AbstractsGeography &GIS

The fate and transport of citrate and PVP silver nanoparticles (AgNPs) was determined using large scale mesocosm studies with synthetic water and seasonal variations of natural lake water. We were able to produce a simple diffusion-sedimentation mathematical model which modifies sedimentation and diffusion equations for particles moving through a column. We introduced AgNP parameters including size and starting concentration to predict concentration and infer transport mechanisms in a 1 meter tall column over time. Ionic strength had a direct impact upon the behaviour and transformations observed by the two different surface coated AgNPs. Water collected in summer contained high TOC concentrations with low ionic strength. We observed increased stability to the citrate AgNPs and PVP AgNPs remained as nanoparticles for the duration of the study in the surface water. Winter water had the lowest TOC concentrations with high ionic strength. Citrate AgNPs showed increased aggregation and dissolution, whereas the PVP AgNPs remained stable. At different times of the year the transformations of the NPs change and during the warmer months AgNPs persist in particulate forms for longer periods of time in the surface waters.