Adsorption of Cr(VI) from Aqueous Solutions on Organic Modified Laponite
Adsorption of Cr(VI) from Aqueous Solutions on Organic Modified Laponite
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DOI：
10.7503/cjcu20160462
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发表时间：
2017-02-10
影响因子：
1
通讯作者：
Lu Xianjun
中科院分区：
文献类型：
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作者：
Cao Xiaoqiang;Yan Bingqi;Lu Xianjun
采用水热法合成锂皂石，并用十六烷基三甲基溴化铵（CTMAB）对其进行改性。采用间歇吸附法研究了改性合成锂皂石（CTMABL）对Cr（VI）的吸附，考察了pH、CTMABL用量、离子强度、接触时间和温度对吸附的影响。结果表明，改性后样品的比表面积和孔容减小，平均孔径增大。改性后CTMABL的d（（001））值从1.23 nm提高到1.79 nm，与未改性的CTMABL相比，d（001）值提高了1.79 nm。表明CTMAB已进入锂皂石层间。研究了Cr（VI）的去除方法。随着溶液pH值的升高而增大。在pH99%，投加量为4g/L时，酶活力最大。离子强度对Cr（VI）的吸附影响不明显。CTMABL对Cr（VI）的吸附动力学数据可用拟线性方程描述。一下级动力学模型，吸附速率受膜内扩散和膜内扩散的影响。粒子扩散Cr（VI）在CTMABL上的吸附等温线可用Langmuir模型描述。不同温度下CTMABL对Cr（VI）的吸附热力学参数表明，该吸附过程是自发的吸热过程。Cr（VI）在CTMABL上的吸附主要以表面络合作用为主，静电引力也能促进Cr（VI）在CTMABL上的吸附。
Laponite was synthesized by hydrothermal method and modified by cetyltrimethyl ammonium bromide(CTMAB). The adsorption of Cr(VI) on modified laponite(CTMABL) as a function of pH, CTMABL dosage, ionic strength, contact time, and temperature was studied via batch technique. The results showed that the specific surface area and pore volume of modified samples were decreased, while the average pore size was increased. The d((001)) value of CTMABL raised from 1.23 nm to 1.79 nm after the modification, which in. dicated that the CTMAB had entered into the interlayer of laponite. The removal of Cr(VI) from solution in. creased with the increase of solution pH value. At pH99% at the dosage of 4 g/L. The effect of ionic strength on the adsorption of Cr(VI) was not obvious. The adsorption kinetic data of Cr(VI) on CTMABL were well described by the pseudo. second. order kinetics model, and the adsorption rate was influenced by the membrane diffusion and intra. particle diffusion. The adsorption isotherms of Cr(VI) on CTMABL can be described well by the Langmuir model. The thermodynamic parameters of Cr(VI) adsorption on CTMABL at different temperatures indicated that the adsorption was endothermic and spontaneous. The adsorption of Cr(VI) was dominated by surface complexation, whereas electrostatic attraction could also promote the Cr(VI) adsorption on CTMABL.