零价铁-过二硫酸盐连续运行体系去除水中硝基苯

水中硝基苯(NB)的高毒性对人体健康具有极大的危害,因此,本文建立了零价铁-过二硫酸盐(Fe0-PS)连续运行体系以降解水中NB.研究结果表明,单独Fe0柱可还原降解NB,Fe0对不同浓度NB的还原效果均较好,随着流速的减慢及初始pH的降低,NB还原效果变好;但还原体系中总有机碳(TOC)基本没有去除,只是生成了中间产物苯胺(AN).Fe0-PS联合体系中,随着PS的投加,产生的Fe2+活化PS,发生了类Fenton反应,从而使还原产物AN得以氧化降解,TOC去除率可达54.8%;随着Fe0填充量的增加,氧化产物Fe2+随之增加,还原产物AN随之减少.可见,Fe0-PS连续运行体系,以Fe2+为媒介巧妙结合还原与氧化作用,能有效去除NB.

Degradation of nitrobenzene in aqueous solution by zero-valent iron/persulfate continuous operation system

Nitrobenzene (NB) in water poses significant health risks because of its persistence and high toxicity. A continuous operation system combining zero-valent iron (Fe⁰) and persulfate (PS) was developed to degrade NB in aqueous solution. Firstly, for Fe⁰ column-only system, NB removal increased with the decrease of the flow rate and that of the initial pH of solution. However, there was a negligible total organic carbon (TOC) removal because NB has merely been changed into aniline (AN), the intermediate product of NB reduced by Fe⁰. Secondly, for Fe⁰-PS system, as the PS dosing, a Fenton-like reaction took place during the reaction between the produced Fe²⁺ and the added PS. The probable production of sulfate radicals was attributed to the degradation of AN. The TOC removal was able to reach a rate as high as 54.8%. With the increasing of the dosage of Fe⁰, the concentration of Fe²⁺ increased and more AN was removed. In conclusion, the Fe⁰-PS continuous operation system, combined with reduction and oxidation via the medium, Fe²⁺, can effectively degrade NB in aqueous solution.