What effect does recarbonation have on the pH of water?

Recarbonation is a water treatment process in which carbon dioxide is added to water, typically to adjust its pH and enhance the stability of calcium carbonate in the water. When carbon dioxide is introduced into water, it reacts with water to form carbonic acid, which can then dissociate to release hydrogen ions. This release of hydrogen ions leads to a decrease in pH, thus making the water more acidic.

This adjustment is particularly important in processes such as softening water or controlling scale formation in distribution systems. Lowering the pH can help in maintaining a balance that prevents corrosion of pipes, which is more likely in alkaline conditions. In summary, the addition of carbon dioxide during recarbonation effectively lowers the pH of water, which is essential for various water treatment processes.