Synergistic degradation performance and mechanism of 17β-estradiol by dielectric barrier discharge non-thermal plasma combined with Pt-TiO2

A synergistic system of dielectric barrier discharge non-thermal plasma (DBD) combined with Pt-TiO2 was developed to investigate the degradation performance of 17β-estradiol (E2) by making full utilization of the UV light formed from the discharge zone. The Pt-TiO2 was prepared by impregnation-reduction method. The results of EDS analysis indicated that Pt was load on TiO2, the atomic percentage of Pt and amount loaded were 0.27% and 0.91 at.%, respectively. The removal efficiency and degradation yields were obviously increased from 72.0% to 98.9% and 329.2 × 10−6 to 468.1 × 10−6 g/kW h by addition Pt-TiO2 to DBD system as the peak voltage, E2 concentration, pH value, and photocatalyst additive amount were 12 kV, 400 μg/L, 5.6, and 50 mg/L, respectively. Results demonstrated that the UV light formed could be utilized to strength the degradation performance of E2. The results also elucidated that the degradation process followed the first-order kinetic model, and the experimental parameters had significant effect on the first-order kinetic constants and removal efficiency of E2. Furthermore, six intermediate products were identified and their proposed structures were provided. The degradation mechanisms revealed that the active species of hydroxyl radicals and ozone had a key function in the degradation of E2 in the synergistic system.