Reclamation of urban brownfields through phytoremediation: implications for building sustainable and resilient towns

Adverse environmental effects related to unsustainable development are compelling people to welcome recent advances in technology that rely on principles of sustainability. The regeneration of contaminated brownfields has immense developmental potential that includes economic, social and environmental benefits, while reducing pressure on surrounding greenfield areas. Phytoremediation is a green technology that is highly suitable for most brownfield sites where pollution is moderate and environmental contaminants are dispersed over large surface areas. The current review centers on a description of phytoremediation, especially using woody plants, as an active component of the urban landscape. An overview of the additional environmental (i.e., beyond soil cleansing) and social benefits associated with this technology is provided, including the technical constraints and knowledge gaps that should be further addressed to make this technique efficient on a larger scale. The use of trees for the reclamation of brownfields shows several benefits in addition to depollution. Most tree species used for phytoremediation may actively reduce the volume of stormwater runoff and mitigate the risk of local flooding events. They can actively contribute to CO2 sequestration and function as highly aesthetic living barriers for noise and air pollution (PM) attenuation. Some uncertainties associated with the use of this reclamation technique in urban areas (i.e., BVOC emission, pollen production) still need to be addressed. Nevertheless, within the large family of green technologies, phytoremediation has huge potential to be used as an effective tool for the cleanup of contaminated urban brownfields, thus contributing to the development of more sustainable modern towns.