During which stage of water treatment are large solids primarily removed?

The removal of large solids primarily occurs during the sedimentation stage of water treatment. During this process, water contains various particles, including sand, silt, and other organic and inorganic matter. When water is allowed to settle in large tanks, these heavier particles gradually sink to the bottom due to gravity. This settling method effectively clarifies the water by separating out large solids from the liquid phase.

Sedimentation is crucial because it prepares the water for further treatment processes by removing a significant amount of suspended solids, which can later interfere with filtration and disinfection stages. Once sedimentation is complete, the clearer water can then proceed to filtration where smaller particulates are removed, as well as to chlorination for disinfection. This step is essential in creating safe drinking water as it helps in improving water quality before any chemical treatments or filtration takes place.