The design of the reactor internals of the two-phase Continuous Stirred Tank Electrochemical Reactor (CSTER) was studied under different conditions. Two types of air distributors were tested (cubic and circular) according to the bubble size produced by each, measured by a high-speed camera. Two impeller types were tested (Rushton turbine 4 and 6 blades). The results indicate that the bubble size increases with increasing airflow, but the cubic distributor has a smaller bubble diameter than the circular distributor under all conditions. The value of average time for the 4-blades turbine was more than it for the 6-blades turbine at a lower mixing speed, but at 600 rpm, the 6-blade turbine has a value of average time closer to the ideal space-time.