Supported metal catalyst for degradation of toxic organic pollutants in industrial effluent

Abstract

The study investigates the process of catalytic wet air oxidation (CWAO) of acetic acid by using a catalyst (iron with different weight percentages, supported on alumina), prepared by the Excess Solution Impregnation (ESI) method. Brunauer-Emmett-Teller (BET) surface area measurement and thermogravimetric analysis (TGA) were used for the characterization of the catalyst. The BET analysis yielded data on the catalyst's specific surface area, which was determined to be 77.97 m2/g and the analysis offered information on the catalyst's adsorption capacity. The TGA analysis revealed insights into the catalyst's thermal stability and breakdown properties and results showed a total weight loss of -17.6 wt. % in the temperature range of 70oC to 760oC. The activation energy was found to be 95.901 kJ/mol. Various key reaction parameters, including temperature, mixing speed, metal loading, and initial acetic acid concentration, were varied to carry out the catalytic wet air oxidation of acetic acid. The maximum level of degradation of acetic acid was achieved under the optimum conditions of a temperature of 80°C, a mixing speed of 400 rpm, an iron loading of 1.5 wt.%, and an initial concentration of 1000 ppm. The introduction of a power law model to the reaction kinetics provided mechanistic insights into the CWAO process. The process of acetic acid oxidation by an iron catalyst, with the involvement of molecular oxygen, has been explained, emphasizing the mechanism of the reaction. The iron catalyst supported on alumina showed satisfactory performance in the catalytic wet air oxidation (CWAO) of acetic acid, with a maximum conversion rate of 88.5% under the most optimum conditions.