• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.61-68
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• 2009

The main objective of this study was to examine the removal of heavy metals from water by inflated vermiculites. The component of vermiculites was analyzed by XRF, and the concentration of metal ion was measured by ICP-AES. Serial batch kinetic tests and batch sorption tests were conducted to determine the removal characteristics for heavy metals in aqueous solutions. As a result, solution pH values of tests with the inflated vermiculites generally increased and then stabilized. Equilibrium pHs were generally established within 5 hrs. In addition, removal rates of inflated vermiculites were tested at the initial concentration of 3 mg/L. As a result, at equilibrium concentration, except for chromium (36.23%), Most of the heavy metals were effectively removed (96.08~98.54%). Finally, sorption data were correlated with both Langmuir and Freundlich isotherms. The Qmax obtained from Langmuir isotherm were determined to Pb $725.4mg\;kg^{-1}$, Cd $568.8mg\;kg^{-1}$, Zn $540.2mg\;kg^{-1}$, Cu $457.2mg\;kg^{-1}$ Cr $0.9mg\;kg^{-1}$ respectively. The results of the study indicate that inflated vermiculites can be properly used as an adsorbent for various heavy metals because of its outstanding removal rate.

• 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.