Ontario Operator-in-Training (OIT) Practice Exam

Coagulation is the process of mixing coagulants with water to achieve what?

1. Increase pH levels

2. Form floc

3. Remove heavy metals

4. Decrease water temperature

The correct answer is: Form floc

Coagulation is a crucial step in water treatment processes that involves adding coagulants to water, which helps to destabilize and aggregate smaller particles into larger clusters known as floc. This is achieved because coagulants, such as alum, neutralize the electric charge on suspended particles, allowing them to come together and form larger masses. As these floc particles grow, they can more easily be removed in subsequent processes like sedimentation or filtration, leading to clearer and cleaner water. The formation of floc is essential in improving the overall efficiency of water treatment by enabling the removal of smaller, often harmful contaminants. The other options, while related to water treatment, do not directly describe the primary goal of coagulation. For instance, increasing pH levels, removing heavy metals, and decreasing water temperature are not the primary processes facilitated by the coagulation step. Instead, these may be seen in different treatment processes or as secondary effects depending on the specific nature of the water being treated.