Evaluating the Ability of Alyssum murale to Extract Aged Nickel From Nickel-Enriched Organic Soils

Port Colborne, Ontario, has an area of nearly 30km2 that has been contaminated by
emissions from a nickel (Ni) refinery that was in operation between 1918 and 1984.
Emissions from the process of converting Ni-rich ores to marketable forms of Ni have
left elevated Ni concentrations in the surrounding soil. These elevated Ni concentrations
are causing phytotoxicity and are suspected of reducing crop yield in some agronomic
species. Common remediation techniques (such as ‘dig and dump’) are not feasible or
economically efficient because of the large area that has been contaminated.
Phytoremediation would be a cost-effective and sustainable alternative, if its efficacy
could be demonstrated on spatial and temporal scales.
Nickel hyperaccumulating plant species are able to accumulate at least 1000 mg kg-1 of
Ni in their dry biomass without succumbing to toxicity. Alyssum murale, a
hyperaccumulator of Ni that is native to Ni-rich serpentine soils from Mediterranean
Europe, is a species of interest for phytoremediation. Extensive research has been
conducted regarding the ability of A. murale to extract Ni from Ni-enriched soils (Chaney
et al., 1998, 2000, 2005; Li et al., 2003; McNear et al., 2007; Fellet et al., 2009;
Centofanti et al., 2012). Research shows that A. murale is able to extract Ni from soils
with elevated concentrations of Ni without showing signs of toxicity; however the spatial
and temporal capacity of this species as a perennial crop to measurably reduce the
concentration of Ni in soils has not been demonstrated.