Li Xiaohong, Zhu Kun, Hao Xuekui
School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, 88 Anning Road West, Lanzhou, China.
Water Sci Technol. 2009;60(2):329-37. doi: 10.2166/wst.2009.315.
The surface of zeolite was modified by cationic beta-cyclodextrin (CCD), which was synthesized with 2, 3-epoxypropyltrimethylammonium chloride (ETMAC) and beta-cyclodextrin (beta-CD), to prepare a novel and effective sorbent for removal of p-nitrophenol (p-NP) from aqueous solution. FTIR, SEM and EDS were used to characterize the surface modification. It was found that CCD, which was synthesized at different conditions such as the mole ratio of ETMAC against beta-CD and pH, made an impact on sorption capacity of p-NP on CCD-modified zeolite (CCDMZ). Given ETMAC: beta-CD = 7:1 and pH = 13, the cationic process of beta-CD might be optimum for CCD to bond to zeolite surfaces. In addition, CCD concentration and modification time affected sorption capacity of p-NP on CCDMZ too. The sorption of p-NP on CCDMZ, activated zeolite (AZ) and natural zeolite (NZ) was investigated by contact time, initial p-NP concentration and sorption isotherms with the batch sorption experiments. The results showed that the sorption of p-NP on CCDMZ satisfactorily fitted the known Langmuir model and the sorption capacity of CCDMZ was higher than that of AZ and NZ although the contact time of CCDMZ appeared to be shorter than other two.
用2,3-环氧丙基三甲基氯化铵（ETMAC）和β-环糊精（β-CD）合成的阳离子β-环糊精（CCD）对沸石表面进行改性，以制备一种新型高效的吸附剂，用于从水溶液中去除对硝基苯酚（p-NP）。采用傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和能谱仪（EDS）对表面改性进行表征。研究发现，在不同条件（如ETMAC与β-CD的摩尔比和pH值）下合成的CCD对p-NP在CCD改性沸石（CCDMZ）上的吸附容量有影响。当ETMAC:β-CD = 7:1且pH = 13时，β-CD的阳离子化过程可能最有利于CCD与沸石表面结合。此外，CCD浓度和改性时间也会影响p-NP在CCDMZ上的吸附容量。通过分批吸附实验，研究了接触时间、初始p-NP浓度和吸附等温线对p-NP在CCDMZ、活化沸石（AZ）和天然沸石（NZ）上的吸附情况。结果表明，p-NP在CCDMZ上的吸附符合已知的朗缪尔模型，尽管CCDMZ的接触时间比其他两者短，但其对p-NP的吸附容量高于AZ和NZ。
