Degradation of antibiotic wastewater based on high-pressure submerged cavitation jet and synergetic methods

摘要

In the present work, degradation of antibiotic wastewater is carried out using high-pressure submerged cavitation jet technique in combination with multiple synergetic methods, that is, UV/Fenton, analogous Fenton, and photocatalytic oxidation. Three kinds of common antibiotics, such as amoxicillin, doxycycline, and sulfadiazine sodium, are selected as model pollutants. Individual operation of hydrodynamic cavitation under different nozzle inlet pressure conditions is first carried out. It is observed that higher jet inlet pressure is more favorable for chemical oxygen demand (COD) reduction and the maximum COD reduction is 13.52%. Then, the degradation process is intensified by introducing UV/Fenton method. Effects of important parameters are investigated and the optimum operating conditions are obtained, that is, pH of 2.7, H2O2/COD molar ratio of 1.99 and FeSO4 concentration of 8.33 mg/L. The maximum COD reduction of 51.10% is achieved under these optimum conditions and the synergetic index is 2.121. Subsequently, the analogous Fenton and photocatalytic oxidation are successively introduced for further enhancing the COD reduction, and the synergetic indices of various combinations are evaluated. The comparison of the different approaches indicates that the most effective and economical approach for antibiotic wastewater treatment is the combination of hydrodynamic cavitation, UV/Fenton, analogous Fenton, and photocatalytic oxidation, with the maximum COD reduction of 66.63% and the synergetic index of 2.581.