壳聚糖-g-聚丙烯酸/海泡石复合物对Pb^(2+)的去除性能研究  

Adsorption of Pb^(2+) onto Chitosan-Grafted-Poly (Acrylic Acid)/Sepiolite Composite

作　　者：郑易安[1] 谢云涛[1,2] 王爱勤[1] 

机构地区：[1]中国科学院兰州化学物理研究所,兰州730000 [2]中国科学院研究生院,北京100049

出　　处：《环境科学》2009年第9期2575-2579,共5页Environmental Science

基　　金：国家自然科学基金项目(20877077);甘肃省科技支撑项目(0804GKCA03A)

摘　　要：制备了一种壳聚糖接枝聚丙烯酸/海泡石复合吸附剂,考察了吸附剂对Pb2+吸附的pH依赖性、吸附等温线、吸附动力学以及吸附剂的重复使用性能.结果表明,聚丙烯酸成功接枝到壳聚糖骨架上,形成有机-无机复合吸附剂.吸附剂表面呈现粗糙多孔、凹凸不平的形貌,有利于吸附体系更快达到吸附平衡.在pH=6.00、吸附时间30 min、Pb2+溶液初始浓度0.02 mol.L-1和吸附剂用量0.10 g的条件下,复合吸附剂对Pb2+的平衡吸附量达到638.9 mg.g-1,约为海泡石的3倍.重复吸附-脱附5次,复合吸附剂对Pb2+的吸附量下降到489.2 mg.g-1,仍可达初始吸附量的76.6%,而海泡石使用3次之后即对Pb2+丧失吸附性能.与海泡石相比,复合吸附剂具有更高的吸附容量、更快的吸附速率和更好的重复使用性能.A composite adsorbent chitosan-grafted-poly（acrylic acid）/sepiolite was prepared,and its pH-dependence for removing Pb^2＋,as well as adsorption isotherm and kinetics were estimated.The results indicate that poly（acrylic acid） has been grafted onto the backbone of chitosan,forming an organic-inorganic composite adsorbent.As-prepared adsorbent shows a coarse,porous and accidented surface,which can contribute to its adsorption kinetics.Under the conditions of pH 6.00,contact time of 30 min,initial Pb^2＋ concentration of 0.02mol·L^-1 and amount of adsorbent of 0.10 g,the adsorption capacity of developed adsorbent for Pb^2＋is found to be 638.9mg·g^-1 about three times than that of sepiolite.When five cycles of adsorption-desorption process were carried out,the adsorption capacity decreased to 489.2mg·g^-1 76.6% to its original adsorption capacity.However,when sepiolite was used as the adsorbent,no sorption can be observed after three cycles of adsorption-desorption process.Compared to sepiolite,this composite adsorbent presents higher adsorption capacity,faster adsorption rate and better reusable ability

关 键 词：复合吸附剂 海泡石 壳聚糖 铅 吸附 

分 类 号：X703.1[环境科学与工程—环境工程]