Electrokinetic Desalinization of Kaolin Soil with Acetic Acid

Sodium and chloride both dissolve in water and are carried into the ground by precipitation runoff. This runoff pollutes the soil, negatively impacting wildlife and vegetation. The use of electrokinetic remediation (EKR) techniques has been demonstrated to remove salt, heavy metals, and other contaminates from soil. One issue during the process is that chloride ions buildup near the anode, and are not removed. This experiment was performed to determine if using acetic acid as the cathode fluid during EKR would remove this buildup and increase the total amount of chloride removed. Three acrylic tubes were packed with kaolin clay with an initial concentration of 8000ppm NaCl. Each tube used tap water as the anode purge solution. The cathode purge solution was initially tap water; after two days, the purge solution for Tubes 2 and 3 were switched to 0.1M acetic acid and 0.5M acetic acid, respectively. The electrodes were flushed at a rate of 50.00μL/min. The tubes were hooked up to a DC power source providing 15V for 11.5 days. Ion selective electrodes, a spear-tipped pH probe, and a handheld multi-meter were used to collect data. 55.8% of the chloride ions were removed from Tube 1, 56.7% from Tube 2, and 53.1% from Tube 3. Tube 3 also had the greatest concentration of chloride ions remaining near the anode at 9220ppm. As the concentration of acetic acid increased, the amount of chloride remaining near the anode increased. The use of acetic acid did not affect the overall removal of chloride ions.https://ecommons.udayton.edu/stander_posters/2290/thumbnail.jp