Ionizing radiation effect on the removing of antibiotic pollutants from pharmaceutical wastewater: identification of radio-degradation products

Electron beam radiation is applied in wastewater treatment to destroy pollutants, including antibiotics. Standard solutions of oxytetracycline, enrofloxacin, erythromycin, and sulfamethoxazole (10-100 ppm) were irradiated at 10-50 kGy. Increasing irradiation dose and concentration increased and decreased degradation efficiency, respectively. Most antibiotic standard samples, irradiated at 25 kGy, showed destruction efficiency more than 90%. Erythromycin and enrofloxacin as target antibiotics, were identified in real pharmaceutical wastewater, with degradation efficiency of 100% and 90%, respectively, at 25 kGy. Byproducts found by LC/MS in irradiated samples had acceptable toxicity. Therefore, electron beam irradiation is an efficient way to eliminate antibiotics from pharmaceutical wastewater.