Phytoremediation is a plant-based remediation process for treating contaminated soils. The overall aim of this thesis was to determine whether phytoremediation could be applied to co-contaminated soils. Copper (Cu) and pyrene, and Chromium (Cr) and Benzo[a]pyrene (B[a]P) were used as contaminants.
The first study involved the joint effect of Cu and pyrene or Cr and B[a]P on the early seedling growth of Lolium perenne. Results suggest that co-contamination showed several types of interactions for seedling growth with different combinations of the pollutants. The second study involved the role Brassica juncea and Zea mays during the remediation of Cu and/or pyrene, and Cr and/or B[a]P co-contaminated soils respectively. Brassica juncea and Z. mays showed contrasting results for metal and polycyclic aromatic hydrocarbon (PAH) remediation. The third study compared freshly spiked soils and aged soils. Ageing affected the plant biomass, metal phytoextraction and PAH dissipation in different ways when compared to fresh soils. Finally, the efficiency of ethylenediaminetetraacetic acid-EDTA and/or citric acid as chelators in co-contaminated soils was studied. The combined application of EDTA and citric acid was more effective in co-contaminated soils.
The overall findings from the four studies suggest that phytoremediation could be applied to co-contaminated soils
