纳米Fe/Ni及其反应后FeOOH耦合去除水中对氯硝基苯及其脱氯产物的研究

Removal of p-chloronitrobenzene and its dechlorination product by n-Fe/Ni coupling with FeOOH produced from the reaction

用纳米Fe/Ni(n-Fe/Ni)去除水中对氯硝基苯,对反应前后的材料进行了SEM和XRD表征。结果表明,n-Fe/Ni与对氯硝基苯反应8 h后,形貌由球形转变成板条形,晶相由Fe(0)转化为纤铁矿、四方纤铁矿和针铁矿(化学组成均为FeOOH),n-Fe/Ni及其反应后生成的FeOOH可通过耦合分别将对氯硝基苯及其脱氯产物-苯胺去除。耦合去除历程和机制为:n-Fe/Ni中Fe(0)提供电子还原硝基为胺基,并在Ni催化下将对氯苯胺脱氯为苯胺,同时自身被对氯硝基苯、溶解氧和水氧化为FeOOH,FeOOH再吸附脱氯产物苯胺,从而将对氯硝基苯及苯胺从水中彻底去除。pH=2~9时,耦合去除能够良好进行;温度在15℃~35℃范围内时,升高温度可以加速反应。本研究为氯代有机物污染水体的彻底修复提供了一种新思路。

Nano-Fe/Ni(n-Fe/Ni)was employed to remove p-chloronitrobenzene from aqueous solution and the materials before and after the reaction were characterized by SEM and XRD.The results show that n-Fe/Ni changes from sphere to lath-like and transforms from Fe(0)into lepidocrocite,akaganeite and goethite after reaction(their chemical composition is FeOOH).P-chloronitrobenzene and its dechlorination product,aniline,can be removed by n-Fe/Ni coulpling with FeOOH produced from the reaction,respectively.The mechanism of coulpling removal can be attributed to that Fe(0)in n-Fe/Ni acts as an electron donor to reduce p-chloronitrobenzene to p-chloroaniline,and then dechlorinates p-chloroaniline with the catalysis of Ni.Meanwhile,n-Fe/Ni is oxided to FeOOH by p-chloronitrobenzene,dissolved oxygen and water.Subsequently,aniline,the dechlorination product of p-chloroaniline,is adsorbed on the surface of FeOOH.As a result,both p-chloronitrobenzene and aniline can be removed completely.The coulpling removal can be conducted smoothly when pH=2~9.Additionally,the reaction can be accelerated by increasing the temperature when the temperature is in the range of 15℃~35℃.This study may provide a new idea for the remediation of aquatic system contaminated with chloroorganics.