Abstract:

A novel photo-Fenton-like system consisting of PW11O39Fe(Ⅲ)(H2O)4-[PW11Fe(Ⅲ)(H2O)] was applied to degrade the aqueous bio-refractory organic pollutant aniline(ArNH2). The homogeneous photo-catalysis of PW11Fe(Ⅲ)(H2O) for ArNH2 degradation was studied in detail under an artificial UV irradiation in the presence of hydrogen peroxide(H2O2), in which the effects of initial ArNH2, H2O2 and PW11Fe(Ⅲ)(H2O) concentration on the photo-catalytic rate of ArNH2 degradation were examined. The experimental results show that a complete ArNH2 degradation was obtained in less than 60 min in a pH=6.86 mixed phosphate solution containing 0.1 mmol/L PW11Fe(Ⅲ)(H2O)+0.2 mmol/L H2O2+0.1 mmol/L ArNH2 under a 300 W Hg lamp irradiation, and a total organic carbon(TOC) removal of ca. 52% was achieved. A mechanism of photocatalytic decomposition of H2O2 to hydroxyl radicals by PW11Fe(Ⅲ)(H2O) was proposed and a comparison of ArNH2 photo-catalytic degradation in acidic and neutral solutions was discussed.

Key words: Iron-substituted heteropolyanion, Homogeneous photocatalysis, Aniline degradation, Hydrogen peroxide