Removal of Sulfamethoxazole and Erythromycin from Aqueous Solution by O3/H2O2

The performance of sulfonamide and macrolide antibiotics in a spiked water removed by O₃ and O₃/H₂O₂ was evaluated uder different conditions such as ozone dosage, pH and H₂O₂/O₃ mole ratio. The results showed that O₃ and O₃/H₂O₂ were proved to be effective to oxdize sulfamethoxazole of sulfonamides containing the aromatic ring and erythromycin of macrolides, which were built of mostly saturated hydrocarbon structure, and O₃ was preferentially to oxidize sulfamethoxazole. With the reaction time of 30 min, when the ozone cocentrations were 2mg/L and 3mg/L, sulfamethoxazole and erythromycin removal efficiency was 93% and 91%, respectively. The sulfamethoxazole and erythromycin were removed completely within 30 min with ozone 6 mg/L. Degradation of sulfamethoxazole containing unsaturated C-C bonds occured easier at low pH only by O₃. Degradation of erythromycin with fully saturated structure was difficult, but the improved removal efficiency could be obtained at higher pH. The high concentratins of H₂O₂ to ozonation was favor to remove those antibiotics. At the 0.5 mole ratio of H₂O₂/O₃ ,the highest removal efficiency could be reached for all the antibiotics .