What Anodes are Used for Electrochemical Wastewater Treatment

What Anodes are Used for Electrochemical Wastewater Treatment?

The selection of the anode material is probably the most important factor affecting the effectiveness of the electrochemical treatment of wastewater. The anode material can determine the current efficiency and overpotential, Inappropriate anode materials can cause problems of dissolution or passivation during operation.

Many types of anodes are readily available for the oxidation of organic compounds including some surface modified composite materials. Certain anodes are specifically developed for organic synthesis and fuel cells applications, so they are targeted to partial conversion and/or selective oxidation of the organic compounds.  

There are different anode materials that have been tested for the purpose of electrochemical wastewater treatment. The sacrificial anodes, including iron and aluminum, are used more often for electro-coagulation. Noble metals exhibit high catalytic activity towards the oxygen evolution reaction and are used for oxygen production. Their catalytic ability towards oxygen evolution reaction may be a problem because it competes with the oxidation of organics. Graphite based electrodes represent a family of low-cost electrodes, but they are easily consumed during the electrolysis. Another family of carbon-based electrodes is the boron-doped diamond (BDD) anodes, which have very high efficiency, but they are limited by the amenability to large-scale industrial production and operation. Finally, the titanium/metal-oxide electrodes are a family of intermediate performance but versatile anode materials. This material possesses the greatest potential as future anode materials for wastewater treatment.