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

In order to solve the problem that the traditional biochar(BC) has insufficient removal ability of enrofloxacin and TiO is difficult to recycle. In this study, TiO-modified biochar composites were prepared by impregnation method. Through characterization analysis, The BET specific surface area results indicated that after loading TiO, the specific surface area of TiO-biochar(Ti-BC), TiO-ironized biochar(Ti-FBC) and TiO-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 TiO 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, the enrofloxacin degradation rate of 100 mg·L reached 85.25%. The quenching test confirmed that the active substance O• 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.