Urban wastewater treatment plants as hotspots for the release of antibiotics in the environment: A review

Urban wastewater treatment plants (UWTPs) are among the main sources of antibiotics’ release into various compartments of the environment worldwide. The aim of the present paper is to critically review the fate and removal of various antibiotics in wastewater treatment, focusing on different processes (i.e. biological processes, advanced treatment technologies and disinfection) in view of the current concerns related to the induction of toxic effects in aquatic and terrestrial organisms, and the occurrence of antibiotics that may promote the selection of antibiotic resistance genes and bacteria, as reported in the literature. Where available, estimations of the removal of antibiotics are provided along with the main treatment steps. The removal efficiency during wastewater treatment processes varies and is mainly dependent on a combination of antibiotics’ physicochemical properties and the operating conditions of the treatment systems. As a result, the application of alternative techniques including membrane processes, activated carbon adsorption, advanced oxidation processes (AOPs), and combinations of them, which may lead to higher removals, may be necessary before the final disposal of the effluents or their reuse for irrigation or groundwater recharge.Nireas-International Water Research Center is a project co- funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Founda- tion (Strategic Infrastructure Project NEAYPODOMH/STPATH/ 0308/09), and the University of Cyprus. The authors would like to thank EU for the support provided through Cost Action "TD0803: Detecting evolutionary hot spots of antibiotic resis- tances in Europe (DARE)". Luigi Rizzo wishes to thank University of Salerno for funding the project "Effect of solar photolysis on antibiotic degradation, antibiotic resistant bacteria inactivation as well as on their capacity to develop antibiotic resistance in surface water", Ex 60%, anno 2011. Christophe Merlin and Christophe Dagot wish to thank the ANR national program ECOTECH, the EU interreg PILLS Program, and the Zone Atelier Moselle (ZAM) for supporting investigations regarding parameters affecting antibiotic resistance gene transfer in environmental matrices