The Adsorption And Photodegradation Of Tylosin On Graphene Titanium Dioxide Composite

Antibiotics was much use for medicine and breeding industry, making many antibiotics enter the environment with the form of a technical or metabolitest, because the antibiotics are still has certain biological activity, will cause potential harm for ecological environment.Antibiotics as a new "false persistence" pollutant, its environmental behavior and pollution control causes the extensive concern for environmental workers in recent years.However, the removal technology of antibiotics has the low efficiency, with the shortcomings like secondary pollution. Ti O2 photocatalytic oxidation has stable properties, no secondary pollution, and high degree of mineralization to pollutants, however Ti O2 can only sensitive by ultraviolet, that limits its practical application in pullution control field.. In order to improve the use efficiency of visible light, this study use graphene modify titanium dioxide and prepared a new type of graphene titanium dioxide composite photocatalytic materials(G-Ti O2), selection of tylosin(tylosin, TYL) as a typical representative of antibiotics, studied the adsorption behavior of TYL on G-Ti O2 and TYL photolysis features in visible light, which provide technical guide for antibiotics pollution control. The study found that:1. Prepared G-Ti O2 used graphene as template,found titanium dioxide is mainly exist with the form of linear, and the diameter of 20~50 nm, is arranged on the surface of graphene, graphene and titanium dioxide combined Ti-O-C chemical bonds, and crystal phase of Ti O2 was anatase in G-Ti O2 composite.2. Adsorption of TYL on G-Ti O2 has obvious nonlinear, the adsorption process followed the pseudo-second order model, adsorption data can fit with Langmui model, adsorption capacity increased with the increase of solution p H value increases, the overall adsorption process is probably control by electrostatic interactions, vander Waals forces, hydrogen bonding interaction.3. Under simulated natural light, the photodegradation of G-Ti O2 to TYL has a good performance, when graphene doping amount to 1% can reach 55.4%, and good reusability of catalyst. Photolysis rate is inversely proportional with the initial concentration of TYL; With the increase of solution p H showed a trend of decrease after the first increase. The photolysis mechanism of TYL on G-Ti O2 mainly related electronic-hole separation efficiency improvement of the catalyst.