阳离子柱[5]芳烃改性膨润土对橙黄Ⅳ的吸附研究

Preparation of cationic pillar[5]arene modified bentonite and its adsorption to orangeⅣ

采用水热法制备了阳离子柱[5]芳烃(CP5A)改性膨润土(BT)的新型吸附剂材料(CP5A/BT).通过红外吸收光谱(FTIR),X射线粉末衍射(XRD),扫描电子显微镜(SEM)对吸附剂材料CP5A/BT进行了表征.以阴离子染料橙黄Ⅳ(OIV)为目标吸附质,考察了CP5A浓度、吸附剂投加量、溶液pH值、接触时间和染料初始浓度对吸附效果的影响,采用吸附动力学和吸附等温线模型对吸附过程进行了研究.通过“吸附−解吸”循环对CP5A/BT吸附剂的再生性进行了考察.结果显示,CP5A成功负载在BT上,改性后的CP5A/BT表面形貌和结构发生了改变.经CP5A改性后的BT表面有大量的活性位点,对OIV的去除在45 min内能迅速达平衡状态,且酸性及弱碱性条件下的吸附量高于强碱性条件.经动力学模型、Langmuir和Freundlich模型分析得出,CP5A/BT对OIV的理论吸附量可达230.4247 mg·g^(−1),且伪二级动力学和Freundlich等温线模型能较好地拟合CP5A/BT对OIV的吸附过程,此吸附过程主要以化学吸附为主.CP5A/BT吸附剂具有较好的再生性.

A new adsorbent material(CP5A/BT)of cationic pillar[5]arene(CP5A)modified bentonite(BT)was prepared by the hydrothermal method.The CP5A/BT was characterized by infrared absorption spectroscopy(IR),X-ray powder diffraction(XRD)and scanning electron microscopy(SEM).Nionic dye orange yellowⅣ(OIV)was used as the target adsorbate.The adsorption effect of the concentration of CP5A,the amount of adsorbent added,solution pH,contact time and initial OIV concentration were investigated.The adsorption process was studied by adsorption kinetics and adsorption isotherm models.Through the"adsorption-desorption"cycle,the regeneration of CP5A/BT adsorbent was investigated.The results showed that CP5A was successfully loaded on BT,and BT has different surface morphology and structure after CP5A modification.The surface of BT modified by CP5A has a large number of active sites,and the adsorption reached equilibrium within 45 minutes.The adsorption capacity under acidic and weakly alkaline conditions was higher than that of strongly alkaline conditions.According to the analysis of kinetic model,Langmuir and Freundlich model,the theoretical adsorption capacity of CP5A/BT to OIV reached 230.4247 mg·g^(−1),and the pseudo-second-order kinetics and Freundlich isotherm model could better fit the adsorption process of CP5A/BT to OIV.This adsorption process is mainly chemical adsorption.CP5A/BT adsorbent has excellent adsorption-regeneration properties.