• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.25-32
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• 2009

The main objective of this study was to examine the removal properties of Cu from water by inflated vermiculites. The component of vermiculites was analyzed by XRF and the concentration of Copper ion was measured by UV-VIS. Serial batch Kinetic tests and batch sorption tests were conducted to determine the removal characteristics for Cu in aqueous solutions. The result shows that removal rate, $K_{obs}$, of Cu are 0.73, 1.52, and 1.71 for initial pH 3, pH 4, pH 5, respectively, and are 3.19, 1.90, and 0.73 for the initial concentration of $1mg\;L^{-1}$, $5mg\;L^{-1}$, $10mg\;L^{-1}$, respectively. It leads to the conclusion that the removal rates are inversely proportional to the initial Cu concentration and are increased proportionally to the initial pHs. Finally, Sorption data were correlated with both Langmuir and Freundlich isotherms. As a result, Langmuir and Freundlich models were well fitted to batch isotherm data with good values of the determination coefficient. but the determination coefficient value for the Freundlich model fit was slightly higher than that of Langmuir model (0.965 for the Freundlich model and 0.936 for the Langmuir model). Using the Langmuir model, the maximum sorption capacity ($Q_{max}$), Freundlich partition coefficient, and the numerical value of n wrer estimated as $1,250mg\;kg^{-1}$, $635.1L\;kg^{-1}$ and 1.69, respectively. These results show that the inflated vermiculites could be used as an excellent adsorbent for copper contained in various types of aqueous solutions.

• Clean Technology
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• v.16 no.3
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• pp.206-212
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• 2010

The adsorption characteristics of quinoline yellow by granular activated carbon were investigated experimently in the batch adsorber and packed column. The adsorptivity of activated carbon for quinoline yellow were largely improved by acidic pH and higher temperature. When the pH was 3 at $60^{\circ}C$, quinoline yellowcould be removed 97 percent of initial concentration(10 mg/L). It was estabilished that the adsorption equilibrium of quinoline yellow on granular activated carbon was successfully fitted by Freundlich isotherm equation in the temperature range from $25^{\circ}C$ to $60^{\circ}C$. The estimated values of k and ${\beta}$ are 38.71~166.60, 0.380~0.490, respectively. The breakthrough curve of activated carbon-packed column depends on the design variables such as initial concentration, bed height, and flow rate.

• 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 Korea Concrete Institute
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• v.29 no.4
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• pp.389-397
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• 2017

Friedel's salt is an important product of chemical adsorption between cement hydrate and chloride ions because it contains chlorine in its structure. When cement reacts with water in the presence of chloride ions, the $C_3A$ phase, and $C_4AF$ phase react with chloride to produce Friedel's salt. If chloride ions penetrate into concrete from external environments, many calcium aluminate hydrates, including AFm, can bind chloride ions. It is very important, therefore, to investigate the chloride binding isotherm of $C_3A$ phase, $C_4AF$ phase, and AFm phase to gain a better understanding of chloride binding in cementitious materials. Meanwhile, the adsorption isotherm can provide us with the fundamental information for the understanding of adsorption process. The experimental results of the isotherm can supply not only the quantitative knowledge of the cement-Friedel's salt system, but also the mechanism of adsorption and the properties of their interactions. The purpose of this study is to explore the time dependant behaviors of chloride ions adsorption with $C_3A$, $C_4AF$ and AFm phases. The chloride adsorption isotherm was depicted with Langmuir isotherm and the adsorption capacity was low in terms of the stoichiometric point of view. However, the chloride adsorption of AFm phase was depicted with Freundlich isotherm and the value was very low. Since the amount of the adsorption was governed by temperature, the affecting parameters of isotherm were expressed as a function of temperature.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.280-285
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• 2006

Adsorption characteristics of $H_{2}S$ on KOH impregnated activated carbon were evaluated using dynamic adsorption method in a fixed bed. The pore properties, including BET's specific surface area, pore volume, pore size distribution, and mean pore diameter of these KOH impregnated activated carbons, were characterized from $N_{2}$ adsorption/desorption isotherms. Adsorption equilibrium data were correlated with Langmuir and Freundlich isotherms. The adsorption of $H_{2}S$ onto the KOH impregnated activated carbon is better fitted by the Langmuir isotherm. An increase in the content of oxygen affects the performance of KOH impregnated activated carbon to the greatest extent.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.35-38
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• 1984

A laboratory experiment was carried out to investigate the effects of the additions of lime soluble starch on the behavior of silica in submerged soil. 1. Available silica in the submerged soil was increased as pH come up to neutral condition and Eh decreased. 2. Application of soluble starch accelerating the soil reduction nearly doubled the amount of silica sorbed in soil from silica solution. 3. Silica sorption of soil treated with slaked lime was increased to some extent in the low silica solution but was not showed that constancy in high silica solution. 4. The reaction between amount of silica sorbed in soil and silica concentration in solution followed not Lamgmuir but Freundlich adsorption isotherm.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.2
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• pp.27-34
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• 2014

Kinetic and isotherm properties of the cadmium adsorption onto calcium sand and granite soil were evaluated by batch experiments. The pHs of calcium sand and granite soil were 9.51 and 6.33, respectively, showing that the precipitation of heavy metals can be occurred due to the increase of pH when the calcium sand is used as an adsorbent. The pseudo-second-order model described the adsorption kinetics satisfactory with correlation coefficients over 0.999. The equilibrium adsorption capacities of calcium sand and granite soil were 2.10 and 2.16 mg/g, respectively. The adsorption isotherm followed the Freundlich isotherm model, indicating the cadmium adsorbed onto the heterogeneous surfaces of adsorbents.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.439-445
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• 2008

Sawdust is considered one of the cheapest and abundantly available adsorbents, and it is not necessary to regenerate. The spent sawdust can be incinerated or reused as a fuel. The sawdust adsorption can be applied to the removal of color and metal cations from the wastewater. The aim of this study was to evaluate the adsorptive capacities of sawdust with respect to color, COD, SS, turbidity, metal cation from textile wastewater. Langmuir, Freundlich, BET and Sips adsorption isotherm were obtained for the sawdust adsorption of Fe(III). The effects of particle size and amount of sawdust on the adsorption of Fe(III) were also studied. COD, SS, color, turbidity and Fe(III) removal efficiencies were examined at the continuous fixed-bed adsorption test. It was showed the removal efficiencies of SS 50.0%, Fe(III) 25.0%, turbidity 79.4%, color 48.6% and COD 50.9%. In addition, the changes of surface structure between before and after adsorption were investigated through SEM analysis. It is confirmed that the waste sawdust can be successfully used as an adsorbent for wastewater treatment.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.252-256
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• 2005

Removal of heavy metal ions from aqueous solution by brown sea weeds (Hizikia fusiformis, Laminaria, and Undaria pinnatifida) was 80-96% for lead, cadmium, chromium and copper ions. Fifty percent of the adsorption was completed in 4 min. The uptake of lead and cadmium ions followed Langmuir adsorption. In the adsorption experiments using single and multi metal ions 80-95% of metal ions were removed, and the removal efficiency was the best for lead ion.

• Clean Technology
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• v.20 no.3
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• pp.290-297
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• 2014

Batch adsorption studies were carried out for equilibrium, kinetics and thermodynamic parameters for adsorption of coomassi brilliant blue G (CBBG) using activated carbon with varying the operating variables like initial concentration, contact time and temperature. Equilibrium adsorption data were fitted into Langmuir, Freundlich and Dubinin-Radushkevich isotherms. From estimated separation factor of Langmuir and Freundlich, this process could be employed as effective treatment for removal of CBBG. Also from Dubinin-Radushkevich isotherm model, adsorption energy (E) indicated adsorption process is physical adsorption. From kinetic experiments, the adsorption reaction was found to confirm to the pseudo second order model with good correlation. Intraparticle diffusion was rate controlling step. Thermodynamic parameters like change of free energy, enthalpy, and entropy were also calculated to predict the nature of adsorption. The change of enthalpy (406.12 kJ/mol) indicated endothermic nature of the adsorption process. The change of entropy (1.66 kJ/mol K) showed increasing disorder in process. The change of free energy found that the spontaneity of process increased with increasing adsorption temperature.