Fate of ZnO Nanoparticles in Soils and Cowpea (Vigna unguiculata)

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• 作者：Peng Wang ; Neal W. Menzies ; Enzo Lombi ; Brigid A. McKenna ; Bernt Johannessen ; Chris J. Glover ; Peter Kappen ; Peter M. Kopittke
• 刊名：Environmental Science & Technology
• 出版年：2013
• 出版时间：December 3, 2013
• 年：2013
• 卷：47
• 期：23
• 页码：13822-13830
• 全文大小：474K
• 年卷期：v.47,no.23(December 3, 2013)
• ISSN：1520-5851

文摘

The increasing use of zinc oxide nanoparticles (ZnO-NPs) in various commercial products is prompting detailed investigation regarding the fate of these materials in the environment. There is, however, a lack of information comparing the transformation of ZnO-NPs with soluble Zn²⁺ in both soils and plants. Synchrotron-based techniques were used to examine the uptake and transformation of Zn in various tissues of cowpea (Vigna unguiculata (L.) Walp.) exposed to ZnO-NPs or ZnCl₂ following growth in either solution or soil culture. In solution culture, soluble Zn (ZnCl₂) was more toxic than the ZnO-NPs, although there was substantial accumulation of ZnO-NPs on the root surface. When grown in soil, however, there was no significant difference in plant growth and accumulation or speciation of Zn between soluble Zn and ZnO-NP treatments, indicating that the added ZnO-NPs underwent rapid dissolution following their entry into the soil. This was confirmed by an incubation experiment with two soils, in which ZnO-NPs could not be detected after incubation for 1 h. The speciation of Zn was similar in shoot tissues for both soluble Zn and ZnO-NPs treatments and no upward translocation of ZnO-NPs from roots to shoots was observed in either solution or soil culture. Under the current experimental conditions, the similarity in uptake and toxicity of Zn from ZnO-NPs and soluble Zn in soils indicates that the ZnO-NPs used in this study did not constitute nanospecific risks.