Degradation of the emergent pollutant Diclofenac in water by photo-Fenton and toxicity evaluation of its degradation products
Photo-Fenton法降解水中新型污染物双氯芬酸及降解产物的毒性评价

The contribution of the photo-Fenton reaction to the degradation and mineralization of the anti-inflammatory drug, Diclofenac, was investigated and the biological toxicity of its degradation products were evaluated. The study includes the influence of factors such as pH and the initial concentration of H2O2 and Fe2+ on the photo-Fenton reaction; determination of the best operating conditions; comparison of different AOPs (advanced oxidation processes) and determination of the biological toxicities of the degradation products from each process. Results show that the degradation rate of diclofenac through the UV/H2O2/Fe2+ reaction system is strongly affected by its reaction conditions. When the initial concentration of diclofenac is 20 mg·L-1, the best operating conditions are at pH 5 with initial concentrations of 5 mg·L-1 FeSO4 and 200 mg·L-1 H2O2. Under these operating conditions, degradation ability of different AOPs is in the order UV/Fenton>UV/H2O2>Fenton>UV. Because of the appearance of intermediate products during the reaction, the mineralization process of diclofenac is longer than its degradation process and the biological toxicity initially increases and then decreases.