Performance of electroremediation in real contaminated sediments using a big cell, periodic voltage and innovative surfactants

The present work focused on evaluating the electrokinetic (EK) treatment of real contaminated sediments with toxic metals and polycyclic aromatic hydrocarbons (PAHs), using a big laboratory EK cell, periodic voltage and recently tested non-ionic surfactants. The results indicated that the “day on-night off” application mode of voltage, in conjunction with the selected solubilising agents, favoured the overall EK process. Arsenic, nickel and chromium exhibited the highest removal percentages, obtaining 83%, 67% and 63%, respectively, while zinc and lead attained 54% and 41% at the maximum. Furthermore, in the experiments where the non-ionic surfactants were introduced in the electrolyte chambers, there was a major uniformly removal of PAHs from the entire sediment across the EK cell, indicating the high solubilisation capacity of the enhancing agents. Essentially, transport and in some cases removal of PAHs (particularly from sections adjacent to the electrolyte compartments) also occurred in the unenhanced EK run, mainly due their negative charge, their potential weak bonds to the soil matrix and to the periodic application of voltage. Maximum removal was obtained by the use of Nonidet P40 where app. 1/3 (ca. 6498 μg out of 20145 μg) of the total initial amount of PAHs were removed from the cell.