Influence of the structure of azo dyes on the degradation kinetics using photo-Fenton and zero valent iron processes and on toxicity

Abstract

Dyes are synthetic organic compounds widely used in textile, food, cosmetics industry and others. These compounds have been developed to give color resisting to chemical and biological degradation. The effluent containing dyes can cause serious problems for the aquatic environment due to high absorption of light that interferes on the process of photosynthesis in the aquatic medium besides of being potentially carcinogenic, toxic and of low biodegradability. Among the processes for wastewater treatment, Advanced Oxidation Processes (AOP), characterized by the generation of hydroxyl radical, have been studied as an alternative to conventional treatment of effluents in the degradation of various organic pollutants. Thus, this project aims to compare the degradation of different azo dyes using photo-Fenton process with artificial and solar irradiation and the oxidation with zero valent iron process, and to assess the acute and chronic toxicities of the products formed. From these results, to assess the influence of substituents on the efficiency of degradation and toxicity of products formed. (AU)