The Photocatalytic Degradation Of Antibiotics By Titanium Dioxide And Iron-titanium Composite Materials

Titanium dioxide photocatalysts were prepared by solvothermal method using tetrabutyl titanate as titanium source,mixture of glycerol and ethanol as the solvent.The as-prepared samples were characterized by XRD,TG-DSC,FE-SEM,BET,XPS,UV-Vis DRS and PL.The effects of the volume ratio of glycerin and alcohol,the reaction temperature,the calcination temperature and time on the morphology and photocatalytic activity of samples were investigated.The results showed that the morphology and photocatalytic activity of the samples were affected by these synthetic conditions above.Titanium dioxide synthesized in optimum conditions was anatase phase with the particle size about 25 nm and specific surface of 27.38 m2/g.Under the 300W UV light,the initial concentration of tetracycline hydrochloride(TTC)solution was 0.1 g/L,the initial pH value was 9 and the catalyst dosage was 1 g/L,it showed a high photocatalytic activity for TTC and the light removal rate was 98.63%The as-prepared samples were used to dispose water samples in various processing stages of urban sewage plant.The results showed that photocatalytic oxidation technology can remove the organic matter in the wastewater better after it was applied in anaerobic treatment.Iron-titanium composite material was prepared by solvothermal method using tetrabutyl titanate as titanium source,Fe3O4 as iron source,mixture of glycerol and ethanol as the solvent.The as-prepared iron-titanium composite material was characterized by XRD,XPS and VSM.The effects of doping content of iron,reacted temperature and time on the-photocatalytic activity of samples were investigated as well as the adsorption performance of samples for antibiotics and mechanism of photocatalytic activity of samples.The results showed that(Fe2.5Ti0.5)1.04O4 composites can be obtained when the doping content of iron was between 6%to 27%,reaction temperature was at 110?-135? and reaction time was within range of 6h-24 h.When the doping contentof iron was 18%,reaction temperature was 120? and the reaction time was 12 h,the saturation magnetization of the sample was 9.12 emu/g.the forbidden band width is 1.51eV.These iron-titanium composite material had a better adsorption and photocatalytic activity for several kinds' antibiotics.Under the optimum conditions iron-titanium composite material the order of removal efficiency of adsorption were tetracycline>?-lactam>quinolone class>sulfonamides.The order of removal efficiency of photocatalysis were tetracycline>sulfonamides>?-lactam.Under the 300W UV light,the initial concentration of TTC was 0.1 g/L,the photocatalytic removal rate was 94%after three times of material recycling.