Flocculation filtration combines the flocculation process with filtration to remove solids from the water. First, flocculants are introduced into the water to aggregate fine particles into flocs. These larger flocs can then be efficiently removed by a filter unit, such as a sand filter or a membrane filter. This technique is often used in drinking water treatment and wastewater treatment to reduce the concentration of particles in the water and increase filtration efficiency. Flocculation filtration is particularly used for heavily contaminated water where pure filtration processes are not sufficient.