摘要
废水中的Ag胶体对生态环境造成了危害,但很少有将其从水中去除的研究。本研究基于Fe^3+与树脂D001以静电吸引为驱动的阳离子交换技术,制备负载Fe^3+的改性氧化性树脂样品,X射线荧光光谱分析(X-ray Fluorescence,XRF)测试表明D001型树脂中Na+离子被Fe^3+完全取代。利用该改性树脂对Ag胶体进行静态吸附试验研究,结果表明:在中性条件下,6.67mg·mL^-1改性树脂对20×10^-6Ag胶体去除率可达92.5%,吸附过程在6h后达到动态平衡,且该吸附过程符合Langmuir等温吸附模型以及准二级动力学方程。X射线光电子能谱分析(X-ray Photoelectron Spectroscopy,XPS)分析证明吸附过程是氧化还原反应和离子交换的协同作用,先是改性树脂将Ag胶体氧化成Ag+,同时Fe^3+被还原为Fe^2+,接着通过离子交换将Ag+吸附,最终实现水溶液中Ag胶体的去除。
[Background] Ag colloids is a hazard to the environment, but little attention has been paid to the research on its removal from waste water.[Purpose] This study aims to make a Fe^3+ modified resin for removing Ag colloids from aqueous solution, and to investigate its adsorption behavior on Ag colloids.[Methods] The adsorption behavior of Ag colloids on the modified resin was studied by dynamic tests, and it was used as a function of pH value, adsorbent dosage, adsorption time and initial concentration. Both the X-ray fluorescence (XRF) and the X-ray photoelectric spectroscopy (XPS) were employed to test the effect of this approach.[Results] In the batch adsorption experiment of Ag colloids, under neutral conditions, the removal efficient of Ag in 20×10^-6 solution of modified resin of 6.67 mg·mL^-1 was up to 92.5%, and the adsorption process reached dynamic equilibrium in 6h.[Conclusions] The adsorption process agreed to the typical Langmuir model and the pseudo-second-order kinetic model. XRF result showed that Na+ existing in the D001 resin was totally exchanged by the Fe^3+. XPS analysis indicated that the modified resin was decorated to Ag+, Fe^3+ and Fe^2+ after absorbing the Ag collide solution. Apparently, Ag was oxidized to Ag+ and Fe^3+ was reduced to Fe^2+ in the adsorption process, which implied that the adsorption mechanism was ion exchange.
作者
顾恩熙
付凌霄
王焕
GU Enxi;FU Lingxiao;WANG Huan(School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
出处
《核技术》
CAS
CSCD
北大核心
2019年第7期25-31,共7页
Nuclear Techniques
基金
国家自然科学基金(No.11675103)资助~~
