The results showed that the treatments affected properties of ENMs and strictly related to kind of ENMs and kind of treatment. Generally, changes in ENMs properties did not affect their behaviour in environmental systems (aggregation rate). There were exceptions, but not visibly related to changed properties or method of treatment. Treatment of ENMs by H2O2, UV, chlorination and ozonation did not affect the release of elements (Zn, Cu) from nanocoated carbon nanoparticles and nanohybrids, thus the bioaccumulation of these elements by plants and insects was negligible. We observed that treatment may change the affinity of ENMs to emerging contaminants (increase or decrease depending on kind of treatment and ENMs), which may have serious environmental consequences. Ecotoxicological results differ depending on organisms tested and kind of ENMs. No effect of UV, H2O2 and UV/H2O2 treatment, as well as ozonation treatment of investigated ENMs, was observed.
1.2.1 Work Package 1
The results showed that the effect of treatment on physicochemical properties of ENMs depended on the method of treatment and material tested. No differences were observed in the properties of ENMs after their treatment between distilled water and modelled wastewater. However in the case of UV/H2O2 treatment as well as ozonation some changes were observed. For functionalized graphene nanoplatelets increasing of the surface area after UV/ H2O2 treatment of hydrocarbon functionalized GFs were observed. Generally, UV and H2O2 treatment of ENMs decreased the carbon content in these materials and increased the other elements, which was confirmed by FTIR spectra.
1.2.2 Work package 2
Size of aggregates with a few exceptions did not change depending on the treatment method and the type of particles. For most of the tested ENMs the treatment did not affect their behaviour in environmental systems and ENMs usually settle down regardless of the treatment after 3-5 days.
No difference in the concentration of Zn and Cu between the control (no nanoparticles) and experiments with pristine and treated ENMs were observed in particular elemental systems.
1.2.3 Work package 3
Phenanthrene (PHEN), triclosan (TCS), diclofenac (DFC), naproxen (NAP) and caffeine (CAF) were the model compounds To a large extent, the impact of individual treatments depended on the ENMs tested. The results varied and largely determined by the type of ENMs and the method of treatment.
1.2.4. Wok package 4
The risk assessment of ENMs before and after treatment in the context of their transformation was evaluated. The following tests were performed with Pseudokirchneriella subcapitata (algae), Lepidium sativum (plants), Vibrio fisheri (bacteria) as well as Folsomia candida (invertebrates).