电场驱动纳米Fe~0在不同介质中的迁移行为研究

发布时间：2019-03-14 19:10

【摘要】：选取四种不同介质(100%石英砂、75%石英砂/25%高岭土、50%石英砂/50%高岭土和100%高岭土),探讨了黄原胶分散的纳米Fe~0在不同介质中的迁移行为。纳米材料投加点设置在介质填充池中间靠近阳极电解池的位置。研究发现,采用该实验装置,100%石英砂的处理中电渗流量最大,这与其较大的孔隙和渗透性有关,加入高岭土的处理中电渗流量较小且各处理流量相当。纳米Fe~0在石英砂中的迁移高于加入高岭土的处理,大部分纳米Fe~0集聚在靠近投加口的部分,在远离投加口的部分铁逐渐由Fe2+向Fe3+转化。100%高岭土中纳米Fe~0的迁移高于混合介质处理,这与其较高的电流强度有关。纳米Fe~0在电动迁移过程中很容易发生溶解和转化,其在高岭土中的迁移是以离子态进行的。μ-XANES(微束X射线近边分析)的分析结果证实电场驱动下高岭土中的铁主要以纤铁矿和磁铁矿形式存在。
[Abstract]:Four different media (100% quartz sand, 75% quartz sand / 25% kaolin, 50% quartz sand / 50% kaolin and 100% kaolin) were selected to investigate the migration behavior of nano-Fe~0 dispersed by xanthan gum in different media. The nano-material adding point is arranged in the middle of the dielectric filling cell near the anode electrolytic cell. It is found that the electroosmotic flow rate of 100% quartz sand is the largest in the treatment of 100% quartz sand, which is related to its larger porosity and permeability. The electroosmotic flow rate in the treatment of adding kaolin is smaller and the flow rate of each treatment is equal. The migration of nano-Fe~0 in quartz sand was higher than that of adding kaolinite, and most of the nano-Fe~0 concentrated in the part close to the feeding port. The migration of nano-Fe~0 in 100% kaolin is higher than that in mixed medium, which is related to its high current intensity. Nano-Fe~0 is easy to dissolve and convert in the process of electromigration. The results of 渭-XANES (micro-beam X-ray near-edge analysis) show that the iron in kaolinite is mainly in the form of pyrite and magnetite driven by electric field.
【作者单位】：中国科学院土壤环境与污染修复重点实验室中国科学院南京土壤研究所;中建中环工程有限公司;
【基金】：国家自然科学基金项目(41471261)
【分类号】：X53;X131.3

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