Potential of Indigenous Plant Species for the Phytoremediation of Arsenic Contaminated Land in Kurdistan (Iran)

To evaluate the potential of the indigenous plant species for Arsenic (As) phytoremediation, a total of 138 plant samples and 138 soil samples from rooting zones were collected from two As-contaminated areas in Kurdistan, western Iran. The areas were the Sari Gunay Gold Mine (SG) and Ali Abad Village (AA). The soil of both areas naturally contains As, with mining activities at SG. Soil and plant samples were collected at five sites in the SG (SG1 to SG5) and at two sites in the AA (AA1 and AA2). Soil samples were analyzed for total and water-soluble As concentration, as well as for the main soil physical and chemical properties such as electrical conductivity (Ec), pH, organic carbon (C_org.), available phosphorus (P_ava.), and soil texture. Plant samples were analyzed for As concentration in their shoots and roots.

The average total and water–soluble As concentrations in soil were 751.6 and 6.2 ppm at SG and 920.8 and 8.0 ppm at AA, respectively. The highest root and shoot As concentration was found in Juncus inflexus (751.5 ppm) at AA2 and in Astragalus gossypinus (158.7 ppm) at AA1, respectively. With regard to phytoremediation strategies, Acantholimon brachystachyum, Astragalus gossypinus, Stipa barbata, and Ephedra major with a high translocation factor (TF) can be potentially used for As phytoextraction. However, Juncus inflexus, Phragmites australis, Bromus tomentellus, and Elymus sp., which show high bioconcentration factor (BCF) and low TF, are suggested as good candidates for As phytostabilization. In general, the TF values of terrestrial plants were higher than those of amphibious plants; meanwhile, BCF values showed the opposite behavior.