Influence of EDTA on lead transportation and accumulation by Sedum alfredii hance.
Hydroponics and pot experiments were conducted to study the effects of ethylenediaminetetraacetic acid (EDTA) on Pb transportation and accumulation by two contrasting ecotypes of Sedum alfredii Hance. In hydroponics experiments, the accumulating ecotype (AE) showed more ability to tolerate Pb toxicity compared with the non-accumulating ecotype (NAE). When treated with equimolar mixtures of EDTA and Pb, maximum Pb accumulation occurred without any phytotoxicity symptoms. Pot experiments with Pb contents of 400 mg kg-1 showed that 5 mM EDTA is the optimum dose for the phytoextraction of soils contaminated with relatively low Pb levels; in contrast, increasing EDTA addition resulted in increased Pb accumulation in the shoots of AE in soils with high Pb content (1200 mg kg(-1)). The post-harvest effects of EDTA on available Pb were strong compared with those without addition of EDTA (CK). Within the initial 7 days almost no differences of water-soluble Pb were noted in soils contaminated with both levels of Pb but after 2 weeks, water-soluble Pb started to decrease significantly compared with before. Considering the toxicity and biodegradability of synthetic chelators, it can be concluded that the chelate-assisted technique is more suitable for soils contaminated with low Pb levels and to avoid environment risks; a suitable dose of chelators must be considered before application.
Liu
Dan
D
Key Laboratory of Environmental Remediation and Ecosystem Health, Ministry of Education, College of Natural Resources and Environment Science, Zhejiang University, Huajiachi Campus, Hangzhou 310029, PR China.
Lia
Ting-Qiang
TQ
Yang
Xiao-E
XE
Islam
Ejazul
E
Jin
Xiao-Fen
XF
Mahmood
Qaisar
Q
D001692:Biological Transport / Q000187:drug effects; D004492:Edetic Acid / Q000494:pharmacology*; D018527:Hydroponics; D007700:Kinetics; D007854:Lead / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D031963:Sedum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012987:Soil
D012987:Soil; D007854:Lead; D004492:Edetic Acid