PHOTODEGRADATION OF ENROFLOXACIN UNDER DIFFERENT CONDITIONS IN AQUEOUS SYSTEMS: KINETICS, PRODUCTS AND QUANTUM YIELD

摘要

The kinetics and products of enrofloxacin (ENR) direct photocatalytic degradation in aqueous solution under high pressure mercury lamp (HPML) were systematically investigated in this paper. The effects of different ENR initial concentrations, pH and light sources and products were explored in this study to assess its ecological fate. The high-performance liquid chromatography (HPLC) - fluorescence detector (FLD) was used to detect the ENR concentrations in the study. And the mass spectrometer (MS) was developed to characterize the main constituents of photodegradation products of ENR. The results showed that ENR degraded fast under the condition that the ENR initial concentration of 2mg L_1, pH=6 and artificial light with the degradation rate constant {k) of 7.30 x l〇 3 min1, 1.21 x i〇-3 min1 and 4.50 x i〇-3 min1, respectively. Furthermore, according to the analysis of ENR photocatalytic degradation products, the reaction process might include the defluorination, depiperazinering, deethylation and methylation. Quantum yield of ENR was measured to be 9.30 x i〇-3 in pure water under the irradiation by light emitting diode (LED) lamps. These results would reveal the direct photodegradation kinetics systematically under some reaction conditions in the lab and understand the hydrolysis characteristic to provide primary evidences to further researches.