Effect of a polycyclic aromatic hydrocarbon on the phytoremediation of zinc by two plant species (Brassica juncea and Festuca arundinacea)

The redevelopment of contaminated land is becoming increasingly necessary under sustainable- development legislation; however, many of the contaminated sites are "orphan" sites and therefore require a low-cost remediation technology. These sites often contain a cocktail of pollutants including organics and inorganics. Phytoremediation provides a possible solution, but there is little information available on the tolerance of plant species to multiple pollutants and their ability to remediate in mixed-contaminant soils. The effect of a polycyclic aromatic hydrocarbon (pyrene) in soil upon the remediation of zinc by Brassica juncea and Festuca arundinacea was investigated under normal climatic conditions in the United Kingdom. Zinc was effectively removed from mixed-contaminant soils in the presence of both species, in comparison to a control treatment. Both species accumulated zinc in plant tissues in the presence of pyrene, but the growth of B. juncea was significantly reduced when zinc and pyrene were supplied in combination. Zinc was predominantly associated with root tissues for F. arundinacea, whereas B. juncea contained higher concentrations in shoot tissues. F. arundinacea provides a possible species to be used for the phytoremediation of brownfield sites, but further research is required to determine a range of species that may be used and their applicability to different contaminants.