Optimization of sonochemical degradation of amoxicillin by sulfate radicals in aqueous solution using response surface methodology (RSM)

Abstract

Efficiency in the sonochemical degradation of amoxicillin using sulfate radicals as a function of initial concentration of amoxicillin, Ag2SO4, Na2S2O8 concentration and power of ultrasonic irradiation was studied. A central composite design (CCD) with response surface methodology (RSM) was used to investigate the influence of individual and interaction of operating variables on removal efficiency with the aim of recognizing the optimum operating conditions. Satisfactory prediction based on a quadratic model with very low probabilities (<0.0001) at a confidence level of 95% was obtained for removal efficiency. The quadratic model was best fitted to the experimental data with high correlation coefficients of 0.9682 and 0.9539 for R2 and R2adj, which was quite satisfactory. The obtained optimum conditions for sonochemical degradation efficiency of amoxicillin were obtained as 0.11mmol/L, 152.3mmol/L, 1.45mmol/L and 233W for AMX, PS, Ag and ultrasound power, respectively; in order to achieve a removal efficiency of >98% in a 60min reaction time. This study effectively demonstrated the usage and advantages of response surface methodology for the modeling and prediction of process response. It was observed that the sulfate radical-based advanced oxidation process (SR-AOP) is an effective and efficient technology for the mineralization of amoxicillin in aqueous solution.