蒙脱石对水中Ni^(2+)的吸附模型研究

Research on the Adsorption Model of Nickel Ions on Montmorillonite

吸附法是一种常用于去除废水中重金属离子的方法。近年来,对新型吸附剂的探索已成为研究的热点。蒙脱石是一种2:1型的粘土矿物,具有较高的比表面积和较强的吸附能力。本文采用拟实验方法,研究了蒙脱石在常温(293 K)对水溶液中Ni2+的吸附特性,考察了初始浓度对吸附效果的影响。结果表明,蒙脱石对Ni2+的吸附等温线可用Langmuir吸附等温方程、Freundlich吸附等温模型和Dubinin-Radushkevich(D-R)等温吸附模型进行描述,其中Langmuir吸附等温方程的拟合效果较佳(R2=0.999)。在293 K时,最大饱和吸附容量为153.85 mg/g,表明蒙脱石对Ni2+的吸附类型是物理吸附。

Adsorption method is one of the most common methods to remove heavy metals from wastewater. In recent years, research on new adsorbents has become a hot spot. Montmorillonite（MMT）, a 2：1 type of clay mineral has high surface area and high adsorption capacity. In this paper, adsorption of Ni2＋ from aqueous solution on MMT was studied at 293 K by using batch equilibrium approach. The adsorption conditions were studied, too. The results show that Ni2＋ adsorption isotherm on MMT can be described by Langmuir adsorption isotherm model, Freundlich isotherm model and Dubinin-Radushkevich（D-R） isotherm model. The fitting result of Langmuir adsorption isotherm model is the best（R2=0.999）. The maximum adsorption capacity is 153.85mg/g at 293 K, which proves that the adsorption process belongs to physical adsorption process.