Chemical and physical properties of soil influencing TiO2 nanoparticles availability in terrestrial ecosystems

Nanotechnology is a new and fast emerging field that involves the design, production and use of structures at the nanoscale. Despite the widespread application of nanotechnology in agricultural, environmental and industrial sectors, a growing concern is coming to light in the recent years about the effects of nanoproducts within different environmental compartments and their likely impacts on human health. Precautionary measures are warranted until possible risks have been elucidated, hence the fate and behavior of nanoparticles in soils and groundwater must be investigated. Using three different Italian soils, we conducted a preliminary investigation of TiO2 nanoparticles (TiO2-NPs) behavior in soil suspensions. Aliquots of TiO2-NPs suspensions with and without soil were periodically collected after their preparation, and monitored for aggregate size distribution and Ti concentration. Experimental results suggest that soil properties affect the behavior of TiO2-NPs, in particular the dissolved organic matter as well as the ionic strength seem to be the main influencing factors.