Removal of formic acid from wastewater using three-phase three-dimensional electrode reactor

A new electrochemical reactor, three-phase three-dimensional electrode reactor, was designed and used to investigate the removal of formic acid from simulated wastewater. The experimental results were assessed in term of Chemical Oxygen Demand (COD) removal efficiency. The results showed that the three-phase three-dimensional electrodes could effectively remove formic acid. Its COD removal efficiency was much higher than those of two-dimensional electrodes and common three-dimensional electrodes, respectively. The COD removal efficiency of the three-phase three-dimensional electrodes using air as a sparge gas increased 13.5% relative to that using nitrogen as a sparge gas. The observation indicated that the sparged air in the three-phase three-dimensional electrodes not only participated in some physical processes but also played an important role in electrochemical reactions to assist COD removal.