Reaction of Ammonia with Chlorine: Breakpoint Chlorination
Presence of ammonia in water or wastewater and the addition of free chlorine results in an available chlorine curve with a “hump”
At chlorine doses between the hump and the dip, chloramines are being oxidatively destroyed and nitrogen is lost (between pH 6.5-8.5).
Chlorine added, mg/L
Combined Cl2 present
Free chlorine present