Influence of enhancing electrolytes on the removal efficiency of heavy metals from Gabes marine sediments (Tunisia)

•Design of laboratory electrokinetic setup for polluted sediment remediation•Maximum removal efficiency for Cd, Zn, Cu, Pb, Cr and Ni higher than 70%•Higher concentration of SDS as saturating solution, better removal efficiency•Citric acid, as enhancing agent, promoted the removal of most heavy metals.•Comparative study with previous research on EK remediation removal results

This study focused on the feasibility of the treatment of heavy metals-contaminated sediments from Gabes harbor (Tunisia) using enhanced electrokinetic process. It presented a laboratory short-time electrokinetic experiment. The enhancing agents, as citric, acetic acids and sodium dodecyl sulfate (SDS) were used regarding their low environmental hazard. The electrokinetic cell was specially designed in order to elaborate two experiments at the same time. This paper is composed of three parts. The first part introduces the characterization of Gabes sediments. The second part describes the design of laboratory electrokinetic cell and the followed methods. The third part is dedicated to the results analysis. Treatment efficiency revealed that more than 80% of lead was removed from Gabes marine sediments. The reduction of cooper concentration, in sediments after treatment, ranged from 74 to 87%. Despite, the high removal of cadmium that ranged from 58 to 79%, treated sediments presented Cd concentration above the threshold limit.