title: Electrokinetic treatment of an agricultural soil contaminated with heavy metals.
abstract: The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen.
authors.affiliation: a Department of Chemical Engineering , University of Vigo , Vigo , Spain.
authors.forename: Arylein
authors.initials: A
authors.lastname: Figueroa
authors.affiliation: a Department of Chemical Engineering , University of Vigo , Vigo , Spain.
authors.forename: Claudio
authors.initials: C
authors.lastname: Cameselle
authors.affiliation: a Department of Chemical Engineering , University of Vigo , Vigo , Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Gouveia
authors.affiliation: b Department of Chemical and Environmental Engineering , Technical University Federico Santa Maria , Valparaíso , Chile.
authors.forename: Henrik K
authors.initials: HK
authors.lastname: Hansen
mesh_terms: D002104:Cadmium / Q000032:analysis; D019343:Citric Acid / Q000032:analysis; D003035:Cobalt / Q000032:analysis; D003300:Copper / Q000032:analysis; D004492:Edetic Acid / Q000032:analysis; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D015032:Zinc / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D019343:Citric Acid; D003035:Cobalt; D003300:Copper; D004492:Edetic Acid; D015032:Zinc
keywords: Electrokinetic remediation; heavy metals; organic matter; soil