Combined Photo-Fenton-SBR Process for Antibiotic Wastewater Treatment

The study examined combined photo-Fenton–SBR treatment of an antibiotic wastewater containing amoxicillin and cloxacillin. Optimum H2O2/COD and H2O2/Fe2+ molar ratio of the photo-Fenton pretreatment were observed to be 2.5 and 20, respectively. Complete degradation of the antibiotics occurred in one min. The sequencing batch reactor (SBR) was operated at different hydraulic retention times (HRTs) with
the wastewater treated under different photo-Fenton operating conditions (H2O2/COD and H2O2/Fe2+ molar ratio). The SBR performance was found to be very sensitive to BOD5/COD ratio of the photo-Fenton treated wastewater. Statistical analysis of the results indicated that it was possible to reduce the Fe2+ dose and increase the irradiation time of the photo-Fenton pretreatment. The best operating conditions of the combined photo-Fenton–SBR treatment were observed to be H2O2/COD molar ratio 2, H2O2/Fe2+ molar ratio 150, irradiation time 90 min and HRT of 12 h. Under the best operating conditions, 89% removal of
sCOD with complete nitrification was achieved and the SBR effluent met the discharge standards.