TiO2光催化降解水中土霉素的动力学研究

环境中抗生素的出现及其引起的危害正受到越来越多的关注。以高压汞灯为光源，选用较为广泛的抗生素土霉素（OTC）为处理对象。考察了初始质量浓度、反应过程中光照、催化剂投加量、溶液起始pH、溶液中DOM和NO^-₃对光催化降解的影响，研究了其光降解动力学。结果表明，TiO₂光催化氧化法能够有效去除水中半微量的OTC，OTC的光降解过程符合一级反应动力学模型；UV/TiO₂联用工艺对TOC也有很好的去除效果，反应90 min，TOC去除率可达74%；OTC的初始浓度从30 mg/L增大到90 mg/L，反应速率从0.0619 min^-1降低到0.0130 min^-1；随着光催化剂投加量的增大，光降解速率常数先增大后减小；增加溶液的pH值，速率常数逐渐减小；溶液中的DOM和NO^-₃也可以影响光降解效率。

Kinetics study on photocatalytic degradation of oxytetracycline(OTC) in water by nano titanium suspended system

The occurrences of antibiotics in aquatic environments have attracted much concern from the public.The photocatalytic degradation of OTC in water by UV/TiO2 was studied in a high pressure mercury lamp.Effects of the initial concentration,different reaction condition,TiO2 dosage,solution pH,DOM and NO-3 on the degradation rates were investigated.The results showed that the removal of OTC by photocatalytic was effective.The photodegradation rate in aqueous solution followed first-order kinetics.And after 90 minutes,74% of TOC was removed.The photodegradation rate constant ranged from 0.0619 min-1 to 0.0130 min-1 in the OTC concentration from 30 mg/L to 90 mg/L.Increasing TiO2 dosage led to the photodegradation rate constant increasing initially,followed by decreasing.Reduction of the rate constant was observed when pH increasing.It can also be affected by DOM and NO-3 in aqueous solution.