PBMA/GMA-SiO_2吸附剂的制备及其高效去除铅离子  

Preparation of PBMA /GMA-SiO_2 Adsorbent and Its Efficient Removal of Lead Ions

作　　者：王芳平[1] 张珺瑛[1] 李晚霞[1] 袁婷[1] 郑文芳[1] 王其召[1] 杜新贞[1] 

机构地区：[1]甘肃省生物电化学与环境分析重点实验室,省部共建生态环境相关高分子材料教育部重点实验室,西北师范大学化学化工学院,甘肃兰州730070

出　　处：《精细化工》2014年第4期486-492,共7页Fine Chemicals

基　　金：国家自然科学基金资助项目(21065010;51262028)~~

摘　　要：以甲基丙烯酸丁酯（BMA）和甲基丙烯酸缩水甘油酯（GMA）功能化的纳米SiO2为单体，通过可逆加成一断裂链转移自由基聚合（RAFT）法制备了PBMA／GMA—SiO2有机／无机复合吸附材料，并将其用于吸附含Pb2＋的水溶液。考察了吸附时间、温度、pH以及Pb2＋初始质量浓度对吸附效果的影响，并对其吸附动力学和热力学特性进行了探讨。结果表明，PBMA／GMA—SiO2对Pb2＋具有良好的吸附性能，其对Pb2＋的饱和吸附量为423．84mg／g，吸附最佳pH=5—6，平衡时间为1h，去除率随Pb2＋初始质量浓度的减小而增加。优化实验条件下，50mg吸附剂在298K时，对pH=6的50mL0．02g／L含Pb2＋溶液的去除率高达100％。热力学和动力学过程模拟结果表明，吸附的动力学过程比较符合准二级动力学速率方程，Langmuir等温方程比Freundlich等温方程更适合于描述此吸附行为。颗粒内扩散过程是吸附速率的控制步骤，但不是唯一的速率控制步骤。吸附剂经过5次脱附、吸附后，依然具有较强吸附Pb2＋的能力。PBMA/GMA-SiO2 adsorbent was synthesized via RAFT polymerization using butylmethacrylate（BMA） and GMA-functionalized silica particles as monomers. The effects of pH, contact time and initial Pb2＋ concentration on adsorption properties were evaluated,and the adsorption thermodynamics and kinetics were also examined. The results show that the PBMA/GMA-SiO2 adsorbent was effective for Pb2＋ removal from water, and the maximal adsorption capacity for Pb2＋ was found to be 423.84 mg/g, the optimum pH value for Pb2＋ removal was 5 to 6, and absorption time was 1 h. The removal efficiency increased with the decreasing of initial Pb2＋concentration. Under optimized conditions,50 mg sorbent could remove 100% of Pb2＋ from 50 mL 0. 02 g/L Pb2＋ solution at pH = 6 and 298 K. The adsorption kinetics could be best described by pseudo second-order kinetic model. Compared with the Freundlich isotherm equation, the Langmuir isotherm equation is more appropriate to describe the adsorption behavior. The adsorption rate is not only controlled by intra-particle diffusionbut also by extra-particle diffusion. Besides, the materials still show good adsorption capacity for Pb2＋ after five times of desorption and adsorption.

关 键 词：Pb2+吸附 动力学 功能材料 水处理技术与环境保护 

分 类 号：TQ424.26[化学工程]