Study of the mechanism action of sodium gluconate used for the protection of scale and corrosion in cooling water system

Abstract

This work based on the mechanism action study of sodium gluconate (SG) for ordinary mild steel used for cooling water system treatment. In the first time, we evaluated the temperature effect on the scale inhibition of SG using statistic scale inhibition method. Result showed that the inhibition efficiency became more important with increasing temperature, at great concentration (10−2 and 10−3 M). This can be explained by forming of stable complex SG–Ca2+. In the second time, the present work focuses on the study of operational parameters and corrosion products effect on SG performance using potentiodynamic polarization and electrochemical impedance spectroscopic method. The obtained results show that SG is a very good inhibitor for corrosion and scale and remains effective in the presence of corrosion products. For this study we were proposed a mechanism action for SG on metallic surface. In addition, the SG keeps its effectiveness in a more aggressive medium such as 3% NaCl. Finally, to complete the formulation, we added a not oxidizing biocide (CTAB) to SG. The results obtained show that SG remains its effective.

Keywords

• EIS
• Corrosion and scale
• Cooling water system