Ontario Operator-in-Training (OIT) Practice Exam

Which treatment processes are essential for public health?

1. Filtration, evaporation, condensation

2. Disinfection, coagulation, flocculation

3. Chlorination, sedimentation, freezing

4. Recycling, desalinization, aeration

The correct answer is: Disinfection, coagulation, flocculation

The choice of disinfection, coagulation, and flocculation as essential treatment processes for public health is grounded in their critical roles in ensuring the safety and quality of drinking water. Disinfection is necessary to eliminate or inactivate pathogenic microorganisms that can cause diseases. This process is vital as it directly addresses public health concerns by ensuring that water is free from harmful bacteria, viruses, and protozoa. Coagulation is the first step in treating water that typically involves the addition of chemicals to destabilize and agglomerate suspended particles and organic materials. This step is crucial as it prepares the water for the subsequent removal of these contaminants, improving the overall quality of the water. Flocculation follows coagulation and involves the gentle mixing of the water to encourage the agglomerated particles to clump together into larger particles, or "flocs," which can then be easily removed through sedimentation or filtration. This step helps further reduce the turbidity of the water and removes pollutants that could pose health risks. Together, these processes form a fundamental part of water treatment protocols focused on safeguarding public health, as they effectively reduce harmful contaminants and ensure safer drinking water for communities. Other treatment processes listed, such as those involving evaporation or freezing, do not specifically