Fe~0对土壤中硝基苯的还原作用

以恒温培养为方法,GC-MS为检测手段,研究了在常温常压下土壤中硝基苯(NB)在Fe0作用下的还原反应。结果表明:Fe0能将硝基苯苯环上的硝基转化为胺基,从而达到降低毒性、增加可生化性目的。反应条件如时间、零价铁用量、初始pH等均对NB的还原效率有重要影响,特别是当初始pH值控制在偏酸时更有利于反应的进行。在硝基苯浓度约为0.0025mmol/g的2.00g模拟污染土壤中,Fe0加入量50mg、初始pH=4、反应时间5h的条件下,零价铁对土壤中NB的还原效率可达到96.58%。此外,本文还对Fe0还原NB的反应机理进行了初步探讨。

Reduction of Nitrobenzene by Zero Valent Iron In Soil

At ambient temperature and pressure,the reduction of nitrobenzene(NB) in soil by zero-valent iron(ZVI)was investigated in the laboratory with isothermal incubation and gas chromatography mass spectrometry(GCMS) as the primary analytical method.GC-MS analysis indicated that NB in soil was reduced to aniline in the presence of ZVI,effectively decreasing the toxicity of NB.Ultimately,biodegradation of aniline resulted in the disappearance of NB in soil.Major factors controlling the reduction of NB were tested and evaluated.Experimental data showed that the reaction time,the quantity of ZVI,and the initial soil pH were important factors for the reduction of NB,and acidic pH was more favorable for the reduction reaction to proceed.It was found that 96.58% of NB in soils could be reduced after 5 hours of reaction with 50 mg of ZVI and at an initial pH of 4.In addition,possible mechanisms of the reduction reaction was proposed and discussed..