Radiation Treatment of Residual Antibiotics in Livestock Wastewater

Abstract

Antibiotics are widely used to treat or feed additives on the livestock farms, and the excreted metabolites via urine or feces are directly distributed to the environment. Occurring in the environment even in low concentrations, these compounds are a threat to human health and ecosystems. Generally, organic compounds in wastewater can be degraded by advanced oxidation processes (AOPs). Recently, radiation technology has been given more attention to treat these micropollutants and to enhance the biodegradability of wastewaters. In this study, the occurrence of a total of eleven antibiotics in the livestock WWTP in Korea was investigated, and the controls of antibiotics in livestock wastewater were carried out. Antibiotics in livestock wastewater were analyzed using a liquid chromatography/electrospray-mass/mass (LC/ESI/MS/MS). The radiation experiments were carried out using an electron accelerator (1 MeV, 40 kW). As results, among eleven antibiotics, high concentrations of sulfathiazole, sulfamethazine, sulfamonomethazine and tetracycline were detected in the influents. The frequencies of chlortetracycline, oxytetracycline, and disinfectants in the influents were high. High concentrations of Lincomycin, chlortetracycline, and formaldehyde were detected in the effluents. The frequencies of chlortetracycline and formaldehyde in the effluents were still high. Antibiotics in livestock wastewater were removed effectively by electron beam irradiation. The concentrations of sulfadimethoxine, sulfamethoxazole, sulfamonomethaxine, and erythromycin decreased more than 80% with a 10 kGy electron beam dose. In an advanced biological treatment process combined with electron beam pretreatment system, the removal efficiencies of the organics and nutrients (N, P) increased due to the biodegradability enhancement by a radiation pretreatment effect.