摘要
为改善纳米零价铁(NZVI)在水溶液中容易发生团聚和易被氧化的缺点.本文研究利用廉价易得的环境友好型材料羧甲基淀粉钠(CMS)对NZVI进行包覆改性,利用空间位阻效应提高其分散悬浮性.利用透射电镜和X射线衍射研究了改性后的纳米铁微观结构及物相组成,通过化学实验研究其对2,4-二氯苯酚(2,4-DCP)的去除效果.结果表明,改性后的NZVI直径大约在80~100 nm,呈链状或分散颗粒分布,主要物质组成为零价铁,具有强还原性.当CMS的比例为80.00%时,悬浮性最佳;经过CMS包覆改性后,NZVI还保留原有的活性,在不同包覆比例对于2,4-DCP的去除效果的实验中发现,同样CMS比例为80%时去除效果最好,达到83.69%,且有明显的脱氯降解过程.
To restrain the nano zero-valent iron （NZVI） in aqueous solution from being reunited and oxidized, this paper used sodium carboxymethyl starch （CMS）, which is an environmentally friendly and cheap material, for coating and surface modification of NZVI so as to improve its dispersity and suspension property. Transmission Electron Microscope （TEM） and X-ray diffraction （XRD） were used to study the microstructure and components of the modified NZVI, and the 2,4-dichlorophenol 2,4-（DCP） removal efficiency was researched through chemical experiment. Experiments showed that the modified NZVI was about 80~100 nm in diameter, present as chain or dispersed particles. The main component was zero-valent iron, and it had strong reducibility. When the proportion of CMS was 80.00%, the suspension property was the best; The NZVI after CMS coating and surface modification retained the original activity. In the experiment investigating the removal effect of 2,4-DCP using different proportion of cladding, the same finding was obtained. When the CMS＇s proportion was 80%, the removal effect was the best, reaching up to 83.69%, and the dechlorination and degradation were apparent.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第6期2385-2392,共8页
Environmental Science
基金
国家科技支撑计划项目(2011BAC12B00)
关键词
地下水修复
纳米零价铁
2
4-二氯苯酚
分散
降解
underground water remediation
nano zero-valent iron
2,4-dichlorophenol
disperse
degradation
