Environmental fate and ecotoxicological behavior of complex contamination of antibiotics and metal ions in aquatic systems

Antibiotics and metal ions are frequently detected in aquatic environments, where they can form complex pollutants through mechanisms such as complexation, adsorption, co-precipitation, and biological interactions. These interactions significantly affect the physicochemical properties, transport dynamics, and ecotoxicity of the pollutants. Because of their persistence, potential for bioaccumulation, and complex interactions, these pollutants pose substantial challenges to water treatment systems and may present risks to human health and ecological balance. This review synthesizes research on the sources (1999-2024), status, and formation mechanisms of these complex pollutants. Initially, it outlines how complex pollutants originate from sources including pharmaceutical residues, agricultural runoff, and industrial discharges, which often coexist and interact to form these pollutants. The review then delves into the interaction mechanisms between antibiotics and metal ions, highlighting the factors that influence these interactions. Complexes (coordination polymers) formed by antibiotics and metal ions consist of infinite structures where metal ions and organic ligands act as the fundamental building blocks, connected through coordination bonds and other weak chemical interactions. Additionally, the review provides a comprehensive overview of various removal techniques, discussing their effectiveness and the technical challenges associated with treating these complex pollutants. The effects of antibiotics and metal ions on the migration and transformation mechanisms of the pollutants are also examined. Moreover, the biotoxicity associated with these composite pollutants is discussed, offering insights that could guide future strategies for effective degradation and control. PRACTITIONER POINTS: Combined contaminants of antibiotics and metal ions widely detected in water Combined contaminants change the physicochemical properties of a single substance. The transport transformation mechanisms of complex contaminants were summarized. The effect of combined contaminants on the removal of antibiotics and metal ions were evaluated.