leaves of Fe and Ephedra nevadensis were generally high in Mn. Lead contamination was apparent in foliage of desert vegetation collected alongside the roadway, reflecting the variation in traffic volume. Lead contents greater than fifteen-fold of normal (low traffic) were found in plant foliage alongside the heavily traveled roadway. Lead content of old foliage by the heavily traveled roadway was as much as 129 ppm but that of new foliage 17 ppm only.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.544-547
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• 2003

The objective of this study is to investigate the contamination levels and dispersion patterns of arsenic and heavy metals and to estimate the bioaccessible fraction of the metals in soil and plant samples in the vicinity of the abandoned Songcheon Au-Ag mine. Tailings, soils, plants (Chinese cabbage, red pepper, soybean, radish, sesame leaves, green onion, lettuce, potato leaves, angelica and groundsel) and waters were collected around the mine site. After appropriate preparation, all samples were analyzed for As, Cd, Cu, Pb and Zn by ICP-AES and ICP-MS. Elevated levels of As and heavy metals were found in tailings. Mean concentrations of As in agricultural soils were higher than the permissible level. Especially, maximum level of As in farmland soil was 513 mg/kg. The highest concentrations of As and Zn were found in Chinese cabbage (6.7 mg/kg and 359 mg/kg, respectively). Concentrations of As, Cd, and Zn in most stream waters which are used for drinking water around this mine area were higher than the permissible levels regulated in Korea. Maximum levels of As, Cd and Zn in stream waters were 0.78 mg/L, 0.19 mg/L and 5.4 mg/L, respectively. These results indicate that mine tailings can be the main contamination sources of As and heavy metals in the soil-water system in the mine area. The average of estimated bioaccessible fraction of As in farmland soils were $3.7\%$ (in simulated stomach) and $10.8\%$ (in simulated small intestine). The highest value of bioaccessible fraction of metal in farmland soils was $46.5\%$ for Cd.

• 한국패류학회지
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• 제27권1호
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• pp.77-86
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• 2011

The unwanted artificial oil-spill has severely contaminated the coastal environment in the world. Level of contamination has so far been monitered by various indicator species including mussel, oysters, flounder, and cockle. In this study, we decided to use the oyster as a model organism to observe the morphological changes being exposed to the artificial oil-spill in the coastal areas in Taean, Korea. The oysters were collected from four local sites (Sindu-ri, Uiwang-ri, Jonghyeon-dong, Ansan and Uihang-ri) exposed to various levels of pollution after an oil spill in Taean. Microscopic analysis of the hepatopancreatic microstructure in the digestive gland from the collected oysters show that the swelling, whorl, and destruction phenomenon of the nuclear membrane, a well-known microstructure induced by heavy metal exposure, was observed. Nuclear body (Nb), another typical characteristic of contamination or infection were also observed in some samples. Necrosis was observed in tissue samples collected from the area with a high degree of oil pollution. In addition, parasite-like particles (virus, perkinsus) were observed in most samples. Taken together, these results suggest that oil contamination in the oyster habitats influences the cytopathological changes in Crassostrea gigas.

• 공업화학
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• 제25권1호
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• pp.27-33
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• 2014

석유누출 사고로 인해 토양과 지하수 오염이 점차 증가되면서, 토양환경에 대한 중요성이 늘고 있다. 토양오염은 다른 환경오염에 비해 많은 정화비용과 긴 정화기간이 요구된다. 이런 이유로 토양오염이 발생되면, 어떤 오염물질에 의해 토양이 오염되었으며, 토양정화의 책임이 있는 오염자가 누구인지 법적 분쟁이 많이 발생되고 있다. 본 연구에서는 토양오염을 발생시킬 수 있는 항공유에 대한 물성 분석과 함께 항공유 내의 특정 첨가제를 분석함으로써 등유와 항공유의 구분법을 찾아내었다. 특히 발색제에 의해 등유 내 화학적 식별제만 발색되었으며, GC-MS 분석결과 항공유에서만 산화방지제와 금속불활성제가 분석되었다. 이는 추후 항공유에 의한 토양오염 야기 시, 어떤 석유제품에 의한 오염인지 쉽게 판단이 가능할 것이다.

• 시스템엔지니어링학술지
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• 제17권1호
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• pp.11-20
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• 2021

Decontamination of systems, structures and components (SSC) during the decommissioning of a Nuclear Power Plant (NPP) can be for a variety of reasons. The main reasons for decontamination are: to reduce the contamination of SSC to a reasonably low level, to reduce the potential for the spread of contaminants into the environment and to reduce the cost of disposal due to the reduced level of contamination in a particular SSC. The decontamination technique can be aggressive or non-aggressive depending on the intent after the decontamination process. Aggressive decontamination technique is used when the intent is not to reuse the SSC while a non-aggressive decontamination technique is used with the intent of SSC reuse. For different SSCs there are different decontamination techniques that can be used, each having its own advantages and drawbacks. Metal components such as pipes in the nuclear power plant account for a large amount of nuclear wastes generated. Some of these wastes can be reused if the contaminant level is reduced to an acceptable level. Laser ablation is a non-aggressive decontamination technique that can be used to reduce the contamination in pipes to an acceptable level with no secondary waste generated during the process. The operation and control of a laser ablation device must be precise to achieve a high decontamination factor. This precision can be achieved by a well-designed motion control system. For this purpose, a motion control system was developed consisting of two parts: the first part being the precise control of the laser ablation device inside the pipe and the second part is the control of the laser ablation device outside the pipe. This paper describes the Systems Engineering approach for the development process of a motion control system for the Laser decontamination system.

• 한국수산과학회지
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• 제55권4호
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• pp.431-436
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• 2022

For the safety assessment of microbiological and chemical hazards in katsuobushi, fifteen samples of katsuobushi were purchased from supermarkets. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria [Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Bacillus cereus, Vibrio parahaemolyticus, Clostridium perfringens, Enterohemorrhagic E. coli (EHEC), Yersinia enterocolitica and Campylobacter jejuni/coli] were quantitatively or qualitatively assessed. Additionally, the heavy metals (total and methyl mercury) content, radioactivity (¹³¹ I, ¹³⁴ Cs⁺ and ¹³⁷ Cs) were quantitatively assessed. Microbial and chemical analyses were performed using standard methods in Korean food code. The contamination level of total viable bacteria was 2.70 (1.18-4.42) log CFU/g. Coliforms, E. coli and S. aureus were not detected in any samples. Other eight pathogenic bacteria were negative in all samples. The contamination levels of total and methyl mercury were 0.366 (0.227-0.481) and 0.120 (0.002-0.241) mg/kg, respectively. In addition, radioactivity was not detected in any samples. The results will be helpful in revitalizing domestic use and boosting exports of katsuobushi because the microbiological and chemical safety of katsuobushi has been assured. Furthermore, the results may be used as a basis for performing chemical and microbial risk assessments of katsuobushi.

• 생약학회지
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• 제38권3호통권150호
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• pp.205-216
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• 2007

South Korea is the representative consumption country of herbal medicines and most of herbal medicines circulating in Korea have been importing from the developing countries of Southeast Asia such as China, Vietnam, Indonesia and so forth. Domestic hygiene and safety are continuously proposed because herbal medicines which are circulating have the possibility could remain contaminants or residues. Physicochemical contaminants such as heavy metals, persistent organic pollutants, radionucleosides, microbial toxins, biological contaminants such as microorganisms and animals, agrochemical residues such as pesticides, substances used for fumigation, antiviral agents, and solvent residues are classified as major contaminants and residues in herbal medicines from 2005 September WHO.$^{1)}$ Currently our administration have established a permission standard and the inspection criteria against the heavy metal, the residual pesticides and a residual sulfur dioxide. Furthermore our administration is continuously monitoring and conducting researches for the policies and their scientific ground against herbal medicines. But the appearances or discoveries of the harmful new species due to environmental and industrial developments are becoming social problems. Therefore it may be necessary to continuously consider and investigate regarding hereupon. Recently, the contamination of the mycotoxins against foods such as cereals, nuts and the powdered red pepper have developed and started became problematic issue, and possibility of contamination against the herbal medicine is proposed. And since populations who are using the herbal medicines very limited to several nations, recognition and researches about contamination of mycotoxins in herbal medicines are very insufficient. Therefore it will be need to more focus on the international regulation of quality control and safety for herbal medicines. Now on, we are going to introduce the importance, occurrence, characteristic properties, World-wide research trends and detoxification of aflatoxins, which is known as the most potent mutagen, carcinogen and teratogen mycotoxins.