Engineered ZSM-5 zeolite composites for advanced water purification: Recent progress and future perspectives

Abstract

The widespread discharge of industrial wastewater containing dyes, heavy metals, pHarmaceuticals, and other persistent pollutants continues to pose serious environmental and public health challenges. Among various treatment technologies, adsorption- and catalysis-based approaches using zeolitic materials have gained increasing attention due to their efficiency, stability, and adaptability. ZSM-5, an MFI-type aluminosilicate zeolite, is particularly attractive owing to its tunable Si/Al ratio, well-defined pore architecture, high thermal and chemical stability, and ease of functionalization. This review presents a comprehensive analysis of the structural characteristics, synthesis strategies, and water-treatment applications of ZSM-5 and ZSM-5-based composites. Emphasis is placed on conventional, template-free, and waste-derived synthesis routes, along with post-synthetic modifications that tailor porosity, acidity, and surface chemistry. The roles of framework topology, pore size, and active site density in governing adsorption, ion-exchange, and catalytic removal of dyes, heavy metals, and emerging contaminants are critically discussed. In addition, the performance of ZSM-5-based systems is evaluated in terms of adsorption capacity, kinetics, regenerability, and multifunctionality, with comparisons to benchmark materials. The review further addresses key limitations affecting real-world performance, including competitive ion effects, organic matter fouling, and pH variability, and highlights strategies to mitigate these challenges through composite design and surface modification. Overall, this work provides a mechanistic and application-oriented overview of ZSM-5-based materials, offering guidance for their rational design and deployment in sustainable wastewater treatment technologies.