零价铁渗透反应格栅中电活化技术对铁表面化学成分的影响

本文通过批-柱实验研究低压直流电流对已被NO3-钝化零价铁渗透中零价铁（ZVI）的催化活化，研究发现：加载12V低压直流电流后，阴极附近TCE的去除速率常数比钝化后ZVI的去除效率高出约4倍，低压直流电流可以催化ZVI去除TCE，去除效果的增加和电压成正相关关系；同时，低压直流电流阴极可以活化已经钝化的ZVI，活化后不加载电流时ZVI对TCE的去除效率仍是钝化后ZVI的去除效率的约3倍。经过NO3-钝化后ZVI表面的氧化膜组成以Fe3O4为主；但在加载低压直流电流后，ZVI表面同时会有理α-/β—FeOOH生成，说明低压直流电可能会使Fe3O4溶解还原。

The Effect of EIR on the Chemicals of the Iron Surface in ZVI PRB

In this study, the batch-type experiment was used to investigate the depassivation of passivated zero-valent iron （ZVI） by electrical induced reduction （3, 6, 12 V; EIR）. With 12 V electricity added, the first order degradation rate k of TCE was 4 times more than the k of the passivated ZVI, EIR is helpful to the TCE removal in ZVI PRB and this accelerate effect is roughly proportional to the electricity level. After EIR added, the k of the restored ZVI was still 3 times more than the k of the passivated ZVI. The most composition of the passivated ZVI surface is Fe3O4, but a lot of α-/β-FeOOH was generated after electricity added. This means that the dissolution and reduction of Fe3O4 during the EIR process.