Fe2+在零价铁还原去除NO3-中的作用效应

零价铁（Fe0） 被广泛用于地下水中硝酸盐原位与异位修复，但二价铁（Fe2+） 的存在对具有氧化膜的Fe0还原硝酸盐的作用效应仍有待研究。以100 目的未经酸化的颗粒状零价铁作为还原剂，采用室内批试验方法，研究了Fe2+在零价铁还原去除NO3-系统中的作用效应。实验结果表明，Fe2+可显著提高Fe0对于NO3-的去除速率与去除效率，且Fe2+浓度越高，去除速率与效率越高；由于未经酸化的Fe0具有氧化膜，反应初期的NO3-还原速率较慢。Fe2+将零价铁表面的Fe2O3氧化膜转化为Fe3O4，加速电子由Fe0向NO3-的转移，促进NO3-还原。此外，在反应系统中加入Fe3O4，可进一步提高Fe0对于硝酸盐的去除能力，若Fe2+不存在，仅添加Fe3O4，NO3-的去除效率没有提高。

Effect of Fe2+ on Nitrate Reduction Using Zero-valent Iron

Zero-valent iron(Fe0) was widely used for in-situ and ex-situ remediation of nitrate in groundwater, however, it remained tobe studied that how existing of Fe2+ worked in the reduction of nitrate by Fe0 which was covered by iron oxides. In this study, batchexperiments were conducted to investigate the effect of Fe2 + on NO3- reduction using 100 mesh untreated zero-valent iron (Fe0) asreductant. The results showed that, Fe2+ could significantly enhance the removal rate and removal efficiency of NO3- in the presence ofFe0, and the removal efficiency increased with elevated Fe2+ concentration; but the reaction experienced an initial stage of low rate dueto the existence of oxide film on the Fe0 surface. Fe2+ could directly revolved in the reaction and transformed Fe2O3 which covers the Fe0to Fe3O4, which accelerates the transfer of electrons from Fe0 to NO3- and promote the reduction of nitrate. What’s more, the removalefficiency of NO3- by Fe0 will be further improved while adding Fe3O4 into the reaction system, however, with the absence of Fe2+ , theadding of Fe3O4 only will not influence the reduction efficiency by Fe0.