采用液相还原法制备纳米零价铁（nZVI），用于去除水中的W（Ⅵ），考察了nZVI的质量浓度、W（Ⅵ）的初始质量浓度、磷酸根（PO₄^3-）对去除效果的影响，并对反应产物进行表征。结果表明，当nZVI的质量浓度为0.3 g/L、W（Ⅵ）的初始质量浓度为20 mg/L时，去除效果最好。投加不同摩尔浓度PO₄^3-会改变W（Ⅵ）的去除效果；W（Ⅵ）被nZVI还原为W（Ⅴ），还原产物W（Ⅴ）的质量分数随着PO₄^3-摩尔浓度的增加呈现递减趋势；少量PO₄^3-存在会改变nZVI的链状结构，当PO₄^3-∶W（Ⅵ）=10∶1（摩尔比）时，nZVI的"核-壳"结构保存完整，这是因为PO₄^3-会在nZVI表面竞争吸附位点并在其表面形成Fe₃（PO₄）₂，抑制nZVI对W（Ⅵ）的去除。

Nano-zero-valent iron (nZVI) is prepared by liquid phase reduction method and is used to remove W(Ⅵ) from water.Influences of the concentration of nZVI,the initial concentration of W(Ⅵ),temperature and phosphate radical (PO₄^3-) on the removal effect are studied and the reaction products are characterized.It is found that the best removal effect can be achieved when the concentration of nZVI is 0.3 g·L^-1 and the initial concentration of W(Ⅵ) is 20 mg·L^-1.The molar concentration of PO₄^3- can affect the removal effect of W(Ⅵ).W(Ⅵ) is reduced to W(Ⅴ) by nZVI and the relative content of the reduction product W(Ⅴ) shows a decreasing trend with the increase of PO₄^3- molar concentration.The presence of a small amount of PO₄^3- can change the chain-like spherical structure of nZVI.When the molar ratio between PO₄^3- and W(Ⅵ) is equal to 10:1,the "core-shell" structure of nZVI is intact and remains complete,which indicates that PO₄^3- and W(Ⅵ) compete each other for adsorption sites on the nZVI surface and simultaneous precipitation Fe₃(PO₄)₂ precipitation forms.

韩梦媛(1994-),女,硕士研究生,研究方向为环境分析化学,mengyuanhan1994@163.com。