Decolorization of textile wastewater by photo-fenton oxidation technology

This paper describes the use of photo-fenton process for color removal from textile wastewater stream. The wastewater sample to be treated was simulat ed by using colorless polyvinyl alcohol (PVA) and reactive dyestuff of R94H . As a result, the hydroxyl radical (HO .) oxidation can effectively remove color, but the chemical oxygen demand (COD) was removed in a slight degree . The color removal is markedly related with the amount of HO . formed. The optimum pH for both the OH . formation and color removal occurs at pH 3-5. Up to 96% of color can be removed within 30 min under the studied conditio ns. Due to the photoreduction of ferric ion into ferrous ion, color resurge nce was observed after 30 min. The ferrous dosage and UV power affect the c olor removal in a positive way, however, the marginal benefit is less signi ficant in the higher range of both. PVA as the major background COD of a te xtile wastewater stream inhibits the color removal insignificantly as its c oncentration increases. (C) 2000 Elsevier Science Ltd. All rights reserved.