Why is lime commonly used for corrosion control in water treatment?

Lime is commonly utilized in water treatment processes primarily because it effectively adjusts both pH and alkalinity in water. Maintaining an appropriate pH level is vital for corrosion control as it influences the solubility and precipitation of metals and minerals present in the water. When lime is added, it increases the pH to a level that helps to form protective layers on metal surfaces within the distribution system, minimizing the potential for corrosion.

Moreover, by raising the alkalinity, lime helps to buffer the water against changes in pH that can be caused by the addition of other chemicals or the introduction of acidic water sources. This buffering action is significant, as it contributes to the stability of the water chemistry, promoting beneficial conditions that further inhibit corrosion.

While lime does have a role in other applications, such as disinfection at high concentrations, its primary function regarding corrosion control in the context of water treatment revolves around its ability to influence both pH and alkalinity effectively.