• Title/Summary/Keyword: 염소계화합물

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The concentration of Hexachlorocyclohexane in air (대기중 Hexachlorocyclohexane(HCH)의 농도)

  • 최민규;여현구;한효경;김태욱;천만영;선우영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.157-158
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    • 2001
  • Hexachlorocyclohexane(HCH, 또한 benzene hexachioride(BHC)라고도 부름)은 세계 도처에서 발견되는 주요 난분해성 유기염소계 화합물들(persistent organochlorine compounds)중 하나이며, 또한 환경중 거동 및 영향들과 관련하여 가장 많이 연구되어진 살충제중 하나이다(Li et al., 1996). Technical HCH mixture($\alpha$-, $\beta$-, ${\gamma}$-, $\delta$- 및 $\varepsilon$-HCH 이성질체들의 혼합물)와 technical lindane(거의 단일의 ${\gamma}$-HCH 이성질체로 구성)은 농업, 산림 및 위생 방면에 다양한 목적을 위해 1940년말 이래로 많은 양이 사용되어져 왔다(Li et al., 1996; Breivik et al., 1999). (중략)

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토양 중 mineral에 의한 염소계 유기화합물 분해 특성 연구

  • Choi Jeong-Yun;Sim Sang-Gyu;Lee U-Jin
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.33-36
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    • 2006
  • The reductive dechlorination of chlorinated organic compounds by soil minerals in soil and groundwater were carried out in this study. FeS, green rust, and magnetite were chosen as the representative soil minerals which were capable of degrading chlorinated compound in soil system. FeS was the most effective reductant in degradation of carbon tetrachloride. The reductive degradation of CT and 1,1,1-TCA by FeS was much faster than that of 1,2-DCB and 2,4-DCP. The reactivity of FeS was effectively improved by the addition of trace metals. The addition of Co to FeS suspension enhanced the reaction rate of 1,2-DCB by a factor of 46 compared to that by FeS without Co.

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A Study on Persulfate Oxidation to Remove Chlorinated Solvents (TCE/PCE) (과황산(persulfate) 산화반응을 이용한 염소계 화합물(TCE, PCE) 분해에 관한 연구)

  • Song, Kyoung-Ho;Do, Si-Hyun;Lee, Hong-Kyun;Jo, Young-Hoon;Kong, Sung-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.7
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    • pp.549-556
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    • 2009
  • In situ chemical oxidations (ISCO) are technologies for destruction of many contaminants in soil and groundwater, and persulfate has been recently studied as an alternative ISCO oxidant. Trichloroethylene (TCE) and tetrachloroethylene (PCE) were chosen for target organic compounds. The objective of this study is to demonstrate the influence of initial pH (3, 6, 9, 12), oxidant concentrations (0.01, 0.05, 0.1, 0.3, 0.5 M), and contaminants concentrations (10, 30, 50, 70, 100 mg/L) on TCE/PCE degradation by persulfate oxidation. The maximum TCE/PCE degradation occurred at pH 3, and the removal efficiencies with this pH condition were 93.2 and 89.3%, respectively. The minimum TCE/PCE degradation occurred at pH 12, and the removal efficiencies were 55.0 and 31.2%, respectively. This indicated that degradation of TCE/PCE decreased with increasing the initial pH of solution. Degradation of TCE/PCE increased with increasing the concentration of persulfate and with decreasing the concentration of contaminants (TCE/PCE). The optimum conditions for TCE/PCE degradation were pH 3, 0.5 M of persulfate solution, and 10 mg/L of contaminant concentration. At these conditions, the first-order rate constants ($k_{obs}$) for TCE and PCE were 1.04 and 1.31 $h^{-1}$, respectively.

Sulfonated poly(arylene ether copolymer)-g-sulfonated Polystyrene Membrane Prepared Via E-beam Irradiation and Their Saline Water Electrolysis Application (전자빔조사를 이용한 술폰화 폴리아릴렌 에테르 술폰-g-술폰화 폴리스틸렌 분리막 제조 및 염수전기분해 특성평가)

  • Cha, Woo Ju;Lee, Chang Hyun
    • Membrane Journal
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    • v.26 no.6
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    • pp.458-462
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    • 2016
  • Saline water electrolysis, known as chlor-alkali (CA) membrane process, is an electrochemical process to generate valued chemicals such as chlorine, hydrogen and sodium hydroxide with high purities higher than 99%, using an electrolytic cell composed of cation exchange membrane, anode and cathode. It is necessary to reduce energy consumption per a unit chemical production. This issue can be solved by decreasing intrinsic resistance of the membrane and the electrodes and/or by reducing their interfacial resistance. In this study, the electron radiation grafting of a $Na^+$ ion-selective polymer was conducted onto a hydrocarbon sulfonated ionomer membrane with high chemical resistance. This approach was effective in improving electrochemical efficiency via the synergistic effect of relatively fast $Na^+$ ion conduction and reduced interfacial resistance.

Biodegradation Pathways of Polychlorinated Biphenyls by Soil Fungus Aspergillus niger (Polychlorinated Biphenyl의 토양 미생물 Aspergillus niger에 의한 생분해 경로)

  • Kim, Chang-Su;Lim, Do-Hyung;Keum, Young-Soo
    • The Korean Journal of Pesticide Science
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    • v.20 no.1
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    • pp.7-13
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    • 2016
  • As of many organochlorine pesticides, polychlorinated biphenyls are ubiquitous organic contaminants, which can be found in the most environmental matrices. Their toxic effects include endocrinedisrupting activity. Most researches with these toxicants performed with mixtures of congeners, namely Aroclor and related study has been done in complex environmental matrix, rather than single biosystems or pure congeners. 5 congeners were synthesized and their fates in pure microbial culture (Aspergillus niger) were determined in this study. Among biphenyl and synthetic congeners, biphenyl, PCB-1 (2-chlorobiphenyl), and PCB-3 (4-chlorobiphenyl) were rapidly transformed to hydrophilic metabolites, followed by PCB-38 (3,4,5-trichlorobiphenyl), while the degradation of PCB-126 (3,3',4,4',5-pentachlorobiphenyl) was not observed. The amounts of transformation for biphenyl, PCB-1, PCB-3, and PCB-38 were 65, 38, 52, and 2% respectively. The major metabolites of the above congeners were identified as mono- and di-hydroxy biphenyls, which are known to give adverse endocrinological effects.

In vitro Response of Cytochrome P450 (CYP) and EROD Activity in Bivalve (Coelomactra antiquata) by DDT, PCB-153 and TCDD (유기염소화합물인 DDT, PCB-153 및 TCDD에 in vitro 노출시킨 명주조개 미크로좀의 CYP및 EROD활성 반응)

  • 전중균;이미희;이지선;이경선;심원준;신영범;이수영
    • Korean Journal of Environmental Biology
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    • v.21 no.2
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    • pp.170-176
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    • 2003
  • The effect of xenobiotics on cytochrome P450 (CYP) and 7-ethoxyresorufin-O-deethylase (EROD) in hepatopancreatic microsome of surf clam, Coelomactra anti-quata, were investigated. The microsome isolated from the digestive gland of the surf clam, collected from the east coast of Korea, was in vitro exposed to p, p -DDT (0.1,0.4 and 1.0 mM) for 30 min and 2,3,7,8-TCDD (0.01, 0.04 and 0.1 ppb) and PCB-153 (0.01, 0.04 and 0.1 ppb) for 7 hr. In the case of DDT exposure, the CYP content and EROD activity of 1.0 mM exposure group increased up to about 117% and 120% of the DMSO solvent control group after 10 min. exposure, respectively. After 2 hr exposure of TCDD, the CYP content and EROD activity were also induced to the range of 103∼110% and 121∼139%, respectively. The PCB-153 exposure group showed 107∼115% of CYP content and 129∼140% of EROD activity after 2 hr exposure. Three test chemicals apparently induced CYP and EROD activity in the microsome of surf clam. The inducing potentials depend en the test chemicals.

Fixed-bed Adsorption of Phenolic Acids on Charcoal in Multi Solutes System (활성탄을 이용한 다성분계 페놀산 용액의 고정층 흡착)

  • Lee, Won-Young;Choi, Yong-Hee
    • Current Research on Agriculture and Life Sciences
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    • v.15
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    • pp.83-91
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    • 1997
  • Phenolic acids are regarded as harmful materials in food and environment science. But recently, regarded as useful materials by their characteristics which bind metal ions and have pharmaceutical effect. It was necessary to remove or recover phenolic acids from solutIon containing phenolic acids. Continuous fixed-bed adsorption was adapted in order to separate phenolic acids from diluted solution and the breakthrough curve was predicted by nonlinear curve fitting method. The larger bed length showed the longer breakpoint time and the slow mass transfer coefficient. Ferulic acid among the phenolic acids was passed through the breakpoint first and the second and. third were p-coumaric acid and gallic acid. These orders were caused by not only ionic strength between adsrobent and adsorbate but also molecular weights.

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Potential Human Risk Assessment of PCBs and OCPs in Edible Fish Collected from the Offshore of Busan (부산 연근해의 해양오염퇴적물과 식용 어류 체내의 PCBs와 유기염소계 농약의 분포 및 잠재적인 인체 위해성평가)

  • Choi, Jin Young;Yang, Dong-Beom;Hong, Gi-Hoon;Kim, Suk Hyun;Chung, Chang Soo;Kim, Kyoung-Rean;Cho, Kyung Duk
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.12
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    • pp.810-820
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    • 2012
  • Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) contents in marine sediment and edible fish (4 species) from the estuary near the Yongho wharf in Busan were determined to assess their presence and their potential health risk to the local population through fish consumption was also assessed. Levels of ${\Sigma}PCBs$ and ${\Sigma}DDTs$ in marine sediment were 3.22~197.65 and 1.77~20.27 ng/g dw, respectively. HCHs and endosulfan sulfate concentrations in bottom sediment were 1.42~6.08, 0.56~13.89 ng/g dw, respectively. The bottom sediment in the offshore of the Yongho wharf may be characterized as semi-polluted status with potential adverse marine biological effects in terms of sediment quality guidelines of US NOAA. The mean concentrations of ${\Sigma}PCBs$ in the tissues of olive flounder (Paralichthys olivaceus), Korean rockfish (Sebastes schlegelii), file fish (Stephanolepis cirrhifer) and abbysal searobin (Lepidotrigla abyssalis) were 67.37, 10.20, 48.26, 22.81 ng/g lw, respectively. DDTs and HCHs were also detected in all fish samples. Lifetime cancer risk and target hazard quotient to local residents due to those fish consumption were found to pose negligible cancer and non-cancer risk.

Environmental Pollutants in Streams of Andong District and Insect Immune Biomarker (안동지역 하천의 환경오염물질과 곤충면역 생체지표 분석)

  • Ryoo Keon Sang;Ko Seong-Oon;Cho Sunghwan;Lee Hwasung;Kim Yonggyun
    • Korean journal of applied entomology
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    • v.44 no.2
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    • pp.97-108
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    • 2005
  • Samples of water, soil, and sediment were taken from 10 streams near Andong, Korea in May 2004. To assess the degree of environmental pollution of each stream, chemical pollutants such as total notrogen (T-N), total phosphorus (T-P), chemical oxygen demand (COD), heavy metals, organophosphorus pesticides, organochlorine pesticides, and dioxin-like PCB congeners were analyzed by standard process tests or U.S. EPA methods. In addition, biomarkers originated from insect immune systems of beet armyworm, Spodoptera exigua, were used to analysis of the environmental samples. Except Waya-chun stream showing T-N content of 9.12 mg/L, most streams were contaminated with relatively low levels of overall pollutants in terms of T-N, T-P, and COD, compared to their acceptable environmental levels designated by the Ministry of Environment. Contents of Pb and Cd in samples of each stream were much lower than environmentally permissible levels. However, several times higherconcentrations of Pb and Cd were found in locations at Mi-chun, Kilan-chun, and Hyunha-chun streams, in comparison with other streams. Diazinon, parathion, and phenthoate compounds among organophosphorus pesticides were detected as concentrations of 0.19, 0.40, and $1.13\;{\mu}g/g$, respectively, from soil sample collected in the vicinity of Mi-chun stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners, known as endocrine disrupting chemicals, selected in this study were not found above the limit of detection. Biomarker analyses using insect immune responses indicated that Waya-chun stream was suspected as exposure to environmental pollutants. Limitation and compensation of both environmental analysis techniques are discussed.

Durability and Crack Control of Concrete Using Fluosilicates Based Composite (규불화염계 복합 조성물을 혼입한 콘크리트의 균열제어 및 내구성)

  • Yun, Hyun-Do;Yang, Il-Seung;Kim, Do-Su;Khil, Bae-Su;Han, Seung-Gu
    • Journal of the Korea Concrete Institute
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    • v.18 no.1 s.91
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    • pp.57-64
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    • 2006
  • The crack presented in concrete structures causes a structural defect, the durability decrease, and external damages etc. Therefore, it is necessary to improve durability through the effort to control the crack. Fluosilicic acid($H_2SiF_6$) is recovered as aqueous solution which absorbs $SiF_4$ produced from the manufacturing of industrial-graded $H_3PO_4$ or HF. Generally, fluosilicates prepared by the reaction between $H_2SiF_6$ and metal salts. Addition of fluosilicates to cement endows odd properties through unique chemical reaction with the fresh and hardened cement. Mix proportions for experiment were modulated at 0.45 of water to cement ratio and $0.0{\sim}2.0%$ of adding ratio of fluosilicate salt based inorganic compound. To evaluate correlation of concrete strength and adding ratio of fluosilicate salt based inorganic compound, the tests were performed about design strength(21, 24, 27 MPa) with 0.5% of adding ratio of fluosilicate salt based inorganic compound. Applications of fluosilicate salt based inorganic compound to reduce cracks resulted from plastic and drying shrinkage, to improve durability are presented in this paper. Durability was evaluated as neutralization, chloride ion penetration depth, freezing thawing resistant tests and weight loss according reinforcement corrosion. It is ascertained that the concrete added fluosilicate salt based inorganic compound showed m ability to reduce the total area and maximum crack width significantly as compared non-added concrete. In addition, the durability of concrete improved because of resistance to crack and watertightness by packing role of fluosilicate salt based inorganic compound obtained and pozzolanic reaction of soluble $SiO_2$ than non-added concrete.