Researchers Rajic and Fallahpour investigated the influence of cathode material on electrochemical hydrochlorination of trichloroethylene and published their results in the peer-reviewed journal Chemosphere. TCE is one of the most commonly found contaminants in groundwater and is found to be carcinogenic and mutagenic to humans. Optimization of the technologies to remove TCE from groundwater is of great importance. The promising approach relies on the use of electrolysis to transform TCE into harmful byproducts. One of the main steps to optimization of electro-remediation for field application is identifying the electrodes materials that are sufficient, easy-to-maintain, commercially available and cost-effective. Rajic and Fallahpour evaluated the use of nickel, iron, copper, carbon and aluminum cathodes in the undivided, flow-through electrochemical cell where the electrodes were placed in order that supports hydrodechlorination (HDC) at the cathode. The study revealed that the cathode material highly influences HDC rate of TCE, which can be explained by the differences in bond strength between cathodes and atomic hydrogen (formed as intermediate of water electrolysis at the cathode). Nickel cathode showed the best performance towards TCE transformation due to high electrocatalytic activity towards hydrogen formation and , therefore, HDC. With higher electrocatalytic activity than Ni, even low amounts of Pd catalyst as cathode coating (0.75 mg cm-2), showed an increase in the removal rate. In addition, study shows that the presence of nitrates, as commonly found chemical species in groundwater, adversely influences the transformation of TCE due to competition for reduction at the cathode.
This work is of great importance for the optimization of electro-remediation technologies and provides important information about the sufficient cathode materials. Read full article here.