Preparo de materiais a partir de lama vermelha e avaliação da atividade catalítica

Abstract

The result of the activity of some of the primary sector industries is accompanied by the generation of large amounts of solid waste. Red mud is a waste product of the aluminum industry has in its constitution metals with interesting properties and various studies have assessed its potential as a catalyst. We studied the utilization of red mud (RM) in the preparation of new materials were tested as catalysts in degradation reactions and adsorption of the organic compound model methylene blue (MB). The first part was used fresh red mud and subjected to treatment with acetic acid (RM_1% and RM_5%). The materials were characterized and tested using the procedures Fenton, photo-Fenton and photocatalysis. Following treatment, the RM increased by about 4 times the surface area. According to oxidation test, it can be seen that the photo-Fenton system proved to be the most active for materials with 100% removal after 3 h of reaction for RM_5 % and after 4 h for RM_1%. In the second part of the work, was first tested the RM subjected to treatment with CO2 and Fe(NO3)3, followed by RM_CO2 test treated with different percentages of Fe(NO3)3. For the characterization it was found that the treatments made changes in the phases present in the RM and improving their catalytic ability. In the first oxidation tests, RM_Nat_CO2_6%Fe removed 82% of color and RM only 48%. In the following tests RM_CO2_6% Fe showed removal capacity of 74%, the RM_CO2_8%Fe was 87% and RM_CO2 29% of removal. Based on the above results, it can be noted that the application of red mud in catalytic processes presents itself as an attractive alternative, contributing to environmental preservation processes, development of sustainable technologies and serving the interests of the aluminum industry and other sectors productive in minimizing its contaminants.