微波-CTMAB膨润土吸附除磷的动力学和热力学研究  

Study on Kinetics and Thermodynamics of Phosphorus Adsorption onto CTMAB Modified Bentonite Enhanced by Micorwave

作　　者：宋珍霞[1] 郑伏安 徐建平[1] 蔡昌凤[1] 

机构地区：[1]安徽工程大学生物与化学工程学院,安徽芜湖241000

出　　处：《非金属矿》2016年第1期27-30,共4页Non-Metallic Mines

基　　金：国家自然科学基金(51274001);安徽省高校省级自然科学研究项目(KJ2011B009);安徽省大学生创新创业训练计划项目(AH201410363230)

摘　　要：通过静态实验,考察了在不同反应时间和温度条件下,原膨润土(OB)、CTMAB改性膨润土(CTMABB)以及微波-CTMAB协同改性膨润土(MCTMABB)对PO43-吸附效果的影响;对3种材料除磷的吸附动力学、吸附速率控制步骤以及吸附热力学模型进行了拟合并计算出相应参数。结果表明,吸附反应15 min(25℃),OB、CTMABB及MCTMABB对PO43-的吸附基本达到平衡,其吸附容量分别达到2.27、3.50和4.88 mg/g。伪二级动力学方程可以很好地描述3种材料对PO43-的吸附(R2>0.99);Elovich方程中的α值大小表现为:αOB<αCTMABB<αMCTMABB,表明膨润土经CTMAB和CTMAB-微波协同改性后其对PO43-的吸附效率依次增强。3种材料对PO43-的吸附反应均受液膜扩散和颗粒内扩散2个步骤控制。3种材料对PO43-的吸附反应均是自发的放热反应,温度升高均不利于3种材料对PO43-的吸附。The adsorption effect of phosphate from aqueous solutions onto original bentonite（OB）, CTMAB bentonites（CTMABB） and microwave-CTMAB bentonites（MCTMABB） under different reaction time and temperature was studied in a batch reactor. The kinetics dynamics, rate controlling step as well as the thermodynamics of phosphate adsorption from aqueous solutions onto the above 3 kinds of adsorption materials was investigated. The results showed that the adsorption equilibrium of the 3 kinds of materials was basically reached within 15 min at 25 ℃, and the phosphate adsorption capacity of OB, CTMABB and MCTMABB were 2.27, 3.50 and 4.88 mg/g, respectively. The phosphorus adsorption on OB, CTMABB and MCTMABB was found to follow pseudo second-order kinetic model well（R^2〉0.99）. The α value of Elovich equation was： αO〈B αCTMABB 〈αMCTMABB, which indicated that the adsorption capacity of phosphate on bentonite could be enchanced orderly by CTMAB modification and the synergistic modification effect of microwave and CTMAB. The adsorption reaction of 3 kinds of materials was controlled by liquid film diffusion and intra-partical diffusion. And also it was a process which was spontaneous and exothermic, therefore, raising temperature was unbeneficial to the adsorption reaction.

关 键 词：微波-CTMAB膨润土 PO43- 吸附动力学 速率控制步骤 吸附热力学 

分 类 号：X703[环境科学与工程—环境工程] TD985[矿业工程—选矿]