title: Removal of PAHs and pesticides from polluted soils by enhanced electrokinetic-Fenton treatment.
abstract: In this study, electrokinetic-Fenton treatment was used to remediate a soil polluted with PAHs and the pesticide pyrimethanil. Recently, this treatment has emerged as an interesting alternative to conventional soil treatments due to its peculiar advantages, namely the capability of treating fine and low-permeability materials, as well as that of achieving a high yield in the removals of salt content and inorganic and organic pollutants. In a standard electrokinetic-Fenton treatment, the maximum degradation of the pollutant load achieved was 67%, due to the precipitation of the metals near the cathode chamber that reduces the electro-osmotic flow of the system and thus the efficiency of the treatment. To overcome this problem, different complexing agents and pH control in the cathode chamber were evaluated to increase the electro-osmotic flux as well as to render easier the solubilization of the metal species present in the soil. Four complexing agents (ascorbic acid, citric acid, oxalic acid and ethylenediaminetetraacetic acid) in the Fenton-like treatment were evaluated. Results revealed the citric acid as the most suitable complexing agent. Thereby its efficiency was tested as pH controller by flushing it in the cathode chamber (pH 2 and 5). For the latter treatments, near total degradation was achieved after 27 d. Finally, phytotoxicity tests for polluted and treated samples were carried out. The high germination levels of the soil treated under enhanced conditions concluded that nearly complete restoration was achieved.
authors.affiliation: Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo, Spain.
authors.forename: Elvira
authors.initials: E
authors.lastname: Bocos
authors.affiliation: Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Fernández-Costas
authors.affiliation: Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pazos
authors.affiliation: Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo, Spain. Electronic address: sanroman@uvigo.es.
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Sanromán
mesh_terms: D001205:Ascorbic Acid; D019343:Citric Acid / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D019815:Oxalic Acid / Q000737:chemistry; D010539:Permeability; D010575:Pesticides / Q000032:analysis / Q000302:isolation & purification*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000302:isolation & purification*; D011743:Pyrimidines; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification*
chemical_list: C045076:Fenton's reagent; D010575:Pesticides; D011084:Polycyclic Aromatic Hydrocarbons; D011743:Pyrimidines; D012987:Soil; D012989:Soil Pollutants; D019343:Citric Acid; C108337:pyrimethanil; D019815:Oxalic Acid; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid
keywords: Citric acid; Complexing agents; Iron; PAHs; Phytotoxicity; Pyrimethanil