Degradação do ácido húmico por processo de ozonização catalítica

Abstract

Humic substances are the main components of natural organic matter in soil and water, and can impair water quality, being responsible for the color, taste and odor of natural waters. Ozonation oxidation is able to efficiently remove unsaturated bonds from organic matter, reducing the coloration of the effluent. However, the use of catalysts aims to increase the yield of products and the selectivity of chemical reactions and to achieve higher rates of mineralization of the organic load. Nanoparticles that have been used for pollutant removal present high catalytic activity, low metal dissolution, large specific surface area and especially easy magnetic separation from water. Thus, the objective of the work is to investigate the catalytic activity of manganese ferrite and cobalt ferrite materials by the catalytic ozonation process of humic acid at different pH values, and results of the evaluation of the catalytic process by analysis of interaction of the materials with the humic acid solution, removal of total organic carbon and color reduction at UV254 and VIS400 wavelengths will be presented. The catalytic ozonation efficiency for humic acid color removal was > 90% for both catalysts and at all pH values studied. Both catalysts proved to be efficient for the mineralization of humic acid at pH 9.5, the efficiency of total organic carbon removal using manganese ferrite was 78 % and cobalt ferrite with 83 %. The materials showed amphoteric character, demonstrating acid-base properties depending on the pH of the solution. Catalytic ozonation provides rapid degradation and based on the scavenger results indicate that hydroxyl radicals are the oxidative species involved in the degradation of humic acid.