Removal of Cesium From Aqueous Solution by Adsorption Onto Si̇vas-Yildizeli̇ (Turki̇ye) Vermiculite: Equilibrium, Kinetic and Thermodynamic Studies

Abstract

In this study, cesium adsorption performance of raw vermiculite obtained from Sivas-Yıldızeli region of Turkey was investigated using batch adsorption method. In order to obtain the optimum adsorption conditions; different adsorbent dosages, contact times, solution pH's, initial cesium concentrations and temperature ranges were investigated. The concentration of cesium in solution was determined by ICP-OES. Kinetic studies demonstrated that adsorption process was in accordance with pseudo-second order kinetic model and equilibrium isotherm modeling studies showed that the process was compatible with Langmuir, Freundlich and Temkin adsorption isotherm models, indicating that Cs adsorption process had both physical and chemical character. Negative Gibbs energy values obtained from thermodynamic studies revealed that the adsorption process was spontaneous and had a high feasibility. Additionally, the negative enthalpy value indicated that process was exothermic, suggesting that the adsorbed Cs + ions decreased with increasing reaction temperatures. Positive entropy value showed that disorderliness between solid-liquid phase increased during adsorption. Results clearly indicate that vermiculite mineral has a promising potential in removing Cs + ions from aqueous media which leads mineral may also be used in decomposing and efficiently removing radioactive cesium from contaminated waters.

Removal of chromium(vi) from polluted wastewater by chemical modification of silica gel with 4-acetyl-3-hydroxyaniline

“…The 1/ n values of the Si-CPTS-AHAP adsorbent are shown in Table 3 , where a value of <1 is an indication of high adsorption density. 73 The K F values as shown in Table 3 show that the newly synthesized Si-CPTS-AHAP adsorbent shows high adsorption of Cr( vi ) metal ions from aqueous solution and industrial wastewater (0.50 and 0.10 mol L −1 ). 74 Values of n > 1 are indicative of suitable adsorption conditions.…”

Modeling and Regeneration Studies for the Removal of Crystal Violet Using Balanites aegyptiaca Seed Shell Activated Carbon

“…These findings were in accord with previous reports where the Freundlich isotherm gives better conformation for the sorption of CV by various adsorbents (31,32). Furthermore, the 1/n value (0.56) demonstrates higher heterogeneity and that physical adsorption administrates the uptake of the dye by the porous carbon (33). The Langmuir model also yield a relatively good match (R 2 = 0.9869), implying compatibility of the data to the model.…”

Adsorption of Methyl Orange Dye onto Raw Maize Cob and Maize Cob Activated Carbon: Isotherms and Thermodynamic Studies

“…The chemical ion exchange happened for the E value 8−16 kJ/mol. The physical and chemical adsorptions occurred when E < 8 and E > 16 kJ/mol, respectively [28]. As shown in Table 1.…”

“…A plot of qe versus lnCe yielded linear lines which enable the determination of the isotherm constants KT and BT from intercepts and slope respectively [24]. Temkin isotherm constant bT derived from BT constant refers to the heat of adsorption and is used to determine the adsorption characteristics, meaning whether it is a physical or chemical process [28]. Empirical results demonstrated that adsorption of dyes onto adsorbents surface showed a physical sorption character since Temkin isotherm constant bT was found to be lower than 8 kJ/mol In addition, good linear regression value of 0.944 and 0.990 with RMC and MCAC respectively indicates that adsorption process is fits closely with Temkin isotherm model.…”