Pot experiments were conducted to evaluate chemical and phyto-remediation of cadmium in Cd-polluted clayey and sandy soils. For each experiment, the experimental design was factorial randomized complete block, with three replicates. Factors and their treatments were as follows: (1) Cadmium pollution (C): three rates of 0, 100, 200 mg Cd kg-1 as cadmium sulphate, i.e. C0, C1, C2 respectively; (2) Soil (S): two soils differing in their texture were used; clayey and sandy textured soils, i.e. S1 and S2, respectively. In the phyto-remediation experiment three plant species were used; elephant grass (Pennisetum purpureum), sunflower (Helianthus Annuus L.) and sorghum (Sorghum biocolor L.); an experiment per each species. The chemical-remediation experiment had two chemical-remediators (extractants), EDTA and DTPA. Elephant grass was the most efficient phyto-remediator for cadmium followed by sunflower and sorghum. It recovered Cd mostly in the shoots especially when soil is polluted with cadmium at a rate of 100 mg kg-1. The EDTA was more effective than the DTPA as a chemical-remediator, it removed more Cd than the DTPA. |
