Influence of electric field on the remediation of polluted soil using a biobarrier assisted electro-bioremediation process

Abstract

In this work, it was carried out the study of the electro-bioremediation of soil polluted with diesel by means of combined electrokinetic soil flushing and biobarriers, using bench scale setups and fourteen days-long tests. Two different biobarriers were evaluated: one of them was developed in the laboratory, with a culture of diesel-degrading microorganisms supported on gravel particles (BB1); the other was obtained by mixing directly clay soil with activated sludge obtained in a municipal wastewater treatment plant (BB2). Biobarriers were placed in a central point of the soil section to be treated, to prevent the negative consequences of pH fronts on microorganisms viability. Potential difference of 0.5 and 1.0 V cm-1 were applied. For the promotion in the transport of the diesel to the biobarrier, a surfactant solution was used as electrolyte (flushing fluid). Results confirm that negative influence of the extreme pH fronts on the microbial viability can be prevented using this electro-bioremediation approach. In the same way, uniform diesel removal was obtained all over the soil by using the surfactant solution. After fourteen days of treatment, in the experiments using the BB1, 19.36% and 27.36% of the total amount of diesel present in the soil were removed applying 0.5 and 1.0 V cm-1 , respectively. In the experiments using BB2, 23.33% and 29.10% referred to the total amount of diesel were removed after the fourteen days tests at 0.5 and 1.0 V cm-1 , respectively, indicating that the non-specific barrier is slightly more efficient despite not containing an acclimated culture.

Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils

“…Due to increase of soil pH near the cathode, heavy metal precipitation was occurred in the cathode region, and resulted in decreasing the ionic concentrations in soil and soil conductivity, and thus decreased the produced current density. Heavy metal precipitation also led to the formation of high soil resistivity zone, which also was response for the decrease in the current production [41,42].…”

Integrating Electrokinetic and Bioremediation Process for Treating Oil Contaminated Low Permeability Soil

“…Surfactants are also capable of making micelle oil that can increase bioavailability and make oil suspended in soil-water pore and move through the electrophoresis process. PR-EKBio and EKSF-Bio have stable levels of moisture content when compared to EK-Bio so combination of surfactants with polarity reversals technique may provide favorable environmental conditions for electrokinetic bioremediation processes [5], [10]. Bearing pH values to protect microorganisms from death is an important factor in this study.…”

“…In bioremediation test (Bio), there is a decrease of TPH concentration although not as drastic using electrochemical process. This may be due to the mixing process and transport of microorganisms, soil and water at the beginning of the test causing contact between the active microorganisms and the contaminants so that the degradation process can occur [10], [14].…”

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

“…Contaminant removal depends on the solution properties, dielectric constant, and viscosity (Mena et al, 2016a;Shi et al, 2008). At low pH, only a small amount of surfactant is available to dissolve phenanthrene, the oxyethylene group on Tween 80 may be attached to the surface of the soil particles (Maturi and Reddy, 2009).…”

“…The success of bioremediation process of diesel contaminated soil is known to use single culture, Bacillus sp. (TMY-2 strain), mixed cultures from contaminated soil and mixed cultures of activated sludge for wastewater treatment (Khodadadi et al, 2011;Mena et al, 2016a).…”