BayCEER Workshop 2024

Mesocosm studies for the evaluation of environmental fate of engineered nanoparticles

P 6.3 in Posters

In the last years, the risk for the release of engineered nanoparticles (ENPs) from different commercial products into the environment is continuously increased. After release into surface waters, ENPs can undergo physico-chemical transformations and interact with abiotic and biotic interfaces. Aquatic-terrestrial transition zones can play an important role in the distribution of ENPs between several environmental compartments. To enhance our understanding of the fate and effects of ENPs in aquatic-terrestrial transition zone, the stream mesocosms simulating floodplain ecosystems were used. The mesocosms were run with natural river water, natural floodplain soil, and quartz sand as sediment. Leaves, amphipods, and filter feeding bivalves were applied as biota. Using such mesocosms, the long-term aging, distribution, and bioaccumulation of silver (Ag-NPs), gold (Au-NPs), titanium dioxide (TiO₂-NPs), and sulfidized silver (S-Ag-NPs) nanoparticles were evaluated. Due to the agglomeration, more than 50% of ENPs accumulated in the top layer of sediment. Furthermore, the high enrichment of ENPs in/on algae, leaves, amphipods, and mussels was observed representing risk for organisms feeding on those resources and for the ENP transfer within the food web. The high accumulation of nanoparticles in sediments and biota suggests that these compartments can act as effective sinks for ENPs. Despite the high extent of agglomeration, a small fraction of nanoparticles remained in the water phase for several weeks suggesting a risk for long-distance ENP transport in the rivers. The results of this study show that mesocosm systems with a high degree of complexity are essential for the understanding of the environmental fate and effects of ENPs.

 

Acknowledgements: The author thanks the German Research Foundation (DFG) for financial support within research unit INTERNANO (FOR 1536) and all internal and external cooperation partners for interesting and unique cooperation.

Keywords: engineered nanoparticles; mesocosms; aquatic-terrestrial transition zone; environmental fate; agglomeration; enrichment, bioaccumulation