UV／负载TiO2对微量磺胺甲恶唑的氧化降解效能

摘要

The immobilized TiO2 film loaded on fiberglass meshes was prepared by sol-gel method. Removal efficiency and influencing factors of sulfamethoxazole (SMX)by the combined process of UV and immobilized TiO2 were studied in detail through pilot test. Results show that SMX can be effectively oxidized by the UV/ immobilized TiO2 process and the first order reaction kinetics model can be used to simulate the oxidation process well. To a certain degree,degradation rate is affected by the initial concentration of SMX and water pH. Lower initial concentration and lower water pH both favor the degradation of SMX. The optimum concentration of H2 O2 for the system is found to be 10μg/L when initial concentration of SMX is 300μg/L. Furthermore,the existence of n-butyl alcohol and KI can reduce the degradation rate of the system on SMX. The reason is that n-butyl alcohol and KI compete with SMX for ·OH. The degradation test of actual water samples which the standard SMX is added to shows that SMX in source water is removed more easily than it in biochemical pool of sewage plant.%采用溶胶凝胶法，以玻璃纤维网为载体负载TiO2薄膜。利用小试试验研究了UV/负载TiO2体系对水中微量磺胺甲恶唑（SMX）的降解效能及影响因素。结果表明UV/负载TiO2体系对纯水中SMX有较好的去除效果，且降解过程很好地符合一级反应动力学模型；SMX的初始浓度和溶液pH值对体系的氧化性能均有一定的影响，较低的初始浓度和较低的pH值均有利于体系对SMX的降解；H2 O2的投加浓度存在最佳值（当SMX初始浓度为300μg/L时，最佳投加量为10μg/L）；此外，正丁醇和KI的存在均会降低体系对SMX的降解速率，原因在于正丁醇和KI会与SMX分子竞争·OH。通过对实际水样加标降解的试验可知，水源水中的SMX较污水生化池出水中的SMX更易去除。