Abstract: The invention relates to a method for the floatation-clarification of difficult water, in particular heavily polluted surface water, urban or industrial wastewater, rainwater or any type of water that floats with difficulty, particularly water which contains a high percentage of mineral matter or requires the injection of a flocculation aid and which originates from filters or membrane technologies such as ultrafiltration, said method comprising: a coagulation step (A1) in which a dose of coagulant (1) is injected into the water to be treated; a flocculation step (B) in which flocculant (2) is injected (B1) into the water after the coagulation step, in order to agglomerate the suspended particles in the form of flocs; and subsequently a floatation step (C) in which the flocculated water is mixed with an emulsion of air micro-bubbles in a floatation apparatus. A second coagulant injection step (A2) is performed downstream of the flocculant injection (B1) and upstream of the floatation (C).

Abstract: The invention relates to a method for the floatation-clarification of difficult water, in particular heavily polluted surface water, urban or industrial wastewater, rainwater or any type of water that floats with difficulty, particularly water which contains a high percentage of mineral matter or requires the injection of a flocculation aid and which originates from filters or membrane technologies such as ultrafiltration, said method comprising: a coagulation step (A1) in which a dose of coagulant (1) is injected into the water to be treated; a flocculation step (B) in which flocculant (2) is injected (B1) into the water after the coagulation step, in order to agglomerate the suspended particles in the form of flocs; and subsequently a floatation step (C) in which the flocculated water is mixed with an emulsion of air micro-bubbles in a floatation apparatus. A second coagulant injection step (A2) is performed downstream of the flocculant injection (B1) and upstream of the floatation (C).