Photodegradation of 17 alpha -Ethynylestradiol in Aqueous Solutionwith Nitzschia hantzschiana or Chlorella vulgaris and Fe super(3+)

摘要

The photodegradation of 17 alpha -ethynylestradiol (EE sub(2)) induced by high-pressure mercury lamp ( lambda greater than or equal to 313 nm, 250 W) in aqueous solution with algae (e. g. Nitzschia hantzschiana and Chlorella vulgaris) and Fe super(3+) was investigated initially. The affecting factors on the photodegradation were studied and described in details, such as algae concentration, Fe super(3+), exposure time, and so on. The concentration of EE sub(2) in distilled water was determined using fluorescence spectrophotometer. The photodegradation of EE sub(2), in aqueous solution exposed to 250 W high-pressure mercury lamp was evident in the presence of algae and Fe super(3+). With the algae concentration increasing, photodegradation rate increased. Fe super(3+) could accelerate the photocatalytic degradation of EE sub(2) in aqueous solution with algae. The colloidal ferric hydroxide particles that might have adsorbed on the algae cells could enhance the photocatalytic degradation of EE sub(2) by algae. The catalysis in photocatalytic degradation reaction mainly resulted from the active oxygen (H sub(2)O sub(2), super(1) O sub(2) and times OH) that was caused by algae and Fe super(3+) under 250 W HPML. In this paper, the mechanism of photocatalytic degradation of EE sub(2) by algae and Fe super(3+) is discussed theoretically in details.