Functionalized Polyacrylic Hydrogels for Efficient Adsorption of Ni(II) and Co(II) From Freshwater

ABSTRACT

Contamination of freshwater resources with heavy metals constitutes a pivotal threat to the environment and human health. Formulating cost‐effective and recyclable materials for efficient metal removal consequently evolved into a major research priority. In this work, we report the design of sustainable and inexpensive polyacrylic hydrogels with improved swelling and adsorption characteristics, enabling the efficient removal of heavy metal ions from water sources. Two hydrogels were synthesized and later comprehensively characterized using Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface analysis, and thermogravimetric analysis (TGA). Contact time, pH, and temperature on the adsorption efficiency were evaluated systematically for Ni ^{2 +} and Co ^{2 +} ions. 4‐Br hydrogel showed a better ion extraction ability, accomplishing 96% for Ni ^{2 +} and 88% for Co ^{2 +} under optimized conditions (pH 6.5, 30°C, 24 h). Also, after multiple cycles of regeneration, the hydrogel retained its adsorption abilities, validating the hydrogel's capabilities for sustainable water treatment. These results emphasize the viability of polyacrylic hydrogels as a relatively low‐cost, recyclable, and highly efficient adsorbent for the detoxification of wastewater from heavy metals and many other environmental management applications.