Activated Sericite:An Efficient and Effective Natural Clay Material for Attenuation of Cesium from Aquatic Environment  

作　　者：D.TIWARI LALHMUNSIAMA S.I.CHOI S.M.LEE 

机构地区：[1]Department of Chemistry,School of Physical Sciences,Mizoram University [2]Department of Health and Environment,Kwandong University [3]Department of Environmental Engineering,Kwangwoon University

出　　处：《Pedosphere》2014年第6期731-742,共12页土壤圈（英文版）

基　　金：Supported by the National Research Foundation(NRF)of MEST,Korea(No.2012R1A2A4A01001539);the Converging Technology Project of the Ministry of Environment,Korea(No.2013001450001)

摘　　要：Sericite is mica-based natural clay that is annealed at 800 ℃ for 4 h, followed by acid activation using 3.0 mol L-1HCl at 100℃. The interaction of cesium(I), Cs(I), with sericite could provide useful data for the study of soil erosion or mass water movement utilizing the natural radioactive Cs. In this study sericite and activated sericite were used to assess their suitability in the attenuation of Cs from the aquatic environment under both batch and column experiments. The surface morphological studies indicated that a disordered and heterogeneous surface structure was exhibited by the activated sericite, whereas the native sericite exhibited a compact and layered structure. The Brunauer-Emmett-Teller(BET) specific surface area results indicated a significant increase in the surface area due to the activation of sericite. The batch reactor data collected for various parametric studies revealed that an increase in p H(from 2.0 to 8.0) and sorbate concentration(from 10.0 to 100.0 mg L-1) apparently favored the attenuation of Cs(I). The timedependent sorption data revealed that Cs(I) uptake was very rapid, and it achieved its saturation value within just 50 min of contact.The kinetic modeling studies indicated that the uptake of Cs(I) followed a pseudo-second-order rate equation; hence, the attenuation capacity of these solids for Cs(I) was estimated to be 0.858 and 4.353 mg g-1for sericite and activated sericite solids, respectively.The adsorption isotherm modeling data showed a reasonably good applicability of the Freundlich model than the Langmuir model.The effect of background electrolyte concentrations(0.001 to 0.1 mol L-1) of Mg(NO3)2indicated that the presence of this electrolyte could not significantly affect the percent removal of Cs(I) by activated sericite. Furthermore, the fixed-bed column reactor operations were performed to obtain the breakthrough data, which were fitted well to the Thomas non-linear equation. Therefore, the loading capacity of Cs(I) was estimated to be 1.585 mg g-1at the initialSericite is mica-based natural clay that is annealed at 800 ℃ for 4 h, followed by acid activation using 3.0 mol L^-1 HCl at 100℃. The interaction of cesium（I）, Cs（I）, with sericite could provide useful data for the study of soil erosion or mass water movement utilizing the natural radioactive Cs. In this study sericite and activated sericite were used to assess their suitability in the attenuation of Cs from the aquatic environment under both batch and column experiments. The surface morphological studies indicated that a disordered and heterogeneous surface structure was exhibited by the activated sericite, whereas the native sericite exhibited a compact and layered structure. The Brunauer-Emmett-Teller（BET） specific surface area results indicated a significant increase in the surface area due to the activation of sericite. The batch reactor data collected for various parametric studies revealed that an increase in p H（from 2.0 to 8.0） and sorbate concentration（from 10.0 to 100.0 mg L^-1） apparently favored the attenuation of Cs（I）. The timedependent sorption data revealed that Cs（I） uptake was very rapid, and it achieved its saturation value within just 50 min of contact.The kinetic modeling studies indicated that the uptake of Cs（I） followed a pseudo-second-order rate equation; hence, the attenuation capacity of these solids for Cs（I） was estimated to be 0.858 and 4.353 mg g^-1 for sericite and activated sericite solids, respectively.The adsorption isotherm modeling data showed a reasonably good applicability of the Freundlich model than the Langmuir model.The effect of background electrolyte concentrations（0.001 to 0.1 mol L^-1） of Mg（NO3）2indicated that the presence of this electrolyte could not significantly affect the percent removal of Cs（I） by activated sericite. Furthermore, the fixed-bed column reactor operations were performed to obtain the breakthrough data, which were fitted well to the Thomas non-linear equation. Therefore, the loading capacity o

关 键 词：adsorption isotherms breakthrough data ELECTROLYTE kinetics RADIONUCLIDE 

分 类 号：TD985[矿业工程—选矿]