Definition - What does Breakpoint Chlorination mean?
Breakpoint chlorination is the point where the demand for chlorine has been fully satisfied in terms of chlorine addition to the water.
When chlorine is added to water, a reaction is produced in the compounds present in the water. These compounds utilize the chlorine, resulting in zero chlorine residual.
Corrosionpedia explains Breakpoint Chlorination
Once chlorine has been added to water, it is consumed by a type of chemical reaction that has a net effect of increasing the chlorine concentration. For a typical addition of chlorine, the reaction rate instantly increases and reduces the chlorine concentration. This is because chlorinated compounds acquire more chlorine.
The pace at which the chlorine atoms are added is comparatively slow, but the rates can be faster because chlorinating increases the reactivity. Once almost all of the chlorine reactions are accomplished then adding more chlorine leads to permanent residual chlorine.
The period where the concentration of chlorine rapidly increases is called the "breakpoint." In some cases, there can be no breakpoint seen because various organic compounds react at different rates.
Breakpoint chlorination is usually measured to determine when chlorination has been satisfied. This is a common practice when disinfecting water in industrial water systems and swimming pools. It is one of the most typical forms of chlorination where adequate chlorine is incorporated into the water to achieve the breakpoint, keeping the water well chlorinated and appropriate for its intended use.