| Abstract |
The invention relates to a water purification installation comprising: a coagulation area (1); a flocculation area (3); an area (5) for mixing, in an upflow, the flocculated water with pressurised water which is delivered by a microbubble-generating pressurisation-pressure reduction system (8); and a flotation area (6). According to the invention, suspended matter, which is brought to the surface by the aforementioned microbubbles, is evacuated from the upper part of the flotation area. Moreover, the lower part of said flotation area comprises means of collecting (10) the clarified water. The inventive installation is characterised in that: the geometry of the flotation area (6) is such that the ratio between the height (H) of the area located above the clarified water collection means (10) and the length (L) of said area is included between 0.3 and 1; and the ratio between the surface (Sa) of the nappe at the outlet of the mixing area (5) and the surface (Sp) of the actual flotation area is included between 0.05 and 0.5 and, preferably, between 0.1 and 0.35. |