Globally, water quality has deteriorated due to the introduction of increasingly complex contaminant mixtures originating from industrial activities, agricultural runoff, and urban expansion into freshwater sources. Heavy metals, synthetic dyes, pharmaceutical residues, and pathogenic microorganisms frequently co-occur, and conventional treatment methods such as coagulation, adsorption, and biological processes often prove inadequate in addressing this complexity. These techniques are typically selective, generate sludge, fail to completely mineralize pollutants, and are expensive. Over the past decade, nanotechnology has presented new opportunities. Materials at the nanometer scale provide high surface areas, customizable pore sizes, and catalytic activities that are not present in bulk materials. Researchers have developed metal oxide nanoparticles, carbon-based structures, polymer composites, and membranes with embedded nanomaterials, which consistently outperform traditional systems in various water matrices. The mechanisms involved—adsorption, photocatalytic oxidation, size exclusion, and antimicrobial action— are rapid and target a broad range of pollutants. However, several challenges persist. Nanoparticles can be unstable, their environmental impact is not well understood, scaling up production is challenging, and their long-term ecological effects remain unknown. A realistic assessment must balance the evident performance improvements with these concerns. Evidence suggests that nanotechnology can significantly enhance advanced water treatment, provided that future research focuses on sustainable synthesis, cost-effective scalability, and robust regulatory frameworks.
Acharya et al. (Sun,) studied this question.