enhancing lead phytoextraction of land cress (barbara verna) using

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.