Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

What is the primary function of a clarifier in the water treatment process?

1. Chlorination

2. Particle settling

3. Filtration

4. Storage

The correct answer is: Particle settling

The primary function of a clarifier in the water treatment process is particle settling. Clarifiers are designed to allow suspended solids in water to settle to the bottom due to gravity, separating them from the clearer water above. This process is crucial as it removes particulate matter from the water, thereby improving water quality before it undergoes further treatment, such as filtration or disinfection. During this settling process, the heavier particles descend to form sludge at the bottom of the clarifier, while the lighter, clearer water can be drawn off the top for further treatment. This stage is essential for effective treatment as it ensures that the subsequent processes, like filtration, operate more efficiently, dealing with significantly reduced particle loads. The incorrect options illustrate other crucial processes in water treatment but are not the primary function of a clarifier. For instance, chlorination refers to the disinfection stage where chlorine is added to kill pathogens; filtration involves the removal of finer particles from water and can take place after clarification; and storage pertains to the holding of treated water before distribution. Each of these processes plays a role in the overall treatment system, yet the clarifier specifically focuses on settling solid particles out of the water.