Vermiculite Modified with Glycidyl Methacrylate, Acrylonitrile, and Phosphoric Acid for the Adsorption of Molybdenum and Rhenium Ions from Aqueous Solutions

This study focuses on the synthesis and characterization of a cationic ion-exchange sorbent derived from vermiculite and epoxy acrylate copolymers, designed to address freshwater scarcity by removing toxic metal ions from aqueous environments. The sorbent was engineered to preserve the chemical integrity of freshwater while adhering to environmental safety standards. Vermiculite served as the base material, modified with glycidyl methacrylate (GMA), acrylonitrile (ACN), and orthophosphoric acid (H3PO4) in a mass ratio of 1:0.35:0.15:3. Optimization experiments explored varying H3PO4 proportions (two- and threefold increases) to refine the synthesis conditions. The materials underwent microwave irradiation at 300 W for 10 min. Infrared (IR) spectroscopy confirmed the presence of functional groups (P=O, P−O−C), enhancing sorption capacity, while scanning electron microscopy (SEM) revealed a porous structure crucial for adsorption. Sorption properties, assessed via atomic emission spectroscopy, demonstrated capacities of 39.80 mg/g for MoO42− and 39.06 mg/g for ReO4−, with extraction efficiencies of 79% and 78%, respectively. Chemical stability tests indicated the sorbent retained up to 90% of its functionality in aggressive environments, highlighting its robustness. The developed sorbent offers a high-performance, cost-effective solution for heavy metal removal from wastewater, advancing sustainable water purification technologies.