Transfer and Accumulation of Some Heavy Metals in Native Vegetation Plants

Phytoremediation procedure can be defined as the use of selected plants in order to eliminate some heavy metals from the soil, or wastewater in a cost-effective method. This study aimed to investigate the concentrations of heavy metals such as Cd, Pb, Cu, Zn and Cr in soils and vegetation plants grown in Wadi Hanifa, Riyadh city, Kingdom of Saudi Arabia. Five sites have been chosen for collected plant samples (shoot and root) for one year, and five plant species have been chosen which distributed in the study area including Ziziphus spina-christi, Prosopis juliflora, Rhazya stricta, Ochradenus baccatus and Conocarpus erectus. Determination of Cd, Pb, Cu, Zn and Cr has been done with ICP. Accumulation coefficient (AC), and translocation factor (TF) have been calculated to evaluate the ability of selected plants to extract the heavy metals from soil. The results indicated that Ziziphus spina-christi and Conocarpus erectus showed the high ability to accumulate the Pb and Zn in its root and shoot compared with other plants. The trend of heavy metal translocation factors for different plants was in the order of Cd > Cr > Pb > Cu > Zn. The accumulation coefficient (AC) of the Cd, Pb, Zn, Cu and Cr in the roots/soil of Ziziphus spina-christi, Prosopis juliflora, Rhazya stricta, Ochradenus baccatus and Conocarpus erectus were varied from 0.80 to 3.60. The order of AC in the shoot as follows: Pb > Cu > Zn > Cr > Cd, while in roots of as follows: Cd > Cr > Pb > Cr > Zn.