title: Sequential application of chelating agents and innovative surfactants for the enhanced electroremediation of real sediments from toxic metals and PAHs.
abstract: This study focused on the sequential application of a chelating agent (citric acid) followed by a surfactant in the simultaneous electroremediation of real contaminated sediments from toxic metals and Polycyclic Aromatic Hydrocarbons (PAHs). Furthermore, the efficiency evaluation of two innovative non-ionic surfactants, commercially known as Poloxamer 407 and Nonidet P40, was investigated. The results indicated a removal efficacy of approximately 43% and 48% for the summation of PAHs (SUM PAHs), respectively for the aforementioned surfactants, much better than the one obtained by the use of Tween 80 (nearly 21%). Individual PAHs (e.g. fluorene) were removed in percentages that reached almost 84% and 92% in the respective electrokinetic experiments when these new surfactants were introduced. In addition, the combined-enhanced sequential electrokinetic treatment with citric acid improved dramatically the removal of Zn and As, compared to the unenhanced run, but did not favor the other toxic metals examined. Since no improvement in metal removal percentages occurred when Tween 80 was used, significant contribution to this matter should also be attributed to the solubilization capacity of these innovative, in electrokinetic remediation, non-ionic surfactants.
authors: School of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100, Greece. Electronic address: john_chach@yahoo.gr.
authors: John N
authors: JN
authors: Hahladakis
authors: School of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100, Greece.
authors: Nikolaos
authors: N
authors: Lekkas
authors: School of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100, Greece.
authors: Andreas
authors: A
authors: Smponias
authors: School of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100, Greece. Electronic address: gidarako@mred.tuc.gr.
authors: Evangelos
authors: E
authors: Gidarakos
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D004563:Electrochemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019015:Geologic Sediments; D020442:Poloxamer / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D011084:Polycyclic Aromatic Hydrocarbons; D011136:Polysorbates; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D020442:Poloxamer; C024062:nonidet; D011092:Polyethylene Glycols; D015032:Zinc; D001151:Arsenic
keywords: Electrokinetic remediation; PAHs; Sediments; Surfactants; Toxic metals