(60aa) Degradation Kinetics of Sulfamethoxazole By Using Heat Activated Sodium Percarbonate

The degradation kinetics of a frequently used antibiotic sulfamethoxazole (SMX) was investigated by using heat activated sodium percarbonate (SPC). Significant degradation (90%) of SMX was observed with a reaction time of 3 hours. The SMX degradation followed pseudo first order kinetic model. The maximum consumption of SMX was experienced during the initial 10 min of the reaction and no longer consumption observed after initial ten minutes thus, decreased the rate of reaction. The SMX degradation pseudo first order rate constant considerably decreased with increasing pH from 7 to 9 and increased with increasing temperature. Quenching experiments elucidated the key role of hydroxyl radicals as compared to superoxide radicals during the SMX degradation by using heat activated SPC oxidation. Although, SPC did not react with SMX without heat activation thus, dominating the effect of pH on hydroxyl radical’s concentration as compared to the effect of pH on SMX degradation. The SMX degradation decreased due to consumption of hydroxyl and superoxide radicals and presence of higher concentrations of dissolved natural organic matter (≥10 mg/L). No significant improvement in mineralization (4.5-4.7%) was observed by increasing the temperature to 90°C. The findings of present study can explore new insights based on the heat activated SPC and capability of this system in environmental contaminants degradation.