Water treatment facility and method

A water treatment facility comprising:

• supply means for feeding the water to be treated (E),
• a flotation reactor (RFlo) comprising at least one first inlet (IFlo) fluidly connected to said supply means,
• a gravity filter (Fg), said flotation reactor (RFlo) being at least partly superimposed on said gravity filter (Fg) and communicating with it so that the water coming from said flotation reactor (RFlo) can flow by gravity into said gravity filter (Fg), to produce flotation-filtered water
• said gravity filter (Fg) having a single-layer filtering media bed distributed over a height of less than or equal to 1 m,
• said gravity filter (Fg) further comprising an outlet (OFg) to discharge the flotation-filtered water,
• at least one high-rate media filter (HRMF), to filter the flotation-filtered water from the gravity filter (Fg), comprising at least one inlet (IHRMF) fluidly connected to the outlet (OFg) of the gravity filter (Fg) and at least one outlet (OHRMF) to discharge the pretreated water, said filtering media bed of the pressure-driven high-rate media filter (HRMF) being distributed over a height equal to or greater than 0.2 m and less than or equal to 1 m and
• supply means leading the flotation-filtered water discharged from the gravity filter (Fg) by the outlet (OFg) towards the inlet (IHRMF) of the pressure-driven high-rate media filter HRMF.