How does the presence of ammonia in water affect chlorine treatment?

The presence of ammonia in water significantly affects chlorine treatment, particularly by decreasing chlorine's residual effectiveness. When chlorine is added to water containing ammonia, it can combine with the ammonia to form chloramines. These chloramines are not as effective as free chlorine in disinfecting water.

As chloramines form, the amount of free chlorine available diminishes, leading to a decrease in the chlorine residual that is critical for ensuring water remains disinfected as it travels through the distribution system. A lower chlorine residual can result in an increased risk of microbial growth and water contamination.

Understanding this interaction is crucial for water treatment professionals to effectively manage disinfection processes and maintain safe drinking water standards.