Among them, NOM has attracted a lot of attention, which has highly heterogeneous compositions and abundant functional groups, leading to the inevitable interactions between NMs and NOM (Lawrence et al. These transformations could result in the alteration of toxicity of NMs (Loza et al. Once released into the environment, NMs will undergo transformations due to the impact of various environmental factors (such as light, ionic strength, water hardness, and natural organic matter (NOM)) (Lowry et al. Moreover, NMs could act as carriers to bring heavy metal ions or organic pollutants into organisms (Fan et al. Lab-scale experiments have showed that NMs could induce oxidative damage or adsorb enzymes to interrupt the metabolic activity of organisms (Borandeh et al. It was estimated that the concentrations of discharged NMs in the surface and effluent waters could reach μg/L levels (Giese et al.

However, the release of manufactured NMs from these consumer products or their emissions through industrial discharge may induce a risk for ecological systems and human beings. Nanotechnology has greatly expanded the application of nanomaterials (NMs) in various fields including cosmetics, medical treatments, electronic industry, and mechanical engineering (Grieger et al. The results showed that more research is needed to investigate the effect of an eco-corona through the development of novel techniques, mathematical modeling, and mesocosm studies. The effects of an eco-corona on the fate and the effects of other pollutants (such as metals and organic pollutants) were also carefully reviewed. The dual effects of an eco-corona on the toxicity/accumulation of NMs were widely present because of the complex molecular composition of NOM, the diverse types of NMs, and the variable environmental conditions. The results showed that an eco-corona could alter the toxicity of NMs by changing the dissolution of NMs, adhesion of NMs and the damages to bio-membranes, internalization, and the generation of NMs-induced reactive oxygen species. The effects of an eco-corona on the bioaccumulation and toxicity of NMs for aquatic organisms were systematically discussed through reported studies. Herein, the mechanisms of the formation of an eco-corona were reviewed based on the representative literatures and their generality was discussed on the basis of the type of NMs, the type of NOM and the environmental conditions. A systematic understanding of the impacts of an eco-corona on the hazards of NMs is crucial for NMs risk assessment in the aquatic environment. The formation of an eco-corona can greatly influence the behavior, risk and fate of NMs in the environment. Nanomaterials (NMs) are able to interact with natural organic matter (NOM) such that NOM is adsorbed on the surface of NMs to form an ecological corona (eco-corona).

Nms carbon nanotubes