Metal-organic frameworks for sustainable aquatic arsenic remediation: A review

Arsenic contamination of aquatic systems poses a serious global threat to environmental safety and public health due to its high toxicity, persistence, and complex aqueous speciation. Conventional arsenic removal technologies often suffer from limited selectivity, high operational cost, and low efficiency, particularly for As(III). Metal - organic frameworks (MOFs) have recently attracted significant attention as advanced adsorbents for arsenic remediation owing to their high surface area, tunable pore structure, and versatile coordination chemistry. This review presents a critical and systematic evaluation of MOFs for sustainable aquatic arsenic remediation. After summarizing arsenic speciation and the limitations of conventional treatment methods, arsenic-specific removal mechanisms in MOFs—including electrostatic interaction, inner-sphere coordination, ligand exchange, and redox-assisted As(III) oxidation—are analyzed. The performance of different MOF families, including Zr-, Fe-, Zn-, Al-based, and mixed-metal frameworks, is comparatively assessed in terms of adsorption efficiency, stability, pH tolerance, and regeneration behavior. Emphasis is placed on elucidating structure–performance relationships rather than cataloging individual studies. Finally, remaining challenges related to cost, scalability, and real-water applicability are discussed, and future research directions are proposed to facilitate the practical implementation of MOF-based arsenic remediation technologies.