Phytoremediation of nanoparticles, as future water pollutants, using aquatic and wetland plants: Feasibility, benefits and risks, and research gaps.

Abstract

The widespread use of nanoparticles (NPs) in recent years and their rapid accumulation as potentially dangerous pollutants can lead to significant environmental risks. Different methods are used to eliminate emerging contaminants such as NPs from aquatic environments. Of these methods, phytoremediation using aquatic and wetland plants (WAPs) is considered the most suitable approach because of their extensive root systems, high rates of biomass production, ability to thrive in diverse habitats, and rapid growth within aquatic ecosystems. Various species of genera Lemna, Salvinia, Spirodela, Phragmites, Elodea, and Pistia have been studied for their potential to remediate NPs or contaminants released by NPs. The findings of the review indicate that the majority of WAPs cannot accumulate NPs within their tissues. Nevertheless, the effective methods for removing NPs from the environment by WAPs involve the surface adsorption of NPs onto their roots and the accumulation of pollutants released by NPs within the plant tissues. In addition to the benefits of NPs phytoremediation through WAPs, including sustainability, efficiency, and affordability, there are risks to consider, such as the potential transfer of NPs into the food chain, the release of toxic compounds from NPs due to (bio)degradation, and interactions between contaminated WAPs and other ecosystem components. Furthermore, several research gaps need to be addressed in the future, including a scarcity of field studies, a limited focus on NP types and plant species, unrealistic NP concentration, comparisons with bulk materials, the use of additives and amendments, and the genetic engineering of WAPs.