Kinetic and Equilibrium Study on Uptake of Iodide Ion by Calcined Layered Double Hydroxides
Iodide contamination removed using calcined MgAl-CO3 layered double hydroxides (denoted as CLDH) was conducted in batch conditions.The equilibrium isotherms of uptake of iodide by CLDH were well fitted by the Langmuir equation,and thermodynamic parameters including △G0,△H0 and △S0 were calculated from Langmuir constants.The negative value of △H0 confirms the exothermic nature of adsorption.The negative values of △G0 at 30,40,50 and 60 oC indicate the spontaneous nature of adsorption.The negative value of △S0 suggests the decreased randomness at the solid/solution interface for the uptake of iodide on CLDH.The influences of initial iodide ion concentration,dosage of CLDH,temperature of iodide removal have been tested in kinetic,respectively.Three kinetic models were used to fit the experimental data,and it was found that the pseudo-second order kinetics model could be used to describe the uptake process appropriately.The value of Ea was calculated to be 100.3kJ/mol,which suggests that the process of uptake iodide ion is controlled by the reaction rate of iodide ion with the CLDH rather than diffusion.The reconstruction of CLDH to I-LDHs due to uptake of iodide ion has been confirmed by X-ray diffraction patterns,FT-IR spectroscopy and TG-MS measurements.
layered double hydroxides calcined equilibrium kinetic iodide uptake
Liang Lv Jing He
College of Chemical & Materials Engineering, Quzhou University, Zhejiang 324000, China State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology, Bei
国内会议
青岛
英文
532-544
2011-06-01（万方平台首次上网日期，不代表论文的发表时间）