Applicability of Heavy-Metal Phytoextraction in United Arab Emirates: An Investigation of Candidate Species

Phytoremediation of contaminated calcareous desert land in the United Arab Emirates has been investigated. Soils from 12 northern UAE sites, suspected of metal contamination, were acid-extracted and analyzed by ICP-OES for Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. Twenty-two plants naturally growing at contaminated sites were sampled and analyzed for their uptake of Co, Cr, Cu, Mn, Ni, Pb, and Zn and eight commercially available plants, grown under controlled conditions, were also studied for their phytoextraction capabilities. The concentration of available Cr was found to be 1300 ± 150 mg/kg in the soil of the Ajman Industrial Zone and 80 ± 10 mg/kg of Pb was found at Bithna. Among the plants investigated, Portulaca oleracea and Iresine herbstii showed potential for Cr(VI) and Pb(II) accumulation, respectively, with bioconcentration factors (BCF) greater than unity. Atriplex halimus accumulated Co(II), Cr(III), and Cu(II) each with a BCF > 1.