Phytoremediation of lead using plants in lead-contaminated soils is a new and safe environmental technology. By adding chelators and increasing plant extraction, the efficiency of this technology can be increased. In this regard, we evaluated the effect of adding EDTA chelates to lead-contaminated soils to investigate the amount of lead accumulation in a medicinal plant, Calendula officinalis. We designed a factorial experiment in the form of a completely randomized, with three replicates in pots and two factors including EDTA at two levels (0, 50 mg kg-1) and lead at four levels (0, 30, 90, and 270 mg kg-1). In this plant, the accumulation of lead was accompanied by an increase in the amount of lead in the soil due to the addition of EDTA to the soil. The results showed that EDTA significantly increased the lead translocation of lead from roots to the aerial part of the plant.
Total Chl. and shoot dry weight decrease significantly in EDTA treatment than control specific at a high level of Pb in the soil. Also, the results showed that EDTA increased lead removal from soil to soil solution and increased lead translocation from roots to the aerial part of the plant of Calendula officinalis. In general, the results of this research showed that with the careful management and EDTA use in lead extraction, it has provided a cost-effective and safe environmentally strategy.