Hydrodynamic cavitation (HC) degradation of tetracycline hydrochloride (TC)

Abstract

• Five different HC reactors were compared to study the degradation of TC. • Degradation performance and kinetics under different operating parameters. • Synergetic degradation of TC by HC + Na 2 S 2 O 8 and HC + O 3 was studied. • Compared with the separate approach, synergistic ways provide superior results. The degradation of organic pollutants by hydrodynamic cavitation (HC) has become a potential research direction. HC reactor has the advantages of simple structure, easy operation, and low maintenance costs. The combination of HC and other advanced oxidation processes (AOPs) can greatly improve the degradation rate and energy efficiency, reduce the consumption of chemicals and save cost. HC technology was used to degrade tetracycline hydrochloride (TC), the effects of reactor type, geometric parameters, and operation conditions on the degradation were investigated. The results indicated that under the optimal inlet pressure of each reactor, the degradation performance of OP 3 was the best, and the degradation rate was 44.9%. After combined HC reaction with 0.10 g/L Na 2 S 2 O 8 for 2 h, the degradation rate was 92.2%. The synergistic index of HC + 0.050 g/L and HC + 0.10 g/L Na 2 S 2 O 8 was 1.56 and 4.41, respectively. The synergistic index of HC + 0.047 g/L O 3 process was 1.60, and the degradation rate reached 95.5% after 80 min. The degradation intermediates were analyzed by UV–Vis absorption spectrum and LC-MS, and the degradation pathway and mechanism were proposed.