Which method is primarily used to remove easily settled sand and grit in water treatment?

The method primarily used to remove easily settled sand and grit in water treatment is presedimentation. This process involves allowing water to stand undisturbed in a storage basin or sedimentation tank for a certain period, enabling heavier particles, such as sand and grit, to settle at the bottom due to gravity.

Presedimentation is particularly effective for removing these larger particles before the water undergoes further treatment steps, such as filtration and disinfection. As a result, it helps to reduce the load on subsequent treatment processes, ultimately improving the efficiency and effectiveness of the overall water treatment system.

While flocculation is aimed at the aggregation of smaller particles to form larger flocs that can settle out, it is not specifically designed for the removal of sand and grit. Aeration helps in reducing the concentration of dissolved gases and can aid in the removal of volatile organic compounds but does not directly address the settling of solid particles. Clarification is a broader term that encompasses processes to separate solids from liquids, but presedimentation specifically targets the initial removal of easily settled solids.