Ontario Operator-in-Training (OIT) Practice Exam

Which of the following processes is NOT typically associated with removing harmful microorganisms from water?

1. Filtration

2. Coagulation

3. Heating

4. Disinfection

The correct answer is: Heating

Heating is not typically associated with the conventional processes used to remove harmful microorganisms from water in the same way that filtration, coagulation, and disinfection are. Filtration involves physically removing particles and microorganisms from water as it passes through a filter medium. This process is effective for various contaminants including bacteria and sediments, ensuring cleaner water. Coagulation is a chemical process where substances are added to water to clump together particles, making them easier to remove, typically through subsequent sedimentation and filtration steps. This method helps in removing suspended solids that can harbor microorganisms. Disinfection specifically targets and eliminates pathogenic microorganisms, making treated water safe for consumption. Common disinfection methods include chlorine treatment, UV light, and ozone treatment. While heating can indeed kill some microorganisms, it is not a standard water treatment process compared to the others listed. Heating water is more commonly associated with preparation for certain applications or maintenance rather than as a standalone method for treating large volumes of water for public consumption. In the context of municipal water treatment, the primary focus is on processes that can be consistently applied to ensure water safety at scale.