Development of a blended corrosion, scale, and microorganism inhibitor for open recirculating cooling systems

摘要

A blended, apparently new, corrosion, scale, and microorganism inhibitor for open recirculating cooling systems was developed from zinc, phosphonates, acrylate copolymer, and isothiazolone. The effects of the inhibitor on carbon steel dissolution in synthetic cooling water were studied through weight loss tests, electrochemical tests, scale tests, and microorganism tests. The obtained results showed that the developed inhibitor revealed very good corrosion, scale, and microorganism inhibition. All measurements indicated that the efficiency of the blended mixture exceeded 90%. Potentiodynamic polarization studies indicated that the blended inhibitor was an anodic and cathodic inhibitor. The nature of protective films formed on the carbon steel was studied by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). The inhibitive effects arose from formation of protective films which might contain zinc hydroxide, zinc phosphonate, calcium phosphonate, and iron oxide.