Effluent treatment using a bipolar electrochemical reactor with rotating cylinder electrodes of wovenwire meshes

Abstract

Background: The behaviour of a bipolar electrochemical reactor consisting of one or more rotating cylinder electrodes of woven wire meshes is reported using copper and cadmium deposition from dilute solutions as test reactions. Results: The best performance related to electrode number was determined for copper deposition and was achieved by an arrangement with two bipolar electrodes, for which the conversion in a single pass was approximately 47%. The specific energy consumption was 3.27 kWh kg-1 with a normalised space velocity of 23.05 h-1. The copper powder obtained showed a nodular and dendritic surface morphology. This reactor configuration was also analysed for cadmium deposition, in which hydrogen evolution takes place simultaneously as a side cathodic reaction, considering the effect of flow rate and total current. The maximum conversion per pass for cadmium removal was 38.91%. In this case the reactor with two bipolar electrodes showed a performance similar to that of a monopolar reactor operated at a rotation speed three times higher. Conclusion: A continuous electrochemical reactor with two rotating bipolar electrodes of woven wire meshes presents a good performance for copper or cadmium removal from dilute solutions.