<p>The removal of heavy metal ions (HMIs) such as copper (Cu) and nickel (Ni) from aqueous solutions is critical for addressing water pollution and ensuring environmental sustainability. This study investigates the efficacy of xanthated starch-based hydrogel (AHS hydrogel) in adsorbing Cu²⁺ and Ni²⁺ ions from water. The best grade of the hydrogel viz. AHS-3, has been characterized using various analytical techniques including scanning electron microscope (SEM), thermogravimetric (TG) analysis, point of zero charge (ΔpH_PZC) analysis, gel permeation chromatography (GPC), UV-Visible (UV-Vis) spectroscopy and Fourier transform infrared <i>(</i>FT-IR) spectroscopy. The swelling ratio of the AHS-3 hydrogel has been found to be 272.05&#xa0;g/g at pH of 11. This indicates AHS-3 hydrogel exhibits remarkable swelling capacity. The removal efficacy has been found to be 98.38% for Cu²⁺ and 96.89% for Ni²⁺ ions under optimum conditions. The results demonstrated that the hydrogel exhibited excellent adsorption capacity with 317.46&#xa0;mg/g for Cu²⁺ and 311.52&#xa0;mg/g for Ni²⁺ ions, according to the Langmuir isotherm model. Kinetic studies revealed that the adsorption process is governed by second-order kinetic model. The rate constants have been found to be 3.48 × 10^− 4 g/(mg.min) for Cu²⁺ and 2.76 × 10^− 4 g/(mg.min) for Ni²⁺ ions. In addition, AHS-3 hydrogel shows a remarkable desorption efficiencies of 89.49% for Cu²⁺ ions and 86.12% for Ni²⁺ ions for fifth cycles. The study underscores the potential of hydrogel-based materials as cost-effective, reusable, and eco-friendly adsorbents for remedying industrial wastewater and mitigating heavy metal pollution.</p> Graphical abstract <p></p>