摘要
利用扫描电镜对离心法、水热反应法和回流法制备的ZnO-ZnAl水滑石(ZZA)进行了表征分析,发现了其明显的正六边形结构。通过静态批次实验考察了ZZA吸附磷酸盐的吸附动力学、吸附等温线和吸附热力学。结果表明,吸附分两个阶段,前10 h发生快速吸附,10 h后发生慢速吸附,其对磷的去除率稳定在55.68%,符合伪二级动力学模型;在15,25,35℃的吸附环境下的最大磷吸附容量分别为30.54,32.40,33.54 mg/g,表明吸附过程是一个吸热反应,符合Langmuir模型方程,吸附过程是均质表面单分子层化学吸附;热力学指标分析表明,该吸附过程是一个自发的、吸热的和熵量增加的过程。ZZA对磷酸盐去除率可以达到70%,吸附效果要好于钠基改性膨润土、煤渣、沸石。
By using scanning electron microscopy analysis the ZnO-ZnAl hydrotalcite（ ZZA） that prepared by centrifugation,hydrothermal reaction and refluxing method. It is found that the hexagonal structure is obvious. The adsorption kinetics,adsorption isotherms and adsorption thermodynamics of ZZA adsorbed phosphate were investigated by static batch experiments. Results show that,the adsorption was divided into two stages,the first 10 h was adsorbed rapidly,and the slow adsorption occurred after 10 h,phosphorus removal rate steady at 55. 68%,pseudo-second-order kinetic model. At 15,25,35 ℃,the maximum phosphorus adsorption capacity of the adsorption of environment were 30. 54,32. 40,33. 54 mg/g,showed that the adsorption is an endothermic reaction,consistent with the Langmuir model equation,the adsorption process is a homogeneous surface monomolecular layer chemisorptions. Thermodynamic analysis shows that,the adsorption process is a spontaneous,endothermic and entropy increasing process. The phosphate removal rate of ZZA can reach 70%,the adsorption effect is better than sodium base bentonite,coal cinder,zeolite.
出处
《应用化工》
CAS
CSCD
北大核心
2017年第10期1888-1893,共6页
Applied Chemical Industry
基金
国家自然科学基金项目(51168013)
江西省自然科学基金资助项目(20132BAB203033)
关键词
水滑石
吸附
磷酸盐
hydrotalcite
adsorption
phosphate
