• Title/Summary/Keyword: Hydrogen Ions ($H^+$)

Search Result 204, Processing Time 0.026 seconds

Elctrokinetic-Fenton 기법 적용시 토질조건과 오염원의 종류에 따른 과산화수소의 주입특성

  • 김정환;김병일;한상재;김수삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2002.04a
    • /
    • pp.30-33
    • /
    • 2002
  • In this study, feasibility of using hydrogen peroxide as a chemical oxidant for in-situ treatment by EK-Fenton technology were investigated. Kaolinite, kaolinite/sand mixture and illitic soil spiked by phenol and phenanathrene were used and variation of electrochemical characteristics were examined by EK-Fenton test. For kaolinite that having low buffer capacity, hydrogen peroxide was injected effectively from anode reservoir. However illitic soil that having relatively higher buffer capacity had low hydrogen peroxide introducing efficiency. The test results showed that Hydrogen ions generated by current increased during the treatment decreased under pH 3 in the most of kaolinite specimen. Therefore, stabilized hydrogen oxide was injected more effectively in the kaolinite specimen. This study suggests that efficiency of hydrogen peroxide injection by EK-Fenton thechnoloty is dependent of variation of pH in the soil

  • PDF

Surface energy change and hydrophilic formation of PE, PS and PTFE films modification by hydrogen ion assisted reaction

  • Jung Cho;Ki Hyun;Koh, Seok-Keun
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 1999.07a
    • /
    • pp.202-202
    • /
    • 1999
  • The Polyethylene (PE), Polystyrene (PS) and Polytetrafluoroethylene (PTFE) surface modification was investigated by hydrogen io assisted reaction (H-IAR) in oxygen environment. The IAR is a kind of surface modification techniques using ion beam irradiation in reactive gas environment. The energy of hydrogen ion beam was fixed at 1keV, io dose was varied from 5$\times$1014 to 1$\times$1017 ions/$\textrm{cm}^2$, and amount of oxygen blowing gas was fixed 4ml/min. Wettability was measured by water contact angles measurement, and the surface functionality was analyzed by x-ray photoelectron spectroscopy. The contact angle of water on PE modified by argon ion beam only decrease from 95$^{\circ}$ to 52$^{\circ}$, and surface energy was not changed significantly. But, the contact angle using hydrogen ion beam with flowing 4ml/min oxygen stiffly decreased to 8$^{\circ}$ and surface energy to 65 ergs/cm. In case of PS, the contact angle and surface energy changes were similar results of PE, but the contact angle of PTEE samples decreased with ion dose up to 1$\times$1015 ions/$\textrm{cm}^2$, increased at higher dose, and finally increased to the extent that no wetting was appeared at 1$\times$1017 ions/$\textrm{cm}^2$. These results must be due to the hydrogen ion beam that cleans the surface removing the impurities on polymer surfaces, then hydrogen ion beam was activated with C-H bonding to make some functional groups in order to react with the oxygen gases. Finally, unstable polymer surface can be changed from hydrophobic to hydrophilic formation such as C-O and C=O that were confirmed by the XPS analysis, conclusionally, the ion assisted reaction is very effective tools to attach reactive ion species to form functional groups on C-C bond chains of PE, PS and PTFE.

  • PDF

Zundel- and Eigen-like Surface Hydrated Protons on Pt(111)

  • Kim, Youngsoon;Park, Youngwook;Shin, Sunghwan;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.167.1-167.1
    • /
    • 2016
  • The interaction between adsorbed water and hydrogen on metallic surfaces is important for fundamental understanding of heterogeneous catalysis and electrode surface reactions in acidic environment. Here, we explore a long-standing question of whether hydronium ion can exist or not on a Pt surface coadsorbed with atomic hydrogen and water. Studies based on mass spectrometry and infrared spectroscopy show clear evidence that hydrogen atoms are converted into hydrated protons on a Pt(111) surface. The preferential structures of hydrated protons are identified as multiply hydrated $H_5O_2{^+}$ and $H_7O_3{^+}$ species rather than as hydronium ions. The multiply hydrated protons may be regarded as two dimensional zundel ($H_5O_2{^+}$) and Eigen cation ($H_7O_3{^+}$) in water-metal interface. These surface-bound hydrated protons may be key surface intermediates of the electrochemical interconversion between adsorbed hydrogen atoms and solvated protons.

  • PDF

Hydrogen ion-selective membrane electrodes based on tetrabenzylalkylenediamine (Tetrabenzylalkylenediamine을 이용한 수소이온 선택성 막전극)

  • Kim, Jae-Woo;Cho, Dong-Hoe;Jeong, Seong-Suk;Chung, Koo-Chun;Park, Myon-Yong
    • Analytical Science and Technology
    • /
    • v.10 no.3
    • /
    • pp.161-167
    • /
    • 1997
  • This is on hydrogen ion-selective memebrane electrodes which were made of tetrabenzylmethylenediamine (TBMDA), tetrabenzylethylenediamine (TBEDA), tetrabenzylpropylenediamine(TBPDA) and tetrabenzylhexylenediamine(TBHDA) as neutral carriers. Their response potentials to carbon number between amino groups showed linear selectivities to hydrogen ion in the range of pH 1~pH 9, pH 2~pH 9, pH 3~pH 9 and pH 4~pH 9 and slopes were 48mV/pH, 52mV/pH, 64mV/pH, 59mV/pH respectively. The interferences effect on the cations were measured to alkali metal ions($Li^+$, $Na^+$, $K^+$), alkaline earth metal ions ($Mg^{2+}$, $Ca^{2+}$, $Sr^{2+}$, $Ba^{2+}$), transition metals ions($Cu^{2+}$, $Ni^{2+}$, $Co^{2+}$) and anions($I^-$, $Br^-$, ${NO_3}^-$, $SCN^-$), and selectivity coefficients were measured by separate-solution method. The membrane electrode made of TBMDA among the electrodes showed the best selectivity in acidic solution.

  • PDF

Preparation and Clinical Application of pH-ISE(Ion Selective Electrode) Based on Tribenzylamine Ionophore (Tribenzylamine Ionophore를 이용한 pH-ISE의 제조 및 임상응용)

  • Cho, Dong-Hoe;Park, Chung-Oh
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.38 no.1
    • /
    • pp.59-64
    • /
    • 2006
  • The pH-ISE(ion selective electrode) based on tribenzylamine as a hydrogen ion carrier was prepared and its electrochemical characterization was studied. It responded linearly to hydrogen ions in the range of pH 3.1 - pH 11.0 and the Nernstian slope showed 55.0 mV/pH (at $20{\pm}0.2^{\circ}C$), it also showed a fast response time of 8 sec. When it was directly applied to human blood(pH 6.0-8.5), we could get the same satisfying results. A good reproducibility and stability were shown with the precision of 2 mV (${\pm}0.1$). The pH-ISE based on tribenzylamine exhibited biocompatibility in clinical applications.

  • PDF

An Efficient Sulfuric Acid- and Hydrazine-based Process for Recycling Wastewater Generated From U(VI)-Contaminated Soil-Washing

  • Hyun-Kyu Lee;Byung-Moon Jun;Tack-Jin Kim;Sungbin Park;Seonggyu Choi;Jun-Young Jung;Hee-Chul Eun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.22 no.2
    • /
    • pp.159-171
    • /
    • 2024
  • This study aimed to develop an efficient recycling process for wastewater generated from soil-washing used to remediate uranium (U(VI))-contaminated soil. Under acidic conditions, U(VI) ions leached from the soil were precipitated and separated through neutralization using hydrazine (N2H4). N2H4, employed as a pH adjuster, was decomposed into nitrogen gas (N2), water (H2O), and hydrogen ions (H+) by hydrogen peroxide (H2O2). The residual N2H4 was precipitated when the pH was adjusted using sulfuric acid (H2SO4) to recycle the wastewater in the soil-washing process. This purified wastewater was reused in the soil-washing process for a total of ten cycles. The results confirmed that the soil-washing performance for U(VI)-contaminated soil was maintained when using recycled wastewater. All in all, this study proposes an efficient recycling process for wastewater generated during the remediation of U(VI)-contaminated soil.

Mechanism of Intercalation Compounds in Graphite with Hydrogen Sulfate (I. Study of Intermediate Phase between 2 Stage and 1 Stage in Graphite Hydrogen Sulfate with Anodic Oxidation) (흑연에 황산을 Intercalation 시킬때의 Mechanism 규명 (I. 전기적 산화방법에 의한 Graphite Salts의 중간상에 관한 연구))

  • 고영신;한경석;이풍헌
    • Journal of the Korean Ceramic Society
    • /
    • v.22 no.6
    • /
    • pp.5-8
    • /
    • 1985
  • Graphite has been oxidized to graphite hydrogen sulfate in concentrated $H_2SO_4$. Anodic oxidation and chemical oxidation of graphite in $H_2SO_4$ generally leads to the formation of intercalation compounds of the ionic salt type through incorporation of $H_2SO_4^-$ions and $H_2SO_4$ molecules into the graphite. Several other reactions also accur at various points of the charging cycle. But there is no satisfactory kinetics and mechanism of intercalationin graphite. We have studied them with anodic oxidation and chemical oxidation. We found six distinct phenomena between 2nd stage and 1st stage in chemical oxidation. We examined them in detail by the following in the measurements electrical oxidation. X-ray diffractions UV-Vis spectroscopy density measurements. We could obtained a equation for kinetic according to the reaction rate from this results and mechanism of intercalation between 2nd stage and 1st stage with hydrogen sulfate in graphite. Three thesis were written for the mechanism of intercalation compounds in graphite with hydrogen sulfate ; first thesis is anodic oxidation second thesis is chemical oxidation and definition of transit phase between 2nd etc the third thesis is the kinetic mechanism of intercalation compounds in graphite with Hydrogen sulfate. This thesis is the first paper among three thesis as anodic oxidation.

  • PDF

Spectroscopic Studies on Electroless Deposition of Copper on Hydrogen-Terminated Si(111) Surface in NH4F Solution Containing Cu(II) Ions

  • Lee, In-Churl;Bae, Sang-Eun;Song, Moon-Bong;Lee, Jong-Soon;Paek, Se-Hwan;J.Lee, Chi-Woo
    • Bulletin of the Korean Chemical Society
    • /
    • v.25 no.2
    • /
    • pp.167-171
    • /
    • 2004
  • The electroless deposition of copper on the hydrogen-terminated Si(111) surface was investigated by means of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, scanning tunneling microscopy (STM), and energy-dispersive spectroscopy (EDS). The hydrogen-terminated Si(111) surface prepared was stable under air atmosphere for a day or more. It was found from ATR-FTIR that two bands centered at 2000 and 2260 $cm^{-1}$ appeared after the H-Si(111) surface was immersed in 40% $NH_4F$ solution containing 10 mM $Cu^{2+}$. On the other hand, STM image included the copper islands with a height of 5 nm and a diameter of 10-20 nm. The EDS data displayed the presence of copper, silicon and oxygen species. The results were rationalized in terms of the redox reaction of surface Si atoms and $Cu^{2+}$ ions in solutions, which are changed into $Si(OH)_x(F)_y$ containing $SiF_6^{2-}$ ions and neutral copper islands.

Investigation on Source Strength to Acid Rain in the Seoul Area (서울시 산성비의 원인물질에 관한 연구)

  • 신응배;이상권;안규홍
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.2 no.2
    • /
    • pp.66-74
    • /
    • 1986
  • Rain samples were collected at 10 sites in the Seoul area during the period of August through November, 1985. THe concentrations of the major cations $(H^+, Ca^{++}, MG^{++}, Na^+, K^+, NH_4^+)$ and the major anions $(SO_4^=, NO_3^-, Cl^-)$ were measured to characterize the main sources of chemical ions in rainwater. Correlating concentrations of ions to pH, calculated coefficients ranged from 0.1485 to 0/4296. Sulfate shows the largest coefficient indicating that sulfate is more closely associated with hydrogen ion than other ions. This may suggest that sulfuric acid contributes more to the acidity of rainwater in Seoul. It appears that the major chemicals measured in rainwater are from the anthropogenic sources of air pollution. Predominant chemicals are acidic at the Guro-, the Sinseol-, the Yangnam-, and the Ssangmun-dong with sulfate being the most predominant. IT also indicates that alkaline substances resulting from soil and dust have a significant effect on pH values of rainwater by neutralizing actions. According to Granat-model analysis, it is estimated that the relative contributions to the rainwater acidity in Seoul are 84% from sulfuric acid, 8% from nitric acid and 8% from hydrochloric acid.

  • PDF