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The increasing use of tungsten in the production of green energy in the aerospace and military industries, and in many other hi-tech applications, may increase the content of this element in soil. This overview examines some aspects of the behavior of tungsten in soil, such as the importance of characteristics of soils in relation to bioavailability processes, the chemical approaches to evaluate tungsten mobility in the soil environment and the importance of adsorption and desorption processes. Tungsten behavior depends on soil properties of which the most important is soil pH, which determines the solubility and polymerization of tungstate ions and the characteristics of the adsorbing soil surfaces. During the adsorption and desorption of tungsten, iron, and aluminum oxides, and hydroxides play a key role as they are the most important adsorbing surfaces for tungsten. The behavior of tungsten compounds in the soil determines the transfer of this element in plants and therefore in the food chain. Despite the growing importance of tungsten in everyday life, environmental regulations concerning soil do not take this element into consideration. The purpose of this review is also to provide some basic information that could be useful when considering tungsten in environmental legislation.

Phytoextraction is a low-cost technology with negligible environmental impacts. A major issue at the field scale is the heterogeneity of contaminant concentration since the entire site needs to be treated evenly even though zones may need different incisiveness in the treatment. The concentration ratio (C-shoot/C-soil) is generally used to evaluate plant species performance and it includes for simplicity an assumption of linearity in the uptake behavior, although deviation from linearity has been observed in several studies. This work describes a phytoextraction feasibility test, conducted at a greenhouse scale for the remediation of an arsenic-contaminated site. Since a feasibility test should also provide an uptake model that accounts for plant growth in heterogeneous areas, the investigation focused on defining the uptake behavior of the various selected species growing in a site with homogeneous soil properties, but with considerable differences in arsenic concentration. Among the many models selectable to describe the soil-to-plant transfer, the Freundlich-like approach was tested. While remaining easy to handle, the non-linear model selected proves to be adequate to predict the arsenic uptake despite the complex contamination considered, thus allowing a more realistic prediction of the potential of a field-scale phytoremediation procedure.