Non-saturation correction in the NanoFASE model

The NanoFASE model uses the non-saturation correction factor to take into account empirically the effect of air-water interactions in the transport calculation of nanomaterials in porous media such as soils and sediments. The correction basically modifies the attachment efficiency, making it higher when the degree of saturation is lower. 

\(\alpha _{non-saturated}(\theta )=\alpha _{saturated} +f_{non-saturated}\times 1\) 

\(\alpha _{non-saturated} (\theta )\) is the non-saturated attachment efficiency < link from new page1 in this ppt> at a given water content \(\theta\). The saturated attachment efficiency \((\alpha _{saturated} )\) is determined using saturated column transport experiments.

\(\alpha _{non-saturated}\) can then be calculated using the non-saturation correction factor (\(f_{{non-saturated}}\)).



Several unsaturated column tests are needed to fit \(f_{air-water}\) to the \(\alpha _{non-saturated}(\theta)\)relation. This relation was found to be linear in NanoFASE, but in a limited set of experiments only. Further research is needed to confirm this relationship. Potentially, the straining factor would depend more clearly on the water content in soil.


Non-saturated correction factor

Used for


\(\frac{dC}{dt}=v\theta \frac{dC}{dz}-\)




Air/water interaction Transport calculation


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Consult the NanoFASE Library to see abstracts of these deliverable reports:

NanoFASE Report D7.2 Soil property - NM fate relationships 

NanoFASE Report D7.4 Module for NM exposure prediction in soils to couple to overall framework  

OECD technical guideline 312





  Geert Cornelis

  Swedish University of Agricultural Sciences (SLU)