FR2856054A1 - Treatment system for effluent from livestock rearing has first pump immersed in receiving post that feeds continuous circuit, with separator fed by branch pipe - Google Patents

Abstract

The treatment system consists of a receiving post for the effluent, a separating post for solids and liquids, an aerobic treatment post for the liquid effluent with a tower, and a decanting post. A first pump immersed in the receiving post feeds a continuous effluent circuit, while the separating post is fed by a branch from the continuous circuit which has a throughput below that of the pump. The treatment system consists of a receiving post (1) for the effluent, a separating post (2) for solids and liquids, an aerobic treatment post for the liquid effluent with a tower (31), and a decanting post (4). A first pump (11a) immersed in the receiving post feeds a continuous effluent circuit (12, 13, 14, 16), while the separating post is fed by a branch (15) from the continuous circuit which has a throughput below that of the pump. A flow regulating tank (13) is incorporated between the effluent receiving and separating posts, and the continuous circuit is such that the first pump draws the effluent from the receiving post towards the tank (13) through a first feed pipe (12), while a return pipe (14) has its intake end (17) in the tank at a height that requires a certain level of effluent in the tank before the continuous circuit can operate.

Description

1 I

  The present invention relates to the treatment of farmers such as liquid manure and in particular a device for liquid effluents.

  The treatment of liquid manure or other biological residues 5 necessary for regions with intensive farming in order to pollute including pollution of groundwater and rivers.

  Liquid effluents treatment of such from farming is a diverse prevention of pollution. A traditional possibility of reuse of liquid manure is spreading, but this spreading, in addition to polluting when done in large quantities, gives off a foul odor.

  Effluent treatment techniques with a view to reducing the nuisance of such effluents and possibly with a view to recovering reusable residues as fertilizer exist and in particular the document FR 2 815 028 A1 relates to a device for biological treatment of effluents comprising two phases biological treatment, one anaerobic, the other aerobic effluents which are then used liquids. According to this document, there is no separation of an aqueous liquid phase and a solid residue phase.

  Document FR 2 744 119 for its part performs several stages of solid liquid separation on an effluent before subjecting this effluent to an ultrafiltration operation then a reverse osmosis operation separating a permeate from a concentrate and aerobic fermentation of '' a mixture made from the concentrate to make an organic fertilizer.

  The methods according to these two documents remain cumbersome and complex, in particular the document FR 2 744 1 19 comprises a reverse osmosis phase and the document FR 2 815 028 involves significant processing times.

  The present invention aims to provide a simple, inexpensive effluent treatment device 5 applicable to small farms, for which the solid parts of the effluents are separated from a liquid part, the liquid part being reusable in a chain. washing of breeding rooms or treated to go in a natural environment.

  For this, the invention mainly relates to an effluent treatment device 10, in particular from livestock effluents, comprising an effluent receiving station, a station for separating the solid materials and the liquid part of the effluent, a station for aerobic treatment of the liquid part of the effluent comprising an aerobic culture tower and a decanting station, the device being such that a first pump, immersed in the effluent receiving station, feeds a continuous effluent circuit , the effluent separation station being supplied by a bypass of the continuous circuit, this bypass having a flow rate less than the flow rate of the first pump.

  Advantageously, the continuous circuit performs mixing of the 20 effluents.

  In a particular embodiment, a flow regulation tank can be interposed between the effluent reception station and the solid matter separation station, the continuous circuit being such that the first pump sucks the effluents from the reception station towards the regulation tank through a first pipe, for supplying effluent, and such that a second pipe, back to the effluent reception station, has its mouth disposed in the regulation tank at a height such that a determined level of effluent is present in the regulation tank during the operation of the continuous circuit, the regulation tank comprising a third pipe, for supplying effluents to the separation station, forming said bypass.

  In an alternative embodiment, the continuous circuit may include a main outlet and a bypass outlet, the bypass outlet comprising a pipe for supplying effluents to the separation station.

  The first pump may in particular be a low-flow vortex type pump.

  A second pump may be provided to supply a circuit for mixing the effluents.

  The separation station may in particular comprise a grid separator device 10, a solids recovery tank and an outlet pipe for the liquid part of the effluents, this liquid part flowing through the outlet pipe to an aerobic treatment station. of the liquid part and of the means for extracting solid materials of the worm screw type associated with the recovery tank.

  Advantageously, the aerobic treatment station for the liquid part comprising an aerobic culture tower further comprises a treatment pit, a pump, immersed in the treatment pit, a first riser pipe bringing the effluents to the top of the culture tower, a second tubing for the return of effluents from a lower part of the aerobic tower to the treatment pit, a third tubing, for short-circuiting the aerobic tower, connected to the first tubing at an intermediate connection point of the first tubing and descending towards the treatment tank, a fourth tube, for the outlet of the effluents towards the decantation station, connected in the lower part of the tower, switching means being arranged at the intermediate connection point, these switching means allowing, either an increase in effluents in the first tubing to the aerobic tower, or a decrease in effluents by the third tu bulb, first means of opening / closing of the second tubing allow to authorize / prohibit the return of the effluents towards the aerobic treatment pit 30, second means of opening / closing of the fourth tubing allow to authorize / prohibit the effluent outlet to the decantation station.

  The referral means and the first and second opening / closing means are in particular controlled according to a cycle such that the effluents ascend in the aerobic tower and descend into the aerobic treatment pit continuously for 23 to 24 hours and are rejected. from the aerobic tower to the settling station for 0 to one hour.

  The decanting station can in particular comprise a circuit for the return of the treated liquid effluents to the effluent receiving station, the return circuit comprising a pump immersed in the decanting station and a return line for the treated liquid effluents. The decanting station can also include an overflow device allowing the decanted effluents to flow into a pit, forming the first filtering marsh, the bottom of which is covered with a waterproof membrane or without membrane in a clay soil.

  The first filtering marsh can in particular be followed by one or more marshes, the marshes being sown with plant species with high absorption capacity for fertilizers.

  The aerobic tower can be made of plastic material and formed from cylinder portions assembled and stacked.

  The device may be such that at least one of the reception stations, aerobic treatment stations and decanting stations comprises a pit consisting of a tank of cylindrical upper section, of conical lower section, the conical section ending in a lower pan in which a submerged pump is housed.

  Such a reservoir can in particular be made of plastic material, the cylindrical part consisting of assembled cylinder portions.

  Other advantages and characteristics will be better understood on reading the following description of a particular embodiment of the invention with reference to the figures which represent: In FIG. 1: A schematic view of a processing device 30 effluents according to various aspects of the invention; In Figure 2: A schematic perspective view of an embodiment of a reception station and a separation station according to the invention; In Figure 3: A schematic perspective view of an embodiment of an aerobic treatment tower according to the invention.

  As described in the general diagram of FIG. 1, a device for treating livestock effluents in accordance with the present invention comprises a station 1 for receiving the effluents, a station 2 for separating the solid materials and the liquid part of the effluent, a station 3 for aerobic treatment of the liquid part of the effluent and a decantation station 4.

  Such a device is suitable for many operating sizes and in particular applicable for small operations without being prohibitively expensive.

  According to FIG. 1 or 2, the effluent reception station is mainly organized around a pit or a reservoir 19. The effluents are brought either by skips or by a pipe not shown coming directly from the breeding room where find the animals.

  A first pump 11 a, immersed in the tank 19, feeds a continuous circuit 12, 13, 14, 16 of effluents. This continuous circuit allows permanent circulation and mixing of the effluents in the tank 19.

  According to the example shown, a second pump 18 is provided to supply an annex circuit for mixing the effluents. The mixing of the effluents is necessary to avoid decantation or sedimentation of the solid parts and to limit possible fermentation.

  According to the device of FIG. 1, the continuous circuit includes a tank 13 for regulating the flows. This tank is interposed between the station 1 for receiving the effluents and the station 2 for separating solids, the continuous circuit being such that the first pump 1 1a sucks the effluents from the station 1 for receiving to the tank 13 for regulating the through a first pipe 12, for supplying effluent, and such as a second pipe 14, returning to the effluent receiving station, at its mouth 17 disposed in the regulation tank 13 at a height such that a determined level of effluent is present in the regulation tank 13 during the operation of the continuous circuit.

  According to this circuit, the tank 13 serves as a regulating buffer tank for the separation station 2, the continuous circuit making it possible to maintain a constant level of effluents always renewed in the tank 13.

  The regulation tank has a third pipe, for supplying effluents to the separation station. To allow the constant level to be kept in the regulation tank, this pipe allows a flow rate lower than the flow rate of the first pump 11a. The effluent supply line 10 to the separation station thus forms a bypass 15 of the continuous circuit. This arrangement is advantageous in the case of a 1 l pump with a high flow rate, the separation station possibly being of small capacity but operating continuously.

  According to FIG. 2, a simplified variant makes it possible to dispense with the regulation tank 15. According to this variant, the continuous circuit comprises a main output 14 and a bypass output 15, the main output always performing a mixing. The bypass outlet is produced by a tapping on the continuous circuit, the pipe 15 for supplying the effluents to the separation station again being of a section allowing a flow rate lower than the flow rate 20 of the continuous circuit.

  According to the invention, the first pump 11a is a pump of the vortex type, such a pump easily accepting the feathers of a poultry farm or the straws.

  The separation station described succinctly in FIG. 1 comprises a separating device 21, for example a separating device with a vibrating grid of the order of 40 to 100 micrometers with possibly a coarser separation upstream, the liquid flows from the grid under the separator while the solid materials move on the vibrating grid to fall into a tank 23 for recovering solid materials. In the case of raising 30 ducks, the organic matter composition of the liquid phase generates a COD (chemical oxygen demand) of the order of 24,000 mgO2 / liter. The separator allows to go from a mass of 200Kg / m3 to 15Kg / m3 of solid in the liquid phase.

  In the lower part of the separator, receiving the liquid, there is a pipe 22 for outlet of the liquid part of the effluents, this liquid part 5 flowing through the pipe 22 for outlet to a station 3 for aerobic treatment of the liquid part.

  The solid materials are extracted from the tank 23 by means 24 of worm-type extraction associated with the tank 23 for recovery. The solid materials which represent up to 20% by weight of the starting juices or effluents are optionally stored under a tarpaulin to avoid fermentation which generates bad odors in the event of rain.

  The liquid effluents leaving the separation station 2 flow by gravity into an outlet pipe 22 towards the station 3 for aerobic treatment of the liquid part. This station includes an aerobic culture tower 31 or bacterial bed comprising, for example, partitioned tubes or a honeycomb type lining allowing the development of bacteria capable of degrading biological materials.

  The aerobic treatment station 3 further comprises a treatment pit 32, a pump 11b, immersed in the treatment pit 32, a first rising tube 33 connected to the pump, intended to bring the effluents to the top of the tower 31 culture, a second tubing 34 for the return of effluents from a lower part of the aerobic tower 31 to the treatment pit 32, a third tubing 35, for short circuit of the aerobic tower, connected to the first tubing at a connection point intermediate 25 36 of the first tube and descending towards the treatment pit, a fourth tube 37, for the outlet of the effluents towards the decantation station 4, connected in the lower part of the tower.

  The station 3 for aerobic treatment of the liquid part comprises switching means 38, arranged at the intermediate connection point 36 of the first tube 33. In order to perform the aerobic treatment, the switching means 38 allow, either a rise of the effluents in the first tubing 33 up to the tower 31 of aerobic culture, ie a descent of the effluents by the third tubing 35.

  To allow either the return of the effluents to the treatment pit, or the transfer of the effluents to the decantation station, first and 5 second means 39a, 39b for opening / closing the second tubing 34 and the fourth tubing 37 are provided.

  Aerobic treatment includes a long cycle of continuous flow of effluents between the tower and the pit. The referral means 38 and the first and second opening / closing means 39a, 39b are controlled 10 according to a cycle such that the effluents rise into the tower 31 and descend into the pit 32 of continuous aerobic treatment for approximately 23 hours .

  For this, the switching means close the tubing 35 and open the tubing 33 while the first opening / closing means in the tubing 34 are in the open position and the second means 15 for opening / closing the fourth tubing. 37 are in the closed position.

  At the end of the 23 to 24 hour circulation cycle, an emptying cycle is carried out, this cycle starting with filling the tower with closing of the first opening / closing means, then emptying of the tower with the opening of the second opening / closing means allowing the effluent to be discharged into the decantation pit, the procedure ending with the tower being switched off by the switching means directing the effluents into the pipe 35 for the return to the treatment pit. This aerobic treatment allows a reduction of 60 to 90% of the COD of the liquid.

  The decantation station 4 comprises a circuit for the return of the treated liquid effluents to the effluent reception station, the return circuit comprising a pump 1 c immersed in the decantation station and a pipe 43 for the return of the treated liquid effluents. According to the example, as for the other stations, the pump 1 c is placed in a lower pan of the tank 44 forming a settling tank. Thus the pump 30 disposed in the bottom of the tank is capable of returning any remaining solid parts which tend to sediment to the reception station.

  The decantation station 4 includes an overflow device 42 allowing the decanted effluents to flow into a pit 51, forming the first filtering marsh 5, a pit whose bottom can be covered with a waterproof membrane 52 or use the characteristics of the existing land in the presence of sufficient clay in quantity and quality to make the soil impermeable.

  The first filtering marsh 5 is followed by one or more marshes 6, 7, the marshes being sown with plant species with high absorption capacity for fertilizers.

  To allow the construction of a highly modular device, the aerobic tower 31 in particular is made of plastic material and formed from cylinder portions assembled and stacked 31a, 31b, 31c, 31d.

  Still according to the example shown in FIG. 1, the receiving station 1, the aerobic treatment station 2 and the decanting station 3 comprise pits consisting of reservoirs 70 of cylindrical upper section 71, of conical lower section 72, the section conical 72 ending in a pan 73 in which a submerged pump 11 is housed.

  The reservoirs may, according to a preferred embodiment more particularly shown in FIG. 2, be made of plastic material 20 thus simplifying the maintenance of the device and being insensitive to acid effluents. For these tanks, advantageously, the cylindrical part can be made up of assembled cylinder portions 71a, 71b. For the realization of the tank, the cylindrical portions are assembled and for this purpose comprise fixing means such as ribs 74, these ribs 74 possibly coming to enclose a gasket 77 being secured by means such as bolts 76 or any other means of fixation. Likewise, the cylindrical portions and the conical lower section may comprise flange elements 75 intended to provide a sealed fixing of the cylindrical portions with the conical lower section.

  In the case for example of a duck force-feeding operation, the device makes it possible to economically treat a quantity of the order of 5 m3 per day with a receiving pit of the order of 10 m3, a treatment pit aerobic on the order of 7m3, the tower height being on the order of 7.5m, the settling tank having a volume on the order of 5m3.

Claims (13)

R E V E N D I C A T 0 N S   1 - Device for treating livestock effluents comprising a station (1) for receiving effluents, a station (2) for separating solids and the liquid part of the effluent, a station (3) for aerobic treatment of the liquid part of the effluent comprising an aerobic culture tower (31) and a decantation station (4), characterized in that a first pump (11a), immersed in the effluent reception station, supplies a continuous effluent circuit (12, 13, 14, 16), the effluent separation station (2) being supplied by a bypass (15) of the continuous circuit, this bypass having a flow rate less than the flow rate of the first pump (1 la).   2 - Device for treating livestock effluents according to claim 1 characterized in that the continuous circuit (12, 13, 14, 16) performs mixing of the effluents.   3 - Device for treating livestock effluents according to claim 1 or 2 characterized in that a tank (13) for regulating the flow is interposed between the station (1) for receiving the effluents and the station (2) separation of solid materials, the continuous circuit being such that the first pump (1a) sucks the effluents from the receiving station (1) towards the regulation tank (13) through a first pipe (12), effluent supply, and such as a second pipe (14), back to the receiving station for 20 effluents, at its mouth (17) disposed in the tank (13) for regulation at a height such that a determined level of effluent is present in the regulation tank (13) during the operation of the continuous circuit, the regulation tank comprising a third pipe, for supplying effluents to the separation station, forming said bypass (1 5 ).   4- Device for treating livestock effluents according to claim 1 or 2 characterized in that the continuous circuit comprises a main outlet (14) and a bypass outlet (15), the bypass outlet (15) comprising a effluent supply pipe to the separation station.   - Device for treating livestock effluents according to one of the preceding claims, characterized in that the first pump (11a) is a vortex type pump with low flow rate.   6 - Device for treating livestock effluents according to one of the 5 preceding claims, characterized in that a second pump (18) is provided to supply a circuit for mixing the effluents.   7 - Device for treating livestock effluents according to one of the preceding claims, characterized in that the separation station comprises a grid separator device (21), a tank (23) for recovering solid materials and a pipe. (22) for leaving the liquid part of the effluents, this liquid part flowing through the outlet pipe (22) towards a station (3) for aerobic treatment of the liquid part and means (24) for extracting the materials solids associated with the recovery tank (23).   8 - Device for treating livestock effluents according to one of the preceding claims, characterized in that the station (3) for aerobic treatment of the liquid part comprising an aerobic culture tower (31) further comprises a pit ( 32) treatment, a pump (11 b), immersed in the treatment pit (32), a first rising tube (33) connected to the pump, bringing the effluents in the upper part of the culture tower (31), a 20 second tubing (34) for the return of effluents from a lower part of the aerobic tower (31) towards the treatment pit (32), a third tubing (35), for short-circuiting the aerobic tower, connected to the first tubing at an intermediate connection point (36) of the first tubing and descending towards the treatment pit, a fourth tubing (37), for the outlet of the effluents 25 towards the decantation station (4), connected in the lower part of the tower , the aerobic treatment station (3) for the liquid part comprising switching means (38), disposed at the intermediate connection point (36) of the first tube (33), these switching means (38) allowing, either an ascent of the effluents in the first tube (33) up to '' at the aerobic tower (31), ie a descent of the effluents by the third tube (35), comprising first means (39a) for opening / closing the second tube (34) allow to authorize / prohibit the return effluents to the aerobic treatment pit (32) and comprising second means (39b) for opening / closing the fourth tube (37) make it possible to authorize / prohibit the exit of the effluents to the decanting station (4).   9 - Device for treating livestock effluents according to claim 5 8 characterized in that the switching means (38) and the first and second means (39a, 39b) of opening / closing are controlled according to a cycle such that the effluents rise into the aerobic tower (31) and descend into the continuous aerobic treatment pit (32) for 23 hours and are discharged from the aerobic tower to the decantation station (4) for one hour.   10- Device for treating livestock effluents according to one of the preceding claims, characterized in that the station (4) for settling comprises a circuit for the return of the treated liquid effluents to the station for receiving the effluents, the return circuit comprising a pump (11c) immersed in the decanting station and a pipe (43) for returning the 15 treated liquid effluents.   11 - Device for treating livestock effluents according to one of the preceding claims, characterized in that the station (4) for settling comprises an overflow device (42) allowing the decanted effluents to flow into a pit (51), forming the first filtering marsh (5), the bottom 20 of which is covered with a waterproof membrane (52), the first filtering marsh (5) being followed by one or more marshes (6, 7), the marshes being sown with plant species with high absorption capacity for fertilizers.   12- Device for treating livestock effluents according to one of the preceding claims, characterized in that the aerobic tower (31) is made of plastic material and formed of portions (31a, 31b, 31c, 31d) of assembled cylinders and stacked.   13- Device for treating livestock effluents according to one of the preceding claims, characterized in that at least one of the reception station (1), aerobic treatment station (2) and settling station (3) 30 comprises a pit consisting of a reservoir (70) of cylindrical upper section (71), of conical lower section (72), the conical section (72) ending in a pan (73) in which is housed a submerged pump ( 11).   14 - Device for treating livestock effluents according to the preceding claim characterized in that the tanks are made of plastic material, the cylindrical part consisting of assembled cylinder portions (71a, 71b).