Vol. 7, Issue 1, Part B (2025)

Heavy metal contamination in environmental systems remains a critical global concern due to its persistence, bioaccumulation, and severe health effects. Conventional remediation strategies such as chemical precipitation, ion exchange, and membrane filtration often lack selectivity, generate secondary waste, and are inefficient at low metal concentrations ^[1,2]. Surface-modified nanomaterials have emerged as a promising alternative, offering high adsorption capacities, tunable selectivity, and the ability to mitigate toxicity at the molecular level ^[3,4]. This study synthesizes findings from peer-reviewed research on functionalized nanomaterials, including zero-valent iron (nZVI), graphene oxide (GO), carbon nanotubes (CNTs), metal-organic frameworks (MOFs), and metal oxides. Surface modifications—such as thiolation, amination, carboxylation, and polymer or biopolymer coating—were analyzed for their influence on removal efficiency, regeneration performance, and biological impact. Reported data indicate that functionalized nanomaterials can achieve >90 % removal efficiency for metals such as Pb(II), Cd(II), and Cr(VI) at environmentally relevant concentrations ^[5-7]. Mechanistic insights reveal that targeted adsorption suppresses heavy metal-induced oxidative stress, mitochondrial dysfunction, and genotoxicity ^[8,9]. Despite these advantages, challenges remain in large-scale synthesis, environmental persistence, and ecotoxicological safety. This review highlights the dual role of surface-modified nanomaterials in environmental remediation and toxicity pathway disruption, and outlines research priorities for green synthesis and life-cycle risk assessment.