| In the present paper is researched efficiency and effects of hexvalent chromium Cr(Ⅵ) by iron powder and iron nanoparticles. The kinetics of Cr(Ⅵ) removal by iron powder was also analyzed. First-order rate coefficient A and the super ficial active energy was obtained in this research. The effect of different dispersant on the removal efficiency of the Cr(Ⅵ) is researched. Effect of treatment factual wasterwater containing chromium(Ⅵ) is researched.The results are as following:1. The effect factors of Cr(Ⅵ) removal contain iron powder addition, initial pH value, reaction temperature, precipitation pH value and precipitation time. The removal efficiency increased with the increasing of iron powder addition and reaction temperature, low pH value could accelerate the rate of Cr(Ⅵ) removal.2. The reduction of Cr(Ⅵ) by iron powder was pseudo-first-order reaction. First-order rate coefficient A increased with increasing iron powder addition but inversely with initial pH value.According to the Arrehenius equation, the superficial active energy E=25.2kJ/mol and A=3210 min-1 was obtained in this research.3. With the increasing of iron nanoparticles addition, the effect of Cr(Ⅵ) removal is increased. But the increasing rate is slow, because the nanoparticles agglomeration.4. Cu(Ⅱ) could accelerate the rate of Cr(Ⅵ) removal. With the increasing of the concentration of Cu(Ⅱ), the effect of Cr(Ⅵ) removal is obviously increased.5. The capability of different reduction system on the removal of Cr(Ⅵ) is in the degrading order:iron nanoparticles> iron powder> waste iron.6. The dispersion effect of different dispersants on the nano-sized iron powder removal of Cr(Ⅵ) is in the degrading order:PVP>oleic acid>starch soluble> SDBS. |
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