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

The homogeneous photocatalytic degradation of cationic acridine orange mono hydrochloride (AO) and anionic alizarin violet 3B (AV) in photo-Fenton syst em under visible irradiation was studied. The generated intermediates and d egradation processes of AO were investigated by EPR, IR and GS-MS. It was f ound that visible irradiation not only enhances apparently the generation o f 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-di methyl acetamide were found during the degradation of AO. Ammonium ions wer e also formed during the degradation of AO through the ion-selective electr ode analysis. (C) 2000 Elsevier Science S.A. All rights reserved.