Fly ash deposits revegetation

Plants that grow on heavy metals polluted sites, resulting from human activities, as well as in the surrounding areas contain large amounts of these metals. Given the fact that laying a vegetal layer over the fly ash disposal site would attract birds and wild animals, this study aims to establish an in situ revegetation strategy and assess the level of heavy metal accumulation within the aerial part of the vegetal layer. The addition of a mixture consisting of modified volcanic tuff and biosolids lowers the heavy metal content within the aerial part of Lolium perenne by 20-26% and for Onobrychis viciifolia the decrease is three times higher. Despite this finding, the amounts of accumulated heavy metals within plants are remarkable. By using this kind of treatment, the heavy metal (chromium, copper, nickel and lead) accumulation within Onobrychis viciifolia is up to 14.6 – 20.4 mg/kg dried matter. This result requires the continuation of the studies in order to identify other materials that are able to abate the metal accumulation within plants or to remove the bioaccumulation species.