Earth, Energy & Environment
Received: 17 Sep 2018 , Published: 22 September 2018
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|1||Win Mi Htwe|
A pot experiment was conducted to evaluate the effects of EDTA and citric acid on the uptake of lead by using high biomass plants (Brachiaria decumbens; signalgrass and Paspalum atratum; atratum). Application levels (0, 1.5, 2.5, 5 and 10 mmol kg–1 soil) of EDTA and citric acid were added to 150 mg kg–1 of lead contaminated soil one week before harvesting. The experimental period was 45 days. The results showed that signalgrass was able to grow in the presence of EDTA and citric acid showing no visible symptoms of phytotoxicity and could have the ability of metal tolerance. EDTA (1.5, 2.5 and 5 mmol kg–1) treated soil significantly increased the concentrations of lead in the shoots of signalgrass by 1.4, 1.5 and 1.3-fold, respectively, in comparison with the control and were clearly more effective in stimulating the translocation of lead from roots to shoots. In atratum, the control plants were more efficient in the uptake and translocation of lead than when EDTA and citric acid were added. Two investigated grass species did not show the same results to the applied chelates. It is imperative to note that the plant species, chelator source and level will make a difference in uptake and translocation of lead. Both EDTA and citric acid were ineffective as an amendment to enhance the lead phytoextraction by atratum. Signalgrass showed comparative high dry matter while accumulating high concentrations of lead in their shoots and then could be suggested as a suitable candidate for chelate-induced phytoextraction of lead.
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