E. Babaeian; M. Homaee; R. Rahnemaie
Abstract
Phytoextraction is a remediation technology for contaminated soils with lead (Pb). The application of chelating agents can be resulted in high efficiency in this method. In current study, the effect of synthetic and natural chelates applicationon efficiency of lead phytoextraction from soil by carrot ...
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Phytoextraction is a remediation technology for contaminated soils with lead (Pb). The application of chelating agents can be resulted in high efficiency in this method. In current study, the effect of synthetic and natural chelates applicationon efficiency of lead phytoextraction from soil by carrot was investigated. The experiment factors were 1) six levels of Pb (0, 100, 200, 300, 500 and 800 mg Pb kg-1 soil, added as Pb(NO3 )2, 2) chelates (EDTA, NTA and oxalic acid, and 3) chelate concentration (0, 2.5, 5 and 10 mmol kg-1 soil). The results indicated that EDTA effectively increased the Pb content in soil solution. At the highest applied rate (10 mmol EDTA kg-1), it resulted in 463-fold increase in extractable Pb, compared to the control treatment. Pb content in the shoot and taproot increased with the chelates application rates.The highest Pb content in the shoot (342.2±13.9 mg kg-1) and root (310 ±15.5 mg kg-1) occurred in 10 mmol kg-1 EDTA when Pb level was 800 mg kg-1. Pbphytoextraction potential increased with increasing thechelate and Pb concentration. Maximum Pb extraction from soil (1208±26.6 g ha-1 yr-1) during growth season occurred in 10 mmol kg-1 EDTA, when soil Pb level was 800 mg kg-1. It may be concluded that carrot can take up high amount of Pb and concentrate it in its roots and shoots. Thus, it can be introduced as a lead accumulator to phytoextractPb from contaminated soils.
E. Babaeian; M. Homaee
Abstract
Abstract
Enhancing phytoextraction with aminopolycarboxylic acids (APCAs) associated with fast growing and metal tolerant plants species has been proposed for the clean-up of heavy metal contaminated soils. The objectives of this study were to assess the efficiency of EDTA and NTA for desorbing Pb from ...
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Abstract
Enhancing phytoextraction with aminopolycarboxylic acids (APCAs) associated with fast growing and metal tolerant plants species has been proposed for the clean-up of heavy metal contaminated soils. The objectives of this study were to assess the efficiency of EDTA and NTA for desorbing Pb from soil and to compare their effects for enhancing of Pb extraction with Land Cress (Barbara verna). The experimental factors were including 0, 100 and 800 mg Pb kg-1 soil, EDTA and NTA (0, 5 and 10 mmol kg-1 soil). The results indicated that EDTA was much more efficient for enhancing root to shoot Pb translocation. In 800 mg Pb kg-1 soil, as a result of 10 mmol EDTA kg-1 soil, a value of 1075 mg Pb kg-1 DW shoot was obtained. The soils treated with EDTA showed higher values of soluble Pb concentration than NTA and no chelate. Also, MLPI was higher (0.87) in presence of 5 mm EDTA kg-1 concentration. In high concentrations of Pb and APCAs, both EDTA and NTA caused acute symptoms on leaves which showed wilting, necrotic areas and curling of borders. Finally, Land Cress due to high lead resistance can be introduced as a Pb hyperaccumulator to chelate-induced phytoextraction technology.
Keywords: Soil Contamination, Phytoextraction, Land Cress (Barbara Verna), Lead, Aminopolycarboxylic Acids
