改性蔗渣纤维对稀土离子吸附特性研究  

Adsorption of Rare Earth Ions on Modified Bagasse Cellulose

作　　者：张红云[1] 杨慧珠[1] 薛印 程乾坤 石太宏[1] 

机构地区：[1]中山大学环境科学与工程学院,广州广东510006

出　　处：《中国稀土学报》2017年第2期231-237,共7页Journal of the Chinese Society of Rare Earths

摘　　要：为了提高甘蔗渣的吸附量,通过均苯四甲酸二酐(PMDA)改性蔗渣纤维制备PMDA-SCB以提高其吸附回收稀土离子的能力。FTIR和SEM表征分析,蔗渣纤维表面接枝了大量的羧基基团,为吸附目标离子提供大量的活性位点。实验结果表明:pH值对吸附剂吸附效果影响较大,最佳pH值为6。PMDA-SCB对La^(3+),Gd^(3+),Y^(3+)的Langmuir等温吸附量分别为74.85,88.90和43.30 mg·g^(-1),是未改性蔗渣SCB的9.2,9.1和10倍。准二级动力学方程能更好地描述吸附方程,其R2大于0.999。PMDA-SCB经过4次吸附解析循环后,其吸附量降低率比较少,说明PMDA-SCB能有效去除并回收废液中的稀土离子。Pyromellitic dianhydride（PMDA） modified sugar cane bagasse（SCB） was prepared to improve its adsorption capacity for rare earth ions. The adsorbent was characterized by FTIR and SEM. Due to the presence of a large number of carboxyl groups the bagasse provides PMDA-SCB a large number of active site for target ions adsorption. The results showed that pH had a great influence on adsorption capacity. Modified SCB had the maximum adsorption capacity at pH = 6. Experimental results showed the adsorption capacities of PMDA-SCB for La3＋,Gd3＋and Y3＋were 74. 85,88. 90 and 43. 30 mg·g-1respectively,which were 9. 2,9. 1 and 10 times as amount as the unmodified bagasse,according to Langmuir equation. Kinetic studies showed better correlation coefficients（R2〉0. 999） for a pseudo-second-order kinetic model,confirming that the sorption rate was controlled by a chemisorption process. After 4 adsorption-desorption cycles,its adsorption capacity showed a slight decrease,implying that PMDA-SCB can be used as an effective adsorbent for the removal and recovery of La3＋,Gd3＋and Y3＋from aqueous solution.

关 键 词：蔗渣纤维 改性 吸附 稀土离子 La3+ Gd3+ Y3+ 

分 类 号：O647.33[理学—物理化学]