Strategically engineering advanced nanomaterials for heavy-metal remediation from wastewater

Addressing water pollution with toxic metals offers a significant global One health challenge, aggravated by uncontrolled contamination consequential of urbanization and industrialization on a massive scale. Nanoremediation is an impending and economical solution for wastewater remediation, predominantly for heavy metal ions, notwithstanding concerns concerning the ecotoxicity of nanotechnology. Nanomaterials demonstrate suitability for wastewater remediation owing to their tremendous adsorption efficacy, vast stoichiometry, tunable physicochemical properties, and rich surface chemistries. This comprehensive review summarizes the state-of-the-art strategically engineered nanomaterials and their advanced nanocomposites for remediating a range of heavy metals from wastewater. Diverse nanomaterials-based heavy metal remediation mechanisms, including adsorption, photocatalysis, nano-filtration, sensing and biosorption, and disinfection, are described. It explores the tailoring of different physicochemical attributes (surface chemistry, surface area, morphology, porosity, band gap, regeneration capability) of diversified nanomaterials including metals, polymers, metal oxides, carbon nanomaterials, activated charcoal, zeolites, and advanced 2D nanomaterials (graphene and its derivatives, borophene, boron nitride, phosphorene and MXenes) and environmental factors (temperature, contact time, pH, and adsorbent dosage) for selective heavy metal remediation from contaminated water. Furthermore, the review delves into the impact of nanoremediation on One Health by evaluating the ecological footprint, associated challenges, potential solutions, and prospects for combination with modern-age technologies for wastewater treatment, converging on advancing environmental sustainability.