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

Abstract

In order to solve the problem that the traditional biochar(BC) has insufficient removal ability of enrofloxacin and TiO 2 is difficult to recycle. In this study, TiO 2-modified biochar composites were prepared by impregnation method. Through characterization analysis, The BET specific surface area results indicated that after loading tio 2 , the specific surface area of TiO 2-biochar(Ti-BC), TiO 2ironized biochar(Ti-FBC) and TiO 2-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 2 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 O 2 •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.

Removal of COD in wastewater by magnetic coagulant prepared from modified fly ash

“…Due to the limited adsorption performance of y ash, the removal capacity of COD was gradually reduced after several coagulations. Through acid-base modi cation of y ash and mixed magnetic operation, the surface of the new coagulant Fe-AFA was rougher, the adsorption sites were increased, thus enhancing the adsorption and occulation capacity of the coagulant (Wang et al 2020). What is interesting about the data in Figure 8 is that the COD removal rate by Fe-AFA remained above 60% after ve recycling.…”

“…This was due to the corrosive effect of base and acid, which increased the surface defects of y ash, enriched the porosity, and increased the speci c surface area. Therefore, the coagulation provided more adsorption sites, and the adsorption capacity were enhanced, which makes more COD enriched on the surface of coagulations and removed by sedimentation through the coagulation process (Wang et al 2020). The magnetic mixing operation of the modi ed y ash can further improve the coagulant's ability to remove COD and greatly reduce the time required for occulation reaction.…”

Synthesis of a magnetically separable LDH-based S-scheme nano-heterojunction for the activation of peroxymonosulfate towards the efficient visible-light photodegradation of diethyl phthalate

“…Therefore, the calculated bandgap values were 3.25 eV, 2.85 eV, and 1.72 eV, for Fe 3 O 4 , CuCr-LDH, and Fe 3 O 4 @CuCr-LDH, respectively. Consequently, in comparison with the pure magnetite and CuCr-LDH, their composite has a smaller bandgap, which in turn results in its appropriate excitation under the visible light irradiation to form more electron-13 hole pairs and improve the photocatalytic activity under visible light [32].…”

Novel BiOBr by compositing low-cost biochar for efficient ciprofloxacin removal: the synergy of adsorption and photocatalysis on the degradation kinetics and mechanism insight

“…TiO 2 is the most common photocatalytic material, which has been applied in the eld of photocatalysis. [8][9][10] However, it only responds to ultraviolet light, resulting in its low utilization of sunlight. Visible light accounts for 43% of the sunlight.…”