Abstract:
Phytoextraction has been introduced as a new technology to clean up soils contaminated with heavy metals as the use of
conventional methods to clean up the soil is very expensive and destructive to the ecosystem. However, using plants to
clean up contaminated soils takes a considerable period before the contaminants are removed from the soil by the plants.
This has necessitated the use of amendments to enhance phytoextraction in order to shorten the period of contaminants
removal by plants. In view of this, a pot experiment was conducted to study the effect of various aminopolycarboxylic
acids (EDTA, EDDS, NTA dry and NTA liquid) and two commercial fertilizers which are Hortrilon® and Fetrilon® on
their ability to solubilize Cd and Zn in contaminated soils. It was observed that the inducing effect of EDTA on the
solubility of Cd and Zn persisted throughout the experimental period. Initially, EDDS enhanced the solubility Cd and
Zn, however, its effect dissipated with time. The application of both NTA dry (powder) and NTA liquid had a significant effect on the solubility of Zn as a result of the formation of Zn-NTA soluble complexes. Hortrilon® and Fetrilon®
solubilized significant concentrations of both Cd and Zn with Hortrilon® having the greatest inducing effect on the
solubility of Cd and Zn
