Bioaccumulation of some heavy metals by the soil and leaves of Ziziphus spina-christi in Khouzestan Oxin Steel Company

In this study, the accumulation of heavy metals included iron, manganese, lead, and cadmium in a native species of Christ's thorn jujube (Ziziphus spina-christi) was investigated. To this, random samples were collected from tree leaves and soil at the bottom of the trees from five stations in Khouzestan Oxin Steel Company. Station 1 was located in the company center and adjacent to the source of pollution. Station 2 was situated 100 m away from the company and in the path of wind direction. Stations 3 and 4 were located approximately 200 meters from the source of pollution . Station 5 was placed three kilometers from the company in the opposite direction of the prevailing wind. The results showed that the lowest concentrations of all elements in the leaves of the trees and the soil of the trees were found to be at station 5 and the highest at station 1, therefore, it can be concluded that the distance from the company and the dominant wind direction were effective for this results. The calculation of the bioconcentration factor for four heavy metals showed that the trees were only able to absorb cadmium from the soil with a BCF value of more than one. Considering the usefulness of this tree in fore absorption of cadmium and direct use of fruit and leaves of trees, it is suggested that this tree can be used in areas with cadmium contamination in Khuzestan and areas with similar climate and soil conditions with considering environmental conditions.