Acid Orange 61, Acid Red 97 and Acid Brown 425 dyes were
obtained from Trumpler Española, S.A. (Barberà del Vallès, Barce-
lona, Spain). H2O2 (30%) was purchased from Scharlau. Degrada-
tion solutions were prepared in ultrapure Milli-Q water from a
system supplied by Millipore (USA).