Abstract: A device for injecting a secondary fluid into a main liquid, includes a first part able to convey a secondary fluid in a substantially longitudinal direction; a second part able to eject the secondary fluid from the device, so as to inject the secondary fluid into a main liquid, the second part being in fluidic connection with the first part and comprising an open end; the device comprising at least a first position, referred to as the low position, and a second position, referred to as the high position, and further comprising a positioning means able to position the device in a position comprised between the first position and the second position.

Abstract: Apparatus for clarifying a sludge-containing effluent, comprising a clarification basin (2), at least one arm (7) able to move over the upper surface of the liquid in the basin; at least one trough (8) supported by the arm so that it can be immersed over part of its height in the liquid of the basin, suction tubes (T1, T2) held relative to the trough, each tube comprising at the top a vertically adjustable sleeve (B1, B2) opening into the trough, and a means of removing sludge from the trough; the sleeve (B1, B2) of at least one suction tube (T1, T2) is free to slide vertically relative to the mobile arm (7) supporting the trough, and to the tube (T1, T2) and a reserve of buoyancy necessary and sufficient for keeping the overspill end (E1, E2) of the sleeve in the trough (8) continuously out of the water is installed on the sleeve (B1, B2) so that the overspill level of the sleeve adjusts automatically in relation to the level (16) of liquid and sludge in the trough.

Abstract: Apparatus for clarifying a sludge-containing effluent, comprising a clarification basin (2), at least one arm (7) able to move over the upper surface of the liquid in the basin; at least one trough (8) supported by the arm so that it can be immersed over part of its height in the liquid of the basin, suction tubes (T1, T2) held relative to the trough, each tube comprising at the top a vertically adjustable sleeve (B1, B2) opening into the trough, and a means of removing sludge from the trough; the sleeve (B1, B2) of at least one suction tube (T1, T2) is free to slide vertically relative to the mobile arm (7) supporting the trough, and to the tube (T1, T2) and a reserve of buoyancy necessary and sufficient for keeping the overspill end (E1, E2) of the sleeve in the trough (8) continuously out of the water is installed on the sleeve (B1, B2) so that the overspill level of the sleeve adjusts automatically in relation to the level (16) of liquid and sludge in the trough.

Abstract: The invention concerns a method for regulating a wastewater or sludge treating plant. Ponds and cells provided with aerating means are used for eliminating carbonaceous, nitrogenous, and phosphate pollutants. The invention is characterized in that an automaton uses periods during which the plant is underloaded to impose on it abnormal operating conditions. The automaton analyses the response of the plant to the abnormal operating conditions to simulate and optimize the plant operating parameters for heavy-load periods, by automatically adjusting the parameters of the automaton logic.

Abstract: The invention concerns a method for regulating an effluent treating plant, in particular for waste water or sludge derived from that type of treatment, using in particular ponds and cells provided with aerating means, for eliminating carbonaceous, nitrogenous, phosphate pollutants and a regulating automaton operating on the analysis of the evolution of predetermined operating parameters of the plant. The invention is characterised in that: the automaton uses periods during which the station is under-loaded-to impose on it abnormal operating conditions, and the automaton analyses the response of the plant to said abnormal operating conditions to update and optimise the plant operating parameters for heavy-load periods, by automatically adjusting the parametering of the automaton logic. In the implementing example, the method is used for controlling the aeration of a purification plant.