Physico chemical treatment is used for the separation of colloidal particles. To achieve it quickly, chemicals (called coagulants and flocculants) are added. These transform the physical state of the colloids, allowing them to remain in an indefinitely stable form and therefore form particles or flocs with settling properties.

  • Tube Settler :
    Tube settlers are commonly used in rectangular clarifier to increase the settling capacity of rectangular sedimentation basins by reducing the vertical distance. The floc particles would settle before agglomerating to form larger particles. The settlers use multiple tubular channels sloped at an angle and adjacent to each other, which combine to form an increased effective settling area.

  • Dissolved Air Flotation (DAF)) :
    Dissolved air flotation is used to clarify wastewater having suspended matter such as oil. Contaminants are removed through the use of dissolved air in the water solution produced by injecting air under pressure in the flotation tank basin. The released air forms tiny bubbles which adhere to the suspended matter, causing the suspended matter to float on the surface of the water where a skimmer may then remove it.

  • Clarifier :
    Clarifiers are the settling tanks used to separate solid particulates deposited by sedimentation.