Study On Treatment Of Antibiotic Wastewater By TiO₂ Photocatalytic Oxidation Technology

China is a big country in the use of antibiotics and has played a huge role in the pharmaceutical industry.However,antibiotics that have not been absorbed and used will be discharged into the environment,migrated and transformed into the human body through various channels,have an impact on human health,and how to degrade the environment.Residual antibiotics have become the focus of current research.Under the current environmental protection development concept,TiO2 photocatalysis is more stable and efficient than other treatment methods.It can degrade organic pollutants in water into CO₂ and H₂O₂ to avoid secondary pollution.However,TiO₂ has shortcomings such as insufficient utilization of ultraviolet light and weak catalytic activity.These shortcomings make TiO2 not widely used in wastewater treatment.How to improve the utilization of TiO₂ to ultraviolet light and its photocatalytic activity have become the main research directions at present.In the experiment,tetrabutyl titanate and ferric nitrate nonahydrate were used as the main raw materials.Pure TiO2 was prepared by hydrothermal method,and TiO2-Fe2O3 composite materials with different Fe2O3 ratios were prepared by oxytetracycline and tetracycline as targets.The effects of factors such as the ratio of Fe2O3 to TiO2,the reaction system,the amount of catalyst added,the pH,and the number of recycling times on the degradation rate of oxytetracycline and tetracycline were studied.XRD,BET,XPS,TEM and other technical methods were used to conduct composite materials.Characterization analysis.Various characterization results show that Fe2O3 successfully composites with TiO2,which reduces the crystal size of the catalyst and increases the specific surface area,which effectively improves the photocatalytic activity of TiO₂.Compared with pure TiO2,the composite photocatalyst can also utilize ultraviolet light with lower energy intensity,which improves its utilization of ultraviolet light.Degradation of oxytetracycline by the composite catalyst shows that under the condition of pH=7,trace H₂O₂?volume V=1ml,concentration C=4mmol/L?,the degradation rate of oxytetracycline by TiO₂-5%Fe₂O₃ composite catalyst can reach 10minutes.90.01%,which is 30.92%higher than the degradation capacity of pure TiO2;the composite catalyst is recycled and reused twice,and the degradation rate of oxytetracycline can reach 86.06%after 40 minutes of reaction.The experiment of degradation of tetracycline by the composite catalyst shows that under the system of pH=7 and trace H2O2?volume V=1ml,concentration C=4mmol/L?,the degradation rate of tetracycline by TiO2-5%Fe2O3 composite catalyst can reach 80.11%in 15minutes,The degradation ability of pure TiO2 has been increased by 16.07%;the composite catalyst has been recycled and reused twice,and the degradation rate of tetracycline can still reach 80.01%after 70 minutes of reaction.The active species quenching experiments showed that the degradation of oxytetracycline and tetracycline by the composite catalyst is in line with the second-order reaction kinetics.The active substances that play an oxidation role in the reaction are·OH and holes.Fe³⁺can capture the TiO₂ generated after absorbing ultraviolet light Electron,Fe³⁺is reduced to Fe²⁺.After the reduction,Fe²⁺reacts with H₂O₂ to oxidize to Fe³⁺again to achieve the mutual conversion of Fe³⁺and Fe²⁺,which accelerates the conduction rate of electrons on TiO₂,enables rapid generation of·OH and holes,and improves the photocatalytic rate.