NanoFASE Mesocosm study: Bioaccumulation of Ag2S-NPs in freshwater organisms

The extensive production and use of nanoparticles (NPs) has led to their release in several environmental compartments. Freshwater systems are important sinks for NPs, especially the sediment phase, where benthic organisms can be exposed through water and sediment. To achieve more realistic environmental conditions, it is advisable to conduct mesocosms studies, therefore NanoFASE performed an aquatic mesocosm experiment simulating a freshwater stream environment. Toxicokinetics and bioaccumulation of a simulated aged form (Ag2S-NP), produced by the NanoFASE partner AppNano, were studied in freshwater organisms.

Study aim
 
  1. Validate kinetic parameters of Ag2S-NPs derived in previous studies.
  2. Determine bioaccumulation and trophic transfer of Ag2S-NPs in aquatic organisms.

Experimental approach

Overview
 

Compartment involved:

Soil

NP type/size:

Ag2S NPS were provided by AppNAno

Species:

Turnip
Wheat (Triticum aestivum L.)
Mealworm (Tenebrio molitor)
Isopods (Porcellio scaber)
Earthworms (Lumbricus rubellus)

Assay:
Soil column 
  • 36 units (rivers)
  • 14 days of exposure
  • Water and sediment phases
  • Daily contamination of water at 10 µg Ag.L-1
  • Low flow and recirculation
  • Organisms sampled at days 2, 7 and 14

 

  • Ceramic tiles with biofilm were placed in each river
  • Fish were fed with daphnids every day
  • Daphnids were fed every day with microalgae
  • Snails fed on biofilm
  • Planarians fed on snails and chironomids
  • Chironomids fed on sediment + ground leaves

Results

Output Modelling Parameters
 
Results are under analysis (Summer 2019).
  • k1 - uptake kinetic rate constant (L.g-1dw organism.day-1)
  • k2 - elimination kinetic rate constant (day-1)
  • SF – stored fraction (0 ≤ SF ≤1) (unitless)

Read more
 

NanoFASE Report D9.2: Parameter sets on uptake and toxicokinetics of selected pristine NMs in aquatic and terrestrial organisms

See extraordinary close-up biota photography and experimental set up in the NanoFASE scientific video: Nanomaterials in Mesocosms: A Needle in a Haystack

Contact

 

Susana Loureiro

University of Aveiro

Email: sloureiro@ua.pt
 

 

Patrícia V. Silva

University of Aveiro