朝阳某钙基膨润土有机改性及吸附性能研究

Research on the Organic Modification of Chaoyang Ca-bentonite and Its Adsorption Properties

以朝阳某天然钙基膨润土为原料,以十二烷基三甲基溴化铵为改性剂,通过超声辅助法制备有机改性膨润土,利用X射线衍射分析(XRD)、红外吸收光谱(FTIR)、比表面积(BET)和zeta电位等技术手段对改性膨润土进行表征,研究改性膨润土对甲基橙和苯酚的吸附性能,考察反应时间、污染物初始质量浓度及pH值对吸附效果的影响规律。结果表明,改性剂成功插入钙基膨润土层间,致其层间距增大,zeta电位升高;改性膨润土对甲基橙和苯酚的吸附行为均符合准二级动力学和Langmuir等温吸附模型,饱和吸附量分别为197.63 mg/g和10.34 mg/g,吸附机理以物理吸附和电荷吸附为主。

The organo-bentonite was prepared with the assist of ultrasound by using the natural Ca-bentonite from Chaoyang as the raw material and dodecyl trimethyl ammonium bromide as the modifier. The modified bentonite was characterized by XRD, FTIR, BET and zeta potential measurement. The adsorption properties of the modified bentonite for methyl orange and phenol were studied. The influences of reaction time, initial concentration and p H value on the adsorption process were investigated. The result showed that the modifier intercalated into the interlayer space of Ca-bentonite successfully, which contributed to the expansion of organo-bentonite and increase of zeta potential. The adsorption of methyl orange and phenol can be both well described by pseudo-second-order kinetics and Langmuir adsorption model, and the adsorption capacities were up to 197.63 mg/g and 10.34 mg/g, respectively. The adsorption mechanisms for methyl orange and phenol were mainly due to physical adsorption and electrostatic attraction.