Comparison of phytoremediation of heavy metals by woody species used in urban forestry of Sanandaj city

Phytoremediation is an emerging, safety, cost-effective and potentially effective technology applicable for restoration of heavy metals contaminated environment. In order to study the remediation ability of woody plants used in Sanandaj urban forestry, we measured accumulation of Pb, Zn, Cd and Mn in five woody species, including Platanus orientalis, Ulmus carpinifolia, Fraxinus rotundifolia, Biota orientalis and Pinus nigra, planted in the center of Sanandaj, capital of Kurdistan province of I.R. Iran (as a pollutant area) and Kurdistan university court (as a control area) as well. Impact of the metals on some physiological traits of the species were also studied. For this reason, a completely randomized factorial experiment design with two factors, including 1- site at two levels (control and pollutant area) and 2- species at five levels (crock cypress, black pine, ash, elm and plane) with five replications, was used. Results showed that the accumulation of Pb, Zn and Cd in most species in the pollutant area was significantly higher than that of the control area (ρ<0.05). Maximum accumulation of Pb and Cd was observed in B. orientalis, Zn in F. rotundifolia and Mn in U. carpinifolia. The chlorophyll pigment in the leaves of all species in the pollutant area was lower than in the control area, while proline was higher. The highest amount of chlorophyll and proline was observed in P. orientalis and U. carpinifolia, respectively.