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

Abstract

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 g out of 20145 g) of the total initial amount of PAHs were removed from the cell.

Groundwater Remediation in Low‐Permeability Settings: The Evolving Spectrum of Proven and Potential

“…Although EK approaches have been applied for decades to enhance contaminant migration, recent work shows the technology offers new promise if applied to deliver remediation reagents into low‐permeability zones and increase overall reagent distribution uniformity in geologically heterogeneous settings. A number of recent laboratory studies have demonstrated the potential for EK techniques to enhance the delivery of permanganate (Reynolds et al ), lactate and bacteria (Mao et al ), and surfactants (e.g., Hahladakis et al ). More specifically, in laboratory experiments, Mao et al () were able to distribute Dehalococcoides and lactate ions at transport rates of approximately 3.2 cm/day across a bentonite clay, resulting in the complete dechlorination of PCE.…”

[Preprint] An overview of electrokinetic soil flushing and its effect on bioremediation of hydrocarbon contaminated soil

“…EDTA is a complexing agent that can increase solubilization of hydrophobic contaminants but due to high alkalinity and toxicity, EDTA provides losses to microbial activities and communities in soil (Dong et al, 2013;Hahladakis et al, 2016;Kim et al, 2010). β-cyclodextrin contained in the starch is known to be used to improve the electrokinetic bioremediation process of contaminated soil.…”

The combined effects of surfactant solubilization and chemical oxidation on the removal of polycyclic aromatic hydrocarbon from soil

“…Specifically, the 4-6 ring PAHs are toxic and carcinogenic to humans, which are recalcitrant to biodegradation by indigenous microorganism (Moon et al, 2006;Mousset et al, 2014;Biache et al, 2015). Consequently, there is significant emphases placed on remediation technologies that can effectively degrade PAHs in soils (Hahladakis et al, 2016;Bezza and Chirwa, 2016;Ranc et al, 2016).…”