Florida Drinking Water Operator "B" Practice Test

What process uses microsand added to the flocculation stage to encourage floc setting?

1. Ballasted flocculation

2. Coagulation

3. Sedimentation

4. Filtration

The correct answer is: Ballasted flocculation

The process that involves the addition of microsand during the flocculation stage to promote the setting of floc is known as ballasted flocculation. In this method, microsand acts as a ballast or weight that enhances the settling characteristics of floc particles. When microsand is added to the floc, it becomes attached to the floc aggregates, increasing their density. This increase in density facilitates faster settling in the sedimentation phase that follows. The key benefit of ballasted flocculation is that it allows for more efficient removal of suspended solids, particularly in systems where rapid separation is desired. The use of microsand can also help improve the overall performance of the treatment process, resulting in clearer effluent and reduced chemical usage. Coagulation refers to the initial step in which coagulants are added to destabilize particles in the water, while sedimentation is the stage where the floc settles to the bottom of the treatment vessel. Filtration is a further step that typically occurs after sedimentation or flocculation, aimed at removing any remaining particles. These processes do not specifically involve the addition of microsand to encourage floc setting, which is why they are not the correct answer.