Avaliação do potencial de carepa de aço como agente catalítico em Processo de Oxidação Avançada (POA) tipo fenton

Abstract

Issues related to environmental contamination affect society and urge researchers and environmental specialists in the constant search for technological methods of efficiency, not only minimizing them, but also ensuring that no other pollutants are generated in the process. A relevant option to treat waste of environmental importance is through Advanced Oxidative Processes (POA's), which are characterized by the production of hydroxyl radicals (•OH), species with high oxidizing potential and that are able to modify the structure of pollutants transforming them. on elements with little or no polluting capacity. The objective of the present work was the characterization of a steel residue (steel scale), a byproduct from steel production, formed on the surface of billets leaving the blast furnace by the reaction of the steel at high temperature with air, oxidizing and forming a Iron oxide “shell” that can serve as a source of iron in Fenton-type Advanced Oxidation Processes, where hydrogen peroxide (H2O2) is used with iron as a catalyst for the production of •OH. The characterization of the material showed that iron oxides wustite (FeO), hematite (Fe2O3) and magnetite (Fe3O4) represent more than 90% of the constitution of the scale and due to their ferromagnetic nature, the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets, becomes a substance that is easily separated from waste after treatment. The results showed that in a condition with 20 g of scale, 1 mL of H2O2 and pH = 3, a better performance in degradation of the model compound used, 2,4-Dinitrophenol and its reaction intermediates was achieved, also reducing medium acute toxicity in Escherichia coli (E. coli), Scaling reusability experiments in a continuous flow reactor, where the reactor body is continuously agitated by aeration and supplied with feed while the same volume is discharged to keeping the level constant inside the reactor, with the effluent current identical to that remaining inside the tank, also indicated a significant degradation potential of the model 2,4-DNF compound, in the scale model 40 g, 2 mL of H2O2, and pH = 3,0.