[Spatiotemporal Distribution Characteristics， Influencing Factors， and Ecological Risk Assessment of Antibiotics in a River of a Typical Northern City].

Abstract

With the rapid advancement of urbanization and industrialization， antibiotic pollution in aquatic environments has emerged as a critical environmental challenge threatening ecosystems and public health. As a significant urban river in Hebei Province， the Fuyang River faces ecological risks posed by antibiotic contamination. However， systematic studies on the characteristics of antibiotic pollution in this river remain scarce. In this study， the Fuyang River in Handan City， a typical northern city， was selected as the research area. Solid-phase extraction and liquid chromatography-tandem mass spectrometry （SPE-LC-MS/MS） methods were employed to detect and analyze the spatiotemporal distribution characteristics， pollution sources， and ecological risks of four classes of antibiotics， sulfonamides （SAs）， quinolones （QNs）， macrolides （MLs）， and tetracyclines （TCs）， encompassing twelve specific compounds， in surface water and sediments. All twelve antibiotics were detected， with concentration ranges of ND to 67.80 ng·L^-1 in surface water and ND to 33.95 ng·g^-1 in sediments. Trimethoprim （TMP） showed the highest detection frequency in surface water （93.75%）， while sulfamethazine （SMZ） had the highest detection frequency in sediments （71.875%）. The total detected concentrations of antibiotics were significantly higher in the wet season than in the dry season， with the urban midstream section exhibiting the most severe pollution. Correlation analysis revealed no significant association between antibiotic distribution and water quality parameters， indicating that human activities and wastewater discharge practices in different regions were the primary influencing factors. Ecological risk assessments suggested that tetracycline （TCY） and sulfamethoxazole （SMX） posed higher ecological risks to fish， while ofloxacin （OFX）， lomefloxacin （LOM）， and erythromycin （ERY） exhibited certain ecological risks to algae.