Enhanced electrokinetic treatment of marine sediments contaminated by heavy metals and PAHs.
Dredged sediments contaminated by heavy metals and PAHs were subjected to both unenhanced and enhanced electrokinetic remediation under different operating conditions, obtained by varying the applied voltage and the type of conditioning agent used at the electrode compartments in individual experiments. While metals were not appreciably mobilized as a result of the unenhanced process, metal removal was found to be significantly improved when both the anodic and cathodic reservoirs were conditioned with the chelating agent EDTA, with removal yields ranging from 28% to 84% depending on the contaminant concerned. As for the effect on organic contaminants, under the conditions tested the electrokinetic treatment displayed a poor removal capacity towards PAHs, even when a surfactant (Tween 80) was used to promote contaminant mobilization, indicating the need for further investigation on this issue. Further research on organics removal from this type of materials through electrokinetic remediation is thus required. Furthermore, a number of technical and environmental issues will also require a careful evaluation with a view to full-scale implementation of electrokinetic sediment remediation. These include controlling side effects during the treatment (such as anodic precipitation, oxidation of the conditioning agent, and evolution of toxic gases), as well as evaluating the potential ecotoxicological effects of the chemical agents used.
Colacicco
Antonio
A
University of Rome "La Sapienza", Department of Hydraulics, Transportation and Roads, Via Eudossiana 18, 00184 Rome, Italy.
De Gioannis
Giorgia
G
Muntoni
Aldo
A
Pettinao
Emmanuela
E
Polettini
Alessandra
A
Pomi
Raffaella
R
D002614:Chelating Agents / Q000737:chemistry; D004560:Electricity; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D007700:Kinetics; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry*; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
D002614:Chelating Agents; D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical