• 제목/요약/키워드: chemical elements

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Submicron 부유분진의 화학적 조성 및 분포에 관한 연구 (Studies on the Chemical Compositions and Distributions of Ambient Sumicron Aerosols)

  • 황인조;김동술
    • 한국대기환경학회지
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    • 제14권1호
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    • pp.11-23
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    • 1998
  • The purpose of this study was to survey chemical distribution of inorganic elements and ions in the submicron particles, to characterize qualitatively emitting sources by factor analysis, and finally to reveal existing patterns in terms of chemical compounds by a stepwise multiple regression analysis. Total of 141 samples were collected by a cascade impactor from 1989 to1996. Fifteen chemical species (Al, Ba, Cd, K, Pb, Cu, Fe, Ni, $Cl^-, NO_3^-, SO_4^{2-}, K^+, Mg^{2+}, Ca^{2+}, and Na^+$) were characterized by AAS and IC. The study showed that average seasonal levels of submicron particulate matters $(d_p<0.43 \mum)$ were 18.7 $\mug/m^3$ in spring, 15.5 $\mug/m^3$ in summer, 15.7 $\mug/m^3$ in fall, and 24.5 $\mug/m^3$ in winter, respectively. All of the anion concentrations in the particle were highest in the winter season. By applying a factor analysis, 5 source patterns were qualitatively obtained, such as sulfate related source, nitrate related source, oil burning source, calcium related source, and coal combustion source. Finally, when applying a stepwise multiple regression analysis, the results clearly showed that $Na^+ and Ca^{2+}, K^+ and Ca^{2+}, NO_3^-$ and relative humidity, $Cl^-$ and ambient temperature, $Ca^{2+} and Cl^-, Mg^{2+} and SO_4^{2-}, Na^+ and NO_3^-, and Ca^{2+} and NO_3^-$, respectively, are negatively contributed to each other. As a result of those statistical analysis, we could suggest that some chemical compounds in the submicron particles such as$NaNO_3, MgSO_4, Ca(NO_3)_2, and CaCl_2$ may not exist on the filter as final composing products; however, other compounds may possibly exist in the form of $Mg(NO_3)_2, CaSO_4, Na_2SO_4, K_2SO_4, MgCl_2, NaCl, and KCl$. Thus, it must be necessary to identify differences between the results of above statistical analysis and of the real world by laboratory experiments.

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고체 폐기물 시료 중의 무기 Priority Pollutants 추출법 비교 연구 (The Comparison Study in the Extraction of Inorganic Priority Pollutants from Solid Wastes)

  • 안태호;이혁희;이석근
    • 분석과학
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    • 제10권6호
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    • pp.395-402
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    • 1997
  • 시료의 매질에 따른 추출법의 문제점과 사용 가능성을 조사하기 위해 환경처 발행의 폐기물공정시험방법과 EPA 3050법을 비교 연구하였다. 이를 위해 sludge와 개펄 시료에 12종의 무기 priority pollutants(Cd, Cr, Cu, Pb, Ni, Zn, As, Sb, Se, Hg, Be, Tl)를 첨가하여 분석용 시료를 조제하고 AAS, HG-AAS, 그리고 ICP/MS를 사용하여 각 추출방법에 대한 대상 원소의 회수율, 상대표준편차 및 method detection limit를 측정하었다. EPA 3050법에 따라 추출한 경우 회수율이 좋지 않은 As, Sb, Se를 제외한 평균 회수율은 93%였다. 그러나 폐기물공정시험방법의 용출시험방법으로 실험한 경우는 전반적으로 회수율이 32%로 매우 좋지 않을 뿐만 아니라 시료의 매질에 의한 영향을 심각하게 받는 것으로 조사되었다.

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Responses of Low-Quality Soil Microbial Community Structure and Activities to Application of a Mixed Material of Humic Acid, Biochar, and Super Absorbent Polymer

  • Li, Fangze;Men, Shuhui;Zhang, Shiwei;Huang, Juan;Puyang, Xuehua;Wu, Zhenqing;Huang, Zhanbin
    • Journal of Microbiology and Biotechnology
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    • 제30권9호
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    • pp.1310-1320
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    • 2020
  • Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg-1 super absorbent polymer, 3 g·kg-1 humic acid, and 10 g·kg-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.

Photoluminescent Graphene Oxide Microarray for Multiplex Heavy Metal Ion Analysis

  • Liu, Fei;Ha, Hyun Dong;Han, Dong Ju;Park, Min Su;Seo, Tae Seok
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.281.2-281.2
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    • 2013
  • Since heavy metal ions included in water or food resources have critical effects on human health, highly sensitive, rapid and selective analysis for heavy metal detection has been extensively explored by means of electrochemical, optical and colorimetric methods. For example, quantum dots (QDs), such as semiconductor QDs, have received enormous attention due to extraordinary optical properties including high fluorescence intensity and its narrow emission peaks, and have been utilized for heavy metal ion detection. However, the semiconductor QDs have a drawback of serious toxicity derived from cadmium, lead and other lethal elements, thereby limiting its application in the environmental screening system. On the other hand, Graphene oxide (GO) has proven its superlative properties of biocompatibility, unique photoluminescence (PL), good quenching efficiency and facile surface modification. Recently, the size of GO was controlled to a few nanometers, enhancing its optical properties to be applied for biological or chemical sensors. Interestingly, the presence of various oxygenous functional groups of GO contributes to opening the band gap of graphene, resulting in a unique PL emission pattern, and the control of the sp2 domain in the sp3 matrix of GO can tune the PL intensity as well as the PL emission wavelength. Herein, we reported a photoluminescent GO array on which heavy metal ion-specific DNA aptamers were immobilized, and sensitive and multiplex heavy metal ion detection was performed utilizing fluorescence resonance energy transfer (FRET) between the photoluminescent monolayered GO and the captured metal ion.

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단구 퇴적층의 화학 조성 변화에 대한 연구 - 정동진 단구의 세립 물질을 사례로 - (A study on the change of chemical composition of sediment particles of terrace deposits - A case of fine sediments at Jeongdongjin area -)

  • 김종연
    • 한국지형학회지
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    • 제23권2호
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    • pp.29-45
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    • 2016
  • Chemical composition of fine sediments from Jeongdongjin area are analyzed with XRF method. The results are compared with previously reported results of sandstones of the nearest Simgok port. The weight percentage of $SiO_2$ of the samples are far lower than those of sandstones of Simgok. It is supposed to be happened by the selective elution of $SiO_2$ from the sediment layer of coastal terrace, as there's no evidence of selective input or precipitation of other elements from outside. As a result of chemical alteration or weathering of sediment at coastal terrace, weight percentage of $Al_2O_3$ and $Fe_2O_3$ of samples show far higher values than those of Simgok sandstone. In addition, the relative portion of $Al_2O_3$ and $Fe_2O_3$ are decreased to upward within outcrop of terrace sediment layers. It could be caused by the chemical weathering progress with time. However Chemical Index of alteration(CIA) of sediment samples are no larger than 90 and it could be interpreted that it would take over 100ka for total weathering of sediment in this area. Meanwhile the ratio of $SiO_2/Al2O_3$ of terrace sediment showed as 3.48~6.0 and it is far smaller than those of Simgok sandstones(23.9~49.0). The ratio of $SiO_2/Fe_2O_3$ of terrace sediment(19.19~55.85) showed similar pattern with $SiO_2/Al2O_3$ (Simgok sanstone: 119.6~601.8). The ratios have a weak trend of decreasing upwards within the outcrop, there also a huge difference in value among the samples. Chemical composition of reddish brown and gray layers which suspected as the result of psudogleization reveals that reddish brown parts have higher concentration of $Fe_2O_3$ than other parts, while there was no significant difference in concentration of $Al_2O_3$ and CaO.

Bench-Top ED-XRF 및 휴대용 XRF를 이용한 토양 시료 중의 중금속 비교 분석 (Comparison of the Heavy Metal Analysis in Soil Samples by Bench-Top ED-XRF and Field-Portable XRF)

  • 최수정;김종혁;이석근
    • 분석과학
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    • 제22권4호
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    • pp.293-301
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    • 2009
  • 휴대용 형광 분석기의 개발을 위한 사전 기초연구로서 bench-top ED-XRF 및 휴대용 XRF를 이용하여 토양 시료 중의 Cr, As, Se, Hg, Pb, Cd 등 6종의 유해금속 성분들을 비교 분석하였다. 유해금속 원소를 0~1500 mg/kg 농도 범위로 오염시킨 토양 인증표준물질을 구입하여 XRF 분석의 중요 인자인 X-선 튜브 전압 및 측정 시간 등에 따른 최적 분석조건을 확립하고, 각각의 유해 중금속에 대한 검량선을 작성하였다. 유해금속 원소가 포함된 토양 인증표준물질 외에 7종의 다른 토양 시료 중의 유해금속 원소에 대해서도 empirical 법 및 fundamental parameter 법으로 정량분석하고 그 결과를 비교 분석하였다.

이민에 기초한 질소주개 리간드의 전이금속 착물 합성, 화학적 특성 및 촉매활성 (Synthesis, Chemical Characterization and Catalytic Activity of Transition Metal Complexes Having Imine Based Nitrogen Donor Ligand)

  • Hussain, Raja Azadar;Badshah, Amin;Asma, Maliha
    • 대한화학회지
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    • 제54권1호
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    • pp.23-26
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    • 2010
  • Schiff 리간드인 (Z)-N-((Z)-2-(sec-butylimino)-1,2-diphenylethylidene)butan-2-amine을 벤질과 sec-부틸아민과의 축합반응에 의해 합성하였다. 일 주기 전이금속인 망간(II) 및 니켈(II)과 리간드와의 착물반응을 시도하였다. 리간드 및 착물의 특성을 FTIR, 원소분석 및 열무게분석으로 고체 상태에서, 그리고 NMR ($^1H,\;^{13}C$)로 용액 상태에서의 각각 조사하였다. 두 착물 모두 온화한 조건에서 methylaluminoxane (MAO) 존재 하에 부타디엔 올리고화 반응의 조촉매로 좋은 촉매활성을 보였다.

Chemical Properties of the Individual Asian Dust Particles Clarified by Micro-PIXE Analytical System

  • Ma, Chang-Jin;Kang, Gong-Unn;Kasahara, Mikio;Tohno, Susumu
    • Asian Journal of Atmospheric Environment
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    • 제8권3호
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    • pp.154-161
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    • 2014
  • The present study was undertaken to evaluate the chemical characteristics of Asian dust (hereafter called "AD") particles with the aid of the most advanced micro-PIXE (Particle-induced X-ray emission) analytical technique. To this end, size-selected particles were sampled on a rural peninsula of Korea (Byunsan, 35.37N; 126.27E) during AD and non-AD periods in 2004. The coarse particle (> $2{\mu}m$) number density during an AD event were 170 times higher than those of the non-AD counterpart. The average net-count of silica in individual particles collected on AD event was roughly 11 times higher than that of non-AD counterpart. The X-ray net-counts of trace elements (Zn, Co, Mn, and V) were also considerably high in AD relative to the non-AD day. Particle classification based on the inter ratio analysis of elemental net-count suggests that a large portion of the coarse particles collected during AD event underwent chemical transformation to a certain degree. The visual interpretation of micro-PIXE elemental maps and elemental localization data in and/or on individual AD particles clarified the internal mixture of AD particles with sea-salt and artificial metallic particles.

마이크로파 분해장치와 유도결합 플라스마 원자방출분광법을 이용한 윤활유 시료 중 S, P 및 Zn의 동시 분석 (Simultaneous Determination of Sulfur, Phosphorus, and Zine in Lubricating Oils by Microwave Digestion System and ICP-AES)

  • 조성일;임헌성;이석근
    • 분석과학
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    • 제14권4호
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    • pp.324-330
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    • 2001
  • 마이크로파 분해법과 유도결합 플라스마 원자방출분광법(ICP-AES)을 이용하여 윤활유내의 S, P와 Zn의 분석을 하였다. 윤활유는 질산 또는 질산-과산화수소의 혼합산을 분해용액으로 하여 밀폐형 마이크로파 분해장치로 분해시켰다. 기존의 분해방법과 비교하여 펄스 방식에 의해 작동되어지는 단계적인 가열 프로그램은 윤활유 매질을 안전하게 분해하는데 3~4배 빠르고 효율적이었다. 제의된 분해방법은 검출된 원소들에 대해 3% 미만의 상대표준편차(RSD)를 보여주었다.

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AlF3-(Mg+Sr+Ba)F2-P2O5 유리에 관한 연구 제3보 : 화학적내구성 (Studies on AlF3-(Mg+Sr+Ba)F2-P2O5 Glasses III. Chemical Durability)

  • 김정은;이종근
    • 한국세라믹학회지
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    • 제24권4호
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    • pp.321-328
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    • 1987
  • The chemical durability of six alumino fluorophosphate glass samples studied. The composition of glass varied with MgF2 content from 0 to 12.5wt% in 30AlF3-2MgF2-(50-x)MF2-10P2O5(M; Sr, Ba). Samples were maintained in distilled water at 95$^{\circ}C$ from 1 to 100hrs. Weight loss, pH change and leached elements of the solution, and IR transmittance of samples were measured and also their surfaces were observed by SEM. Chemical durabilities of these samples were increased with increasing MgF2 contents. The following various properties were increased rapidly up to 10 hours after that changed slowly. The sample after leached at 95$^{\circ}C$ during 100 hrs showed 0.5mg/$\textrm{cm}^2$ in weight loss. The pH of leached solution is 6.2 and concentration of Mg, Sr, and Ba element of that leached solution were 24,115 and 125 ppm, respectively. The infrared transmittance of leached sample decreased 7% compare to unleached one. And also SEM photomicrograph and EDS analysis showed that the corrosion of samples were decreased with respect to increasing MgF2 content.

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