[4] The electrolytic solutions serve both as a conducting media (or pore fluid) and as a means to extract contaminants and introduce chemicals or biological entities.
By pumping, processing and testing the electrolytic solution at each electrode site you can extend the life and efficiency of the system.
When current is applied, by the direct power source, to the electrodes, migrations occur beneath the soil surface.
This diffused double layer will aid in the ionic drift that will occur as the current passes through the soil and surrounding liquid, this process is called electroosmosis.
[1] The thickness of the diffused double layer is a function of ionic composition of bulk solution and the average charge density of hydration products.
For electromigration to occur absorbed material must be dissolved to an ionic form whether they are metals, organic or inorganic particles.
This low pH environment inhibits metallic contaminants from being sorbed onto soil particle surfaces which aids in the formation of compounds making electrokinetics possible.
[1] Other heavy metal species that are tested and reported to be treatable include; mercury, zinc, iron, lead, copper, and magnesium.
Electrokinetics can also be used to treat polar organic compounds (phenol and acetic acid) and radionucleotides (radium), toxic anions (nitrates and sulfates), dense, non-aqueous-phase liquids (DNAPLs), cyanide, petroleum hydrocarbons (diesel fuel, gasoline, kerosene and lubricating oils), halogenated pollutants, explosives, halogenated and polynuclear aromatic hydrocarbons.
Because ion distribution effects the efficiency of the electrokinetics system, engineers like John Dzenitis have done comprehensive study to find key reactions around the electrodes that can be used to create models for ionic flowrate prediction.
[6] Large metal objects that are buried underground also pose as a limitation to electrodes because they offer a path to short circuit the system.
For instance: Activation polarization can occur during the electrokinetic remediation process removing gas bubbles that form on the surface of the electrodes during conductivity.
[9] For this site soil pH was a parameter of great importance because of an increased amount of copper present as ionic solution.
By creating active barriers or exchange membranes that prevent ions from traveling from the electrode compartment into the soil.
Called the Lasagna Process, it simply is the creation of several horizontal permeable zones used to provide treatment through the contaminated soil matrix by adding different admixtures to the electrolytic solution.
Coupling of the horizontal electrodes with a vertical pressuring system make this method especially effective in removing contaminants from deeper layers of the soil.