Study of the degradation of the textile Reactives Dyes Blue 19 and Black 5 via H2O2 electrogenerated and electro-fenton (H2O2 electrogenerated/fenton) and via direct electrooxidation in electrodes of TI/BDD

Abstract

The pollution of water resources has been one of the major problems of modern society, since water is essential for the life of all species. The excessive population growth together with increased industrial activity corroborate this environmental problem. The textile industry has a special feature, because it generates large volumes of wastewater that are highly colored due to the presence of dyes that do not remain on the fiber during the dyeing process. These textile effluents when not properly treated, can cause visual pollution, changes in biological cycles affecting mainly the processes of photosynthesis, furthermore, studies have shown that some classes of dyes, especially azo-dye, and byproducts, can be carcinogenic and/or mutagenic. In general terms, the wastewater containing organic compounds can be treated by oxidation chemical, biological digestion or thermal incineration, however, most commercially used dyes are resistant the biodegradation, photodegradation and the oxidizing agents, so it is necessary the development of appropriate technologies for water treatment and wastewater to be able to destroy or immobilize toxic compounds more effectively and economically as possible. The electrochemical technology offers efficient and versatile means to control water pollution through redox reactions, through direct reactions between the pollutants species and the electrode surface or the synergism of these processes with the power of oxidizing species generated in situ. In this context, the aim of this work is to study the processes of degradation of reactive dyes Reactive Blue 19 (RB-19) and Reactive Black 5 via electrogeneration cathodic hydrogen peroxide (H2O2), electro-fenton (H2O2 electrogenerated/Fe (II)), H2O2 electrogenerated/O3/UV and conjugates processes, furthermore, to the direct electrochemical oxidation using type electrodes DSA and TI/DDB. The efficiency of the processes of degradation of the reactive dyes will be evaluated by removing the coloration, the concentration decays, by the formation of inorganic ions and reducing of the total organic carbon content depending on the electrode material, current and/or applied potential, as well as the efficiency of in situ generation of H2O2. With the development of this project is hoped to obtain the best experimental results of degradation of dyes, combined with lower treatment costs, safe operation and total mineralization of the pollutant. (AU)