Degradation of nanoplastics in the environment: Reactivity and impact on atmospheric and surface waters

Atmospheric Micro and Nanoplastics: An Enormous Microscopic Problem

“…However, until now, only a limited number of studies investigated the reactivity of MP and NP towards atmospheric oxidants and further studies are needed to understand the fate of these plastics in the air. For example, Vicente et al [46] report the formation of degradation products by oxidation of PS nanoparticles in the presence of O 3 , while our previous study [50] estimates the reactivity constant between PS nanoparticles and • OH. To date, the effect of chemical degradation on plastic has only been studied for macro and mesoplastics, with special attention to plastic films, while little is known for MP and NP.…”

“…Once in the atmosphere, plastic particles are transported following air masses movements [17,43] and could act as ice nuclei, facilitating the formation of ice crystals [44]. The atmospheric oxidant capacity probably has a key role in their transformation, since MP and NP are exposed to sunlight [45], gas-phase oxidants (ozone, hydroxyl and nitrate radicals) [46][47][48][49] and aqueous phase oxidants (hydroxyl and nitrate radicals) [50] with higher concentrations compared to soil and water bodies. However, little is known about the fate and transformation of MP in the atmosphere.…”

“…Density separation and sample treatment increase the potential loss of sample and can damage the plastic particles, especially the ones with smaller sizes. Indeed, both hydrogen peroxide and the Fenton reaction produce hydroxyl radicals, which were shown to react efficiently with some NP [50]. For this reason, separation and purification steps have not been employed in several studies, however this might increase the difficulties in the detection and the identification of MP [34,37,42,55].…”

“…Besides, until now MP and NP have been considered as inert particles while recent studies show that they can react and interact with light and oxidants, like ozone and hydroxyl radicals [46,50]. Their degradation in the gaseous and aqueous phase releases a myriad of organic compounds from Figure 3.…”

Ionic Liquids as Extractants for Nanoplastics

“…To verify this hypothesis, we modified the surface of the PNPs, and decorated it with polar groups, which are consistent with possible oxidation processes. [87,88] In one set of simulations -OH groups were added at 49 randomly chosen interfacial sites, while in another set -CHO substituents were introduced at the same sites. In case of the shorter side chains it is clearly possible for these polar groups to be covered by the polar domain, since the overwhelming majority of the liquid consists of the ionic moieties (see r N in Table 3).…”