چكيده لاتين
The increasing contamination of water resources with heavy metals such as nickel (Ni²⁺) and thallium (Tl⁺), resulting from industrial activities, poses a serious threat to the environment and human health. In this study, a composite hydrogel based on phosphorylated starch (SSP), carboxymethyl cellulose (CMC), and polyacrylamide (AM) was synthesized using sodium phytate as a reinforcing agent and NMBA as a crosslinker. The primary aim of this research was to develop an efficient, biodegradable, and low-cost adsorbent for the removal of heavy metals from industrial wastewater. The synthesized hydrogel was characterized using various techniques, including FTIR, TGA, SEM, BET, ICP, and EDS. The results demonstrated that surface modification of starch with phosphate groups and the presence of sodium phytate significantly enhanced the thermal stability and adsorption capacity of the hydrogel for heavy metal removal. Investigation of the adsorption parameters revealed that the optimum conditions for nickel adsorption were at pH = 5 and 60 minutes, while for thallium they were at pH = 6 and 30 minutes. Furthermore, kinetic and isotherm studies indicated that the adsorption process followed a pseudo-second-order kinetic model and Langmuir isotherm, suggesting chemisorption and accessibility of all binding sites across the hydrogel surface. The adsorption capacities of the hydrogel for nickel and thallium were measured at 590 mg/g and 446 mg/g, respectively, which outperformed similar adsorbents. After three adsorption–desorption cycles, the hydrogel retained more than 85% of its initial efficiency, highlighting its reusability and cost-effectiveness. Due to its unique features such as biocompatibility, low cost, and high performance, this hydrogel can be considered a promising candidate for industrial applications in the treatment of heavy metal-contaminated wastewater.
