羧甲基纤维素钠改性零价铁在石英砂中的迁移能力.pdf

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CHEMICAL INDUSTRY AND ENGINEERING PROGRES203年第32卷第7期
研究开发
羧甲基纤维素钠改性零价铁在石英砂中的迁移能力
殿其亮',李筱琴2,李英',肖阳
('华南理工大学环境科学与工程学院,广东广州510002华南理工大学,工业聚集区污染控制与生态修复
教育部重点实验室,广东广州51000
摘要:利用羧甲基纤维素钠(CMC)对零价铁进行改性,通过Zeta电位、粒型粒度和沉降曲缄的变化探讨改
性剂添加量影响零价铁分散的机理,同时考察改性剂添加量、流速和多孔介质类型对零价铁迁移的影响。结果
表明,CMC对零价铁的分散机理符合DLVO模型,静电空间位阻带来的势垒增加量与CMC添加量成正相关,
能促进零价铁的分散;经500%CMC(CMC与零价铁的质量比)改性的零价铁分散性能最好,成颗粒状、吸光
度在90min下降31%。受零价铁与石英砂作用能、填充介质的吸附位点和剪切力的影响,零价铁的迁移能力随
着CMC添加量的增多,填充介质粒径的增大和流速的增加而增强
关键词:零价铁;羧甲基纤维素钠;沉降;迁移
中图分类号:TM271文献标志码:A文章编号:1000-6613(2013)07-1598-06
DOI:10.3969/issn.1000-6613.2013.07,024
Transport of CMC modified zero-valent iron particles in quartz sand
IN Oiliang L1 Xiaogin", LI Ying, XIAO Yang
College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006
Guangdong, China: Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of
Education, South China University of Technology, Guangzhou 510006, Guangdong, China)
Abstract: The dispersion mechanism of carboxymethyl cellulose(CMC)modified zero-valent iron
(ZVD)particles in quartz sand was studied. Influences of porous medium, flow rate on transport were
also investigated. The results showed that dispersion mechanism of CMC modified ZVI particles
followed the DLVO model. Potential barrier increment brought by electrostatic repulsion and steric
hindrance had positive correlation with CMC concentration, promoting the dispersion of ZVI. Zero
valent iron particles modified with 500% CMC(mass ratio of CMC to ZV)were fully dispersed as
observed from SEM and light absorbance decreased by 31% in 90 minutes. Influenced by interaction
energy between ZVI and quartz sand, filling medium adsorption sites and shear force, transport ability
had positive correlation with CMC dosage, and increased with bigger medium size and higher fluid
elocity
Key words: zero-valent iron sodium carboxymethyl cellulose; DLVO; transport
近年来,零价铁因具有大比表面积和高反应活易在多孔颗粒表面沉积,严重影响它在多孔介质中
性,能迅速降解含氯有机物、硝胺、有机染料、重
金属和无机离子,而被越来越多的应用于环境修基金项目:广东省科学技术厅省际合作项目(201E0oo0,教
复领域。
育部高校博士点基金(20090172120034)及华南理工.大学基本科研业
但因为磁力和范德华力的作用,零价铁粒子很
务费(2011ZM0051)项
第一作者及联系人:殷其亮(1985一),男,硕土研究生,主要从事零
容易团聚,团聚体的粒径和表面电势导致它非常容价纳米铁去除地下水中重金属的研究。E-mailwoshiyql@sina.com