Degradation and Detoxicity of Tetracycline by an Enhanced Sonolysis

Abstract

Tetracycline is named by its four special benzene rings in molecular structure, which has been proven as a strong inhibition chemical for many kinds of bacterial. To solve the problem of residual tetracycline containing in municipal and medicine industrial wastewater effluents, this study tried to combine the ultrasound with transition metals (including Co2+, Ag+ and Fe2+) and oxidizing agents (persulphate ions, S2O8 2– and hydrogen peroxide, H2O2) with a continuous dosing mode as an innovative “Enhanced sonolysis” for degrading the tetracycline. Experimental results indicated that the addition of Fe2+ and H2O2 with ultrasound showed the better performance than other combinations by Co2+, Ag+ and S2O8 2–. As the ultrasound coupled with 0.2 mM Fe2+ and 2 mM H2O2, more than 90.7% and 45.9% of tetracycline were degraded and mineralized. In addition, the toxicity was significantly reduced while the cell viability increased from 53.1% (un-treated) to 87.5% (treated). Effect of pH on the degradation of tetracycline in this study was insignificant but pH 3 showed the better efficiency. It was concluded that the enhanced sonolysis was effective on the degradation, mineralization and detoxicity of tetracycline