摘要
零价铁纳米颗粒具有许多异于本体物质的独特性质,在废水处理方面应用潜力巨大。以蒙脱石为载体和分散剂,通过硼氢化钠液相还原法制备了零价铁纳米颗粒。采用电镜及多种谱学技术手段对所得铁纳米颗粒进行了表征。结果表明,铁纳米颗粒大致呈球状形貌,平均粒径约为55 nm,在蒙脱石表面分散良好,具有零价铁内核-铁氧化物外壳结构,提高了纳米铁在空气氛中的稳定性。通过批次实验考察了负载型铁纳米颗粒净化Cr(Ⅵ)的效率、过程及机理。净化效果受p H值影响显著,在最优p H值为1.0条件下,零价铁内核因其表面氧化膜酸溶而出露,可作为有效成分快速高效去除水体中Cr(Ⅵ)污染物,机理为零价铁将吸附至其表面的Cr(Ⅵ)异相还原为Cr(Ⅲ)而去除。属自发放热吸附过程,动力学行为符合准二级模型,吸附等温线可用Langmuir方程较好拟合。研究成果为新型纳米零价铁材料的制备及其铬污染治理提供了理论支撑。
nanoparticle;chromium pollution;zerovalent iron;montmorillonite
作者
樊明德
王睿哲
贾时雨
杨青
贾子豪
邢浩云
FAN Ming-de;WANG Rui-zhe;JIA Shi-yu;YANG Qing;JIA Zi-hao;XING Hao-yun(Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau,School of Ecology and Environment,Inner Mongolia University,Hohhot 010021,Inner Mongolia,China)
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2018年第5期860-868,共9页
Acta Petrologica et Mineralogica
基金
国家自然科学基金项目(41202029
41562004)~~
关键词
纳米颗粒
铬污染
零价铁
蒙脱石
Due to their many novel physicochemical properties different from the bulk counterparts
zerovalent iron nanoparticles are of great potential in contaminants removal from waste water. Montmorillonite-supported zerovalent iron nanoparticles were prepared using borohydride solution reduction method. As revealed by combined spectroscopic and microscopic techniques
the resultant iron particles were nearly spherical core-shell entities （about 55 nm mean diameter） well dispersed on the montmorillonite surface
in which the shell （iron oxide） preserved the core （metallic iron） from complete oxidation in air atmosphere. Batch tests were carried out to investigate the adsorption of Cr（Ⅵ） by thus obtained composite. At the optimized solution pH of 1.0
the Cr（Ⅵ） uptake was mainly governed by the reduction of Cr（Ⅵ） to Cr（Ⅲ） at the interface of metallic iron
which could be accessed by Cr（Ⅵ） owing to the dissolved oxide shell in acidic media. The kinetics of the adsorption followed the pseudo-second-order model
the adsorption data fitted well with the Langmuir equation
and the adsorption was spontaneous and exothermic in nature. These results are important for developing advanced nanomaterials based on zerovalent iron and for their use in remediation of Cr（Ⅵ）-contaminated water.
