EK Remediation with Calcium Addition Increases Chloride Removal and Improves Soil Conditions

Chris Athmer
Sr. Environmental Engineer
Terran Corporation
Beavercreek, Ohio, USA

Salt contamination from brine releases can cause long lasting damage to soil structure and productivity and chloride can leach or migrate to precious drinking water sources. Since salt neither decays nor volatilizes, removal (and replacement) or dilution are the only mechanisms to rehabilitate contaminated soils and groundwater. Because of the difficulty in treating brine impacted soils, many release sites are not addressed and linger as barren or scarred land. Treatment of such soils can be accomplished using electrokinetic (EK) treatment. Taking advantage of the electromigration process, chloride and sodium ions can be removed at anodes and cathodes installed throughout the salt or brine contaminated area. To help rejuvenate sodic soils, calcium addition at the anode can help in restoring the calcium balance in the soil. As an additional benefit, calcium addition at the anode may increase the overall chloride removal. Two tests were performed that compare the use of EK treatment with calcium addition at the anode and EK treatment alone, without calcium addition. The addition of calcium at the anode during electrokinetic treatment of brine soils increased chloride removal by 30% and increased calcium content. This is a surprising and potentially huge benefit to future desalinization projects.