Degradation of tetracycline by heat/peroxymonosulfate and ultrasound/ peroxymonosulfate systems: performance and kinetics

Abstract

In recent decades, water pollution caused by emerging contaminants such as pharmaceuticals, has attracted much attention. Antibiotics are commonly used pharmaceuticals, and their residue in water may accelerate the development of antibiotic resistance genes, which can produce resistance to the treatment of diseases. In this study, two energy-based systems, heat/peroxymonosulfate (PMS) and ultrasound (US)/ PMS were chosen to treat the typical antibiotic tetracycline (TC) in water. The influencing factors and kinetic equations of TC degradation by heat/PMS and US/PMS were investigated and the rates of TC degradation by the two systems were compared. The results showed that the optimal PMS concentration required for TC degradation in both systems was 0.3 mM, and neither system was affected by solution pH. The power of the US in the US/PMS system was as important as the temperature in the heat/PMS system because they provided activation energy. Both heat and US could activate PMS to degrade TC, and US was slightly superior with 80% TC removal under the conditions of [TC] ¼ 20 mg/L, [PMS] ¼ 0.3 mM, pH ¼ 6.4, T ¼ 20 °C, and US power ¼ 550 W. US is considered to be more advantageous in activating PMS to degrade TC.