多级孔ZSM-5分子筛对亚甲基蓝的吸附性能

以多级孔ZSM-5分子筛为吸附剂,吸附水中的亚甲基蓝（MB）,考察了吸附条件对吸附效果的影响,并探讨了吸附的热力学和动力学特征。实验结果表明：在溶液pH为11、分子筛加入量为800 mg/L、吸附温度为303.15 K、吸附时间为60 min、初始MB质量浓度为20 mg/L的条件下,该分子筛对MB的吸附率达97%;溶液pH为5~12时,吸附率均达89%以上,说明该分子筛具有宽的pH适应范围;该分子筛对MB的吸附热力学符合Langmuir和Freundlich方程,293.15~313.15 K的饱和吸附量达50.51~62.11 mg/g,吸附为吸热、自发过程;吸附动力学符合拟二级动力学方程。

Adsorption of methylene blue on hierarchically porous ZSM-5 molecular sieve

The hierarchically porous ZSM-5 molecular sieve was used as to adsorb methylene blue（MB）in water. The effects of adsorption conditions on adsorption were investigated,and the adsorption thermodynamics and kinetics characteristics were also discussed. The experimental results show that：Under the conditions of solution pH 11,molecular sieve dosage 800 mg/L,adsorption temperature 303.15 K,adsorption time 60 min and initial MB mass concentration 20 mg/L,the adsorption rate of MB on the molecular sieve is up to 97%;when the solution pH is 5-12,the adsorption rates are all above 89%,which indicates that the molecular sieve has a wide adaptation range of pH;The adsorption thermodynamics of methylene blue on the molecular sieve follows the Langmuir and Freundlich adsorption equation,the adsorption capacity reaches 50.51-62.11 mg/g at 293.15-313.15 K,and the adsorption process is endothermic and spontaneous;The adsorption kinetics fits the pseudo-second-order kinetic model.