Bromate removal by electrochemical reduction at boron-doped diamond electrode

The electrochemical removal of bromate ions was performed with BDD electrodes in a two-compartment electrolytic reactor. Bromate ions removal and the production of Br− were observed and determined. The removal of bromate ions occurred at an applied bias potential of −0.45 V (vs. SCE). And, the removal rate increased with the applied bias potential. Within 2 h, nearly 90% of bromate ions were removed with the applied bias potential of −1.0 V (vs. SCE). Effect of pH on bromate ions removal was slight. SO42− and Cl− ions inhibit the electrochemical reduction of bromate ions, which can be explained by the competitive adsorption of coexisting anions at the electrode surface with the bromate ions. In comparison, the graphite and carbon paper electrode exhibit low catalytic activities toward reduction removal of bromate ions under the same experimental conditions. A possible reason was proposed.