Preparation and characterization of a Syrian pumice-based ion exchanger for copper (II) ion adsorption

Heavy metal contamination of water resources, particularly by copper Cu(II) originating from industrial effluents, poses a significant threat to ecosystems and human health due to its toxicity and non-biodegradability. While adsorption is a widely recognized remediation technique, its economic viability is often hampered by the high cost of conventional adsorbents like activated carbon and synthetic ion-exchange resins. This economic constraint has driven the search for sustainable, low-cost alternative materials derived from abundant natural resources. Naturally occurring pumice, a volcanic rock with inherent porosity, has emerged as a promising candidate due to its global availability and low cost. However, a critical review of the literature reveals that the raw pumice typically exhibits limited adsorption capacity , restricting its practical application. Furthermore, while some studies have explored chemical activation to enhance its performance, the potential of Syrian pumice deposits remains significantly underexplored . There is a distinct lack of comprehensive studies that systematically investigate (a) a highly effective yet cost-effective chemical modification route for this specific pumice type, (b) a detailed analysis of its adsorption mechanisms beyond simple isotherm fitting, and (c) a rigorous economic assessment comparing it to incumbent technologies. This study addresses these critical gaps by presenting a novel, cost-effective adsorbent synthesized from locally sourced Syrian pumice for the efficient removal of Cu(II) ions. Through a simple alkaline modification, we produced a sodium hydroxide-treated pumice (P Na ) ion exchanger. The research quantitatively demonstrates an 18-fold increase in specific surface area and characterizes the material’s exceptional adsorption performance across a wide range of operational parameters. We comprehensively analyze the kinetics, equilibrium isotherms, and thermodynamics to elucidate the hybrid adsorption mechanism. Crucially, this work demonstrates that the developed P Na material achieves performance comparable to conventional adsorbents while incurring production costs 70-90% lower, thereby establishing Syrian pumice as a sustainable and economically transformative alternative for wastewater treatment.