Evaluating the ability of Alyssum murale to extract nickel from nickel-elevated soils from Port Colborne, Ontario

Abstract

Alyssum murale, a hyperaccumulator of Ni that is native to Ni-rich serpentine soils, is a species of interest for phytoremediation of Ni-elevated soils resulting from industry emissions in Port Colborne, Ontario. To determine the feasibility of using A. murale for Ni mass transfer, two phytoextraction studies were conducted. A 30-day scoping study determined short term extraction capability and results showed a decrease in total soil Ni concentration over time. To determine extraction efficiency over a growing season, a100-day study was conducted. Results showed a proportional decrease in total and extractable soil Ni concentrations and a constant partitioning coefficient over time, suggesting bioaccessibility of Ni did not decrease. Despite reduction in soil Ni concentration, there was not a mass balance between soil Ni mass reduction and A. murale Ni mass accumulation. Using modeling software and data from the phytoextraction studies, a hypothetical timeline for reduction in soil Ni mass was established.