What component is NOT typically included in primary disinfection methods?

Primary disinfection methods are focused on the immediate elimination or deactivation of pathogenic microorganisms in water. The primary methods generally involve the use of chemical disinfectants or physical processes that directly affect pathogens.

Coagulation is primarily a treatment process aimed at removing suspended solids and colloids from water rather than disinfecting it. It involves the addition of chemicals that cause smaller particles to clump together into larger aggregates, which can then be removed through sedimentation or filtration. While coagulation can be an important step within the overall water treatment process, it does not function as a disinfection method by itself.

In contrast, filtration, UV light, and chlorine are directly associated with disinfection processes. Filtration can physically remove pathogens, UV light destroys the genetic material of microorganisms, and chlorine is a widely used chemical disinfectant that actively kills or inactivates pathogens. Thus, coagulation stands out as the choice that is not involved in primary disinfection methods.