不同改性方法对沸石吸附对硝基苯酚能力的影响

利用酸改性、热活化、有机改性及联合改性等方法对沸石进行改性,制备了不同种类的改性沸石。通过紫外分光光度法对这些改性沸石吸附对硝基苯酚的能力进行检测,并用扫描电镜及X射线衍射对改性沸石的结构进行表征,着重比较改性过程中酸改性和灼烧改性实施顺序不同对沸石吸附能力的影响。结果表明,与500℃灼烧相比,900℃灼烧对沸石吸附能力的提高更为明显,但对沸石的结构有所破坏。酸改性可以去除沸石所携带的大量杂质,使孔道的连通性更好,从而使酸改性沸石对对硝基苯酚的吸附能力比灼烧改性沸石高。未经酸洗涤的沸石中所含杂质可能会在灼烧过程中对沸石的结构产生影响,先采用酸改性再结合热活化的方式对沸石进行改性比较合适。酸改性＋热活化（500℃）后再与有机改性结合,可以使改性沸石对对硝基苯酚吸附量大大增加。不同改性沸石的吸附能力依次为：有机改性沸石〉酸热联合改性沸石〉酸改性沸石〉灼烧（500℃）改性沸石〉天然沸石。

Effects of Different Modification Methods on Adsorption Capacity of Zeolite to P-Nitrophenol

Different kinds of modified zeolite were prepared by several methods,such as acid modification,heat modification,acid heat joint method,and organic modification.Organic zeolite was made by loading Cetyltrimethyl Ammonium Bromide（CTMAB）after acid heat joint pre-activation.Structures of the different modified zeolite were characterized by SEM and XRD,and the adsorption capacities of modified zeolite were tested.Effects of different order applying acid and heat modification on the modified process on adsorption capacity were studied.The results indicated that,compared with 500 ℃ calcination,900 ℃ calcination process got higher adsorption capacity of zeolite,but destroyed the structure of zeolite.Acid modification method had significant effects on removing impurities carried by zeolite,which developed connectivity within pores and improved the adsorption capacity of P-Nitrophenol significantly.It was proved that acid modification zeolite had better absorption capacity than calcined zeolite.It was shown that the impurities contained in zeolite without acid washing might change the zeolite structure during the calcination process.Accordingly it was more appropriate by using acid modification process first,combined with heat modification to activate zeolite.It was also proved that modified zeolite by utilizing organics modification process after acid heat（500 ℃）joint pre-activation could largely improve the adsorption capacity of P-Nitrophenol.The absorption capacity of modified zeolites could be ranked in order of most to least effective as follows：organic zeoliteacid heat joint modified zeoliteacid modified zeolite 500 ℃ calcined zeolitenatural zeolite.