Heavy metals removal from dredged sediments using electro kinetics

Abstract

This study focuses on the use of a remediation process to remove particle-bound recalcitrant pollutants (heavy metals) from dredged harbor sediments which must be previously treated before reuse in civil engineering. Electrokinetic (EK) remediation is generally accepted as one of the most suitable technologies for extracting cationic heavy metals from fine grained sediments. Many batch tests were performed to better understand the capacity of various additives to improve sediment decontamination (when applying a constant voltage gradient of 1 V.cm-1), and the combination of enhancing agents (acids + surfactants) were assessed to obtain an efficient removal of heavy metals. We succeeded in proving that mixing citric acid and a nonionic surfactant (Tween 20), additives which are environmentally friendly, was a good association to enhance heavy metals (Cd, Cr, Cu, Pb and Zn) removal.

Keywords

• Heavy metals
• electro kinetics
• dredged sediment
• remediation
• electro-migration