FR3076829A1 - DEVICE AND METHOD FOR TREATING WASTEWATER, INTEGRATING A PLANT FILTER TYPE PURIFICATION BASIN AND A BIOLOGICAL REACTOR - Google Patents

Abstract

The invention relates to a device (1) for treating wastewater, comprising a planted filter-type purification basin (2), in which the circulation of wastewater has a vertical flow, the basin comprising: - means of supply of wastewater (20) to the surface of the basin; - at least one layer of filtering material (21); - drainage means (22) located at the bottom of the basin; the device comprising a biological reactor (3) with a fixed culture of aerobic bacteria, the reactor (3) being located downstream of the basin (2) in a direction of circulation of the waste water.

Description

Wastewater treatment device and method, including a planted filter type purification tank and a biological reactor

The field of the invention is that of the design and manufacture of wastewater treatment systems. More specifically, the invention relates to the design of a wastewater treatment device using a planted filter type technology.

Wastewater treatment by planted filter has experienced very strong development over the past twenty years. As a reminder, the term “planted filter” denotes a filter bed planted with plants where waste water is purified when it percolates through the bed thanks to the filter material, bacteria, and plants. This type of treatment system is mainly applied for the treatment of domestic effluents from small communities. It has many advantages:

- good landscape integration;

- easy and inexpensive maintenance;

- low production of sludge;

- no energy or chemical consumption;

- good purification performance;

- good adaptation to load variations.

Filters planted with vertical percolation or with horizontal percolation are known.

In the horizontal filters, the effluent into the beds is carried out on one side. These effluents then flow horizontally through the massif to be recovered at the other end.

In filters with vertical percolation (or vertical flow), the wastewater is sent to the surface, percolates vertically through the filter mass and is recovered at the bottom by a drainage network. These filters are mainly maintained in aerobic condition thanks to passive aeration mechanisms among which:

- the supply of oxygen excreted by the roots of plants;

- convection linked to the piston effect of the displacement of the water blades brought to each tarpaulin;

- the diffusion, both from the surface and from the bottom thanks to ventilation means which include ventilation chimneys.

The main pollutants eliminated are suspended matter, organic matter, and nitrogen compounds.

In vertical filters, the purification mechanisms are governed by physical (filtration, adsorption) and biological (aerobic microbial degradation, nitrification, plant assimilation) mechanisms. It should be noted that in these filters, the overall nitrogen treatment is weak because it is limited to nitrification by nitrifying bacteria under aerobic conditions (leading to the oxidation of ammoniacal nitrogen to nitrites then to nitrates).

In these devices, the main roles of plants planted on the surface are as follows:

- maintain the permeability of the filter bed thanks to the hydraulic paths created by their stems, roots and rhizomes (prevention of clogging phenomena);

- promote aerobic microbial activity near the roots and rhizomes which serve as biofilm supports, in particular thanks to the supply of oxygen from plants;

- promote the dehydration of the solid materials retained on the surface if necessary, via the evapotranspiration of the reeds.

In France, the most widely applied sector consists of two stages (or basins) of vertical filters in series, with a total surface area of filters from 2 to 2.5 m ² / PE (1.2 to 1.5 m ² / PE on the first floor and 0.8 to 1 m ² / PE on the second floor; with PE = Equivalent-Habitant, which corresponds to the daily pollution generated by a person, most often 60 gDBO ₅ / d, 120gDCO / d, 90gMES / d, 15gNTK / d and 2.4gPT / d).

One of the peculiarities of this sector is that it does not include any pre-treatment (except rough screening) and sends the raw effluents directly to the surface of the first floor. Thus, the particulate matter contained in wastewater is retained by surface filtration mechanisms, where it is gradually dehydrated and mineralized.

The accumulation of sludge in this process is thus low (approximately 1.5 cm / year), which results in widely spaced cleaning frequencies (once every 10 to 15 years). In addition, the quality of the sludge is compatible with agricultural upgrading without additional treatment.

It is now known that this two-tank system, consisting of two vertical filters in series, allows high purification yields to be obtained for domestic effluents (> 90%) on pollutants: suspended matter (MES), organic matter ( BOD ₅ and COD) and reduced nitrogen (NTK).

On the other hand, the performances of this sector are limited (<30%) for global nitrogen (NGL) and phosphorus (PT). This sector also has the disadvantage of having a relatively high land footprint (2 to 2.5 m ² / pe).

The prior art has proposed other solutions intended to be more efficient in treatments and less consuming of space.

We thus find mixed supply chains constituted by the association of vertical and horizontal type filters, in series, such a supply chain always has a high land footprint but makes it possible to improve the performance of treatment on global nitrogen by favoring the reactions of nitrification and denitrification.

Solutions are also known which use a single compact filter with vertical percolation in which layers of material are superimposed. These layers of materials are composed of porous filtering materials having different particle sizes and being capable of thus promoting the development of microorganisms while making it possible to reduce the area of land and limit the operating costs of the device.

These more compact one-stage variants are described in particular in patent documents published under the numbers FR2942791 and FR2973796. Such channels have a single stage and thus considerably reduce the land use of the device. The devices described in these documents include a single purification tank of the planted filter type and have improved purification capacities.

However, these streams with a single purification tank do not allow advanced treatment of ammoniacal nitrogen (NTK) or phosphorus (PT).

Beyond the improvements made to a filter type sector planted with reeds using a single purification basin, the prior art also describes another type of very compact alternative technology.

This very compact technology for wastewater treatment uses "micro-stations". These micro-stations are based on biological purification technology with a fixed culture of bacteria. They allow advanced treatment of ammoniacal nitrogen (NTK), and if necessary phosphorus (PT), thanks to the addition of reagents.

However, this micro-station technology has a much higher operating cost than that of the filter planted with reeds technology. This difference in operating cost is notably due to a high energy consumption caused by the operation of the micro-station as well as the need to carry out emptying of sludge produced by the microstation, these emptying being very frequent in practice.

The invention particularly aims to overcome the drawbacks of the prior art.

More specifically, the invention aims to provide a wastewater treatment device which allows an optimized treatment, both in terms of yield and in economic terms, of the various pollutants of domestic effluents from small communities.

The invention also aims to provide such a wastewater treatment device which has a more limited land area than that of the treatment channels comprising several purification basins of the filter type planted with reeds.

The invention also aims to provide such a wastewater treatment device which does not have operating costs and maintenance requirements as high as those presented by the micro-stations described in the prior art.

These objectives, as well as others which will appear subsequently, are achieved thanks to the invention which relates to a device for treating wastewater, comprising a purification tank of the planted filter type, in which the circulation of water waste is vertically flowing, the basin comprising:

- means of supplying wastewater to the surface of the basin;

- at least one layer of filtering materials;

- drainage means located at the bottom of the basin;

characterized in that it comprises a biological reactor with a fixed culture of aerobic bacteria, the reactor being located downstream of the basin in a direction of circulation of the wastewater.

The planted filter type purification basin forms a filter bed.

Such a device is more advantageous than a device according to the prior art using two distinct pools of filters planted with reeds (occupying 2m ² / PE). Indeed, the device according to the invention can be more compact (<1.3m ² / PE) while presenting better purification performance (NTK <5 to 10 mg / l) and lower investment costs.

Compared with conventional fixed culture micro-stations according to the prior art, the treatment device has the advantage of producing less sludge and storing it over several years. In addition, it consumes less energy and has lower operating costs.

This device is particularly suitable for treating domestic wastewater from small communities (20-500EH) or private structures such as camping, hotels, residences ...

The device according to the invention is also suitable for non-collective sanitation (<20EH), and for the sanitation of effluents originating from small agro-food industries such as cheese factories, delicatessens, dairies, pastries ...

The combination of the biological reactor and the planted filter type purification basin produces a synergy.

Indeed, the purification treatments carried out by these two elements combine by limiting the drawbacks relating to each element taken separately. More specifically, the planted filter makes it possible to degrade the primary sludge (of the wastewater to be treated) and / or the secondary sludge (residual sludge from the reactor), and the reactor makes it possible to carry out a purification complementary to that carried out in the planted filter , consuming little energy and not requiring intensive maintenance thanks to the degradation of the sludge produced in the planted filter.

Also, the wastewater arriving at the reactor is first treated in the purification tank. Pre-treatment of this wastewater in a planted filter-type purification basin thus makes it possible to have a smaller biological reactor, which produces less sludge and consumes less energy.

Preferably, the device comprises a circuit for recirculating sludge produced by the device upstream of the basin according to the direction of circulation of the wastewater.

In this way, any sludge produced by the device is reinjected at the top of the wastewater treatment device and is caused to be spread over the surface of the purification tank of the planted filter type. This sludge produced by the device can be considered as secondary sludge. This secondary sludge is added to the primary sludge intended to be treated by the treatment device, and is then stored, dehydrated and mineralized on the surface of the purification basin.

According to an advantageous solution, the device comprises a clarifier located downstream of the tank and the reactor in the direction of circulation of the wastewater, and the recirculation circuit comprises means for collecting sludge integrated into the clarifier.

The integration of these collection means into the clarifier makes it possible to optimize the collection of sludge due to the capacity of the clarifier to collect this sludge to prevent it from being released at the end of the treatment circuit of the water treatment device. waste.

According to an advantageous characteristic, the drainage means comprise a network of drains located at the bottom of the basin, the network of drains being coupled to an aeration chimney.

To this end, a single network of drains is located at the bottom of the purification basin for the drainage function, this network also participating in the passive aeration of the planted filter.

According to an advantageous embodiment, the device comprises a way of incorporating into the reactor a reagent for the treatment of phosphorus.

In this way, the device according to the invention makes it possible to reach phosphorus levels in particularly low released water (PT <2 mg / l thanks to the addition of the chemical reagent), and this at low cost.

For example, and as will be detailed later, the reagent can correspond to ferric chloride or to aluminum salts which make it possible to precipitate phosphorus.

According to an advantageous embodiment, the biological reactor comprises a tank in which is located at least one bacterial support intended to be immersed, the support being mounted mobile or fixed in the tank.

In the reactor vessel, bacteria attach and proliferate on the bacterial support.

This support allows for a higher concentration of bacteria. This support also makes it possible to maintain a sludge age higher than the hydraulic residence time, thus making it possible to treat more pollution while reducing the volume of the reactor.

According to an advantageous characteristic, the bacterial support (s) have a specific surface equal to or greater than 200 m ² .m-3.

A high specific surface promotes the development of purifying bacteria.

The invention also relates to a process for treating wastewater, comprising:

- a treatment step in a planted filter with vertical flow;

a treatment step in a biological reactor with a fixed culture of aerobic bacteria, the treatment step in a biological reactor following the treatment step in a planted filter.

Such a wastewater treatment process according to the invention makes it possible to effectively treat wastewater while requiring land use for the implementation of the process which is not excessive, and also having low operating costs.

More specifically, the method according to the invention does not lead to little or no production of secondary sludge (resulting from the implementation of the method during the treatment of primary sludge to be treated).

According to an advantageous characteristic, the method comprises:

- a step of collecting sludge produced by the process;

- an injection stage in the wastewater upstream of the stage, the stage of treatment in a planted filter, of the sludge collected during the collection stage.

Thanks to this characteristic, the method according to the invention makes it possible to optimize the fate of secondary sludge possibly produced. More specifically, these secondary sludges are reinjected at the level of the treatment step in a planted filter, which causes these secondary sludges to be stored, dehydrated and mineralized on the surface of the planted filter.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment of the invention, given by way of illustrative and nonlimiting example, and of the appended drawings among which:

- Figure 1 is a schematic representation of the wastewater treatment device according to the invention, this device also implementing the treatment method according to the invention;

- Figure 2 is a schematic representation along a cross section of the purification tank type planted filter;

- Figure 3 is a schematic representation in cross section of the biological reactor of the device according to the invention;

- Figure 4 is a schematic representation in cross section of the clarifier of the processing device according to the invention;

- Figure 5 is a flowchart illustrating the treatment method according to the invention.

With reference to FIG. 1, the device 1 for treating wastewater according to the invention comprises:

- a purification tank 2 of the planted filter type, in which the circulation of the wastewater is of vertical flow;

a biological reactor 3 with fixed culture of aerobic bacteria;

- a clarifier 4.

The device 1 also includes:

- a screen 10;

- an intermediate feeding equipment 11, such as a lifting station or a flush;

- a measurement channel 12.

As illustrated in FIG. 1, the device 1 for treating wastewater has a configuration in series. In other words, the purification tank 2, the biological reactor 3 and the clarifier are placed one after the other in a direction of circulation of the wastewater, thus forming a circuit for circulation of the wastewater.

Referring to Figure 1:

- the clarifier 4 is located downstream of the basin and the reactor according to the direction of circulation of the wastewater;

- the reactor 3 is located downstream of the basin 2 according to the direction of circulation of the wastewater.

According to another embodiment not illustrated, the purification tank 2 can be located after the biological reactor 3 with fixed culture of aerobic bacteria.

As illustrated in FIG. 1, waste water to be treated first passes through the screen 10, then enters the intermediate supply equipment 11, then is successively treated in the purification tank 2 of the planted filter type, in the biological reactor 3 with fixed culture of aerobic bacteria, and finally in the clarifier 4.

Under this circuit, the waste water which has been treated can be analyzed by means of the measurement channel 12 which terminates the circuit for circulating the waste water.

With reference to FIG. 2, the purification tank 2 comprises:

- means for supplying wastewater 20 to the surface of the basin;

- at least one layer of filter materials 21;

- drainage means 22 located at the bottom of the basin;

- Aeration means 23 coupled to a network of drains 230 located at the bottom of the basin, and communicating with the latter.

The basin 2 is delimited by a border 250 as well as a sealing complex 251 located on the sides and at the bottom of the basin and coupled to the border 250.

This waterproofing complex can take the form, for example, of a high density polyethylene geomembrane placed on an anti-puncture geotextile.

The edges 250 are arranged around the basin. These edges can for example be made of polypropylene, wood or concrete. These borders are designed to protect the planted filter from runoff, and to protect the sealing complex from external damage.

According to the illustrated embodiment, the basin comprises a layer of filtering materials 21.

According to another embodiment not illustrated, the basin may for example comprise three superposed layers of filtering materials, these layers of filtering materials having an average particle size increasing with the depth of the layers. This basin thus presents:

- a lower layer, located at the bottom of the purification tank, and having a particle size varying from 20 to 40 mm, or from 20 to 80 mm;

- an intermediate layer, having a particle size varying from 4 to 10 mm, or from 4 to 20 mm;

- an upper layer, with a particle size of 2 to 4 mm, or 3 to 8 mm.

The upper layer forms a filtration layer which can have a height varying from 30 to 60 cm.

The intermediate layer, for its part, can have a height varying from 15 to 30 cm.

Finally, the lower layer can have a height varying from 15 to 30 cm.

As specified above and as illustrated in FIG. 2, the purification tank 2 is of the planted filter type and for this purpose includes reeds 24.

Still according to FIG. 2, the wastewater supply means 20 are of the tarpaulin type. To this end, the wastewater supply means 20 comprise diffusers 200 coupled to a pipe through which the wastewater is conveyed. This pipe can be buried in the filter, as illustrated in Figure 2, or aerial.

The effluent (the wastewater to be treated) arrives discontinuously, by "tarpaulin". This addition by tarpaulin promotes good distribution over the entire surface of the wastewater basin and allows better oxygenation of the layer of filter materials 21 by a convection effect.

The means of supplying waste water, of the tarpaulin type, may include supply means such as a tank with pump, a tank with self-priming siphon, or even a tank with automatic valves.

According to the present embodiment, the drainage means 22 comprise a network of drains 230, and an evacuation outlet 220 coupled to the drain network. This network of drains 230, located at the bottom of the basin, also participates in the passive aeration of the purification basin. Indeed, the aeration means 23 take the form of a chimney coupled to the network of drains 230, thus allowing outside air to penetrate inside the network of drains 230 and to diffuse oxygen within of the layer of filter materials 21.

The drainage means can also include, for example, a layer of coarse gravel (depending on the lower layer of filtering materials) or a cellular floor.

Furthermore, the filter-type purification tank planted with the treatment device according to the invention may include one or more characteristics of the purification tanks described in the patent documents published under the numbers FR2942791 and FR2973796 (this or these characteristics must of course be be compatible with the processing device according to the invention).

Referring to Figure 3, the biological reactor 3 is of the fixed culture type of aerobic bacteria.

The reactor 3 comprises a tank 30. The effluents enter the tank via a supply pipe 300 and leave the tank via an outlet pipe 301.

The supply pipe 300 is a plunging pipe which opens into the interior of the tank near its bottom 304, near a first side wall 302 of the tank.

The outlet pipe 301, meanwhile, has a mouth situated inside the tank 30, near a second side wall 303 opposite the first side wall 302.

The reactor 3 comprises an air supply system 32 which comprises:

- a booster 320;

- air lines 321;

- air diffusers 322.

The air supply system 32 can operate continuously or sequentially.

The booster 320 thus supplies the air diffusers which are located at the bottom of the tank.

Air diffusers are of the medium bubble or fine bubble type (for example: micro-perforated membrane, tubular diffuser ...). These air diffusers provide ventilation and mixing of the reactor water.

The air blower (s) supply the bacteria with oxygen. It can for example be a side channel booster or a lobe blower.

In the case of sequential aeration, the ventilation control can be configured to operate using a clock or via a servo using a redox and / or oxygen sensor .

A second booster can be installed safely. In case of failure of the first booster, this second booster takes over to ensure the operation of the station during the repair of the first booster.

The reactor 3 also includes bacterial supports 31.

These bacterial supports are intended to be immersed inside the tank. The bacterial support has a high specific surface (> 200 m ² / m ³ ). These bacterial supports also advantageously have a large void percentage (> 90%). Such bacterial supports can be manufactured in a non-biodegradable manner with a material which may be polypropylene, polyethylene or high density polyethylene, so that these supports have a long service life.

The bacterial supports can for example take a cylindrical shape, a shape of ribbon, of corrugated sheet, a spherical shape of honeycomb, or even a shape of tubular lattice. The bacterial supports are fixed, or mobile (bacterial support of cylindrical shape mobile in the reactor for example). Alternatively, the bacterial carriers can be packaged in bags.

As illustrated in FIG. 3, the air diffusers 322 are located below the bacterial supports 31.

According to the present embodiment illustrated by FIGS. 1 and 3, the waste water, pretreated by the planted filter purification tank, then reaches the bottom of the tank 30 of the biological reactor 3 via the supply pipe, where residual organic pollution is degraded by aerobic bacteria.

In this reactor, the ammoniacal nitrogen is nitrified by autotrophic nitrifying bacteria.

According to the embodiment illustrated in FIG. 1, the device 1 can also include an incorporation route 6 into the reactor 3 of a reagent for treating phosphorus. This incorporation route 6 comprises for example a storage tank for the reagent (ferric chloride, aluminum salts, etc.) and a metering pump for adding the reagent to the biological reactor.

With reference to FIG. 4, as well as to FIG. 1, at the outlet of the biological reactor 3, the treated water is directed by gravity to the clarifier 4 (which forms a secondary settling compartment).

Inside the clarifier, the secondary sludge from biological treatment is decanted and concentrated in a settling cone 501 located in the lower part of compartment 40 of the clarifier 4.

According to an embodiment not illustrated, the biological reactor and the clarifier can be produced in the same assembly which is then compartmentalized.

As illustrated in FIG. 1, the device 1 comprises a recirculation circuit 5 of sludge produced by the device upstream of the basin according to the direction of circulation of the wastewater.

This recirculation circuit 5 includes means 50 for collecting sludge, these means being integrated into the clarifier 4 by means of the settling cone 501.

As illustrated in FIG. 4, the collection means 50 also include a pump 500 located in the settling cone.

With reference to FIG. 1, the recirculation circuit 5, via the pump, sends the secondary sludge concentrated by the settling cone in the clarifier 4 to the intermediate supply equipment 11 located upstream of the filter planted in relation to the direction of wastewater circulation.

With reference to FIG. 4, the purified water can leave the clarifier 4 by gravity. These waters therefore have a quality in accordance with accepted discharge standards.

The clarifier may also include a guarantor (siphon partition, filter, etc.) which prevents the intrusion of a floating body into the receiving environment.

The device 1 as illustrated in FIG. 1 achieves purifying performance and a quality of rejection at output better than that of a filter planted with conventional reeds with one single or two stages (for information, the values for a conventional household effluent can be the following: 20 mg / L MES; 30 mg / L BOD; 90 mg / L COD and 5 mg / L NTK).

The process for treating wastewater according to the invention is illustrated in FIG. 5. This process is implemented by the treatment device 1 according to the invention illustrated in FIG. 1.

With reference to FIG. 5, the treatment method comprises:

a treatment step in a planted filter 70 with vertical flow, the treatment step being more precisely implemented in the purification tank of the planted filter type, in which the circulation of the waste water is in vertical flow;

a step of treatment in a biological reactor 71 with fixed culture of aerobic bacteria;

a clarification step 72 which follows the treatment steps in the planted filter 70 and the treatment step in the biological reactor 71, the clarification step being carried out in the clarifier.

The treatment step in a biological reactor 71 follows the treatment step in a planted filter 70.

In addition, the method also includes:

a step 73 of collecting sludge produced by the process;

a step 74 for injecting the sludge collected during the previous collection step, into the waste water intended to be purified in the treatment step in a planted filter.

The collection and injection steps are implemented by the device's recirculation circuit.

Thanks to the completion of the treatment step in the planted filter prior to that in the biological reactor, the process has several advantages:

- The reactor may have a small size, in particular compared to a biological reactor of a micro station according to the prior art (with equivalent capacity for treating wastewater);

- The reactor presents a low risk of clogging of the supports on which the bacteria are located;

- the process is easy to set up in the case of improving the performance of existing planted filters (in particular for NTK and PT).

Claims (9)

1. Device (1) for treating wastewater, comprising a purification tank (2) of the planted filter type, in which the circulation of wastewater is of vertical flow, the basin comprising: - means for supplying wastewater (20) to the surface of the basin; - at least one layer of filtering material (21); - drainage means (22) located at the bottom of the basin; characterized in that it comprises a biological reactor (3) with fixed culture of aerobic bacteria, the reactor (3) being located downstream of the basin (2) in a direction of circulation of the wastewater. 2. Device (1) according to the preceding claim, characterized in that it includes a recirculation circuit (5) of sludge produced by the device upstream of the basin (2) according to the direction of circulation of the wastewater. 3. Device (1) according to the preceding claim, characterized in that it comprises a clarifier (4) located downstream of the tank (2) and of the reactor (3) according to the direction of circulation of the wastewater, and in that the recirculation circuit (5) comprises means for collecting (50) sludge integrated into the clarifier (4). 4. Device (1) according to any one of the preceding claims, characterized in that the drainage means comprise a network of drains (230) located at the bottom of the basin (2), the network of drains being coupled to a chimney d 'aeration. 5. Device (1) according to any one of the preceding claims, characterized in that it comprises a way of incorporation (6) in the reactor (3) of a reagent for a treatment of phosphorus. 6. Device (1) according to any one of the preceding claims, characterized in that the reactor (3) comprises a tank (30) in which is located at least one bacterial support (31) intended to be immersed, the support being mounted mobile or fixed in the tank. 7. Device (1) according to the preceding claim, characterized in that the bacterial support (s) (31) have a specific surface area equal to or greater than 200 m ² .nr ³ . 8. Wastewater treatment process, comprising: - A treatment step in a planted filter (70) with vertical flow; - a treatment step in a biological reactor (71) with fixed culture of aerobic bacteria, the treatment step in a biological reactor (71) following the treatment step in a planted filter (70). 9. Method according to the preceding claim, characterized in that it comprises: - A collection step (73) of sludge produced by the process; - an injection step (74) in the wastewater upstream of the treatment step in a planted filter (70), of the sludge collected during the collection step. 1/3 Fig. 1 2/3 Fig. 4 Fig. 5 3/3 FRENCH REPUBLIC irai - I NATIONAL INSTITUTE PROPERTY INDUSTRIAL PRELIMINARY SEARCH REPORT based on the latest claims filed before the start of the search National registration number FA 849150 FR 1850308 EPO FORM 1503 12.99 (P04C14) DOCUMENTS CONSIDERED AS RELEVANT Relevant claim (s) Classification attributed to the invention by ΙΊΝΡΙ Category Citation of the document with indication, if necessary, of the relevant parts X X X X AT AT FR 2 989 368 Al (BONNOTTE DANIEL [FR]) October 18, 2013 (2013-10-18) * page 6, line 10 - page 7, line 34 * * figures IA, IB, ID * CN 104 692 598 A (WATER RESOURCES RES INST SHANDONG PROVINCE) June 10, 2015 (2015-06-10) * figure 1 * * paragraph [0022] * CN 106 746 190 A (UNIV ZHEJIANG TECHNOLOGY) May 31, 2017 (2017-05-31) * figure 1 * * paragraphs [0028], [0029] * KR 101 110 710 B1 (JEONG SU WON [KR]; YEO IN BONG [KR]) February 22, 2012 (2012-02-22) * figure 2 * * paragraphs [0027] - [0038] * W0 2016/110657 Al (NEIGHBOR J [FR]) July 14, 2016 (2016-07-14) * page 14, lines 10-11 * US 3,480,144 A (BARTH EDWIN F ET AL) November 25, 1969 (1969-11-25) * figure * * column 2, lines 68-71 * * claims 1-5 * 1-9 1-9 1-9 1-9 1-9 1-9 C02F3 / 06 C02F3 / 34 TECHNICAL AREAS SOUGHT (IPC) C02F Research Completion Date Examiner May 30, 2018 Onel Inda, Santiago CATEGORY OF DOCUMENTS CITED T: theory or principle underlying the invention E: patent document with an earlier date X: particularly relevant on its own at the filing date and which was not published until that date Y: particularly relevant in combination with a deposit or at a later date. other document of the same category D; cited in request A: technological background L: cited for other reasons O: unwritten disclosure P: interlayer document &: member of the same family, corresponding document ANNEX TO THE PRELIMINARY RESEARCH REPORT RELATING TO THE FRENCH PATENT APPLICATION NO. FR 1850308 FA 849150 This appendix indicates the members of the patent family relating to the patent documents cited in the preliminary search report referred to above. The said members are contained in the computer file of the European Patent Office on 30-05-2ül8 The information provided is given for information only and does not engage the responsibility of the European Patent Office or the French Administration