Factors Affecting UV/H₂O₂ Oxidation of 17α-Ethynyestradiol in Water

In this study, bench-scale experiments were conducted to examine the UV/H₂O₂ oxidation of 17α-ethynyestradiol (EE2) in water in a batch operation mode. The EE2 degradation exhibited pseudo-first-order kinetics, and the removal was ascribed to the production of hydroxyl radicals (^•OH) by the UV/H₂O₂ system. Typically, the EE2 oxidation rate increased with increasing UV intensity and H₂O₂ dose, and with deceasing initial EE2 levels and solution pH. At EE2₀=650μg/L, UV intensity=154μW/cm², H₂O₂=5mg/L, and neutral pH, the UV/H₂O₂ treatment was able to remove 90% of the EE2 content within 30min. Four anions commonly present in water were found to inhibit EE2 degradation to varying degrees: HCO₃^->SO₄^2->Cl^- >NO₃^-. Our results demonstrate that the described UV/H₂O₂ process is an effective method to control EE2 pollution in water.