REMOVAL OF SALICYLIC ACID BY CATALYTIC WET OXIDATION PROCESS USING PEROVSKITE TYPE OXIDE

Abstract

The removal of salicylic acid from waste water by catalytic wet air oxidation (CWAO) process using perovskite type oxide LaFeO3 catalyst gives efficient results at the lower temperatures of 140◦C. The conversion of salicylic acid was also done by the CWAO on La 2O3 and Fe2O3 catalysts, and the results compared with the activities on all the three catalysts. The conversion percentage on LaFeO3 is very high as compared to the La2O3 and Fe2O3 because of its intramolecular H-bonding structure. Due to the presence of high acidity of intramolecular Hbonding the basic center of LaFeO3 catalysts adsorbed salicylic acid effectively and the total oxidation reactions took place. As temperature was raised above 140◦C, the intramolecular Hbonding of salicylic acid destroyed, which indicate the key role of intramolecular H-bonding in catalytic wet air oxidation process. Moreover, the perovskite type oxide LaFeO3 catalyst also indicated the greater stability in the catalytic wet air oxidation (CWAO) process of salicylic acid.