The effect of common groundwater anions on the aqueous corrosion of zero-valent iron nanoparticles and associated removal of aqueous copper and zinc
The effect of common groundwater anions on the aqueous corrosion of zero-valent iron nanoparticles and associated removal of aqueous copper and zinc
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DOI：
10.1016/j.jece.2017.01.038
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发表时间：
2017-02
影响因子：
7.7
通讯作者：
H. Pullin;R. Crane;D. Morgan;T. Scott
中科院分区：
文献类型：
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作者：
H. Pullin;R. Crane;D. Morgan;T. Scott
这项工作研究了常见的地下水阴离子（Cl−,NO3−，SO42−和HCO3−）对纳米级零价铁颗粒（nZVI）上铜（Cu）和锌（Zn）离子的腐蚀行为和相关去除的影响。在每一种阴离子浓度为10 mM的溶液中暴露16周后，观察到nZVI腐蚀成不同的铁（氢）氧化物相（用XRD测定），这取决于阴离子的存在：HNO3−产生针铁矿颗粒；NO3−主要产生磁铁矿/磁铁矿颗粒；SO42−和Cl−均产生了磁铁矿/磁铁矿、绢云母和针铁矿等混合相。对于含有不同阴离子和0.3 mM浓度的Cu或Zn的溶液，在所有测试系统的反应初始阶段（例如<24 h）记录了几乎全部金属在nZVI上的去除。然而，当Cl -和SO42 -也存在时，记录了显著的后续脱附，并归因于阴离子点蚀的影响。相比之下，在含有NO3−的批处理体系中，没有记录到Cu或Zn的脱附，这是由于Cu或Zn在混合价氧化铁壳中的包裹。因此，本文的结果表明，NO3−可以与nZVI一起使用，以改善其在原位水处理应用中的长期性能。
This work has investigated the influence of common groundwater anions (Cl−, NO3−, SO42−and HCO3−) on the corrosion behaviour and associated removal of copper (Cu) and zinc (Zn) ions onto nanoscale zero-valent iron particles (nZVI). After 16 week exposure to solutions containing each anion at 10 mM concentrations, nZVI was observed to corrode into different iron (hydr)oxide phases (determined using XRD), depending upon the anion present: HNO3−produced goethite particles; NO3−produced predominantly magnetite/maghemite particles; both SO42−and Cl−produced a mixture of phases, including magnetite/maghemite, lepidocrocite and goethite. For solutions containing the different anions and 0.3 mM concentrations of Cu or Zn, near-total metal removal onto nZVI was recorded in the initial stages of the reaction (e.g. <24 h) for all systems tested. However, when Cl−and SO42−were also present significant subsequent desorption was recorded and attributed to the influence of anionic pitting corrosion. In contrast, no Cu or Zn desorption was recorded for batch systems containing NO3−, which was attributed to the enmeshment of Cu or Zn in a mixed-valent iron oxide shell. Results herein therefore demonstrate that NO3−could be utilised alongside nZVI to improve its long-term performance for in situ water treatment applications.