• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.127-130
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• 2015

In this study, the adsorption equilibria of acetic acid on activated carbon were investigated at the temperatures of 313.15 K and 323.15 K. The obtained adsorption data were then fitted by Langmuir, Bi-Langmuir, and Freundlich models, in which the relevant model parameters were determined by minimizing the sum of the squares of deviations between experimental data and calculated values. The comparison results revealed that Bi-Langmuir model could account for the adsorption equilibrium data of acetic acid with the highest accuracy among the three adsorption models considered.

• Journal of the Korean Ceramic Society
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• v.23 no.3
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• pp.35-43
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• 1986

The equilibrium dsorption of starch on activated alumina and kaolin was studied to provide the fundamental data for investigating the effect of polymer adsorption on the flocculation of solid particles. The new polymer adsor-ption model(PAH-FH) predicting the adsorption equilibria of polymers on the solid surface has been developed using the solution theory and the concepts of Gibbs dividing surface in conjunction with the Flory-Huggins eq-uation and the adsorption behaviors of polymers were examined by this model The accurate adsorption equilibrium data of starch on alumina and kaolin were determined within the tempera-ture range of 298-318K by the ignition loss method. Using these experimenta data the model developed in this study was evaluated. It was shown that this model could predict the adsorption isotherm more accura-tely than the Langmuir model as well as could describe the characteristics of the adsorption equilibria through model parameters.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.371-379
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• 2005

Adsorption equilibria of the gases $H_2$, $CH_4$, and $C_2H_4$ and their binary mixtures on activated carbon (Calgon co.) have been measured by static volumetric method in the pressure range of 0 to 18 atm at temperatures of 293.15, 303.15, and 313.15 K. From the parameters obtained from single component adsorption isotherm, multi-component adsorption equilibria could be predicted and compared with experimental data. The binary experimental data were applied to four models : extended Langmuir, extended Langmuir-Freundlich, Ideal Adsorbed Solution theory (IAST), and Vacancy Solution Model (VSM). The models were found to describe the experimental data with a reasonable accuracy. Extended L-F model predicts equilibria of mixture better than any other model.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1609-1618
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• 2014

In this study, as a fundamental study for the remediation of the radionuclides-contaminated soil, the adsorption of cobalt, strontium, and cesium on natural soil and kaolin were experimently investigated and adsorption characteristics were evaluated by using several adsorption kinetic and isotherm models. The pseudo-first-order kinetic model (PFOM), pseudo-second-order kinetic model (PSOM), one-site mass transfer model (OSMTM), and two compartment first-order kinetic model (TCFOKM) were used to evaluate the kinetic data and the pseudo-second-order kinetic model was the best with good correlation. The adsorption equilibria of cobalt, strontium, and cesium on natural soil were fitted successfully by Redlich-Peterson and Sips models. For kaolin, the adsorption equilibria of cobalt, strontium, and cesium were fitted well by Redlich-Peterson, Freundlich, and Sips models, respectively. The amount of adsorbed radionuclides on natural soil and kaolin was in the order of cesium > strontium > cobalt. It is considered that these results could be useful to predicting the adsorption behaviors of radionuclides such as cobalt, strontium, and cesium in soil environments.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.175-183
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• 2008

Adsorption equilibria of the gases $CO_2$, CO, $CH_4$ and $H_2$ and their binary mixtures on Li-X zeolite (UOP) were obtained by static volumetric method in the pressure range of 0 to 20 bar at temperatures of 293.15, 303.15, and 313.15 K. Using the parameter obtained from single-component adsorption isotherm. Multicomponent adsorption equilibra could be predicted and compared with experimental data. Extended Langmuir isotherm, Extended Langmuir-Freundlich isotherm (L-F) and dual-site Langmuir isotherm (DSL) were used to predict the experimental results for binary adsorption equilibria of $H_2/CO_2$, $H_2/CO$, and $H_2/CH_4$ on Li-X Zeolite. Extended Langmuir-Freundlich isotherm predicted equilibria of $CH_4$ and $H_2$ better than any other isotherm. One the other hand DSL isotherm predicted equilibria of $CO_2$ and CO very well.

• Clean Technology
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• v.24 no.4
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• pp.348-356
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• 2018

The adsorption equilibria of oxygen, nitrogen and argon on carbonaceous adsorbent with slit-shaped and randomly etched graphite (REG) pores were calculated by molecular simulation method. Reliable models of adsorbents and adsorbates for adsorption equilibria are important for the correct design of industrial adsorptive separation processes. At the smallest physical pore of $5.6{\AA}$, only oxygen molecules were accommodated at the center of the slit-shaped pore, and from $5.9{\AA}$ nitrogen and argon molecules could be accommodated in the pores. Slit pores showed higher adsorption capacity compared with REG pores with same averaged reenterance pore size due to dead volume and inaccessible volume in defected pores. And it was shown the adsorption capacities of oxygen and argon was same in larger pore size. From calculated adsorption isotherms at 298 K it showed that the adsorption capacity ratio of oxygen to nitrogen is increased as pressure is increased.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.460-467
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• 2006

Adsorption experiments for $H_2$, $CO_2$, CO, and their binary mixtures on zeolite 5A were performed by static volumetric method. Experimental data were obtained at temperatures of 293.15, 303.15 and 313.15 K and at pressures to 25 atm. The parameters obtained from single component adsorption isotherm. Multicomponent adsorption equilibria could be predicted and compared with experimental data. Langmuir isotherm, Langmuir-Freundlich isotherm and Dual-Site Langmuir isotherm be used to predict the experimental results for binary adsorption equilibria of $CO_2/CO$ and $H_2/CO_2$ on zeolite 5A. Dual-Site Langmuir isotherm showed the best agreement with the experimental results.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.661-666
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• 1998

Liquid phase adsorption equilibria of amines in an aqueous solution onto high silica zeolite pellets (HSZ), macroreticular resin particles (MR) and granular activated carbon (GAC) were determined using a batch bottle technique at 298K. The isotherm curves of HSZ-amines and GAC-amines indicate the nonlinear relationship of unfavorable adsorption type of HSZ-amines and favourable one of GAC-amines. However the curves of MR-amines represent the linear pattern of an adsorption isotherm. Among various equilibrium isotherms, the three parameters of the Redlich-Peterson equation and the two parameters of the Freundlich equation are found to be the most satisfactory within the range of this study. The two parameters of the Langmuir isotherm were not applicable to the present adsorption systems. The amines were adsorbed on the HSZ, MR and GAC in the following sequence of adsorptivity; aromatic amines > primary amines > secondary amines. The product of the Freundlich constants, k and n, proportionally increased with the boiling point, molar volume and dissociation constants of amines adsorbed on HSZ, MR and GAC.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.1
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• pp.37-45
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• 2005

Adsorption equilibrium data of pure solvent vapors (n-Hexane, Toluene, MEK) as well as their binary mixtures on activated carbon (sorbonorit $B_4$) were experimentally determined in the range of 293.2~323.2 K and beyond saturated vapor pressure corresponding to experimental temperature. Langmuir, Freundlich, LRC, W-VSM, FH-VSM were estimated for the predication of single component as well as binary mixtuer systems. The isosteric heat of adsorption at infinite dilution of pure n-hexane, toluene, MEK on activated carbon were 45.18, 25.85, 34.62 Kcal/mol, respectively, also, n-hexane-toluene binary adsorption of activated carbon formed an azeotrope at 293.2 K and total pressure 5.1~10.3 mmHg.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.15-18
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• 2001

Sorption/desorption studies were conducted to determine sorption/desorption characteristics of phenolic compounds (phenol and 4-chlorophenol) in organically modified natural bentonite. The cationic exchange capacity (CEC) of bentonite was exchanged with a cationic surfactant, hexadecyltrimethylammonium (HDTMA), to enhance the removal capacity of organic phenol contaminants dissolved in aqueous solution. This modification produces a change of the surface property of bentonite from hydrophilic to organophilic. The single-solute and bi-solute competitive adsorptions were performed In batch mode to investigate the removal of two toxic organic Phenols, chlorophenol and 4-chlorophenol on the HDTMA-bentonite. The adsorption affinity of the 4-chlorophenol was higher than phenol due to higher octanol:water partition coefficient (Kow). The single-solute and bi-solute competitive desorptions were also performed investigate the competitive desorption of the phenolic compounds from HDTMA-bentonite. Freundlich model was used to analyze the single-solute adsorption/desorption results, while the IAST model predicted the hi-solute adsorption/desorption equilibria. The IAST model well predicted hi-solute competitive adsorption/desorption behaviors.