High-Efficiency removal of Cu2+, Zn2+, and Mg2+ from contaminated water using a conductive hydrogel based on gellan Gum/Ti3C2 MXene/PEDOT-S:H/Aluminum oxide silicate composite

Industrial wastewater contamination by heavy metal ions such as Cu 2+ and Zn 2+ poses severe threats to the ecosystems and human health, with traditional adsorbents limited by high costs, low adsorption capacities, poor mechanical stability, and slow kinetics. To address these problems and to improve adsorption performance, this study developed a novel hydrogel composite composed of Gellan gum, Ti 3 C 2 MXene, Poly(3,4-ethylenedioxythiophene): sulfonate (PEDOT-S:H), and aluminum oxide silicate, named GMPA. The GMPA composite, optimized at a mass ratio of 20:2.25:4:2.5, was characterized and exhibited enhanced mechanical properties, improved thermal stability, and a high density of active binding sites. Under optimal conditions (1.2 g/L adsorbent dose, pH levels of 5.9–9.5, and adsorption duration of 30–300 min), the composite removed Zn 2+ , Cu 2+ , and Mg 2+ from a 50 mg/L metal ion solution with removal efficiencies of 99%, 77.1%, and 80% respectively, with capacities of 42.81 mg/g for Zn 2+ , 26.32 mg/g for Cu 2+ , and 21.51 mg/g for Mg 2+ . Kinetics followed the pseudo-first and second order models, indicating chemisorption and physisorption-influenced mechanisms. This novel hydrogel enables applications in water purification and the removal of heavy metals from aqueous environments.