Electrokinetic Migration of Permanganate Through Low‐Permeability Media

Abstract

This research was conducted to evaluate the combination of electromigration and potassium permanganate as a potential remediation method for low-permeability media (e.g., soil and sediment) contaminated with dissolved and sorbed organic contaminants. The experimental procedure was composed of two stages: determination of migration rates of permanganate through homogeneous cores and a primarily qualitative analysis of migration in more heterogeneous, two-dimensional scenarios. Results indicated that transport of permanganate through fine-grained porous media and clays can be undertaken using electromigration, and electromigration rates were found to be at least 400% faster than diffusion alone. In addition, the use of an applied electric field in a flushing scenario was shown to result in almost 100% sweep efficiency of a domain consisting of clay blocks interspersed in a glass bead medium. The results of the study show that there is potential for this method to be able to deliver permanganate and other potential remedial agents to treat contaminated zones within heterogeneous and low-permeability porous media through in situ chemical oxidation or other processes.

Constant Head Injection for Enhanced In Situ Chemical Oxidation

“…If multiple wells/rods are installed, the temporary well injection method could be completed as a multiple well injection array, further increasing flexibility in operations. Pore dilation—the use of proprietary injection equipment designed to use pressure waves to temporarily dilate the intergranular/fracture pore throats, facilitating increased rates of injection and more homogeneous distribution. Recirculation—the use of recirculation zones within an aquifer where injectate distribution can be closely controlled. These mixing zones may be completed in vertical zones (in thicker aquifers) or in horizontal zones (injectate flood). Electrokinetics—the use of impressed electric potential to move charged particles (of permanganate, for example) in the subsurface (Reynolds et al., ) at rates greater than advection or diffusion. Electrokinetic approaches thus far have remained limited for large‐scale mainstream remediation. Soil heating—use of various forms of thermal energy (e.g., heat, steam, electrical current, and microwave) to heat the target soils.…”

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.…”

PHT3D: A Reactive Multicomponent Transport Model for Saturated Porous Media

“…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 2008), lactate and bacteria (Mao et al 2012), and surfactants (e.g., Hahladakis et al 2016). More specifically, in laboratory experiments, Mao et al (2012) 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.…”