Aeration

The process of aeration has a number of useful functions in water treatment.  If water has a high concentration of free carbon dioxide, it will have a low pH which can cause corrosion of pipes when the water is distributed.  Aeration allows some of the carbon dioxide to leave the water and enter the air, raising the pH to a more normal level. 

Aeration can also remove iron and manganese from the water. By mixing the water with air, oxygen in the air comes in contact with these minerals.  The minerals are oxidized and precipitate, or settle out of the water. 

Hydrogen sulfide and other compounds can cause foul odors in water.  Aeration will reduce the odors caused by these compounds.  It will also strip organic contaminants from the water.