Patent FR-2971949-A1 (FR)
Title: Installation for purifying effluent such as domestic origin wastewater, comprises first chamber such as inlet chamber having inlet for raw effluent, second chamber such as clarifier having outlet for purified effluent, and passing unit
Inventor: VACHE ALAIN
IPC: B01D21/34
Filed: 2011-02-24
Abstract: The installation for purifying effluent such as domestic origin wastewater, comprises a first chamber such as an inlet chamber (1, 2) having an inlet (10) for raw effluent, a second chamber such as a clarifier (3) having an outlet for purified effluent, a unit for passing effluent from the inlet chamber to the clarifier, and a unit for determining a volume of effluent evacuated from a supply unit. The clarifier comprises: a unit for supplying the purified effluent to the outlet of the clarifier; and a unit (4) for recirculating a part of effluent from the clarifier to the inlet chamber. The installation for purifying effluent such as domestic origin wastewater, comprises a first chamber such as an inlet chamber (1, 2) having an inlet (10) for raw effluent, a second chamber such as a clarifier (3) having an outlet for purified effluent, a unit for passing effluent from the inlet chamber to the clarifier, and a unit for determining a volume of effluent evacuated from a supply unit. The clarifier comprises: a unit for supplying the purified effluent to the outlet of the clarifier; and a unit (4) for recirculating a part of effluent from the clarifier to the inlet chamber and for sending back a part of sludge and a supernatant liquid of the effluent from the clarifier to the inlet chamber. The inlet chamber comprises: a first compartment such as a pre-decanter equipped with the raw effluent inlet; a second compartment such as a biological reactor, which is distinct from the pre-decanter, including a bacterial bed and an oxygenation unit (20); and a unit such as an equalization unit for passing effluent from the pre-decanter to the biological reactor. The recirculation unit comprises a set of pipes including a first pipe and a second pipe, which is connected with the first pipe, where the pipes have an opening such as an aspiration opening for sludge. A contact region of the first and second pipes is disposed above the aspiration opening. The first pipe has an upper inlet opening such as a supernatant liquid inlet opening, which is disposed at a top of the contact region and is adapted to emerge in the effluent to allow passage of the supernatant liquid to pass through the inlet opening. The second pipe has an outlet opening configured for emerging in the inlet chamber. The pipes are equipped with a unit for injecting pressurized gas such as compressed air in the second pipe for entraining a flow of the sludge and the supernatant liquid in a direction of the inlet chamber. The first pipe comprises an obturation system to seal the first pipe when a level of effluent in the first pipe decreases from the given level such as threshold level and to release the passage of effluent through the first pipe when the level of effluent exceeds the threshold level. The equalization unit comprises a column, which has an effluent supply inlet and is equipped with the compressed air injection unit. The supply unit comprises a reservoir, which has an effluent inlet and an outlet connected with the outlet of the clarifier. A maximum level of effluent is detected by a sensor connected with the reservoir. The reservoir is equipped with the pressurized gas injection unit to evacuate a part of the effluent contained in the reservoir. The equalization unit, the oxygenation unit and the recirculation unit are equipped with a unit for controlling an activation of an equalization phase corresponding to the passage of effluent from the pre-decanter to the biological reactor.