Liu, B., G. Li, K.G. Mumford, B.H. Kueper, and F. Zhang.
Chemosphere 250:126209(2020)

A Cu-Ni bimetallic cathode was tested in an electrokinetic remediation system to couple electrokinetic migration and in situ electrochemical hydrodechlorination as a technique to remediate TCE in a low-permeability zone. Aqueous phase TCE was originally added into the anolyte to obtain breakthrough curves through the low permeability porous soil compartment. The curves also allowed for a better understanding of TCE migration driven by electroosmosis flow using different cathodes. The Cu-Ni cathode resulted in 7.64 mg of TCE migration compared to 5.99 mg with a Ni cathode and 4.22 mg with mixed metal oxide (MMO) cathode, suggesting that the Cu-Ni cathode could drive more TCE flux out of the contaminated soil. About 98.4% of TCE flux that reached the Cu-Ni cathode was electrochemically reduced, which was much higher than that MMO cathode (77.9%) or Ni cathode (59.6%). TCE mass that was transported by electroosmosis flow increased from 2.04 to 6.68 mg when the voltage gradient increased from 1 to 4 V/cm, with the normalized energy consumption increasing from 0.06 to 0.16 kWh/kg per unit water movement, and from 0.54 to 2.55 kWh/g per unit TCE transport. For TCE that did reach the cathode compartment, > 98% degradation maintained at the Cu-Ni cathode with various voltage gradients.