Occurrence and fate of OMPs and ARGs in innovative full-scale WWTPs

The presence of antibiotic resistance determinants in wastewater treatment plants (WWTPs) presents a potential risk for human health and for the environment (Manaia et al., 2018). The scientific knowledge related to this topic is still limited, while new technologies are being implemented to reduce the environmental impact associated to conventional WWTPs. Besides removing conventional pollutants; innovative technologies should deal with contaminants of emerging concern (CECs). CECs are typically divided into chemicals (for example pharmaceuticals and other organic micropollutants, OMPs) and biological pollutants, such as pathogens or antibiotic resistant microbes (ARMs). The aim of this study is to evaluate the occurrence and fate of some CECs in two full-scale urban WWTPs based on advanced technologies. The selected CECs were 8 OMPs (antibiotics) and 35 antibiotic resistance genes (ARGs). Two sampling campaigns were performed to determine the presence and the removal efficiencies of the selected CECs in each treatment step. The results of the first sampling campaign showed moderate removal efficiencies for OMPs, between 20 and 80 %; and a higher distribution of ARGs in the sludge line, compared to the water line, where a removal of 2-3 log10 units was achieved. A second campaign was already completed and the results will be available in coming weeks. Acknowledgments This research was supported by the Spanish State Research Agency (EEA) through ANTARES (PID2019-110346RB-C21) project. The authors also want to acknowledge the companies FCC Aqualia and Viaqua for the technical support