College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, Shandong Province, 266042, PR China; Qingdao Hengli Environmental Technology Research Institute Co., Ltd., Qingdao, Shandong Province, 266000, PR China.
College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, Shandong Province, 266042, PR China.
Chemosphere. 2020 Jul;251:126432. doi: 10.1016/j.chemosphere.2020.126432. Epub 2020 Mar 6.
Environmental applications and potential risks of iron-based materials have attracted increasing attention. However, most previous studies focused on a single material. Comparative research using different iron-based materials under the same experimental conditions is still lacking. Here, six iron-based materials, including micro-sized and nanoscale FeO (i.e., mFeO and nFeO), bulk and bare nanoscale zero-valent iron (i.e., mZVI and B-nZVI), starch-supported nZVI (S-nZVI), and activated carbon-supported nZVI (A-nZVI), were studied to compare their phytotoxicity in mung bean grown in suspensions with doses of 0, 300, 600 and 1000 mg/L. Taking the four toxicology parameters (seed germination rate, germination index, seedling elongation and biomass) together, the iron-based materials except mFeO generally produced no significant phytotoxicity to mung bean even at 1000 mg/L. nFeO and B-nZVI showed no higher phytotoxicity than their micro-sized counterparts (mFeO and mZVI). All the materials resulted in increased Fe concentrations in seedlings particularly in roots, and mZVI and B-nZVI produced more significant effects. However, the Fe in the roots was difficultly translocated to the shoots. Compared to B-nZVI, nFeO had lower bioavailability and bioaccumulation potential. XRD results confirmed that most FeO and B-nZVI remained unchanged during seedling growth, while support materials accelerated the corrosion and transformation of S-nZVI and A-nZVI. In conclusion, the tested nanoscale iron-based materials generally possess no obvious phytotoxicity within the dose range, but cause excess Fe accumulation in seedlings. Introduction of support materials may reduce such risk, allowing safer applications of these iron-based materials.
铁基材料的环境应用和潜在风险引起了越来越多的关注。然而，大多数先前的研究都集中在单一材料上。在相同的实验条件下，使用不同铁基材料的比较研究仍然缺乏。在这里，研究了六种铁基材料，包括微米和纳米级 FeO（即 mFeO 和 nFeO）、块状和裸露纳米零价铁（即 mZVI 和 B-nZVI）、淀粉负载纳米零价铁（S-nZVI）和活性炭负载纳米零价铁（A-nZVI），以比较它们在浓度为 0、300、600 和 1000mg/L 的悬浮液中对绿豆的植物毒性。综合考虑四个毒理学参数（种子发芽率、发芽指数、幼苗伸长和生物量），除 mFeO 外，其余铁基材料即使在 1000mg/L 时对绿豆通常没有明显的植物毒性。nFeO 和 B-nZVI 没有比其微米级对应物（mFeO 和 mZVI）更高的植物毒性。所有材料都导致幼苗中 Fe 浓度增加，特别是在根部，mZVI 和 B-nZVI 产生的影响更为显著。然而，根部的 Fe 难以向地上部分转移。与 B-nZVI 相比，nFeO 的生物可利用性和生物累积潜力较低。XRD 结果证实，在幼苗生长过程中，大多数 FeO 和 B-nZVI 保持不变，而支撑材料加速了 S-nZVI 和 A-nZVI 的腐蚀和转化。总之，在所测试的纳米铁基材料剂量范围内，一般没有明显的植物毒性，但会导致幼苗中 Fe 积累过多。引入支撑材料可能会降低这种风险，使这些铁基材料更安全地应用。
