Cutting-edge nanotechnology approaches for efficient mercury remediation: Mechanisms, innovations and future...

Mercury contamination poses a significant threat to the environment and human health due to its persistence, bioaccumulation, and toxicity. Conventional remediation methods such as chemical precipitation, coagulation, and membrane filtration often fall short due to limitations like incomplete removal, secondary pollution, and low selectivity. In response, advanced nanomaterials, defined as engineered nanostructures with high surface area, tunable surface chemistry, and exceptional mercury-binding capabilities, have emerged as powerful alternatives. This review critically evaluates five major classes of nanomaterials, such as carbon-based nanomaterials, metal and metal oxide nanoparticles, functionalized polymer nanocomposites, biosynthesized nanoparticles, and hybrid nanomaterials, with a focus on their mercury removal efficiency, regeneration capacity, environmental safety, and real-world applicability. While these materials have been previously reported, this work offers a unique comparative analysis that synthesizes fragmented data across the literature to highlight performance trade-offs and implementation feasibility. Furthermore, nanotechnology-assisted techniques including adsorption, photocatalysis, membrane-based separation, and hybrid treatment systems are systematically reviewed, emphasizing removal efficiencies, operational parameters, and scalability. Among these, hybrid nanomaterials and multifunctional systems demonstrate the highest potential, achieving mercury removal rates exceeding 95 % and offering adaptability to complex contaminated matrices. Rather than introducing new experimental data, this review identifies key research gaps, unresolved challenges such as nanoparticle toxicity and recovery, and the lack of field-scale validation. It concludes with a roadmap to guide future research toward the development of safe, cost-effective, and environmentally sustainable nanotechnology-driven mercury remediation strategies. This work aims to support informed decision-making among researchers, engineers, and environmental policymakers working to mitigate mercury pollution effectively.