The utilization of microwaves in revitalizing peroxymonosulfate for tetracycline decomposition: optimization via response surface methodology

Abstract

Antibiotic contamination in water has received significant attention in recent years for the reason that the residuals of antibiotics can promote the progression of antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs). It is difficult to treat antibiotics using conventional biological treatment methods. In order to investigate an efficient new method of treating antibiotics in water, in this study, microwave (MW) was employed in revitalizing peroxymonosulfate (PMS) to treat typical antibiotic tetracycline (TC). The Box–Behnken design (BBD) was applied to organize the experimental schemes. The response surface methodology (RSM) optimization was run to derive the best experimental conditions and validated using actual data. Moreover, the main mechanisms of PMS activation via MW were resolved. The results demonstrated that the relationship between TC removal rate and influencing factors was consistent with a quadratic model, where the P-value was less than 0.05, and the model was considered significant. The optimal condition resulting from the model optimization were power = 800 W, [PMS] = 0.4 mM, and pH = 6.0. Under such conditions, the actual removal of TC was 99.3%, very close to the predicted value of 99%. The quenching experiment confirmed that SO4•− and •OH were jointly responsible for TC removal. HIGHLIGHTS MW/PMS was employed to treat tetracycline.; BBD was applied to design the experimental protocol.; The equation between TC removal and influences was established.; RSM was used to predict optimal conditions.; TC was co-oxidized by SO4•− and •OH to CO2 and H2O.;

Keywords

• box–behnken design
• microwave
• peroxymonosulfate
• response surface methodology
• tetracycline