• 제목/요약/키워드: Cd concentration

검색결과 1,408건 처리시간 0.023초

대기 부유분진의 입경별 특성에 관한 연구 (Study on Characteristics by Aerodynamic Diameter of Airborne Suspended Particulate Matters)

  • 김성천;강달선;차영희
    • 한국환경보건학회지
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    • 제26권2호
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    • pp.108-115
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    • 2000
  • The mass fraction of PM10 had a bimodal distribution in the middle of between 2.1 ${\mu}{\textrm}{m}$, and the average mass fraction of particles less than 2.1~3.1 ${\mu}{\textrm}{m}$ was 54.1% for Pb and 890.8 ng/㎥ for Fe, respectively. For the concentration of PM10 and metallic elements by seasonal variation, PM10 showed bimodal distribution, while metallic elements showed different distributions by their sources. The ratios of fine particles to total mass were 0.45 for PM10, 0.41 for Cr, and 0.20 for Fe, 0.57 for Zn, 0.68 for Cd and 0.63 for Pb, respectively. That facts indicated that PM10, Zn, Cd, Cr and Pb were from anthropogenic sources, and Fe was from natural source. The geometric means and geometric standard deviations by seasonal variations were 3.6 ${\mu}{\textrm}{m}$ , 2.31 ${\mu}{\textrm}{m}$ in winter, 3.0 ${\mu}{\textrm}{m}$ , 2.49 ${\mu}{\textrm}{m}$ in spring, 2.7 ${\mu}{\textrm}{m}$ , 2.03 ${\mu}{\textrm}{m}$ in summer respectively. And, total efficiency of cascade impactor by seasonal variations were 49.6% in winter, 45.9% in spring and 44.5% in summer.

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공업도시의 금속원소 조사와 특성 연구 (Study on Investigation and Characteristics of Metallic Elements in Industrial Complex)

  • 김성천
    • 한국환경보건학회지
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    • 제37권3호
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    • pp.209-217
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    • 2011
  • Objectives: In this study, the size distribution of airborne particulates ($PM_{10}$) was measured by using Cascade Impactors. The purpose of this study was to assess the size distribution of metal and ionic materials of $PM_{10}$. Methods: Samples were collected in the Kunsan industrial complex from April 2006 to January 2007. Results: The mass fraction of $PM_{10}$ had a bimodal distribution between 2.1-3.1 ${\mu}M$, and the average mass fraction of particles less than 2.1-3.1 ${\mu}M$ was 47%. Average concentrations of PM10 were 68.05 ${\mu}g/m^3$ and seasonal concentration 95.44 ${\mu}g/m^3$ for spring, 49.03 ${\mu}g/m^3$ for summer, 81.99 ${\mu}g/m^3$ for fall, 52.66 ${\mu}g/m^3$ for winter, respectively. Conclusions: Seasonal variations of $PM_{10}$ were significant for showing peak values in spring. The average concentrations of Cd, Cr, Pb, and Fe were 1.54, 4.51, 14.11, and 254.3 $ng/m^3$, respectively. The ratios of fine particles to total mass were 0.47 for $PM_{10}$, 0.45 for Cr, and 0.16 for Fe, 0.91 for Cd and 0.49 for Pb, respectively.

삼천포화력발전소 주변해역 표층퇴적물중의 중금속원소함량 분포 연구 (A Study on the Distribution of Heavy Metal Concentrations in Marine Surface Sediments around Samcheonpo Power Plant)

  • 이두호;임주환;전병열;정년호
    • 환경영향평가
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    • 제9권1호
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    • pp.1-11
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    • 2000
  • An environmental geochemical survey of heavy metal distribution in marine surface sediments around the ocean of Samcheonpo coal-fired power plant was conducted to investigate the possibility of coal-ash leakage from ash pond and the associated heavy metal pollution in sedimental deposits due to the operation of the coal-fired power plant. The X-Ray Diffractometry (XRD) analysis showed that the main leakage point of coal-ash was limited to a single site of the first ash pond. It also appeared that the amounts of organic carbon and metal elements were positively correlated to the grain size distribution, and that Co, Cr, Cu, Fe, Ni, and Zn were bounded to organic ligands. However, the distributions of Cd, Hg, and Mn did not have any significant correlation with the sediment grain size and organic matters. In particular, the distribution of Cd appeared to be affected by the concentration of the carbonate materials in the study area.

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Characterization of Stress Responses of Heavy Metal and Metalloid Inducible Promoters in Synechocystis PCC6803

  • Blasi, Barbara;Peca, Loredana;Vass, Imre;Kos, Peter B.
    • Journal of Microbiology and Biotechnology
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    • 제22권2호
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    • pp.166-169
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    • 2012
  • In several biotechnological applications of living bacterial cells with inducible gene expression systems, the extent of overexpression and the specificity to the inducer are key elements. In the present study, we established the concentration ranges of $Zn^{2+}$, $Ni^{2+}$, $Co^{2+}$, ${AsO_2}^-$, and $Cd^{2+}$ ions that caused significant activation of the respective promoters of Synechocystis sp. without concomitant unspecific stress responses. The low expression levels can be increased up to 10-100-fold upon treatments with $Cd^{2+}$, ${AsO_2}^-$, $Zn^{2+}$, and $Co^{2+}$ ions and up to 800-fold upon $Ni^{2+}$ treatment. These results facilitate the development of conditional gene expression systems in cyanobacteria.

Stoichiometry and Stability of Complexes Formed between 18-Crown-6 as well as Digenzo-18-Crown-6 Ligands and a Few Metal Ions in Some Non-aqueous Binary Systems Using Square Wave Polarography

  • A. Nezhadali, Gh. Rounaghi;M. Chamasaz
    • Bulletin of the Korean Chemical Society
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    • 제21권7호
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    • pp.685-689
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    • 2000
  • The complexation reaction between Pb2+,TI and Cd2+ions and macrocyclic ligands, 18-crown-6 ( 18C6) and dibenzo- 18-crown-6 (DB 18C6), was studied in dimethylsulfoxide (DMSO)-nitromethane (NM) and dimethyl-formamide (DMF)-nitromethane binary system s by square wave polarography (SWP) technique. The stoichiometry and stability of the complexes were determined by monitoring the shifts in half-waves or peak potentials of the polarographic waves of metal ions against the Iigand concentration. In most cases, the stability constants of complexes increase with increasing amounts of the nitromethane in mixed binary solvents used in this study. The complexes formed between 18C6 and DB18C6 and these metal cations in all cases had a stoichiometry of 1 : 1. The results obtained show that there is an inverse relationship between the formation constant of complexes and the donor number of solvents based on a Gatmann donocity scale and the stability constants show a high sensitivity to the composition of the mixed solvent systems. A linear behavior was observed for variation of log Kf of I8C6 complexes vs the composition of the mixed solvent systems in NM/DMSO and NM/DMF,but a non-linear behavior was observed in the case of DB 18C6 complexes in these binary systems. In most of the systems investigated, the Pb2+ cation forms a more stable complex with the 18C6 than other two cations and the order of selectivity of this Iigand for cations is: Pb2+ > TI+,Cd2+.

Correlation Analysis of General Parameters and Metals in the Lake Sediments of Geum River Basin

  • Lee, Jun-Bae;Cho, Yoon-Hae;Huh, In-Ae;Khan, Jong-Beom;Oh, Da-Yeon;Yang, Yoon-Mo;Gil, Gi-Beom;Lee, Soo-Hyung;Cheon, Se-Yeok;Lee, Bo-Mi
    • 한국토양비료학회지
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    • 제50권6호
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    • pp.684-696
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    • 2017
  • An investigation of grain size, organic compounds and metal distribution in lakes from Geum river basin (Republic of Korea) was conducted in two years (2014 and 2015). The samples of sediment were collected from the 3 lakes (12 sites). The samples were analyzed the concentration of metals (Pb, Zn, Cu, Cr, Ni, As, Cd, Hg, Al, and Li) and general indices including grain size. Spearman correlation coefficients were determined using general indices and metal concentrations respectively. The organic qualities of sediments were improved in 2015 compared with 2014. The concentrations of metals were lower than Sediment Criteria of Lakes in Korea. The significant Spearman correlation coefficients were presented only sand-clay, clay-water content, COD-TOC, Cu-Ni, Cd-Li, Zn-Li, and Cr-Ni of general and metal parameters in 2014, 2015 and both of two years.

Adsorptive and kinetic studies of toxic metal ions from contaminated water by functionalized silica

  • Kumar, Rajesh;Verma, Sunita;Harwani, Geeta;Patidar, Deepesh;Mishra, Sanjit
    • Membrane and Water Treatment
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    • 제13권5호
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    • pp.227-233
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    • 2022
  • The objective of the study, to develop adsorbent based purifier for removal of radiological and nuclear contaminants from contaminated water. In this regard, 3-aminopropyl silica functionalized with ethylenediamine tetraacetic acid (APS-EDTA) adsorbent prepared and characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Prepared APS-EDTA used for adsorptive studies of Cs(I), Co(II), Sr(II), Ni(II) and Cd(II) from contaminated water. The effect on adsorption of various parameters viz. contact time, initial concentration of metal ions and pH were also analyzed. The batch method has been employed using metal ions in solution from 1000-10000 ㎍/L, contact time 5-60 min., pH 4-10 and material quantities 50-200 mg at room temperature. The obtained adsorption data were used for drawing Freundlich and Langmuir isotherms model and both models were found suitable for explaining the metal ions adsorption on APS-EDTA. The adsorption data were followed pseudo second order reaction kinetics. The maximum adsorption capacity obtained 1.3037-1.4974 mg/g for above said metal ions. The results show that APS-EDTA have great potential to remove Cd(II), Co(II), Cs(I), Ni(II) and Sr(II) from aqueous solutions through chemisorption and physio-sorption.

모발의 탈색 및 퍼머넌트 웨이브 효과에 따른 다-원소금속 성분의 함량 분석 (Analysis of multi-elemental concentration in hair according to effect of permanent wave and bleaching agents)

  • 김준광;하병조
    • 분석과학
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    • 제20권6호
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    • pp.524-528
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    • 2007
  • Variations of the twenty one metal components (Mg, Al, V, Cr, Co, Sr, Ba, Na, K Mn, Fe, Cu, Zn, As, Hg, Pb, Ca, P, Mo, Cd, Sb) were analyzed in human hair sample by inductively coupled plasma mass spectrometry (ICP-MS). The effect of bleach and permanent wave manipulation on the elemental composition of hair were investigated. It was found that the composition of hair varied with hair bleach and permanent wave. Hair sample was collected from male in the age of thirties. Hair sample (0.05 g) was added to the Teflon digestion bomb together with 1.5 mL of nitric acid and an appropriate amount of In as an internal standard. The sample was then decomposed in the microwave digestion system. In normal hair, the contents of V, Cr, Mn, Fe, Co, Cu, Zn, As, Mo, Cd, Sb and P were increased in permanent wave hair, and Mg, Al, V, Co, Sr, Ba, Na and K were increased in bleached hair. But Mg, Al, Sr, Ba, Hg, Pb, Na, K, and Ca contents were decreased with permanent wave hair, Mn, Fe, Cu, Zn, As, Hg, Pb and Ca contents were decreased with bleached hair.

CTLA-4 항원의 세포막 도달 기작에서 친수성 N말단 아미노산 잔기의 역할 (Role of N-terminal Hydrophilic Amino Acids in Molecular Translocation of CTLA-4 to Cell Surface)

  • 한지웅;이혜자;김진미;최은영;정현주;임수빈;최장원;정용훈
    • IMMUNE NETWORK
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    • 제2권2호
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    • pp.102-108
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    • 2002
  • Background: This study was aimed to differentiate two forms of CTLA-4 (CD152) in activated peripheral blood lymphocyte and clarify the mechanism how cytoplasmic form of this molecule is targeted to cell surface. Methods: For this purpose we generated 2 different anti-human CD152 peptide antibodies and 5 different N'-terminal deletion mutant CTLA4Ig fusion proteins and carried out a series of Western blot and ELISA analyses. Antipeptide antibodies made in this study were anti-CTLA4pB and anti-CTLA4pN. The former recognized a region on extracellular single V-like domain and the latter recognized N'-terminal sequence of leader domain of human CD152. Results: In Western blot, the former antibody recognized recombinant human CTLA4Ig fusion protein as an antigen. And this recognition was completely blocked by preincubating antipeptide antibody with the peptide used for the antibody generation at the peptide concentration of 200 ug/ml. These antibodies were recognized human CD152 as a cytoplasmic sequestered- and a membrane bound- forms in phytohemagglutinin (PHA)-stimulated peripheral blood lymphocyte (PBL). These two forms of CD152 were further differentiated by using anti-CTLA4pN and anti-CTLA4pB antibodies such that former recognized cytosolic form only while latter recognized both cytoplasmic- and membraneforms of this molecule. Furthermore, in a transfection expression study of 5 different N'-terminal deletion mutant CTLA4Ig, mutated proteins were secreted out from transfected cell surface only when more than 6 amino acids from N'-terminal were deleted. Conclusion: Our results implies that cytosolic form of CTLA-4 has leader sequence while membrane form of this molecule does not. And also suggested is that at least N'-terminal 6 amino acid residues of human CTLA-4 are required for regulation of targeting this molecule from cytosolic- to membrane- area of activated human peripheral blood T lymphocyte.

강원도 철원지역과 전라남도 동부지역에 서식하는 한국고라니(Hydropotes inermis argyropus)의 중금속 축적 분석 (Heavy Metal Accumulation Analyses of the Korean Water Deer (Hydropotes inermis argyropus) in Cheorwon, Gangwon Province and the Eastern Part of Jeonnam Province)

  • 박보현;김백준;이상돈
    • 환경생물
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    • 제27권4호
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    • pp.363-368
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    • 2009
  • 한국고라니(Hydropotes inermis argyropus)는 우리나라의 고유종으로 가장 흔한 종의 하나이다. 이 종은 한반도 전역에 널리 분포하며 자연생태계에서 초식자로서 중요한 역할을 하는 것으로 알려져 있다. 따라서 고라니는 서식지의 질을 모니터링하는데 하나의 좋은 생물지표종으로 이용될 수 있을 것이다. 이 연구에서는 강원도 철원지역과 전라남도 동부지역에서 수집된 한국고라니의 서로 다른 3가지 조직(신장, 간, 지라)에서 5가지 중금속(Fe, Cu, Zn, Cd, Pb)의 농도를 측정하였다. 중금속 농도의 분석에 따르면, 철의 농도는 구리, 아연, 카드뮴, 납에 비해 모든 조직에서 높게 나타났다. 이중, 지라(286.50)가 신장(39.40)과 간($23.21\;{\mu}g\;g^{-1}$)에 비해 높은 중금속 축적을 보였다. 일반적으로, 중금속의 농도는 전남 동부지역에 비해 강원도 철원지역에서 조금 높게 나타났다. 특히, 카드뮴과 납의 경우 매우 유의한 차이를 보였다(P<0.05). 이러한 중금속의 농도는 지라의 철을 제외하고는 모두 백그라운드 수준(background level) 내로 낮게 나타났다.