Continuous flow electrosorption-microbial fuel cell system for efficient removal of oxytetracycline without external electrical supply.

The removal of antibiotics from wastewater has attracted much attention. In this research, an intimately coupled autarkical electrosorption (ES)-microbial fuel cell (MFC) system was developed for real-time removal of the antibiotic oxytetracycline (OTC) from wastewater. The removal efficiency was founded to be up to 98.8% at an OTC concentration of 2 mg/L with 3 g/L sodium acetate (NaAC) as co-substrate and 3 MFCs as power supply. The removal efficiencies increased in the ES unit and decreased in the MFC unit with increasing treating time. The adsorption of OTC on activated carbon fibers (ACFs) in the ES unit proceeds via chemical adsorption resulting from electrostatic attraction and cation exchange. The OTC degradation pathways in the MFC unit were proposed by identifying the intermediates with HPLC-MS/MS. The ACFs in the ES unit were proven to be recyclable and the coupled ES-MFC system is applicable for the removal of antibiotics from wastewater.