碱熔融—微波晶化法合成粉煤灰沸石及其对Cd2+的吸附

以粉煤灰为主要原料，采用碱熔融—微波晶化法合成粉煤灰沸石。采用XRD，SEM，TEM等技术表征了粉煤灰沸石的微观结构，并对其吸附Cd²⁺的性能进行了研究。表征结果显示，粉煤灰沸石主要由X型沸石、P型沸石和铝组成，粉煤灰沸石中有排列规则、呈蜂窝状的孔穴和孔道存在，其孔穴和孔道大小分布均匀，致密。粉煤灰沸石的比表面积为108.49 m²/g，平均孔径为3.779 nm，孔体积为0.221 mL/g。实验结果表明，在溶液pH为7、吸附时间30 min的最佳吸附条件下，Cd²⁺去除率均大于94%。粉煤灰沸石对Cd²⁺的吸附可很好地用二级动力学方程进行拟合，相关系数为0.999 99。可用Langmuir等温吸附模型描述该吸附过程，该吸附过程是单分子层吸附，主要是化学吸附，粉煤灰沸石对Cd²⁺的饱和吸附量为49.261 mg/g。

Synthesization of Fly-Ash Zeolite by Alkali Fusion-Microwave Crystallization Process and Adsorption to Cd2+

Fly-ash zeolite was synthesized by alkali fusion-microwave crystallization process using fly ash as raw material,and characterized by XRD,SEM and TEM. Its adsorption capability to Cd²⁺ was also studied. The characterization results indicate that：The prepared fly-ash zeolite mainly consist of X type and P type zeolite and Al,and is full of uniform and regular holes and pores;The specific surface area,average size and pore volume of the fly-ash zeolite are 108.49m²/g,3.779 nm and 0.221 mL/g,respectively. The experimental results show that under the optimum adsorption conditions of solution pH 7 and adsorption time 30 min,the adsorption rate of Cd²⁺ is more than 94%. The adsorption of Cd²⁺ by fly-ash zeolite fits the secondary reaction kinetics equation with 0.999 99 of correlation coefficient. The adsorption process can be described by Langmuir isothermal adsorption model with 49.261 mg/g of the saturated adsorption capacity,which indicates that the reaction is a process of monolayer adsorption and mostly chemical adsorption.