基于WEEE指令超痕量六价铬富集、分离及污染控制  

Enrichment,Separation,and Pollution Control of Ultra-trace Hexavalent Chromium for WEEE Directive

作　　者：华丽[1] 候汉娜[1] 郑平[1] 胡庆兰[1] 

机构地区：[1]湖北第二师范学院化学与生命科学学院,武汉430205

出　　处：《湖北第二师范学院学报》2009年第8期38-43,共6页Journal of Hubei University of Education

基　　金：湖北省教育厅重点资助项目;项目编号:D20093103

摘　　要：为了遵守欧盟WEEE指令，文中采用SPE法，以经处理过的锯屑作为吸附剂富集电子电气产品中超痕量六价铬，研究了pH、吸附剂用量．Cr（Ⅵ）初始浓度、温度对吸附平衡的影响，得出了最优化富集条件和在此条件下动力学、热力学特性。结果显示，通过调节pH值可使三价铬与六价铬发生吸附分离，六价铬在锯屑上吸附是单层、自发、吸热过程，活化能较小，说明吸附是需要消耗时间；其时间变化规律为：前50min内快速吸附（速率控制为主）后数小时慢吸附过程（扩散控制为主）；通过富集，可使目标物浓度浓缩50～100倍，大大降低了痕量浓度检出限至μg·L^-1，ng·L^-1水平，为EE产品中有害物质污染控制提供了技术基础，也为更好地实现废旧电子电气产品中有用物质回收、再利用、再循环提供绿色指导方案。For complying with WEEE directive, solid -phase extraction method with modified sawdust as adsorbent was employed to enrich the ultra - trace hexavalent chromium contained in electronic and electrical equipment. Effects of pH, amount of adsorbent, initial concentrations of Cr（Ⅵ）, temperature were discussed, and the optimal condition of adsorption, kinetics and thermodynamic characteristic were obtained. The result showed that the two chromium species （Cr（Ⅲ） and Cr （Ⅵ） ） can be separated by adjusting pH of adsorption. The process of Cr（Ⅵ） adsorption on sawdust is single - layer, spontaneous, endothermic. The smaller active energy （Ea） proved that the adsorption is time -consuming, the relation law as a function of time is that adsorption is quick during the first 50 min due to rate control, it is slow during the latter several hrs due to proliferation control. The objective content in the sample solutions was concentrated about 50 - 100 fold by enriching like this and limit of detection （LOD） was minimized to μg · L^-1, ng · L^-1 level. Thus provides a technologic base to control hazardous substance pollution in EEE products, also provides a green conductive project to recovery, reuse, and recycle the useful substances of e - wastes.

关 键 词：超痕量 六价铬 富集 锯屑 固相萃取法 WEEE指令 

分 类 号：O656[理学—分析化学]