title: EDTA and HEDTA effects on Cd, Cr, and Ni uptake by Helianthus annuus.
abstract: Phytoremediation has shown great potential as an alternative treatment for the remediation of heavy-metal-contaminated soils and groundwater. However, the lack of a clear understanding pertaining to metal uptake/translocation mechanisms, enhancement amendments, and external effects on phytoremediation has hindered its full-scale application. The objective of this research was to investigate the ability of synthetic chelators for enhancing the phytoremediation of cadmium-, chromium- and nickel-contaminated soil. Ethylenediaminetriacetic acid (EDTA) and N-(2-hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA) were applied to the soil at various dosages to elevate metal mobility. Uptake into and translocation within Helianthus annuus was determined. It was found that EDTA at a rate of 0.5 g/kg significantly increased the shoot concentrations of Cd and Ni from 34 and 15 to 115 and 117 mg/kg, respectively. The total removal efficiency for EDTA was 59 microg/plant. HEDTA at the same application rate resulted in a total metal uptake of 42 microg/plant. These research demonstrated that chelator enhancement is plant- and metal-specific and is subjective to inhibition when multiple heavy metals are present. Results also showed that chelator toxicity reduced the plant's biomass, thereby decreasing the amount of metal accumulation.
authors.affiliation: Department of Civil Engineering, The University of Akron, OH 44325-3905, USA.
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: T
authors.initials: T
authors.lastname: Cutright
mesh_terms: D002104:Cadmium / Q000737:chemistry / Q000493:pharmacokinetics*; D002614:Chelating Agents / Q000737:chemistry; D002857:Chromium / Q000737:chemistry / Q000493:pharmacokinetics*; D004492:Edetic Acid / Q000031:analogs & derivatives* / Q000737:chemistry*; D004787:Environmental Pollution / Q000517:prevention & control; D006368:Helianthus / Q000502:physiology*; D009532:Nickel / Q000737:chemistry / Q000493:pharmacokinetics*; D018517:Plant Roots / Q000737:chemistry; D012989:Soil Pollutants / Q000493:pharmacokinetics*
chemical_list: D002614:Chelating Agents; D012989:Soil Pollutants; D002104:Cadmium; D002857:Chromium; D009532:Nickel; D004492:Edetic Acid; C026060:N-(hydroxyethyl)ethylenediaminetriacetic acid