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The photochemical reduction of Cr(Ⅵ) in aqueous solutions containing Fe(Ⅲ)-alginate complexes was preliminarily explored under a high-pressure mercury lamp.The effects of pH,the initial concentrations of Fe(Ⅲ) and alginate were also discussed in detail.The kinetics and mechanism of Cr(Ⅵ) photoreduction were analyzed.The results indicated that Cr(Ⅵ) could be photo-reduced by iron(Ⅲ)-alginate complex systems.Under the condition of _0=19.2μmol/L,_0=20.0μmol/L,_0=0.5g/L and pH=3.0,the reduction efficiency of Cr(Ⅵ) could achieve 97% after 80 min irradiation with a 125W high-pressure mercury lamp.Over the pH range of 2.0-7.0,the reduction efficiency increased with acidity of the solution.The initial rates of Cr(Ⅵ) photoreduction increased with increasing the intitial concentrations of Fe(Ⅲ) and alginate.Fe(Ⅱ)generated by the photolysis of iron(Ⅲ)-alginate complexes was the main reductant.
The photochemical reduction of Cr (VI) in aqueous solutions containing Fe (III) -alginate complexes was preliminarily explored under a high-pressure mercury lamp. The effects of pH, the initial concentrations of Fe (III) and alginate were also discussed in detail The kinetics and mechanism of Cr (Ⅵ) photoreduction were analyzed.The results indicated that Cr (Ⅵ) could be photo-reduced by iron (Ⅲ) -alginate complex systems.Under the condition of _0 = 19.2 μmol / L, _0 = The reduction efficiency of Cr (VI) could achieve achieve 97% after 80 min irradiation with a 125W high-pressure mercury lamp. Over the pH range of 2.0-7.0, the reduction efficiency increased with acidity of the solution. The initial rates of Cr (Ⅵ) photoreduction increased with increasing the intitial concentrations of Fe (Ⅲ) and alginate. Fe (Ⅱ) generated by the photolysis of iron (Ⅲ) the main reductant.