2026-04-04T02:27:20Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/278542025-12-05T06:02:29Zcom_2072_452955com_2072_2054col_2072_453063

00925njm 22002777a 4500 dc Marizzi del Olmo, Anna author López-Doval, Julio C. author Hidalgo Muñoz, Manuela author Serra Putellas, Teresa author Colomer, Jordi author Salvadó Martín, Victòria author Escolà Casas, Mònica author Subirats Medina, Jessica author Matamoros, Víctor author 2025-04-01 The discharge of treated wastewater from wastewater treatment plants (WWTPs) into river systems is a significant source of pollution, introducing a range of chemical and biological pollutants that impact the chemical and ecological quality status of rivers. This study evaluates the effect of a secondary treated wastewater effluent on the Onyar River, in the northeast of Spain. Water and biofilm samples were collected at one upstream and four downstream sampling points (up to 2.8 km from the discharge point) across four seasons. A wide array of pollutants, including metals, pharmaceuticals, microplastics (MPs), per- and polyfluoroalkyl substances (PFAS), antibiotic resistance genes (ARGs), among other emerging pollutants, were detected downstream, with significant differences between upstream and downstream concentrations. Our results show that WWTP discharge also altered biofilm microbiome composition and ARGs presence, being these changes distinguishable from seasonal variations. Nevertheless, a partial recovery further downstream (525 m) was observed for biofilm microbiome and ARGs composition. These findings highlight the value of microbiome analysis in assessing wastewater impacts on river ecosystems and emphasize the need for further research to improve pollutant attenuation and biofilm recovery strategies in river streams The authors would like to thank the European Union's LIFE programme for funding under grant agreement No. 101074191 6 http://hdl.handle.net/10256/27854 Contaminants emergents en l'aigua Emerging contaminants in water Aigües residuals Sewage Biofilms Holistic assessment of chemical and biological pollutants in a Mediterranean wastewater effluent-dominated stream: Interactions and ecological impacts