NanoFASE Case Study: Influence of Differing Soil Properties on Uptake of Ag-NP Forms in Wheat

Silver nanoparticles can enter the soil through the application of sewage sludge to agricultural land. The silver in the sewage sludge will most likely be in the transformed, sulphidised form. Plants growing on this agricultural land will thus be exposed to silver and have to potential to accumulate silver in their tissues. Varying soil properties can affect the bioavailability and bio-uptake in plants ; NanoFASE has therefore investigated the effect of a range of soils upon the bio-uptake of silver to plant tissues in the crop plant, Triticum aestivum (wheat).

Study aim

This study investigates the uptake of Ag from different Ag forms (Ag0 Engineered NanoMaterials , Ag2S ENM and AgNO3) in wheat, Triticum aestivum, exposed in three different natural soils (Lufa 2.2, Woburn and North Wales).


Experimental approach


  1. Three soils (Lufa 2.2, Woburn and North Wales) were spiked separately with three different forms of silver, each at a concentration of 10 mg Ag/kg. After 7 days, seeds were planted in the spiked soils.
  2. Plants were sampled at 1, 4, 6, 13 and 27 days post-emergence and the silver concentration was measured separately in the plant roots and shoots using graphite furnace atomic absorption spectroscopy (GF-AAS).
  3. Soil pore waters were extracted after 1, 6 and 27 days and total Ag was measured in the pore water and in ultra-filtered pore water samples.

Compartment involved:  


NP type/size:

Ag NP PVP coated - 20nm (AppNano)
Ag2S NP - 27 nm (AppNano)
Wheat (Triticum aestivum)
Bioaccumulation assay



  •  The rate of uptake was highest in the Woburn soil compared to North Wales and Lufa 2.2.
  • The uptake of Ag was highest from the pristine 20 nm Ag NP PVP coated particle, while Ag2S was either lower than or the same as the uptake from the AgNO3 ionic reference.



  • Uptake rate from soil - \(k_{1sc}\)
  • Elimination rate (soil) - \(k_{2sc}\)
  • Uptake rate from soil pore water - \(k_{1PW}\)
  • Elimination rate (soil pore water) -\( k_{2PW}\)
  • Growth rate – \(k_g\)
  • Bioaccumulation factor - \(BAF\)
  • Transfer function – \(TF\)
  • Pore water concentrations    

Read more

Read also


"A Tale of Two Synchrotrons" in NanoFASE News

Visit the NanoFASE Library to read summaries of these reports:

NanoFASE Report D7.2 Soil property – NM fate relationships

NanoFASE Report D9.2 Parameter sets on uptake and toxicokinetics of selected pristine NMs in aquatic and terrestrial organisms (summary of internal report)  


Wang, P., et al. (2015). "Silver sulfide nanoparticles (Ag2S-NPs) are taken up by plants and are phytotoxic." Nanotoxicology 9(8): 1041-1049.

Dolette, C. L., et al. (2015). "Bioavailability of silver and silver sulfide nanoparticles to lettuce (Lactuca sativa): Effect of agricultural amendments on plant uptake." Journal of Hazardous Materials 300: 788-795.

Stegemeier, J. P., et al. (2015). "Speciation Matters: Bioavailability of Silver and Silver Sulfide Nanoparticles to Alfalfa (Medicago sativa)." Environ Sci Technol. 49(14): 8451-8460.



Amaia Green Etxabe

Centre for Ecology and Hydrology (CEH)
Wallingford, UK



Elma Lahive

Centre for Ecology and Hydrology (CEH),
Wallingford, UK