An experiment was carried out on nanoscale zero-valent iron ( NZVI) reducing Cr ( VI) in water to explore effects of NZVI application rate, initial concentrations of Cr( VI) , initial pHs, and organic acids on the reduction. It was found that NZVI efficiently reduced Cr( VI) in water at a rate 7 and 13 times higher than that of iron powder and filings, respectively. Under the condition of the initial concentration of Cr( VI) being 20 mg · L and the NZVI application rate being 5 g · L-1 , the reduction rate reached 82. 7% after 24 h of incubation. Low pH solution promoted corrosion of NZVI, which raised Cr( VI) reduction rate. The highest reduction rate occured in solution being 3.0 in pH. Among organic acids , oxalic acid, malonic acid and succinic acid all significantly improved the effect of NZVI reducing Cr( VI) , and followed the order of oxalic acid > malonic acid > succinic acid.%采用纳米Fe0还原水溶液中的Cr(Ⅵ),考察纳米Fe0投加量、Cr(Ⅵ)初始浓度、溶液pH值和有机酸等因素对Cr(Ⅵ)还原的影响.结果表明,纳米Fe0对Cr(Ⅵ)的还原效果明显,其对Cr(Ⅵ)的还原率分别是铁粉和铁屑的7和13倍.Cr(Ⅵ)溶液初始质量浓度为20 mg·L-1、Fe0投加量为5g·L-1条件下,反应24 h时纳米Fe0对Cr(Ⅵ)的还原率达82.7％.溶液低pH值可以促进Fe0的腐蚀速度,提高反应速率,当pH值为3.0时还原效果最好.草酸、丙二酸和丁二酸对纳米Fe0还原Cr(Ⅵ)均有明显的促进作用,3种有机酸对Cr(Ⅵ)还原率的提高幅度由高到低依次为草酸、丙二酸和丁二酸.
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