Photoassisted degradation of dyes in the presence of Fe3+ and H2O2 under visible irradiation

The homogeneous photocatalytic degradation of cationic acridine orange monohydrochloride (AO) and anionic alizarin violet 3B (AV) in photo-Fenton system under visible irradiation was studied. The generated intermediates and degradation processes of AO were investigated by EPR, IR and GS-MS. It was found that visible irradiation not only enhances apparently the generation of hydroxyl radicals but also accelerates effectively the degradation of the dyes in the presence of Fe3+ and H2O2 N,N-dimethyl formaldehyde and N,N-dimethyl acetamide were found during the degradation of AO. Ammonium ions were also formed during the degradation of AO through the ion-selective electrode analysis. (C) 2000 Elsevier Science S.A. All rights reserved.