Orange II photocatalysis on immobilised TiO2 Effect of the pH and H2O2

The discoloration and mineralisation of the azo-dye Orange II in a photoreactor using TiO2-coated glass rings as immobilised photocatalyst is reported. The variation of pH and the H2O2 addition effect were systematically investigated. The use of the response surface methodology allowed to fit the optimal values of the parameters leading to Orange II abatement. Also, a single polynomial expression modelling the reaction was obtained. The photocatalytic degradation of Orange II was followed by spectrophotometric analysis and total organic carbon (TOC) measurements. (C) 2003 Elsevier B.V. All rights reserved.