Nanotechnology-Enabled Adsorption of Emerging Contaminants: Advances in Smart Nanoadsorbents and Future Prospects

Emerging contaminants (ECs) such as pharmaceuticals, endocrine disruptors, pesticides, PFAS, dyes, microplastics, and personal care products are increasingly detected in municipal and industrial effluents at trace-to-mg/L levels, yet many are poorly removed by conventional treatment. This manuscript provides a focused, qualitative synthesis of smart nanoadsorbents (stimuli-responsive and engineered nanoenabled sorbents) for EC removal, emphasizing how surface chemistry, porosity, and responsive switching (pH, redox, light, magnetic, thermal, and multistimuli) can improve selectivity, adsorption kinetics, and regeneration. Novelty lies in integrating mechanistic adsorption concepts with a commercialization-oriented perspective: We compare reported systems qualitatively using practical readiness indicators (ease of separation and immobilization, reusability, fouling tolerance, secondary release risk, and anticipated cost and scale-up constraints) rather than capacity values alone. Across the surveyed literature, composite architectures (nanomaterials integrated with polymers, membranes, bio-supports, magnetic cores, or granulated matrices) consistently emerge as more deployable than free nanoparticles because they reduce aggregation and leaching while enabling continuous formats such as packed-bed cartridges, coating layers, and hybrid filtration-adsorption units. These insights support near-term industrial applications in polishing steps for hospital and municipal wastewater, textile and pharmaceutical effluents, landfill leachates, and decentralized point-of-use devices, while highlighting remaining gaps in standardized testing, life-cycle safety, and pilot-scale validation.