改性硅藻土负载纳米零价铁去除六价铬  

Removal of chromium(Ⅵ) from water by modified diatomite loaded with nanoscale zero-valent iron

作　　者：陈园园 井琦[1] 任仲宇[1] 李晓宇 CHEN Yuan-yuan;JING Qi;REN Zhong-yu;LI Xiao-yu(College of Civil Engineering and Architecture,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学建筑工程学院,北京100124

出　　处：《应用化工》2020年第3期540-544,共5页Applied Chemical Industry

基　　金：国家重点研发计划(2016YFC0401400);北京市科委项目(Z161100004516015)。

摘　　要：采用改性硅藻土(CD)作为载体,制备了改性硅藻土负载纳米零价铁复合材料(CD-nZⅥ)。利用透射电子显微镜(TEM)、XPS对CD-nZⅥ复合材料进行表征,并讨论CD-nZⅥ复合材料中nZⅥ与改性硅藻土质量比、CD-nZⅥ复合材料投加量、Cr(Ⅵ)初始浓度、pH、反应温度对CD-nZⅥ去除六价铬的影响因素。结果表明,CD-nZⅥ复合材料对六价铬的去除能力高于nZⅥ、改性硅藻土,CD-nZⅥ复合材料中nZⅥ与改性硅藻土质量比为1∶2,CD-nZⅥ投加量为0.8 g/L,反应温度为45℃,反应时间为120 min,pH=3,六价铬初始浓度为20 mg/L时,CD-nZⅥ对六价铬的去除效率高达99.16%。CD-nZⅥ去除六价铬的反应符合准一级反应动力学方程,反应速率常数Kobs随着六价铬浓度的增加而减少。对反应产物进行XPS检测,结果显示,CD-nZⅥ是通过还原、吸附作用去除六价铬,且以还原作用为主。Modified diatomite supported nano-zero-valent iron composites(CD-nZⅥ) were prepared using modified diatomite(CD) as carrier.The composites were characterized by transmission electron microscopy(TEM) and XPS.The effect of mass ratio of nZⅥ to CD of CD-nZⅥ,CD-nZⅥ dosage,initial concentration of Cr(Ⅵ),pH and reaction temperature on the removal of hexavalent chromium by CD-nZⅥ were discussed.The results showed that the removal of hexavalent chromium by CD-nZⅥ composite is higher than that by nZⅥ and modified diatomite,when the mass ratio of nZⅥ to CD was 1∶2,the dosage of CD-nZⅥ was 0.8 g/L,the reaction temperature was 45 ℃,the initial concentration of Cr(Ⅵ) was 20 mg/L,the reaction time was 120 min,pH=3,the removal efficiency of hexavalent chromium by CD-nZⅥ was as high as 99.16%.The removal of hexavalent chromium by CD-nZⅥ conforms to the quasi-first-order kinetics equation,and the reaction rate constant Kobs decreases with the increase of hexavalent chromium concentration.XPS analysis of the reaction products showed that CD-nZⅥ could remove hexavalent chromium through the synergistic effect of reduction and adsorption,and the reduction was dominant.

关 键 词：硅藻土 纳米零价铁 六价铬 动力学 

分 类 号：TQ027.36[化学工程] TQ050.41