PAA/SiO_2材料对含铜废水吸附性能研究  

Adsorption Properties of Poly(allylamine)-Grafted Silica Gel for Adsorbing Cu^(2+) Ions from Aqueous Solution

作　　者：范忠雷[1] 刘海龙[1] 慎金鸽[1] 

机构地区：[1]郑州大学化工与能源学院,河南郑州450001

出　　处：《高校化学工程学报》2012年第4期679-684,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：河南省重点科技攻关计划项目(112102210237);郑州大学研究生教育支持基金

摘　　要：以γ-氯丙基三甲氧基硅烷为偶联剂,将聚烯丙基胺(PAA)接枝到硅胶表面,合成了聚烯丙基胺硅胶材料(PAA/SiO2),研究了其对Cu2+的吸附热力学、动力学和选择特性。结果表明,合成的PAA/SiO2材料的胺基含量为1.81mmol g 1;溶液pH值对PAA/SiO2的铜吸附量影响显著,当溶液pH值为4时,材料的铜吸附量达到0.397 mmol g 1;测定的Cu2+吸附平衡数据符合Langmuir模型,计算了吸附过程的热力学参数,结果表明吸附过程为吸热过程,升温有利吸附的进行;吸附动力学数据可用拟二级吸附动力学方程描述,得到的吸附速率常数与溶液初始浓度有关;铜锌竞争吸附结果表明PAA/SiO2材料对Cu2+有更强的吸附能力,对铜的选择性系数在2~4之间;另外,PAA/SiO2材料容易洗脱再生,5次吸附再生循环后,其铜吸附量维持在91.1%以上。Poly（aUylamine）-grafled silica gel （PAA/SiO2） with amino group content of 1.81 mmol.g-1 was synthesized by using γ-chloropropyltrimethoxysilane as coupling reagent and poly（allylamine） as surface-modifying reagent. The thermodynamics, kinetics and selectivity of Cu^2＋ adsorption by prepared PAA/SiO2 were studied. The experimental results show that the pH value of Cu^2＋ solution affects the adsorption capacity of the PAA/SiO2 significantly, and its adsorption capacity for Cu^2＋ at pH=4.0 is 0.397 mmol.g^-1. The measured adsorption equilibrium data for Cu^2＋ could fit the Langmuir model well. The calculated results of Cu^2＋ adsorption thermodynamic parameters of PAA/SiO2 show that the Cu^2＋adsorption is endothermic spontaneous process, and increasing temperature is conductive to the Cu2＋ adsorption. It was found that the adsorption kinetic data could be fitted by the pseudo-second-order kinetic equation, and the fitted kinetic constants are related with the initial solution concentration. The results of its selectivity study show that the PAA/SiO2 possesses recognizing ability for Cu^2＋ and its selectivity coefficient is about 2-4 in relation to Cu^2＋. Besides, the synthesized PAA/SiO2 is easy to be regenerated and can still maintain up to 91.1% of its initial Cu^2＋ adsorption capacity after five adsorption-regeneration cycles.

关 键 词：聚烯丙基胺硅胶材料 聚烯丙基胺 吸附 CU2+ 

分 类 号：O647.3[理学—物理化学] TQ424.26[理学—化学]