Study of Cadmium Remediation Potential in Different Organs of Ash (Fraxinus rotundifolia Mill.) and Balck locust (Robinia pseudoacacia L.)

Phytoremediation technology is the use of plants to remove pollutants such as heavy metals from the environment and accumulation of them in different plant tissues. In this study the ability of two plant species; Robinia pseudoacacia and Fraxinus rotundifolia to remediate the cadmium، was compared. 90 two-years old seedlings of these two species were cultivated in Alborz Research Centre of Karaj in March 2008. The cadmium chloride solutions with the concentrations of 0، 250، 500، 1000 and 2000 mg L-1 were foliar application on the seedlings in June 2009. Then the leaves were collected from the seedlings during two times a year، in August and at the beginning of autumn. Moreover، some samples were supplied from twigs، roots and pot soils in January 2009. The concentrations of cadmium in samples were determined by ICP and the data were analyzed by completely randomized design in SPSS. Results showed significant different between two species in all the organs. The amounts of Cd concentration in F. rotundifolia were higher than R. pseudoacacia in the mature leaf، fall leaf and roots. The amount of Cd in the stem of R. pseudoacacia was higher than the stem of F. rotundifolia. So، it could be concluded that F. rotundifolia is more valuable in accumulation of the cadmium in short time and R. pseudoacacia is more suitable in long time. The maximum concentration in mature leaf of F. rotundifolia was461. 5 mg-1 kg. Therefore، it may be announced as a hyperaccumulator species based on previous studies.