Abstract: Method of treating liquid by sedimentation in which reagents are injected into a flow of untreated liquid and there is created in the flow a colloid mixing and stabilization area; the flow is passed into an intermediate aggregation area and then into a sedimentation area equipped with separator plates from which clarified liquid is taken; characterized in that insoluble granular material which is more dense than the liquid is injected into the liquid in predetermined proportions in the mixing area where the flow is made turbulent, turbulence is induced in the intermediate aggregation area to maintain the granular material in suspension, virtually all of the granular material is brought into the sedimentation area, the sludge recovered in the sedimentation area is removed, the granular material is removed therefrom (D) and is recycled after cleaning.

Abstract: Water is purified according to the principle of a biomass fixed on an aerated granular bed acting as a filter in a biological reactor.The water to be purified is sent, without presettling, upwardly through a multilayer granular bed placed in the reactor. The injection point of oxygenated gas determines two succesive zones, anaerobic and then aerobic. The water is evacuated from the reactor at the top thereof, or at a certain level of the bed. A sudden downward flushing of the filter with water is provided to eliminate the biomass. The filter is periodically washed with air/water and then rinsed with water.

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.

Abstract: A fermentation unit comprising a scoop wheel equipped with scoops on the periphery thereof, and which moves between bunker silos. The bunker silos are equipped with aeration ducts at the base thereof. Flexible scrapers located around the periphery of the scoop wheel scrape the aeration ducts. Unstacking barbs are also located on the periphery of the scoop wheel. Means are provided to adapt the unit to the type of materials to be treated.

Abstract: An apparatus for processing of residential or industrial solid wastes, including first grinding means, magnetic separation means, first screening means, whose screenings are directed to second grinding means, drying means comprising a hot air generator, gravity separation means, cyclone separation means, second screening means, and press granulating means.The apparatus is used for production of solid fuels in granules, whose net calorific value can be modified by causing the mesh size of the first and second screening means to vary.

Abstract: Reactor having considerable volume or surface for injection and distribution of a gaseous fluid into a liquid mass to be treated, includes a false bottom having over its entire surface a series of nozzles each having a small orifice, incorporated with a pipe, immersed in the liquid, whose perforated base rests on the false bottom and whose closed upper end is provided with slots from which gas bubbles escape into an active zone of the liquid mass.

Abstract: In a biological water purification process polluted water, including surface water to be made potable, sewage water or industrial water, is percolated through a submerged fixed bed of granular material such as activated carbon, chamottes, raw clays, etc., with an oxygenated gas being upwardly injected at an intermediate level of the bed. The water and gas delivery rates are controlled to satisfy the following relations: ##EQU1## wherein Q.sub.1 is the delivery of oxygenated gas in m.sup.3 /hr,Q.sub.2 is the delivery of water to be treated in m.sup.3 /hr,.epsilon. is the porosity of the granular material bed,.alpha. is the maximum fraction of the volume that can be occupied by the gas without affecting the effectiveness of the treatment,S is the bed section in m.sup.2,h is the height of the bed in meters,v is the vertical component of the average speed of the ascending gas bubbles in m/hr,K.sub.1 is a constant corresponding to the fraction of volume of bed occupied by immobilized gas pockets in m.sup.3,K.sub.