A flotation apparatus for separating oil from a dispersion containing water as a continuous phase and oil as a dispersed phase. The apparatus comprises a vessel having one or more longitudinal cell sections in its longitudinal direction, at least one of the one or more longitudinal cell sections comprising: an underflow weir, an overflow weir displaced downstream from the underflow weir, a gas injection structure located below the underflow weir or in the channel formed between the underflow weir and the overflow weir, a removal structure for removing a fraction formed during the operation of the flotation apparatus on the liquid level from the liquid level, and a hydraulic structure for hydraulically pushing the fraction formed during the operation of the flotation apparatus on the liquid level into the removal structure using a liquid stream, a liquid/gas stream and/or a gas stream that is ejected by the hydraulic structure.