Custom Made Electrodes for Electrocoagulation, Electro-oxidation & Water Disinfection
We offer customized electrodes, cathodes, and anodes for Electrocoagulation, Electro-oxidation, and water disinfection equipment and systems.
Electrocoagulation & Electrooxidation Electrodes Material Selection
Electrocoagulation and Electrooxidation electrodes material need to be carefully selected mostly by analysing the pollutants that we want to remove or reduce from the wastewater.
Carbon and Graphite Electrodes
Electrodes based on carbon or graphite are common due to their low cost and high surface area. Also, they are able to promote adsorption of contaminants on their surface while at the same generating the radicals for electro-oxidation.
However, they are not suited for working at high potentials, as at such conditions they experience surface corrosion, resulting in reduced efficiency and progressive degradation of the exposed area. In fact, the overpotential for oxygen evolution is quite low for graphite.
Platinum electrodes provide good conductivity and they are inert and stable at high potentials. At the same time, the oxygen evolution overpotential is low and comparable to that of graphite. As a result, electro-oxidation with Platinum electrodes usually provides low yield due to partial oxidation of the compounds. The contaminants are converted into stable intermediates, difficult to be broken down, thus reducing current efficiency for complete mineralization.
Mixed Metal Oxides (MMOs) Electrodes
Mixed Metal Oxides (MMOs), also called Dimensionally Stable Anodes (DSA), are devices with high conductivity and corrosion resistance for use as anodes in electrolysis.
The kind of electrodes are very popular in electrochemical process industry, because they are very effective in promoting both chlorine and oxygen evolution. In the case of wastewater treatment, they provide low current efficiency, because they favour the competitive reaction of oxygen evolution. Similarly to Platinum electrodes, formation of stable intermediates is favoured over complete mineralization of the contaminants, resulting in reduced removal efficiency.
Due to their ability to promote chlorine evolution reaction, dimensionally stable anodes are the most common choice for processes relying on mediated oxidation mechanism, especially in the case of chlorine and hypochlorite production.
Lead Dioxide Electrodes
Lead dioxide electrodes have long been exploited in industrial applications, as they show high stability, large surface area, good conductivity and they are quite cheap. In addition, lead dioxide has a very high oxygen evolution overpotential, which implies a high current efficiency for complete mineralization. Also, lead dioxide electrodes were found to be able to generate ozone, another strong oxidizer, at high potentials.
Boron-doped Diamond (BDD) Electrodes
Synthetic diamond is doped with Boron to raise its conductivity, making it feasible as electrochemical electrode. Once doped, BDD electrodes show high chemical and electrochemical stability, good conductivity, great resistance to corrosion even in harsh environment and a remarkable wide potential window.
For this reason, BDD is generally considered as the most effective electrode for complete mineralization of organics, providing high current efficiency as well as lower energy consumption compared to all other electrodes. At the same time, the manufacturing processes for this electrode, usually based on high temperature CVD technologies, are very costly.