24小时热门版块排行榜

返回列表

当前主题已经存档。

当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

danmong

木虫 (小有名气)

应助: 2 (幼儿园)
金币: 553.7
散金: 156
红花: 3
帖子: 294
在线: 57小时
虫号: 176028
注册: 2006-02-04
性别: GG
专业: 环境工程

[交流] [欢迎讨论] 最新EST中选择性吸附分离Cd和Ni离子

是HKUST的科学家研究的。主要目的是分离回收电池中的Cd和Ni离子。
比较有意思的在于选择性分离Cd和Ni离子；和我们平时所见不一样，他们利用嫁接氨基改性后的MCM结合Ni和Cd离子。在选择性分离中，他们使用到了EDTA。
利用EDTA和Cd、Ni离子结合性能的不同，一个能够结合形成阴离子络合物；一个不易结合，仍然是阳离子。再通过改变pH值，使得氨化的MCM或者带正电或者不带电。在带正电的情况下能够通过静电作用结合阴离子络合物；在不带电的时候能够让－NH2作为络合基团结合阳离子。从而，pH不同，Cd和Ni离子就能分开。
这篇文章我觉得最有意思的在于这个选择性的非常规实现。很有新鲜感。

【提议】大家以后能够一起分享自己在阅读中看到的文献吗？觉得有意思的，有创新的都可以讨论讨论。我看到别的讨论区经常会分享一些最新的文章。

摘要链接：http://pubs.acs.org/cgibin/abstr ... /abs/es062370e.html
Efficient Approach for Cd2+ and Ni2+ Removal and Recovery Using Mesoporous Adsorbent with Tunable Selectivity
Abstract:

Cadmium pollution from the manufacture and disposal of NiCd batteries remains an important problem in developing countries. Among the available remedial technologies, adsorption is popular because of its low cost and simplicity. The mesoporous NH2-MCM-41 displays good adsorption capacities for cadmium and nickel ions. This work demonstrated for the first time the use of the competition between complexant and sorbent to create high adsorption selectivity. The selectivity was manipulated by the judicious use of a chelating agent, thus achieving on-demand 100% selectivity for either Cd2+ or Ni2+ adsorption. Single and binary components adsorption studies, carried out with different metals and EDTA concentrations, solution compositions and pH, showed that NH2-MCM-41 adsorbs only cadmium with a capacity of 0.56 mmol g-1 from binary mixtures at [EDTA]/[M2+] = 0.5 and pH 5. The NH2-MCM-41 displays 100% selectivity for nickel adsorption at [EDTA]/[M2+] = 0.5 and pH 2 with a measured adsorption capacity of 0.50 mmol g-1. Pure Cd2+ and Ni2+ solutions were recovered by a simple acid wash, and the regenerated adsorbent could be reused without lost of performance (i.e., adsorption capacity and selectivity).

[ Last edited by gzsoger on 2007-4-8 at 08:51 ]

回复此楼