Ecological Restoration of Polluted Soils in Arid Region (Case Study: Bauxite Crusher of Jajarm Alumina)

Soil contamination by heavy metals is a significant environmental problem worldwide. Human activities, including mining, are a source of pollution to natural resources. In this study, the phytoremediation potential of rangeland species including, Artemisia sieberi Besser, Zygophyllum atriplicoides Fisch. and C.A. Mey for the absorption of heavy metals of Ni, Co, As, Cr and V was investigated around the bauxite crusher of the Jajarm alumina mine in the direction of the prevailing wind. Soil sampling was performed at the distances of 450-700, 800-1200, 1400-2000 and 2500-5000 meters from the center of the bauxite crusher, and the control site. For this purpose, the seeds were planted in pots with a 3:1:1 ratio of sand, fertilizer and soil. Two-months later, they were transferred to pots with soils sampled from target distances. After completing of a vegetative period, the phytoremediation potential of the species was performed a factorial experiment in a completely randomized block design with three replications in greenhouse conditions. Results indicated that As, Ni, Cr, and Co absorption in above/underground of A. sieberi tissues were higher than Z. atriplicoides. But V absorption in above/underground of Z. atriplicoides tissues were higher than that for A. sieberi and between the vanadium accumulation in the aerial and underground organs of the target species and distances a significant difference was observed at the level of 1%. The amount of heavy metals transfer factor for A. sieberi and Z. atriplicoides was more and less than one in turn. Therefore, in terms of the transfer factor, A. sieberi has a potential for phyto-extraction and Z. atriplicoides has a potential for phyto-stabilization. The results also showed that A. sieberi and Z. atriplicoides were recognized as hyper-accumulating of nickel and cobalt metals. These species can therefore be recommended for the ecological restoration of soils polluted by heavy metals, especially nickel and cobalt in similar regions.