江汉大学学报（自然科学版）

研究了在高压汞灯(300nm)光照下4种FeIII-多羧酸盐络合物(FeIII-柠檬酸,FeIII-草酸钠,FeIII-酒石酸钾,FeIII-EDTA)对CrVI的光还原试验,比较了它们光还原Cr(VI)的反应速率.具体研究了在FeIII-草酸钠体系中CrVI)的光还原.探讨了各种影响因素:初始pH值,FeIII、草酸盐、CrVI的初始浓度,以及FeIII∶草酸盐的配比,光照强度等对CrVI光还原的影响.结果表明:在不同光化学体系中光还原CrVI的速率在不加FeIII时,光还原CrVI的速率由大到小依次为:EDTA、草酸钠、柠檬酸钠、酒石酸钾.在FeIII-多羧酸盐络合物体系中CrVI的光还原速率由大到小依次为FeIII-酒石酸钾、FeIII-EDTA、FeIII-柠檬酸钠、FeIII-草酸钠.在FeIII-草酸钠体系中CrVI的光还原速率随着pH值的增大而减小;随FeIII、草酸钠初始浓度的增加而增加,而随CrVI初始浓度的增加,光还原CrVI的速率是减少的.

The photochemical reduction of Cr(VI) by Fe(III)-carboxylic salts under the radiation of high-pressure mercury lamp ( 300 nm) containing Fe(III)-citrate complex, Fe(III)-oxalate complex, Fe(III)-tartrate complex, Fe(III)-EDTA are studied and comparing the photoreduction rates. Fe (III)-oxalate complexes were elected to be studied photoreduct Cr(VI). The effects of the initial solution pH value, the initial concentrations of Fe(III), oxalate and Cr(VI) and the ratio Fe(III): oxalate, the light intensity were studied. The results indicate that the rates of photoreduction Cr(VI) decreased from EDTA, oxalate complexes, citrate to tartrate system without Fe(III); but decreased from Fe III -tartrate complexes, Fe III -EDTA complexes, Fe III -citrate complexes, to Fe(III)-oxalate complexes system with Fe(III). The rates of photoreduction Cr(VI) increased with increasing the initial concentrations of Fe(III) and oxalate, however, decreased with increasing the initial concentrations of Cr(VI).