Degradation of p-Acetamidophenol in Aqueous Solution by Ozonation: Performance Optimization and Kinetics Study

The degradation of p-acetamidophenol (APAP), which is a typical component in pharmaceuticals and personal care products (PPCPs), in aqueous solution by ozonation process was studied. The effects of factors that affected the reaction rate, including the initial concentration of APAP, pH value, and O-3 dosage were investigated, and the degradation products and mechanism of ozonation were also discussed. The results showed that the degradation of APAP was affected by the initial concentration of APAP, pH value, and O-3 dosage. The optimized degradation condition was observed at pH 12.0. Under the same condition, increasing the pH value and ozone dosage would improve the degradation efficiency of APAP, while the degradation rate of APAP increased as the initial concentration of APAP decreased. Under the conditions of pH 2.0-12.0, an ozone dosage of 16-64 mg min(-1), a pollutant concentration of 200-3000 mg L-1, and a temperature of 25 degrees C, the degradation followed the pseudo-first-order kinetics. Moreover, the kinetic model was proposed with the function of C = C-0 exp(-11.359Q(O3)(1.3475)C(0)(-0.8487)[OH-](0.0343)t).