• Title/Summary/Keyword: 알칼리금속 효과

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Biogeochemistry of Alkaline and Alkaline Earth Elements in the Surface Sediment of the Gamak Bay (가막만 표층퇴적물 중 알칼리 및 알칼리 토금속 원소의 생지화학적 특성)

  • Kim, Pyoung-Joong;Park, Soung-Yun;Kim, Sang-Su;Jang, Su-Jeong;Jeon, Sang-Baek;Ju, Jae-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.1
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    • pp.1-13
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    • 2012
  • We measured various geochemical parameters, including the grain size, loss on ignition(LOI), total organic carbon(TOC), total nitrogen(TN), total sulfur(TS) and metallic elements, in surface sediment collected from 19 stations in Gamak Bay in April 2010 in order to understand the sedimentary types, the origin of organic matters, and the distribution patterns of alkali(Li, Na, K, Rb) and alkaline earth(Be, Mg, Ca, Sr, Ba) elements. The surface sediments were mainly composed of mud. The concentrations of Chlorophyll-a, TOC, TN, TS and LOI in sediment were the highest at the cultivation areas of fish and shellfish in the northern and southern parts of the bay. The redox potential(or oxidation-reduction potential) showed the positive value in the middle part of the bay, indicating that the surface sediment is under oxidized condition. The organic materials in sediment at almost all of stations were characterized by the autochthonous origin. Based on the overall distributions of metallic elements, it appears that the concentrations of alkali and alkaline earth elements except Ba in sediment are mainly influenced by the dilution effect of quartz. The concentrations of Sr and Ba are also dependent on the secondary factors such as the effect of calcium carbonate and the redox potential.

Effect of Pre-Treatment by Ozone on Chemical Surface Modification of Activated Carbon Fiber (오존에 의한 전처리가 활성탄소섬유 화학적 표면개질에 미치는 영향)

  • Jang, Jung Hee;Han, Gi Bo;Kim, Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.6
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    • pp.415-421
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    • 2013
  • To increase specific surface property of activated carbon fiber(ACF), chemical activation(CA) using alkali metals and surface treatment(ST) using oxidant was widely used. The CA and ST process developed micro-pore on the surface of ACF by chemical reaction of the alkali metals and oxidative of oxidant, respectively. To improve the efficiency of CA process for developing micro-pores on the surface of ACF, the ST process was adopted as an pre-treatment method. After treatment of ST process, ACF properties was investigated depending on the ST pre-treatment process. FT-IR, TG and elemental analysis of the ACF are carried out, and an adsorption property of ACF was also evaluated using toluene(which in typical volatile organic matter). Once the single CA process is used, the surface area and adsorption capacity of ACF were increased from 1,483 to 1,988 $m^2/g$ and from 0.22 to 0.27 $g_{-Tol.}/g_{-ACF}$, respectively. On the other hands, once the ST and CA processes are used successively, the surface area and adsorption capacity of ACF are greatly increase(where the surface area is 2,743 $m^2/g$ and the adsorption capacity is 0.37 $g_{-Tol.}/g_{-ACF}$). It indicates that the combined process of ST and CA can improve the surface process properties of ACF.

Effect of the Addition of Si and Alkali Metal on the Viscosity and Molecular Behavior of Water Glass (Si와 알칼리 금속의 첨가에 따른 물유리의 점도 및 분자결합구조 특성변화)

  • Ryu, Young Bok;Lee, Man Sig
    • Applied Chemistry for Engineering
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    • v.29 no.1
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    • pp.112-116
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    • 2018
  • In this study, the mixing characteristics of water glass and additives (Si, alkali metal), which are one of the main raw materials of silicate based binder used in the production of molds during casting process, were examined. Molecular structures of water glass, additives and mixtures were analyzed FT-IR and viscosity measurements and their correlation were compared. The addition of Si source to the water glass accelerated the Si networking in the material and increased the viscosity. When the alkali metal was added, the viscosity of the water glass decreased by suppressing the Si networking of the water glass. Viscosities of the water glass and lithium silicate (LS) mixtures increased when the content of LS was less than 20 wt% and gradually decreased when the content was more than 20 wt%. By adding KOH to the water glass, the viscosity could be lowered and it could be used effectively to mix with colloidal silica (CS) or potassium methyl siliconate (PMS).

Counterion Specific Conformational Transition and ion Selective Transport of a Poly(L-glutamic acid)/PVA Blend Membrane (Poly(L-glutamic acid)/PVA 블렌드막의 대이온 선택적인 구조전이와 이온투과 특성)

  • 허양일
    • Polymer(Korea)
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    • v.24 no.6
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    • pp.802-809
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    • 2000
  • Counterion-specific helix formation and ion-selective transport of alkali metal chlorides (LiCl, NaCl, KCl, CsCl) were investigated for a poly(L-glutamic acid)(PLGA)/poly (vinyl alcohol)(PVA) blend membrane immersed in aqueous ethanol. The counterion specificity for helix formation of PLG alkali metal salts in the membrane was Li>Na>K>Cs. This specificity is ascribed to a contact ion-pair formation between the PLG carboxyl anion and the bound counterion, which depends on the energy balance between the electrostatic interaction and the desolvation. In aqueous ethanol, an appreciable ion-selectivity was observed for the permeability coefficient, i.e. Li$^{+}{\cdot}$Cl$^{-}$) formation between counterion and coion, and the latter to a specific interaction of diffusing counterions with polymer charges.

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Studies on Ion-Selective Crown Ether Dyes (이온선택성 크라운 에테르 염료에 관한 연구)

  • Sam-Woo Kang;Chong-Min Park;Won-Fae Koo;Keun-Jae Kim;Soo-Min Lee;Choo-Hwan Chang
    • Journal of the Korean Chemical Society
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    • v.32 no.5
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    • pp.443-451
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    • 1988
  • New crown ether dye-Ⅰ and dye-Ⅱ having an azo group(-N=N-) were synthesized from monobenzo-15-crown-5 and dibenzo-18-crown-6. These dyes showed ${\lambda}_{max}$ of 377 and 383nm respectively. The complexes of alkali metal ions ($Na^+$, $K^+$, $Cs^+$) with dye ligands showed band shift (390~400nm) and intensity increased. For a given anion, the extraction constants are in the order of $K^+$ < $Cs^+$ < $Na^+$ for dye-Ⅰ and $Cs^+$ < $Na^+$ < $K^+$ for dye-Ⅱ. These results show that the selectivity of crown ethers toward the alkali metal ions is dependant on the charge density of cation and the size of crown ether cavity. For a given cation, the order of the extraction constant is $Cl^-$ < $Br^-$ < $I^-$ < picrate. This order coincides with the degree of anion solvation effect.

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Der EinfluB von Elektrolyten auf den Protonenaustausch in $H_2{^{17}}O$-haltigen waBrigen Losungen ($H_2{^{17}}O$을 포함하는 수용액에서 양성자 교환속도에 미치는 전해질의 영향)

  • Young-Kook Shin;H. G. Hertz
    • Journal of the Korean Chemical Society
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    • v.33 no.2
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    • pp.185-191
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    • 1989
  • Es wurden die Protonenspektren $wa{\beta}rigerH_2{^{17}}O$-haltige Erdalkalimetall-und Tetraalkylammoniumchlorid-Losungen bei $25^{\circ}$ und verschiededenen pH-Werten mit Hilfe der kernmagnetischen Resonanz-spektroskopie aufgenommen. Aus der Halbwertsbreite der Signale wurde die Austauschrate des Protons im Wassermolekul berechnet. Die Austauschrate, die in diesen Losungen beobachtet werden konnte, ist pH-abhangig. Bemerkernwerterweise ist die minimalle Austauschrate pH-abhangig. Dieses letztere Phanomen wird durch den Strukturbildungseffekt der Erdalkalimetallchloride und die hydrophobe Hydratation an Tetraalkylammoniumionen erklart.

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Development of Porous Sorbents for Removal of Hydrogen Sulfide from Hot Coal Gas -I. Additive Effect of Sorbents for the Removal of Hydrogen Sulfide- (고온석탄 가스에서 황화물의 제거하기 위한 다공성 흡착제의 개발-1. 황화수소가스 흡착제의 첨가물 효과-)

  • 이재복;류경옥
    • Journal of Environmental Health Sciences
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    • v.14 no.1
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    • pp.1-9
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    • 1988
  • 석탄유도가스에 포함된 황화수소를 제거시킬 흡착제를 개발하기 위하여 알칼리 토금속, 천이원소 및 아연의 이온반경보다 이온반경이 작은 금속산화물을 산화아연에 첨가시켜 다공성 흡착제를 제조하였다. 600$\circ$C에서 이들 첨가시료를 2.09vol.% 황화수소와 질소가스 혼합기체로 반응시켜 초기속도를 측정하고, 같은 온도에서 사용된 흡착제를 공기로 재생시켰다. 사용된 금속산화물 첨가 흡착제중에서 CaO, TiO$_2$, $Fe_2O_3$, CuO, $Ga_2O_3$ 및 Si$_2$O가 ZnO 흡착제의 초기속도를 증가시켜 첨가제로 사용할 수 있음을 보였다.

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Hight Efficiency Gasification of Biomass and Tar Reduction by Waste Metal (폐금속을 이용한 바이오매스의 고효율 가스화 및 타르 발생량 저감)

  • Sung, Hojin;Horio, Masayuki
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.179.2-179.2
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    • 2011
  • 바이오매스 가스화 프로세스 개발에 있어서 가장 기본적인 해결과제는 고발열량의 합성가스 제조, 냉가스 효율의 향상, 타르 발생량 저감 및 제거이다. 가스화 효율 향상에 대한 연구는 국내외 적으로 많이 이루어지고 있으나, 타르 발생량 저감에 대한 연구는 많이 이루어져 있지 않다. 타르는 분자량이 큰 방향적 탄화수소로 응축되면 점성이 높아 배관폐쇄, 정제설비의 압력손실 증가로 인해 운전정지 및 가스화율 저하의 원인이 된다. 가스화로에서 타르 발생량을 저감시키는 방법 중에는 Ni계 촉매를 이용하는 방법이 있으나, 카본 누적에 의한 활성저하, 알칼리금속에 의한 응집 등의 문제가 발생할 수 있다. 한편 철산화물은 합성가스 중의 C2-C3계의 타르를 분해하는데 효과가 알려져 있다. 따라서 본 연구에서는 적벽돌, 염색슬러지 회재 등에는 철산화물이 다량 함유되어 있는 것에 착안하여 폐기물중의 폐금속을 이용한 바이오매스 가스화에 대한 연구를 수행하였다. 점토광물계 폐기물인 적벽돌 파쇄물($SiO_2$ 67.2%, $Al_2O_3$ 19.7%, $Fe_2O_3$ 8.7%, $K_2O$ 2.0%, $TiO_2$ 1.2%, MgO 0.7%)을 전처리 한 후 유동매체로하여 우드펠렛을 가스화한 결과, 가스 생성량이 증가하고, 타르 및 탄화수소류가 감소하는 경향을 나타내었다. 특히 타르는 후단의 타르 트랩에서 타르가 거의 검출이 되지 않았다. 전처리를 하지 않은 적벽돌 파쇄물은 반응시간이 경과한 후에 가스화율이 증가함에 따라 철화합이 가스화로내에서 환원되어 타르를 분해하는데에는 어느 정도의 반응시간이 필요한 것을 확인하였다.

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Advancing the Frontier in Alkaline Promoter Performance Evaluation: Exploring Simplified Adoption Methods (알칼리 촉진제 성능 측정의 새로운 전환점: 도입 방식의 단순화를 통한 탐구)

  • Wonjoong Yoon;Jiyeon Lee;Jaehoon Kim
    • Clean Technology
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    • v.30 no.1
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    • pp.62-67
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    • 2024
  • In this study, an alkali metal Na was introduced into iron-based catalysts used in the carbon dioxide-based Fischer-Tropsch process by wet impregnation and physical mixing methods to compare their performance. The as-prepared catalysts were evaluated for reactivity at 3.5 MPa, 330 ℃, feed ratio of H2/CO2 = 3 with a space velocity of 4,000 mL h-1 gcat-1. Comparing the two catalysts, it was found that Na was uniformly distributed throughout the catalyst when wet-impregnated, but Na for physically mixed catalyst was relatively located on the surface of the catalyst. In addition, the wet-impregnated catalyst showed higher liquid hydrocarbon (C5+) yield and lower CO selectivity. In conclusion, the effect of Na distribution in the catalyst on the reaction was identified and can be controlled by the introduction method.

The Separation of Ce, Pr, Nd and Sm from Rare Earth Oxides (1차 분리된 희토류산화물 중 Ce, Pr, Nd 및 Sm의 분리)

  • Yong-Kuen Lee;In-Wha Woo;Young-Gu Ha
    • Journal of the Korean Chemical Society
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    • v.24 no.6
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    • pp.434-443
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    • 1980
  • The purpose of this work was to separate Ce, Pr, Nd and Sm from rare-earth oxides by column chromatography. Rare earth solution were adsorbed into the Amberlite IR-120 resin and were eluted by the ammonia alkali solution of the EDTA. As a result of determinating rare earth metals of each fraction, Ce was separated very effectively and Nd and Sm partially separaed but Pr never separated.

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