纳米零价铁(n ZVI)由于其比表面积大、表面反应活性高以及强还原性,可以作为一种高效的环境修复材料,广泛运用于污染地下水及土壤修复。大量的n ZVI颗粒直接注射到污染位点会增加生态系统的暴露可能性,并且由于n ZVI粒径特别小,能穿过细胞膜和生物体的各类天然屏障,对环境及生态系统存在潜在风险,因此科学家们开始更多地关注n ZVI的生物安全性研究。鉴于n ZVI在环境修复应用中的巨大潜力和可能的毒性效应,对n ZVI环境风险的研究也显得尤为重要。综述了近几年国内外关于n ZVI生态毒性的研究成果,n ZVI对病毒、细菌、微生物群落、以及动植物等都能导致一定的负面效应,尽管其毒性机制尚不明确,但普遍认为n ZVI暴露后铁离子的释放和氧化损伤确实可以引起生物效应,部分研究还分析了环境因素和表面改性对其毒性的影响。文章对其未来的发展方向进行了展望,以期为今后纳米零价铁的研究提供参考。
As an efficient environmental remediation material, nanoscale zero-valent iron (nZVI) has been broadly applied in the remediation of contaminated groundwater and soil for its huge specific surface area, high surface re- activity and strong reducibility. However, the injection of large amount of iron nanoparticles into the contaminated sites should increase its exposure possibility to ecosystem, and thus pose potential risk to environment and ecosys- tem, since it can pass through the cell membrane and the protective screens of organisms resulting from its extreme- ly small particle size. Considering both the broad potential application of nZVI in environmental remediation and its possible toxicity, it is of great importance to investigate the environmental risk of nZVI, and more attention has been paid to the biological safety of nZVI. This paper overviews the research progress on the toxicity effect of iron nanoparticle in these years. NZVI could lead to negative effects on viruses, bacteria, microbial communities, as well as animals and plants. Although the toxicity mechanisms of nZVI remain unclear, a general viewpoint suggests that the toxicity effect should be resulted from the release of iron ions and the following oxidative damage. The effect of environmental factors and surface modification on the toxicity of nZVI is also discussed. In addition, prospect of the development of nZVI is presented to provide some reference for the research on the nZVI in the future.