CIESC Journal ›› 2019, Vol. 70 ›› Issue (S1): 130-140.DOI: 10.11949/j.issn.0438-1157.20181339

• Separation engineering • Previous Articles     Next Articles

Formation of framework supported pore for PVA/ZnO composite and Pb(Ⅱ) adsorption

Sheng XU(),Lingli LIU,Meng CAO,Shangxi ZHANG,Xin DAI,Yang LIU,Zhenxi WANG   

  1. 1. College of Sciences, Nanchang Institute of Technology, Nanchang 330099, Jiangxi, China
  • Received:2018-11-15 Revised:2018-12-25 Online:2019-03-31 Published:2019-03-31
  • Contact: Sheng XU

PVA/ZnO复合材料“骨架支撑”型孔道构建及铅离子吸附

徐胜(),刘玲利,曹锰,张尚玺,戴欣,柳阳,王振希   

  1. 1. 南昌工程学院理学院, 江西 南昌 330099
  • 通讯作者: 徐胜
  • 作者简介:徐胜(1987—),男,博士,讲师,<email>xs2953@163.com</email>
  • 基金资助:
    国家自然科学基金项目(51303074, 21702090, 21706113)

Abstract:

PVA/tetra-ZnO composite was prepared by in-situ chemical crosslinking reaction which was used as the absorbent of Pb(II) in waste water. The FTIR and TGA results indicated the successful grafting of APTES on the tetra-ZnO particles surface and the tetra-ZnO particles dispersed uniformly after modification. A special “framework supported” structure was formed around the pore-channel wall of PVA/tetra-ZnO composite due to the interlocking characteristic of the tetra-ZnO particle s four whisker arms and which was beneficial for the diffusion and adsorption of heavy metal ions solution. The Pb(II) adsorption capacity reached to the maximum at 7% tetra-ZnO content, and the adsorption effect was most significant at pH 4.0. Contrary to the distribution of pore size, the absorbed Pb(II) on PVA/tetra-ZnO composite was graded distribution from the out to inside with a gradual decease trend. The Langmuir model was better fitted the Pb(II) adsorption isotherm process which revealed the homogeneous monolayer adsorption mechanism. The adsorption kinetics indicated the stepwise adsorption process due to the perfect fitting degree of pseudo-first-order model as well the pseudo-first-order model. The intraparticle diffusion kinetics model indicated that the chemical adsorption and intraparticle diffusion played the important role during the whole adsorption process. Besides, the stress stability and thermo stability of PVA/tetra-ZnO composites were improved than neat PVA.

Key words: gel, tetrapod-shaped ZnO whiskers, framework supported structure, heavy metal ions, adsorption, stability

摘要:

通过原位共交联方法制备了多孔型PVA/tetra-ZnO(聚乙烯醇/四针状氧化锌)复合材料作为废水中Pb(II)的脱除吸附剂,研究发现,由于tetra-ZnO四条晶须臂具有互锁特性使其孔壁处形成了“骨架支撑”型孔道结构,从而有利于Pb(II)的传输扩散和吸附络合。复合材料在tetra-ZnO含量为7%时具有最大Pb(II)吸附量,随pH增大,吸附量逐渐增大,复合材料的吸附效应在pH为4.0左右时最为明显。与复合材料的孔径分布相反,吸附的Pb(II)在复合材料中由外至内呈逐渐递减的梯度分布。等温吸附线表明Langmuir模型具有更好的拟合性,其吸附机理为单分子层均质吸附。动力学过程拟合表明其吸附分多步进行,化学吸附和内扩散均具有重要作用。与纯PVA相比,复合材料的应力吸附稳定性和热稳定性得到大幅提高。

关键词: 凝胶, 四针状ZnO晶须, “骨架支撑”结构, 重金属离子, 吸附, 稳定性

CLC Number: