Crosslinked Poly(Acrylic Acid‐Co‐Acrylamide) Applied to Remove Hg( <scp>II</scp> ) and the Effects of Its Exposure on <i>Girardia tigrina</i>

ABSTRACT In this study, an adsorbent was produced by the copolymerization of acrylic acid and acrylamide, followed by cross‐linking. The impact of pH, duration of contact, concentration, presence of interfering ions, and reuse was investigated. The disinfectant capacity of the adsorbent was evidenced by its ability to inactivate total coliform and E. coli in river water. The toxicological impact of the adsorbent on G. tigrina was investigated by analyzing its behavioral and physiological responses. The adsorption process exhibited pseudo‐second‐order kinetics. The Langmuir isotherm demonstrated favorable adsorption, while the Freundlich isotherm indicated favorable and physical adsorption. The Dubinin‐Radushkevich isotherm also indicates a physical adsorption mechanism. The study observed a decline in the adsorption capacity in the presence of K + , Na + , Mg 2+ , and Ca 2+ ions, as well as at pH 2.0. An investigation of the reusability of the adsorbent revealed that the material maintained its removal efficiency after three cycles of use. This study suggests that the tested material has the capacity to act as an adsorbent and exhibits self‐disinfecting behavior. Finally, ecotoxicity tests demonstrated that the material influences the locomotion and regeneration of the G. tigrina auricles, indicating the need to prevent the material from reaching ecosystems.