• 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.

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.130-136
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• 2011

This study investigated the adsorption characteristics of nickel, zinc and cadmium ions from the aqueous solution onto the alginate bead. Adsorption equilibrium capacities of the heavy metal ions increased with increasing initial pH of the solution. The adsorption equilibrium isotherm of the heavy metal ions was well represented by Langmuir equation. The magnitude of adsorption capacity of the heavy metal ions onto alginate bead was the order of cadmium > zinc > nickel. Kinetic parameters were measured in a batch adsorber to analyze the adsorption rates of the heavy metal ions. The internal diffusion coefficient of the heavy metal ions in the intraparticle were determined by comparing the experimental concentration curves with those predicted from the surface diffusion model (SDM) and pore diffusion model (PDM). The internal diffusion of the heavy metal ions in the intraparticles was explained by PDM.

• Journal of Integrative Natural Science
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• v.7 no.2
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• pp.130-137
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• 2014

Resins were synthesized by mixing N-phenylaza-15-crown-5 macrocyclic ligand attached to styrene (2th petroleum in 4th class hazardous materials) divinylbenzene (DVB) copolymer with crosslink of 1%, 2%, 6%, and 12% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, thermo gravimetric analysis (TGA), surface area, and IR-spectroscopy. The effects of pH, equilibrium arrival time, dielectric constant of solvent and crosslink on adsorption of metal ions by the synthetic resin adsorbent were investigated. The metal ions were showed fast adsorption on the resins above pH 4. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium (VI) > zinc (II) > europium (III) ions. The uranium ion adsorbed in the order of 1%, 2%, 6%, and 12% crosslink resin and adsorption of resin decreased in proportion to the order of dielectric constant of solvents.

• Journal of Korean Society on Water Environment
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• v.16 no.4
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• pp.555-563
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• 2000

The study was conducted to evaluate the adsorption equilibrium of heavy metals on bone charcoal made of livestock bone which was sintered at $550{\sim}600^{\circ}C$. Analysis of bone charcoal by XRD and FT-IR showed that crystal structure was similar to that of synthetic hydroxyapatite. Adsorption equilibrium capacity of single component (Pb, Cd, and Zn) on bone charcoal could be expressed as Langmuir, Freundlich, and Sips equations. Sips isotherm was best among the three isotherms. The values predicted by IAST(ideal adsorbed solution theory) showed good relationship to the experimental data in multicomponent adsorption equilibrium. Adsorption affinity was in order of Pb, Cd, and Zn. The order was same in case of activated carbon or synthetic hydroxyapatite. Through the study results. it would be expected that bone charcoal made of livestock could be used in field of wastewater treatment plants as adsorbent to remove heavy metal.

• Carbon letters
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• v.3 no.4
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• pp.219-225
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• 2002

The two-step surface modifications of activated carbon was carried out to improve the adsorption capacity of toxic heavy metal ions in liquid phase. Physical and chemical properties of the as-received activated carbon (AC) and two kinds of surface-modified activated carbons ($1^{st}AC$ and $2^{nd}AC$) were evaluated through the BET analysis, surface acidity, and oxides measurements. Specific surface area and pore volume did not significantly change, but surface oxide-group remarkably increased by the surface modification. Equilibrium and batch adsorptions of the various metals, such as Pb, Cd, and Cr, using AC, $1^{st}AC$, and $2^{nd}AC$ were performed at initial pH 5. The adsorption capacity and rate of $2^{nd}AC$ were higher than those of AC and $1^{st}AC$. The carboxylic/sodium carboxylate complex groups were developed from the two-step surface modification of activated carbon, which strongly affected the adsorption of metal ions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3319-3326
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• 2014

Eosin yellow is used a dye and colorant but it is harmful toxic substance. In this paper, batch adsorption studies were carried out for equilibrium, kinetics and thermodynamic parameters for eosin yellow adsorption by activated carbon with varying the operating variables like pH, initial concentration, contact time. Equilibrium adsorption data were fitted into Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. By estimated Langmuir constant value, $R_L$=0.067-0.083, and Freundlich constant value, $\frac{1}{n}=0.237-0.267$, this process could be employed as effective treatment for removal of eosin yellow. From calculated Temkin constant, value, B=1.868-2.855 J/mol, and Dubinin-Radushkevich constant, value, E=5.345-5.735 kJ/mol, this adsorption process is physical adsorption. From kinetic experiments, the adsorption process were found to confirm to the pseudo second order model with good correlation coefficient($r^2$=0.995-0.998). The mechanism of the adsorption process was determined two step like as boundary and intraparticle diffusion.

• Clean Technology
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• v.27 no.3
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• pp.261-268
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• 2021

Equilibrium, kinetics, and thermodynamics of adsorption of acid black 1 (AB1) by coal-based granular activated carbon (CGAC) were investigated with the adsorption variables of initial concentration of dye, contact time, temperature, and pH. The adsorption reaction of AB1 by activated carbon was caused by electrostatic attraction between the surface (H⁺) of activated carbon and the sulfite ions (SO₃^-) and nitrite ions (NO₂^-) possessed by AB1, and the degree of reaction was highest at pH 3 (97.7%). The isothermal data of AB1 were best fitted with Freundlich isotherm model. From the calculated separation factor (1/n) of Freundlich, it was confirmed that adsorption of AB1 by activated carbon could be very effective. The heat of adsorption in the Temkin model suggested a physical adsorption process (< 20 J mol^-1). The kinetic experiment favored the pseudo second order model, and the equilibrium adsorption amount estimated from the model agreed to that given by the experiments (error < 9.73% ). Intraparticle diffusion was a rate controlling step in this adsorption process. From the activation energy and enthalpy change, it was confirmed that the adsorption reaction is an endothermic reaction proceeding with physical adsorption. The entropy change was positive because of an active reaction at the solid-liquid interface during adsorption of AB1 on the activated carbon surface. The free energy change indicated that the spontaneity of the adsorption reaction increased as the temperature increased.

• Journal of Environmental Science International
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• v.21 no.7
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• pp.805-813
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• 2012

The removal property of Cu and Zn ions by chemical precipitation and adsorption using zeolite(Z-C1) prepared from coal fly ash(CFA) were evaluated in this study. Adsorption kinetic and equilibrium mechanisms described to analyze parameters and correlation factors with Lagergen $1^{st}$ and $2^{nd}$ order model and Langmuir and Freundlich model. Analysis of adsorption kinetics data revealed that the pseudo $2^{nd}$ order kinetics mechanism was predominant. The equilibrium data in pH 3 - 5 were able to be fitted well to a Langmuir model, by which the maximum adsorption capacities($q_{max}$) were determined at 124.9 - 140.1 mg $Cu^{2+}/g$ and 153.2 - 166.9 mg $Zn^{2+}/g$, respectively. We found that Z-C1 has a potential application as absorbents in metal ion recovery with low pH.

• Environmental Engineering Research
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• v.22 no.4
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• pp.384-392
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• 2017

Mango shell (MS) and mango shell activated carbon (MSAC) was used to adsorb crude oil from water at various experimental conditions. The MSAC was prepared by carbonization at $450^{\circ}C$ and chemical activation using strong $H_3PO_4$ acid. The adsorbents were characterized with Fourier Transform Infrared spectroscopy. Investigations carried out included the effects of parametric variations of different adsorbate dose, adsorbent dose, time, temperature, pH and mixing speed on the adsorption of crude oil. The equilibrium isotherm for the adsorption process was determined using Langmuir, Freundlich, Temkin and Dubinin Radushkevich isotherm models. Temkin isotherm was found to fit the equilibrium data reasonably well than others. The result demonstrated that MSAC was more effective for crude oil adsorption than raw mango shell. Optimum conditions were also presented. The enhanced effect from activation was justified statistically using Analysis of Variance and Bonferroni-Holm Posthoc significance test. The pseudo first order kinetics gave a better fit for crude oil adsorption with both MS and MSAC.

• Journal of Integrative Natural Science
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• v.6 no.3
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• pp.151-157
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• 2013

The ion exchange resins were synthesized from 1-aza-18-crown-6 macrocyclic ligand attached to styrene (2th petroleum in 4th class hazardous material) divinylbenzene (DVB) copolymer with crosslinks of 1%, 6%, and 15% by substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, surface area, and IR-spectrum. The object of this study was to seperate the metal ion absorbed in reinforcement water fire extinguishing agent. As the results of the effects of pH, equilibrium arrival time, and crosslink of synthetic resin on metal ion adsorption for resin adsorbent, the metal ions were showed high adsorption at pH 3 or over and adsorption equilibrium of metal ions was about 2 hours. In addition, adsorption selectivity for the resin in water was the order of Al (III) > Ni (II) > Sm (III) ions, adsorbability of the metal ions was in the crosslinks order of 1%, 6%, and 15%.