Abstract: A plant for the treatment of surface water comprises a safety barrier mounted at the exit from the treatment plant and constituted by a physical filter providing, at the exit from the filter, a predetermined minimum quality irrespectively of the quality of the water on entry into the filter, and a pre-treatment installation located upstream from the safety barrier, the treatment intensity of the pre-treatment installation being adjusted as a function of the characteristics of the surface water to be treated through measuring devices located at the entrance to the physical barrier. The safety barrier is advantageously a nanofiltration membrane, coupled if necessary to one or more reverse osmosis membranes mounted downstream in "series-rejection" mode. The disclosed installation can be applied to the treatment of water liable to show great variability in quality, notably to the treatment of surface water or of water with equivalent characteristics.

Abstract: An installation for the treatment of a flow of liquids, notably potable water or effluents, installation of the type wherein the liquids are put into contact with a treatment gas during a pre-determined treatment period, the installation comprising means for the addition of the treatment gas to the flow of liquids so as to form a homogeneous two-phase treatment medium, means for the forced dissolution of the treatment gas in the flow of liquids to be treated cooperating with means for the degassing of the two-phase treatment medium so as to produce a monophase treatment medium and contactor means providing for a plug flow of the degassed monophase treatment medium during the pre-determined treatment period. A particular exemplary application of the installation is to the ozonation of liquids.

Abstract: Apparatus for treating water by gaseous diffusion and flotation comprising a single reactor which is separated into at least two compartments. One compartment is used for gas transfer with a pressurized gas diffuser flushed by a liquid current wherein water to be treated is introduced downwardly. The other compartment is in communication with the first compartment by means of an orifice whose opening diameter and orientation are controlled.