摘要
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Cd^(2+)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 nnm,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,Cd^(2+)去除率均大于94%。粉煤灰沸石对Cd^(2+)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Cd^(2+)的饱和吸附量为49.261 mg/g。
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 A1, 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 Cd^2+ is more than 94%. The adsorption of Cd^2+ 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 ofthe saturated adsorption capacity, which indicates that the reaction is a process ofmonolayer adsorption and mostly chemical adsorption.
出处
《化工环保》
CAS
CSCD
北大核心
2015年第5期547-551,共5页
Environmental Protection of Chemical Industry
基金
国家环保部公益性行业科研专项项目(200909032)
内蒙古科技大学创新基金项目(2011NCL022)
关键词
粉煤灰沸石
铬离子
吸附
碱熔融
微波
fly-ash zeolite
chromium ion
adsorption
alkali fusion
microwave