The Reactive Red 2 dye was photoelectrochem. treated in aq. soln. (concn. 100-1000 mg/L) with NaClO(4) under irradn. (254 nm) and current d. 0.01-0.02 A/cm(2) for 2-4 min by using the Ti/70%TiO(2)-30%RuO(2) and Pt electrodes. Under optimum conditions, the full decolorization of the soln. and a high mineralization of the dye (about 92% according to decrease in total org. C) was achieved. The Box-Hunter exp. design was used for the process optimization.