What is flocculation?

• A. The step of disinfecting water with chlorine
• B. The process of forming larger clumps of particles so they can settle out
• C. The removal of dissolved minerals by filtration
• D. The settling of heavier particles by gravity alone

Answer: (B)

Flocculation is the stage where tiny, destabilized particles are encouraged to collide and stick together, forming larger clumps called flocs so they can be removed later by sedimentation or filtration. After coagulants are added, gentle mixing provides just enough energy for particles to aggregate without breaking apart. This step isn’t disinfection, which uses chlorine to kill microbes, and it isn’t the removal of dissolved minerals by filtration, since dissolved substances don’t form solid clumps. It also isn’t gravity settling on its own, which would occur without creating larger aggregates. So the key idea is forming larger particle clumps to make them easier to remove.