Preparation of TiO2-modified Biochar and its Characteristics of Photo-catalysis Degradation for Enrofloxacin

Abstract

AbstractIn order to solve the problem that the traditional biochar(BC) has insufficient removal ability of enrofloxacin and TiO2 is difficult to recycle. In this study, TiO2-modified biochar composites were prepared by impregnation method. Through characterization analysis, The BET specific surface area results indicated that after loading TiO2, the specific surface area of TiO2-biochar(Ti-BC), TiO2-ironized biochar(Ti-FBC) and TiO2-alkaline biochar(Ti-KBC) increased by 4.34, 10.43 and 11.52 times, respectively. The analysis results of SEM, EDS, FT-IR, XRD and XPS showed that TiO2 was supported on biochar in the anatase state. The UV-vis DRS measurement showed that the band width of Ti-KBC was the smallest and the best catalytic activity. Under 15 W UV lamp (254 nm) irradiation, the photocatalytic degradation process of enrofloxacin by different biochar accords with the first-order kinetic equation. Ti-KBC showed best degradation effect under different initial concentrations of enrofloxacin. When the pH of the solution was 5.0 and the dosage of Ti-KBC was at 2.5 g·L−1, the enrofloxacin degradation rate of 100 mg·L−1 reached 85.25%. The quenching test confirmed that the active substance O2•— played a major role in the photocatalytic degradation process. After five cycles of the test, the degradation rate of Ti-KBC for enrofloxacin was 77.14%, which was still better than that of BC, Ti-BC and Ti-FBC.