New Methods for the Recovery of Post Industrial Areas: Choosing Plants for Phytoremediation

During the last years ecologists have started working on urban ecosystems, considering the interaction of the social, biological and physical components of a city as one of the best way to understand dynamics and driving forces in urban development. Besides, urban design and planning projects have been devoted to find sustainable ways to control increasing phenomena such as urbanization and urban sprawl. In this context urban green areas can carry out many environmental functions in particular related to increasing biodiversity, assessing meso and microclimate, absorbing noise and promoting air and soil quality. Among these phytoremediation is a set of remediation methodologies that are based on the use of plants to remove pollutants, especially metals, from the soil or to reduce their impact on the environment. Ornamental plants can be used for this purpose in urban design, where both environmental and aesthetical solutions are needed. A pilot study was carried out in a post industrial area in the city of Turin ( Italy). Two species have been tested: Helianthus annuus L. 'Holeko H.O.' and Brassica juncea L. 'Red Giant' Physical-chemical characteristics of top soil before and after the experiment were determined. During cultivation growing data on plants were determined. After harvesting, metal contents in plants were measured. Results demonstrated that the use of phytoremediation techniques in urban soils can be an interesting method to control heavy metals accumulation during time. Further studies are required in order to find new ornamental species useful in urban green areas and to evaluate proper methods for their disposal.