Sustainably Polyanionic Hyaluronic Acid-Based Hydrogel for Efficient Removal of Fe3+, Cd2+, and Pb2+ Ions in Soil with Enhanced Sorghum Growth.

Toxic metals damage soil quality and harm human health via bioaccumulation, necessitating eco-friendly removal techniques. Hydrogel-based adsorption offers a promising approach for heavy metal extraction. Nevertheless, the potential of innovative hyaluronic acid (HA)-based hydrogels has not been fully investigated. In this study, levodopa and tannic acid were first grafted onto HA using condensation reactions. Subsequently, the HLDT hydrogel was developed by grafting Na-AMPS onto the HA derivative through free radical polymerization, which enhanced its mechanical properties for metal ion adsorption. The HLDT hydrogel shows superior metal adsorption capacities of 193.3, 316.9, and 49.6 mM/g for Cd, Fe, and Pb, respectively. Notably, the exceptional adsorption, desorption, and regeneration capabilities, make it ideal for recycling. Additionally, the HLDT hydrogel can remove heavy metals from polluted soil efficiently and enhance the sorghum growth characteristics. Our findings provide a potential solution for the sustainable recovery of contaminated farmland while enhancing productivity.