中文摘要：

研究了地下环境中的Fe2＋对硝基苯（NB）的还原衰减作用,模拟了Fe2＋还原硝基苯的过程及不同硬度、CO23-、SO24-、NO 3-、Cl-等地下水化学组成对反应的影响,目的是阐明Fe2＋还原硝基苯的机制及水化学组成对反应影响的原因.结果表明,在温度为10℃、pH为6.8的条件下,Fe2＋和硝基苯浓度皆对其还原衰减有影响,当n（Fe2＋）∶n（NB）为5.88∶1时硝基苯还原效率最高,48 h后其还原效率为57.63%.镁硬度、CO23-对Fe2＋还原硝基苯有一定抑制作用,当镁硬度、CO23-分别达到150 mg/L和50 mg/L时,48 h后硝基苯还原效率最大为51.05%和49.96%,且随着镁硬度、CO32-浓度的增大抑制作用越显著,当Mg2＋浓度增至800 mg/L时,48 h后还原效率仅为6.98%;SO24-、NO 3-、Cl-对还原反应影响较小,48 h后还原效率〈50%;HCO 3-加快了还原反应的进行,8 h后硝基苯的还原效率可达60%.本研究探索了硝基苯污染场地中Fe2＋对其自然衰减的贡献,为定量估算污染场地的自然衰减程度提供了一定的理论依据.

英文摘要：

Experiments were conducted to investigate reductive attenuation of nitrobenzene（NB） by Fe2＋ in subsurface environment and influences of hydrochemical constituents such as water hardness,SO24-,NO 3-and Cl-.Experimental results indicated that concentration of Fe2＋ and NB both had influences on NB reduction.The highest reducing efficiency obtained while n（Fe2＋） ∶ n（NB） was 5.88∶ 1 under the condition of pH 6.8 and 10℃.The deoxidization efficiency of NB was up to 57.63% over 48 h.Mg2＋ and CO32-could inhibit the reduction of NB,and the reduction efficiency reached 51.05% and 49.96% in 48 h while Mg2＋ was 150 mg/L and CO23-was 50 mg/L,respectively;the inhibition was enhanced with increasing of Mg2＋ and CO32-concentration,and the deoxidization efficiency of NB was 6.98% only while Mg2＋ was 800 mg/L.SO42-,NO 3-and Cl-have small influence on NB reduction,the deoxidization efficiency was less than 50% in 48 h.HCO 3-can accelerate the reaction,and the reduction efficiency was up to 60% in 8h.These baseline relationships provide a way to quantitatively evaluate the extent of natural attenuation in contaminated site.