Installation for treating water by flotation, comprising a substantially parallelepipedal
assembly (1) produced by connecting modules (2, 2a), said
assembly comprising a contact tank (3) which is provided with supply means for water to be treated (4) and supply means for
white water (5), a flotation tank (6) which is provided with means for discharging
treated water (7, 7a) and which is separated from said contact tank by a vertical wall (8), and means for discharging floated
sludge, characterised in that said contact tank (3) is provided along said flotation tank (6) and delimits a single
contact zone for said water to be treated with said
white water, and in that said supply means for water to be treated (4) are configured to distribute the water to be treated in said contact tank according to a longitudinal
water supply flow, the water distribution flow in the flotation tank being perpendicular to said
water supply flow in said contact tank.