Harnessing Nanomaterials for Water Decontamination: Insights into Environmental Impact, Sustainable Applications, and the Emerging Role of Polymeric Nanostructures

Nanomaterials provide novel solutions for water treatment because of their unique properties and functions, such as a large surface area, increased reactivity, and interaction with contaminants at the nanoscale. These useful features make nanomaterials highly effective in addressing water-related issues, especially in the remediation of aquatic environments from heavy metals, organic pollutants, and microplastics. However, there are increasing concerns about their persistence in the environment and the possible risks to ecosystems and human health, due to their tendency to bioaccumulate and enter food chains. While some nanomaterials have proven toxic even at low concentrations, most effects that these materials may have on aquatic organisms, plants, and animals remain largely unexplored. Most sources report that polymeric nanomaterials are also the least toxic and most environmentally compatible, particularly when biodegradability forms one of the design parameters. Polymeric nanoparticles can be considered a safer alternative to metal- and carbon-based nanomaterials. However, they can not be used without any risk at all. The long-term environmental accumulation of nanoplastics and their potential chronic ecological impacts have received greater attention recently. This paper reviews major research on the toxicity and environmental behavior of nanomaterials, with a special focus on their long-term ecological effects, for which substantial knowledge exists, yet highlights gaps in existing knowledge and future directions for responsible application in water treatment contexts.