What is the effect of feeding lime to water for corrosion control?

Feeding lime to water for corrosion control primarily results in an increase in pH. When lime, which is calcium hydroxide (Ca(OH)₂), is added to water, it reacts with the water to form hydroxide ions. This increase in hydroxide ions raises the pH level of the water, making it more alkaline.

A higher pH can help to reduce the corrosivity of the water, especially in systems with metal pipes, by promoting the formation of a protective layer on the pipe surfaces. This layer can help prevent leaching of metal ions into the water supply and overall can lead to better water quality in terms of corrosive effects.

While lime can have secondary effects on other characteristics of water, such as flocculation which can lead to reduced turbidity or softening the water, these are not the primary reason for its use in corrosion control. The main focus is on raising the pH to mitigate corrosion issues effectively.