ارزيابي كمي امكان پالايش سبز خاك هاي آلوده به سرب به وسيله شاهي (Barbarea verna)

Quantitative Assessment of Possible Phytoremediation of Lead contaminated soils by Land Cress (Barbarea verna)

Phytoremediation is an emerging technology which uses plants and their associated rhizospheric microorganisms to remove contaminants from soil. Phytoremediation is relatively inexpensive technology compared to technologies that involve the use of large scale energy consuming equipments. Heavy meials are one ol the most common contaminants at hazardous waste sites. Of heavy metals, lead (Pb) is one of the most significant contaminant, posing serious and sometimes life threatening health hazards. The objective of this study was to investigate the potential use of Land Cress to remediate Pb contaminated soils. Consequently, a large quantity of a sandy loam soil was thoroughly mixed to ensure homogeneous concentration levels of 0. 150. 300, 600. 800. 1000 and 1500 mg Pb kg-1 soil by lead. These contaminated soil treatments were transferred to some plastic pots. Land Cress seeds were germinated in pots containing 8 kg of lead contaminated soil. The concentrations of Pb in the soil and plant samples have been determined by llame and graphite furnace atomic absorption speetrometiy. The results indicated that the Pb concentration of Land Cress was increased by increasing Pb concentration in the soil samples. Also, the relative yield of Land Cress was decreased by increasing Pb concentration in the soil. The results were also indicated that the remediated amount of Pb was increased by increasing soil Pb contamination up to l(XX) mg kg-1. However, it decreased in the soil Pb contaminations between l(XX) to 1500 mg kg-1. Results showed that, although. Land Cress tolerates the high levels of soil Pb contamination, it is not of potential to phytoextraet such pollutions. Results, therefore, suggest that Pb- phytoremediation using the Land Cress is not feasible when the soil is highly contaminated. However, Land Cress has the potential to remediate low levels of soil Pb contamination