【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。更多还原

【Abstract】 The soil contaminated by p-nitrotoluene(PNT)was remediated by the zero-valent iron(ZVI,Fe0)reduction technology.The reduc-tion effects in different reaction conditions,the reaction product and the reaction mechanism were investigated in this article.The results indi-cated that PNT in soils was reduced to aniline compound effectively by Fe0 at normal temperature and pressure.PNT was reduced to p-methyl-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 Fe0 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 Fe0 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 ℃.更多还原