Performance of UV and UV/H2O2 processes for the removal of pharmaceuticals detected in secondary effluent of a sewage treatment plant in Japan

The effectiveness of UV-based processes (UV and UV/H2O2) for the removal of pharmaceuticals in real wastewater using bench-scale experiment setup with a treatment capacity of 10 m3/day was investigated. Forty-one kinds of pharmaceuticals including 12 antibiotics and 10 analgesics were detected in secondary effluent used for tested water. For UV process a good removal seems to be expected for just a few pharmaceuticals such as ketoprofen, diclofenac and antipyrine. Especially, the removal efficiencies of macrolide antibiotics such as clarithromycin, erythromycin and azithromycin for UV alone process were found to be very low even by the introduction of considerable UV dose of 2768 mJ/cm2. For UV/H2O2 process, a 90% removal efficiency could be accomplished in 39 pharmaceuticals at UV dose of 923 mJ/cm2, indicating that it will be possible to reduce UV energy required for the effective pharmaceuticals removal by the combination of H2O2 with UV process.