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ALKALINITY, PH, AND COPPER CORROSION BY-PRODUCT RELEASE
Citation:
Edwards, M., M R. Schock*, AND T. E. Meyer. ALKALINITY, PH, AND COPPER CORROSION BY-PRODUCT RELEASE. JOURNAL OF AMERICAN WATER WORKS ASSOCIATION. American Water Works Association, Denver, CO, 88(3):81-94, (1996).
Description:
Contrary to expectations, higher bicarbonate concentrations exacerbate copper corrosion rates and by-product release. In fact, as illustrated by monitoring experiences of large utilities and by laboratory data, the concentration of copper corrosion by-products in drinking water increases linearly with bicarbonate concentration at constant pH. This relationship implicates cupric hydroxide solubility in control of copper release from relatively new (less than a few years old) copper plumbing. Decision-making guidance from a traditional Larson's ratio or Langelier index approach can aggravate copper corrosion problems; consequently, their use should be discontinued for copper corrosion mitigation. In contrast, aeration-CO2 stripping is a particularly attractive strategy because benefits from higher pH are realized without adverse effects from higher alkalinity.