• Journal of the Korean Chemical Society
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• v.15 no.4
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• pp.199-203
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• 1971

The adsorption method for the determination of the formation constants of the metal complexes with organic acids was developed by using membrane filters. The adsorption method involved the measurements of radioactivities of the adsorbed metal on membrane filters and the filtrate solution after the radioactive metal ion were filtered through membrane filters in the presence of organic ions of varying concentration. Comparing the adsorption method with the ion exchange method, it was seen that the adsorption method was simpler and faster than the ion exchange method. As an example of the metal complex with organic acid yttrium citrate complex was chosen, and the formation constant of the complex obtained by the adsorption method showed $K_f=2.0{\times}10^{-4}(l. mole^{-1})$ at a pH of 7. Also the present study revealed that the carrierfree state of yttrium in aqueous solution was present in the completely ionized state.

• Journal of Environmental Health Sciences
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• v.14 no.2
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• pp.65-71
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• 1988

In this study, the method of adsorption by activated carbon in the removal of Hg(II) ion in waste water was treated. The influence of kinds of activated carbon and effect of temperature and the influence of coexistent salt on adsorption rates, the influence of pH in the adsorption, equilibrium and adsorption of mercury from activated carbon were investigated. From the adsorption on activated carbon of mercury(II) ion in the presence of cyanide or thiocyanate ion was found that mercury(II) was easily adsorved onto the activated carbon in the form of complex artion such as Hg(CN)$_4^{2-}$, Hg(SCN)$_4^{2-}$ respectively. ZnCl$_2$ activation method had a higher adsorptive ability than steam activation method in adsorption of Hg on activated carbon. Activated carbon adsorbed iodide ion is very effective on adsorption of Hg.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1195-1202
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• 2012

The purpose of this work is to study the adsorption and desorption characteristics of acetone vapor and toluene vapor from adsorption tower in the VOCs recovery device. The six kinds of activated carbon with different pore structures were used and the adsorption and desorption characteristics were compared according to pore structure, desorption temperature, and adsorption method, respectively. Adsorption capacity of acetone vapor and toluene vapor by batch method was higher than that by dynamic method. Especially, activated carbon with medium-sized or large pores had more difference in adsorption capacity according to adsorption methods as a result of gradually condensation of vapors on relatively mesopore and large pores. Activated carbons with relatively large pores and relatively small saturated adsorption capacity had excellent desorption ability.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1819-1824
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• 2006

The general objective of the present study was to investigate the potential application of the UV spectroscopic method for determination of the polymeric additives present in papermaking fibrous stock solutions. The study also intended to establish the surface-chemical retention model associated with the adsorption kinetics of additives on fiber surfaces. Polyamide epichlorohydrin (PAE) wet strength resin and imidazolinium quaternary (IZQ) softening agents were selected to evaluate the analytical method. Concentrations of PAE and IZQ in solution were proportional to the UV absorption at 314 and 400 nm, respectively. The time-dependent behavior of polymeric additives obeyed a mono-molecular layer adsorption as characterized in Langmuir-type expression. The kinetic modeling for polymeric adsorption on fiber surfaces was based on a concept that polymeric adsorption on fiber surfaces has two distinguishable stages including initial dynamic adsorption phase and the final near-equilibrium state. The simulation model predicted not only the real-time additive adsorption behavior for polymeric additives at high accuracy once the kinetic parameters were determined, but showed a good agreement with the experimental data. The spectroscopic method examined on the PAE and IZQ adsorption study could potentially be considered as an effective tool for the wet-end retention control as applied to the paper industry.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.355-356
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• 2016

It is shown that the maximum value of exchange current is obtained where hydrogen adsorption energy is near 0. This enables to estimate catalytic efficiency of a material with hydrogen adsorption energy, which is relatively easier to calculate with density fuctional theory (DFT) method. Strain dependence of the adsorption energy was studied with DFT method and adsorption energy of 0.04 eV per hydrogen atom is obtained at 30% strain.

• Journal of Environmental Science International
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• v.32 no.8
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• pp.563-572
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• 2023

Scoria from Jeju-island (Jeju scoria) was converted into zeolitic material (Z-SA) via zeolitification using the fusion/hydrothermal method. Jeju scoria could be synthesized into Z-SA to from a surface covered with Na-A zeolite crystals, which was confirmed through an analysis of X-ray diffraction peak patterns and scanning electron microscopy images. Jeju scoria and Z-SA were employed as adsorbents to evaluate the adsorption rate and adsorption capacities for Cu²⁺ and Zn²⁺ ions. The adsorption rates and isothermal adsorption capacities could be well fitted by the pseudo-quadratic adsorption kinetics and Langmuir adsorption isotherm, respectively. The maximum adsorption capacities (q_m) of Z-SA for Cu²⁺ and Zn²⁺ ions were found to be 163.36 mg/g and 120.51 mg/g, respectively, using the Langmuir adsorption isotherm. When Z-SA is synthesized from Jeju scoria via zeolitification using the fusion/hydrothermal method, Z-SA exhibits an adsorption capacity that is more than approximately 100 times the value exhibited by Jeju scoria. As a result, the synthesized Z-SA was regarded as an effective, economic adsorbent.

• Journal of Environmental Science International
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• v.8 no.2
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• pp.211-219
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• 1999

Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values. In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(II) and Cd(II). Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.121-125
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• 2000

An ozone condenser by a selective adsorption on the silica gel surface is constructed. Ozone density is evaluated by three methods; ultraviolet absorption, thermal decomposition and Q-mass analyzing methods. Thermal decomposition method is found to be available to the density evaluation from dilute to highly condensed ozone. The highest ozone density condensed by the adsorption method is evaluated to be 97 mol%.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.60.2-60.2
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• 2010

A $TiO_2$ films in dye-sensitized solar cells was fabricated using $TiO_2$ colloidal sol prepared from titanium iso-propoxide used as a starting material by applying the sol-gel method. It was characterized by particle size analyzer, XRD, FE-SEM, and BET analysis. The adsorption isotherms of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$) and at three different pH (3, 5, 7). The adsorption kinetics of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$. The adsorption experimental data were correlated with Langmuir isotherm model and pseudo-second-order model. Also the isosteric enthalpies of dye adsorption were calculated by the Clausius-Clapeyron equation. In addition, the adsorption energy distribution functions which describe heterogeneous characteristics of nanocrystalline $TiO_2$ film surface were calculated by using the generalized nonlinear regularization method. We found that efficient adsorption of N719 dye from aqueous solution onto $TiO_2$ films can be successfully achieved by dye adsorption conditions and morphology of $TiO_2$ films.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.832-838
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• 2008

Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic panels. Moisture adsorption and desorption of porous materials were investigated and hydrothermal method was applied to fabricate panels. Cheolwon diatomite and Pohang zeolite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Correlation coefficient between surface area and moisture adsorption content of porous materials was 0.93. Moisture adsorption contents were influenced by surface area and pore volume of panels, and surface area more effected on moisture adsorption. Correlation coefficient between surface area and moisture adsorption content of panels was 0.86. Moisture adsorption content of panel with 10% Pohang zeolite was $180\;g/m^2$ and that of 10% Cheolwon diatomite was $170\;g/m^2$. Moisture desorption content of panel with 10% Pohang zeolite was $105\;g/m^2$. Moisture adsorption contents of panel with porous materials were higher than that of panel without porous materials.