In terms of water supply and drainage, pre-treated water, with the exception of some sand-laden raw water and wastewater with heavy mechanical impurities, is mostly composed of lightweight suspended particles. Examples include algae in lakes, reservoirs, and some rivers; plant debris and fine colloidal impurities; dye particles from the printing and dyeing industry; short fibers from the papermaking and chemical fiber industries; droplets of petroleum and organic solvents from the refining and chemical industries; heavy metal ions in electroplating and pickling wastewater; and electrophoretic paint wastewater. These are all lightweight particles with a specific gravity very close to that of water.Traditional sedimentation methods for these raw waters would inevitably be ineffective, especially in winter, when low temperatures degrade the coagulation and hydraulic conditions, making treatment effectiveness even more difficult to guarantee. As you can imagine, forcing these difficult-to-sediment flocs to sink would be counterproductive. Instead, it's better to leverage the situation and artificially introduce air bubbles into the water, causing them to adhere to the flocs, significantly reducing their overall density. The rising speed of the bubbles then forces them to float, achieving rapid solid-liquid separation. In this sense, the advent of flotation technology revolutionized gravity sedimentation, opening up new areas of solid-liquid separation technology.