Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia.
Jožef Stefan International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia; Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, Slovenia.
Sci Total Environ. 2018 Sep 1;634:1259-1268. doi: 10.1016/j.scitotenv.2018.04.081. Epub 2018 Apr 18.
Zero-valent iron nanoparticles (nZVI) exhibit great potential for the removal of metal contaminants from wastewater. After their use, there is a risk that nZVI will remain dispersed in remediated water and represent potential nano-threats to the environment. Therefore, the behaviour of nZVI after remediation must be explored. To accomplish this, we optimised a novel method using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) for the sizing and quantification of nZVI in wastewater matrices. H reaction gas was used in MS/MS mode for the sensitive and interference-free determination of low concentrations of nZVI with a low size limit of detection (36nm). This method was applied to study the influence of different iron (Fe) loads (0.1, 0.25, 0.5 and 1.0gL) and water matrices (Milli-Q water, synthetic and effluent wastewater) on the behaviour of nZVI, their interactions with Cd and the efficiency of Cd removal. The aggregation and sedimentation of nZVI increased with settling time. Sedimentation was slower in effluent wastewater than in Milli-Q water or synthetic wastewater. Consequently, Cd was more efficiently (86%) removed from effluent wastewater than from synthetic wastewater (73%), while its removal from Milli-Q water was inefficient (19%). The trace amounts of Cd that remained in the remediated water were either dissolved or sorbed to residual nZVI. The results of the nanoremediation of effluent wastewater with varying Fe loads showed that sedimentation was faster at higher initial concentrations of nZVI. After seven days of settling, low concentrations of Fe remained in the effluent wastewater at Fe loads of 0.5gL or higher, which could indicate that the use of nZVI in nanoremediation under the described conditions may not represent an environmental nano-threat. However, further studies are needed to assess the ecotoxicological impact of Fe-related NPs used for the nanoremediation of wastewaters.
零价铁纳米颗粒（nZVI）在去除废水中金属污染物方面表现出巨大的潜力。使用后，nZVI 有分散在修复水中的风险，并可能对环境构成潜在的纳米威胁。因此，必须探索 nZVI 修复后的行为。为了实现这一目标，我们优化了一种使用单颗粒电感耦合等离子体质谱（SP-ICP-MS）的新方法，用于在废水基质中对 nZVI 进行尺寸测定和定量。在 MS/MS 模式下使用 H 反应气体，可以对低浓度的 nZVI 进行灵敏且无干扰的测定，检测限低至 36nm。该方法用于研究不同铁（Fe）负载（0.1、0.25、0.5 和 1.0 gL）和水基质（Milli-Q 水、合成水和废水）对 nZVI 行为、它们与 Cd 的相互作用以及 Cd 去除效率的影响。nZVI 的聚集和沉淀随沉降时间的增加而增加。在废水处理厂的废水中，沉淀比在 Milli-Q 水或合成废水中更慢。因此，与合成废水（73%）相比，Cd 从废水处理厂的废水中被更有效地去除（86%），而从 Milli-Q 水中的去除效率则较低（19%）。残留于修复水中的痕量 Cd 要么溶解，要么被残留的 nZVI 吸附。用不同铁负荷对废水进行纳米修复的结果表明，在较高的 nZVI 初始浓度下，沉淀速度更快。沉降 7 天后，在 0.5gL 或更高的铁负荷下，废水中仍残留低浓度的 Fe，这可能表明在所述条件下使用 nZVI 进行纳米修复不会对环境构成纳米威胁。然而，需要进一步研究来评估用于废水纳米修复的与 Fe 相关的 NPs 的生态毒理学影响。
