Adsorptive Elimination of Heavy Metal Ions From Wastewater Utilizing Natural and Synthetic Zeolites: Mechanistic Analysis, Modification Techniques, and Performance Assessment

Heavy metal contamination in wastewater remains a critical environmental challenge due to the persistence and toxicity of metal ions such as Pb 2+ , Cd 2+ , Cr 3+ /Cr 6+ , Cu 2+ , Ni 2+ , and Zn 2+ . Although conventional treatment technologies can achieve high removal efficiencies, their practical application is often limited by high operational costs, energy demand, and secondary pollution. This review critically examines the use of natural and synthetic zeolites as efficient and sustainable adsorbents for heavy metal removal from aqueous systems. Particular emphasis is placed on the fundamental adsorption mechanisms, including ion exchange, surface complexation, and electrostatic interactions, as well as the influence of key physicochemical parameters such as pH, competing ions, and zeolite framework composition. The role of structural modification strategies and zeolite‐based composites in enhancing adsorption performance is also discussed. In addition, the challenges associated with regeneration, stability, and large‐scale application are highlighted. By integrating recent advances with practical considerations, this review provides a comprehensive perspective on the potential and limitations of zeolite‐based materials in real wastewater treatment systems.