• Economic and Environmental Geology
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• v.48 no.3
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• pp.261-271
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• 2015

Toxicity results of metals, nanoparticles (NPs), and soils contaminated with metals were introduced on this review. Following methods were used: seed germination, bioluminescence, enzyme activity, and mutation. In general, different sensitivities were observed, depending on types of bioassays and pollutants. Among tested seeds, sensitivities of Lactucus and Raphanus were greater than others. Of single metal exposure, effect by As(III) was greater than others, and high revertant mutation ratio (5.1) was observed at 1 mg/L arsenite, indicating high mutagenicity. No general pattern was observed on the effect of metal mixture, but synergistic effect was observed with seeds. In case of soils, no correlation was observed between total metal contents and toxicity. Toxicity of NPs was observed as follows: CuO > ZnO > NiO > $TiO_2$, $Fe_2O_3$, $Co_3O_4$. Especially, no considerable effects were observed by $TiO_2$, $Fe_2O_3$, and $Co_3O_4$ under tested concentration (max. 1,000 mg/L). The evaluation results of interactive toxic effects using various bioassays may comprise a useful tool for the bioassessment of various environmental pollutants.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.501-509
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• 2016

The economic feasibility of a commercial indirect liquefaction process with the co-gasification process of petroleum coke which has been recognized as hazardous waste because of high sulfur content and bituminous coal and sub-bituminous coal mixtures was assessed. The 2,000 ton/day scale indirect liquefaction process including co-gasification, clean up, Fischer-Tropsch conversion and so on was assumed and used to analyze economical efficiencies with various conditions. Financial data from previous studies were modified and used and economical sensitivities with various mixture ratios were evaluated in this study. As a result, economic values of petroleum coke were superior than those of coals because of increasing sulfur sale. Also, mixtures with petroleum coke and bituminous coal was more favorable that those with petroleum coke and sub-bituminous coal due to lower moisture content. In case of sub-bituminous coal, the mixture ratio with petroleum coke had to be over 40wt% for the IRR of mixture to surpass 10%.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.106-106
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• 2019

많은 도심의 하천들은 오염물질의 유입에 취약하다. 최근 신소재 공학 등 첨단산업이 발전하게 되면서 유해화학물질의 유입문제는 더욱 대두되고 있으며, 실제로 최근 유해화학물질 유입사고 발생건수가 늘어나고 있다. 특히 국내 취수량의 90%는 지표수에서 취수하고 있어, 하천오염사고는 직접적인 피해로 이어지게 된다. 따라서 이러한 사고에 대응하기 위하여 수환경에 유입된 유해물질의 거동 매커니즘을 반영한 수질해석이 필요하다. 수체 내에 유입된 유해화학물질은 기본적으로 흐름에 따른 이송 확산을 하며 흡 탈착, 휘발, 침전 부유, 생화학 반응과 같은 다양한 반응과 함께 혼합거동을 한다. 특히 소수성물질의 경우 용해된 상태뿐만 아니라, 유사에 흡착된 상태로 수체에 존재하게 된다. 결국 유해화학물질의 거동을 해석하기 위해서는 유체의 흐름 해석뿐만 아니라 수체에 존재하는 유사의 이송 또한 해석해야한다. 본 연구에서는 흐름해석을 위하여 서울대에서 개발한 흐름모형(HDM-2D)을 사용하였으며, 부유사 거동모의를 위해 부유사거동모형(STM-2D)을 개발하였다. 또한 유해화학물질의 거동모의를 위해 서울대에서 개발한 수질모형(CTM-2D)에 생성/소멸항을 추가하였으며 흐름모형과 부유사모형과의 연계를 통해 유해화학물질의 혼합거동 수치모형을 개발하였다. 각 반응항(흡 탈착, 휘발, 침전 부유, 생화학 반응)을 수치모형에 반영 시에는 보통 두 계(물-토양, 물-공기) 사이의 선형 물질교환으로 이해된다. 따라서 물질의 각 반응 별 평형농도와 물질교환속도계수를 추정식을 통해 산정하여 사용하게 된다. 하지만 각 기작이 반영유무에 따라 계산시간 및 필요입력변수가 늘어나게 되므로, 유해화학물질 유입사고와 같은 빠른 대처가 필요한 경우 각 반응 텀의 유의성을 판단하여 모형에 반영여부를 결정을 통해 경제적인 모의를 할 수 있어야 한다. 이에 따라 본 연구에서는 개발된 모형의 각 매개변수들의 민감도를 분석하고, 흐름조건 및 물질의 특성에 따른 반응항의 유의성을 판단하였다. 본 연구에서는 개발된 모형(부유사거동모형, 유해화학물질의 혼합거동모형)은 해석해 및 현장 데이터와 비교검증을 통해 개발을 완료하였으며, 각 반응항의 민감도 분석을 통해 매개변수의 임계값을 결정하였다.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.751-759
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• 2014

In this study, we examined the hepatocyte toxicity and protective effects of an extract of Hericium erinacium cultivated with Artemisia capillaris (HEAC), and also examined the hepatocyte protective and antioxidative effects of a mixture of the HEAC and black garlic. At a concentrations of more than 0.05 mg/mL, the HEAC extract significantly reduced cell viability. The extract of HEAC treated with the same ratio of water and ethanol at $80^{\circ}C$ showed the highest hepatocyte protective effect. No significant difference in the hepatocyte protective effect was observed between the mixtures of HEAC with and without black garlic. In addition, higher antioxidative activity was shown with the addition of less black garlic. As a result of the sensory evaluation, a significant difference of sweetness was observed with varying liquid fructose concentration, but there were no significant differences in bitterness, flavor, thickness and overall acceptability according to the liquid fructose concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.778-784
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• 2004

This study was conducted to investigate the application possibility of leaf and stem extract (LSE) from the mixture of leaf and stem of Panax ginseng. This study measured the general nutritional composition, aminoacid minerals contents and fatty acid composition of LSE. We conducted analysis of the ginsenoside content by HPLC and the cell cytotoxicity tests in normal liver and kidney cells. The approximate composition of LSE was 2.51% of carbohydrate 0.53% of crude ash,0.20% of crude fat and 0.15% of crude protein, respectively. LSE contained 102.56 mg/100 g of K ion and high contents of acidic amino acids such as glutamic acid and aspartic acid. In addition to this, it contained all essential amino acids. The major compositions of fatty acids were 39.99% of palmitic acid 14.96% of linoleic acid, 13.31% of docosatetranoic acid and 12.91% of linolenic acid, The total ginsenoside was 0.82 mg/mL, and ratio of PD/PT was 0.68. Negative effects were not found from the results of the cell toxicity respection. These results imply that leaf and stem of Panax gineng could be used as possible food resources and functional food material and feed stuff.

• Applied Biological Chemistry
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• v.36 no.1
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• pp.64-69
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• 1993

This study was performed to investigate detoxifying enzyme activities of carboxylesterase(CE), glutathione S-transferase(GST) and lactate dehydrogenase(LDH) at variable toxicity levels in fresh water fish, carp(Cyprinus carpio L.). The carp was exposed to single and combined pesticides of IBP, isoprothiolane and cartap for 48 hr at sublethal doses, $LC_{10}$ and $LC_{26}$. The detoxifying enzyme activities were assayed for the liver, head and gut of the carp. The enzyme activities we discovered were as follows: Both activities of CE and GST were increased at the sublethal doses but were declined by increasing doses. In the gut, we found that the CE activity had high levels in the treatment groups of isoprothiolane+IBP and isoprothiolane+cartap. In the head, the CE activity had high levels in the treatment groups of cartap, IBP and isoprothiolane. However, the GST activities were inconsistent in the head and gut of the fish. Also, the GST activity was declined by increasing protein contents. The highest LDH activity was shown in the isoprothiolane treated fish, while the lowest activity was observed in the isoprothiolane+cartap treatment.

• Ecology and Resilient Infrastructure
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• v.8 no.3
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• pp.135-142
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• 2021

Biopolymers have been known as eco-friendly soil strengthening materials and studied to apply levees. However, the effect of biopolymer on vegetation is not fully understood. In this study, we analyzed the root growth of Camelina sativa L. (Camelina) when the xanthan gum was amended to soil in Aluminum (Al) stress conditions. Amendment of 0.05% xanthan gum increased root growth of Camelina under Al stress conditions. Under the Al stress condition, expression of aluminum activate malate transporter 1 (ALMT1) gene of Camelina root was induced but showed a lower level of expression in xanthan gum amended soil than non-amended soil. Additionally, the binding capacity of xanthan gum with Al ions in the solution was confirmed. Using morin staining and ICP-OES analysis, the Al content of the roots in the xanthan gum soil was lower than in the non-xanthan gum soil. These results suggest that xanthan gum amended soils may reduce the detrimental effects of Al on the roots and positively affect the growth of plants. Therefore, xanthan gum is not only an eco-friendly construction material but also can protect the roots in the disadvantageous environment of the plant.

• Journal of Preventive Medicine and Public Health
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• v.36 no.4
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• pp.303-313
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• 2003

General information is summarized, that is necessary to introduce a scientific assessment of the human health and exposure issue concerning dioxin and dioxin-like compound. Scientific literatures were reviewed to assess the background exposures to the dioxin-like compounds for normal residents. Epidemiologic studies were also reviewed to assess malignant and nonmalignant sweets of dioxins. In 1997, the International Agency for Research on Cancer classified 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a human carcinogen, primarily based on occupational cohort studies. The US Environmental Protection Agency made the same decision in it's Draft Dioxin Reassessment. Epidemiologic evidences point to a generalized excess of all cancers, without any pronounced excess at specific sites. Reported non-cancer effects included a range of conditions affecting most systems. Among them, chloracne, elevation in gamma glutamyl transferase(GGT), and alterations in reproductive hormones are related to TCDO, Other adverse outcomes, such as lipid concentrations, diabetes, circulatory and heart diseases, immunologic disorders, neurobehavioral effects, and developmental outcomes require further study before their respective relationships to TCDD can be more definitively assessed.

• Korean Journal of Ecology and Environment
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• v.49 no.3
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• pp.228-235
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• 2016

Aquatic ecosystems are receiving various harmful effects due to anthropogenic chemical pollutions. To protect wildlife, risk assessments of the chemicals are conducted using reference indexes of toxicity estimated by species-level laboratory tests and/or micro-/mesocosm community-level studies. However, the existing micro-/mesocosm communities are structurally too complicated, and it is also difficult to compare the experimental results directly with those from species-level tests. Here, we developed a procedure of a simple bi-trophic microcosm experiment which contains the common species (a green algae, Pseudokirchneriella subcapitata and a cladoceran, Daphnia magna) for testing chemical toxicities. For the proper operation of bitrophic microcosm experiment, the minimum required concentration of primary producer (P. subcapitata) is $5{\times}10^5cells\;mL^{-1}$. The microcosm system showed higher stability when the initially introduced D. magna population was composed of neonates (<24-h old) than adults and those mixture. This simple microcosm system would be an applicable tool to estimate the disturbing impacts of pollutants on plant-herbivore interactions, and linking the species- and population-/community level risk assessments in the future studies.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.193-200
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• 2016

Toxicity assessment of heavy metals (As, Cr and Pb) has been investigated by using the rate of survival and population growth(r) of marine rotifer, Brachionus plicatilis. The survival rate was determined after 24 hours of exposure to As, Cr and Pb. As and Cr reduced survival rate in dose-dependent manner and a significant reduction were occurred at concentration of greater than 30 and $150mg\;L^{-1}$, but Pb had no effect on survival rate. The r was determined after 72 hours of exposure to As, Cr and Pb. As, Cr and Pb reduced r in dose-dependent manner and a significant reduction were occurred at concentration of greater than 5, 25 and $50mg\;L^{-1}$. The toxicity of heavy metals were ranked As>Cr>Pb, with $EC_{50}$ values of 12.98, 82.34 and $110.14mg\;L^{-1}$, respectively. The no-observed-effect-concentration (NOEC) of r in As, Cr and Pb exposure were 1, 12.5 and $50mg\;L^{-1}$, respectively. The lowest-observed-effect-concentration (LOEC) of r in As, Cr and Pb exposure were 5, 25, and $50mg\;L^{-1}$, respectively. From the results, the concentration of As, Cr and Pb (greater than 5, 25 and $50mg\;L^{-1}$, respectively) have toxic effect on the r of B. plicatilis in natural ecosystems. These results (including NOEC and $EC_{50}$) might be useful for the mixing toxicity assessment and toxic guide line of heavy metals in marine ecosystems.