UV体系中3种微量类固醇雌激素的竞争降解及同趋转化

采用UV体系(UV、UV/H2O2和UV/H2O2/TiO2)降解水中同时存在的3种微量类固醇雌激素雌酮(E1)、17-β雌二醇(E2)和17-α乙炔基雌二醇(EE2),结果表明,降解过程均符合一级反应动力学,通过不同UV系统对比发现,关键因素对混合污染降解的影响顺序为H2O2>光强>TiO2.E1光解特性良好,在混合基质中可优势降解;E2和EE2直接光解效果较差,优劣顺序受到光强的影响,光强升高EE2略占优势.H2O2和催化剂TiO2的投加可提高3种物质的降解效果及降解速率常数,但竞争条件下E2和EE2的去除率提高有限.E1,E2和EE2的光化学降解过程具有相似的转化趋势,均可生成与E1结构类似的副产物.

Competitive degradation and transformation trend of three steroid estrogens in UV system

UV(/H2O2/TiO2) was applied to remove three co-existing steroid estrogens, including estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) from aqueous solutions. The degradation fitted first-order kinetic models very well, with the significance of three key impact factors on degradation followed the order of H2O2 > irradiation intensity >TiO2. E1took advantages in competitive degradation for its character of photosensitiveness. The order of degradation rates of E2 and EE2 under UV alone was dependent on UV intensity. EE2 had slight superiority with the increase of UV intensity. Addition of H2O2 and TiO2 facilitated the degradation of E1while with minor impact on E2 and EE2 due to the competition of E1. E1, E2 and EE2 exhibited analogous transformation pathway during photodegradation. Same byproduct structurally similar with E1was detected.