细菌纤维素负载纳米Fe_3O_4的制备及其吸附Cd^(2+)的研究  

Preparation of immobilized nano-Fe_3O_4 on bacterial cellulose and its adsorptive property for Cd^(2+)

作　　者：鲁敏[1,2] 关晓辉[2] 魏德洲[1] 

机构地区：[1]东北大学资源与土木工程学院,沈阳110004 [2]东北电力大学化学工程学院,吉林吉林132012

出　　处：《安全与环境学报》2011年第5期22-25,共4页Journal of Safety and Environment

摘　　要：为提高细菌纤维素(BC)处理含重金属离子废水的效果,以BC和纳米Fe_3O_4为原料,采用共混沉淀法制备了新型的BC负载纳米Fe_3O_4吸附剂(NFBC)。同时将制得的NFBC用于吸附重金属离子Cd^(2+)研究,考察了溶液pH值、吸附时间等因素对吸附效果的影响,并进一步模拟吸附动力学和吸附等温线,初步分析了吸附机理。结果表明:利用纳米Fe_3O_4比表面积大和表面原子配位不足的特点,将其负载于BC表面,提高了对Cd^(2+)吸附,去除率可达70%,单位吸附量最大为27.97 mg/g;pH值是影响NFBC对Cd^(2+)吸附效果的重要参数;吸附动力学符合二级反应动力学,吸附平衡符合Langmuir吸附等温方程,并具有良好的线性,说明NFBC对Cd^(2+)是典型的单分子层吸附;在外加磁场作用下,纳米Fe_3O_4粒子超顺磁性有助于吸附剂能快速有效地从液相分离,克服了BC粉末难于有效分离的不足。The given paper is aimed at presenting our research results on the preparation of nano-Fe3O4 immobilized on bacterial cellulose and its adsorption property of Cd2 ＋. For our research purpose, we have prepared new adsorbents of nano-Fe3O4 immobilized on bacterial cellulose （NFBC） via blending method in hoping to improve the prop- erty of sewage with heavy metal ions. At the same time we have tried a new adsorbent of NFBC to remove the heavy metal Cd2.. In addi- tion, we also have investigated the effect of such characteristic pa- rameters as pH, adsorption time etc. by simulating the adsorptive ki- netics and adsorptive isotherms so as to supply theoretic evidence for the application of our research results. Furthermore, we have also studied the adsorptive property and mechanism of the adsorbent to Cd2 ＋. The results of our research prove that based on the features of huge surface area and lack of surface coordination of nano-Fe304 par- ticles, the immobilization of BC with Fe3O4 is actually favorable for heightening their adsorption effect. reach 74% with the average unit The removing rate can be made to maximum adsorption being 27.97 mg/g. In addition, it is necessary to point out that pH is a key pa- rameter to increasing of the adsorption efiqciency. The highest removing rate of Cd2 ＋ by NFBC could be elevated when the mass ratio of nano-Fe304 to BC was 1 ： 2. Furthermore the removal rate of Cd2＋ can be increased to 64% in a time range of 0 - 10 rain. Besides, with the prolonging of adsorbing time, the removal rate tends to in- crease slowly. That is to say, when it reached 45min, the removal rate of Cd2 ＋ would become equilibrium. In addition, the pseudo-sec- ond rate model and the adsorption equilibrium model can be described by using adsorption kinetics in accordance of the Langmuir isotherm adsorption equation to prove its linear nature ,＂ which helps to describe the typical single-molecule layer adsorption of NFBC for Cd2＋. Under the condition of magnetic field, the of nano- Fe3O4 part

关 键 词：复合材料 纳米n3吼 细菌纤维素 负载 Cd2+ 

分 类 号：TQ342.86[化学工程—化纤工业]