Evaluation phytotoxic effects and decolorization of simulated and real textile wastewaters by UV/H2O2

The discharge of dyes in aquatic ecosystems is of environmental concern due to intense coloration that decrease photosynthetic activity and the possible toxic effects (Hao et al., 2000). Therefore, the development and understanding of processes for the removal of textile dyes in wastewaters, like UV/H2O2, is of major importance. In the present study different textile dyes (Methylene Blue, Eliamine Blue F and Indigo) were used as model pollutants in water (ranging from 5 – 5000 mg/L). and real wastewater containing the Indigo dye was studied. The dyes in solution and the wastewater were treated by UV/H2O2 to study the influence of: the type of dye, the initial concentrations of dye, the initial concentration of H2O2, the initial pH of the solution and the irradiation times in the dye decolourization of the treated solutions. The phytotoxic effect in Raphanus sativus of the treated and untreated dyes and wastewater in solution were evaluated. The Raphanus sativus data indicated that the dyes and the wastewater inhibited the first stage of development before treatment. The assay after treatment with UV/H2O2 of the textile dyes indicated the seed germination of R. sativus were inhibited by Eliamine Blue F and Methylene blue.