摘要
采用零价铁(ZVI,Fe0)还原技术,修复被对硝基甲苯(PNT)污染的土壤,研究不同反应条件对还原效果的影响及随时间推移产物的变化,并对反应机理进行了初步探讨。结果表明,常温常压下,Fe0可有效地将土壤中对硝基甲苯还原为苯胺化合物,反应过程中先生成对甲基亚硝基苯,最终生成对甲基苯胺。土壤含水量达到饱和时能显著提高PNT的还原率,土壤初始酸碱度控制在中性偏酸性有利于还原反应的进行,体系温度上升到25～35℃还原效果较好,当Fe0加入量小于25mg.g-1时增加Fe0用量能有效增大还原率。当2g土壤中PNT的初始浓度约为2.5×10-6mol.g-1,Fe0加入量是25mg.g-1,土壤水含量75%,土壤初始pH值6.8时,于25℃下反应5h后PNT的还原率可达95%以上。
The soil contaminated by p-nitrotoluene（PNT）was remediated by the zero-valent iron（ZVI, Fe^0）reduction technology. The reduction effects in different reaction conditions, the reaction product and the reaction mechanism were investigated in this article. The results indicated that PNT in soils was reduced to aniline compound effectively by Fe^0 at normal temperature and pressure. PNT was reduced to pmethyl-nitrosobenzene firstly, and then to p-methyl-aniline. The saturation moisture condition in soil, the acid or neutral soil, the reaction temperature in range of 25-35 ℃ and the increase of Fe^0 content were helpful to increase the reduction rate of PNT. When the initial concen- tration of PNT in 2 g soil was 2.5×10^-6 mol·g-1, the addition of Fe^0 was 25 mg·g-1, the initial pH of soil was 6.8 and the moisture content was 75%, the reduction rate of PNT reached 95% after 5 hours at 25 ℃.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2009年第2期239-243,共5页
Journal of Agro-Environment Science
基金
广东省自然科学基金委项目(04106270)
关键词
对硝基甲苯
零价铁
还原
土壤
p-nitrotoluene （ PNT）
zero-valent iron （ZVI, Fe^0 ）
reduction
soil
