The remediation of brine contaminated soils has always been a challenge. However, environmental regulatory changes require proper removal of the sodium and chloride contamination, especially in sensitive land areas or where aquifers might be impacted. One approach to this problem is using electrokinetics (EK) to extract the ions from shallow soils. EK is simply the application of DC electric fields in the soil mass to induce electromigration of the soluble ions. During desalinization, the chloride ions migrate toward anode wells and sodium ions migrate toward cathode wells where they are removed. In order to make the process cost effective though, the equipment must be inexpensive and simple to install.
A full-scale EK desalinization process was installed in wetlands area in North Dakota in May 2016 and has been operated for 2 summer periods and shut down during the winter months in between. The system contains a grid of 93 electrode wells, a DC rectifier and simple peristaltic fluid management system. The electrode wells were installed using a Geoprobe® unit. A trailer containing the rectifier and remote data monitoring equipment was placed adjacent to the site. This paper describes the installation at the North Dakota site, operations and maintenance, as well as the results to date.
Sr. Environmental Engineer
Williston, North Dakota