ELECTRODISSOLUTION OF IRON IN SODIUM-SULFATE AND SODIUM-BICARBONATE SOLUTIONS AT PH-8

The effect of sulfate ions on the electrochemical behaviour of iron el ectrodes in the presence of bicarbonate ions has been investigated. In solutions containing sulfate ions only, iron electrodes experience un iform corrosion and sulfate ions are aggressive. In the presence of bi carbonate ions, the sulfate ions become less aggressive and a pitting- repassivation process is observed. The differences in electrochemical behaviour have been compared and explained by examining the formation of probable products and their physicochemical properties during elect rochemical polarization.