What is the typical goal of adding ammonia to chlorine in water treatment?

The typical goal of adding ammonia to chlorine in water treatment is to extend disinfection effects. This process, often referred to as chloramination, happens when ammonia is combined with chlorine to create chloramines, which are more stable and effective disinfectants compared to chlorine alone.

Chloramines provide a longer-lasting residual disinfectant in the water system, which helps maintain the disinfectant's presence as water travels through pipes to reach consumers. This is particularly important because it reduces the risk of pathogens regrowth in the distribution system. Additionally, chloramines produce fewer disinfection byproducts compared to chlorine alone, making it a safer choice for long-term water treatment.

The other options do not align with the primary function of ammonia in this context, as they relate to different aspects of water treatment rather than the disinfection prolongation that chloramination achieves.