Periodic Reporting for period 2 - SAFEnano (Effect of water and wastewater treatment on the properties of engineered nanomaterials (ENMs) in context of their fate, toxicity and interaction with other contaminants)
Reporting period: 2019-10-01 to 2020-09-30
The proposed study is the first which investigates how various water and wastewater treatment methods will influence the physicochemical and ecotoxicological properties of ENMs (Fig. 1). Recognition of this problem has an extremely important aspect of cognition in a situation of increasing ENMs production. Acquired new knowledge on this topic lead to a better understanding of the mechanisms and processes in the environment. The research will contribute to a broad base of knowledge that will be the basis for solving of known or expected future problems related to the use of ENMs. Innovative aspects of the work were:
(1) Investigation of the effects of different water and wastewater treatment process on ENMs properties (WP1);
(2) Determination of ENMs changes during water/wastewater treatment and how these changes affect ENMs fate (aggregation, mobility, bioaccumulation) in the environment (WP2);
(3) Determination of how change in ENMs properties may result in a change in the strength of interactions with other contaminants, thus affecting their bioavailability and toxicity (WP3);
(4) Evaluation of ENMs toxicity to different organisms in connection of changes ENMs properties (WP4).
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).