Phytoremediation of Lead (Pb) via Two-Year Old Thornless Honey Loccust Trees (Gleditsia triacanthos L. var. inermis) Existing in the Borders of

Analyzing the accumulation of toxic elements in plants is considered essential and important for preserving the health and life of the living things. Due to the fact that the absorption of heavy metals by plants is effective in decreasing environmental pollution, the ability of two-year-old Thornless Honey Loccust Trees (Gleditsia triacanthos L. var. inermis), planted in borders of Tehran-Karaj highway, for refining Pb element as a heavy metal using atomic absorption was investigated in the present study which was carried out in randomized complete block design with six replications. The experiment treatments included: three times of sampling (the beginning of leaf growth i.e., the opening of leaves, late June, and before the autumn). The results indicated that Pb concentration significantly increased with the passage of time and near autumn. Total leaf chlorophyll and carotenoid significantly decreased near autumn, but leaf fresh/dry weight ratio increased with the passage of time.