Device for the collection, treatment, storage and reuse of household wastewater

Abstract

Device for the collection, treatment, storage and reuse of domestic wastewater The invention relates to a device for the collection, sanitizing treatment, temporary storage and reuse for watering and irrigation of domestic wastewater (DW), comprising a sealed container (2) open at the top, a filter material bed (3) planted with macrophytes (6) on the surface and at least one means (4, 4') for evacuating the treated water (TW) for its flow to the outside, the filter material bed (3) comprising at least two superimposed layers of different filter media (5, 5', 5'') and incorporating at least one planted top layer (5), the domestic wastewater (DW) being poured onto the surface and the treated water (TW) being extracted from a bottom region (2') of the container.This device is characterized in that the treated water (ET) discharge means (4, 4') constitutes an overflow device and is configured to automatically and passively discharge a controlled quantity of treated water (ET) when the liquid level in the container (2) exceeds a preset maximum level (CMax), so as to reduce this level to a minimum level (Cmin) determining the volume of liquid currently present in the container (2). Figure to be published with the abstract: Fig. 1.

Description

Title of the invention: Device for the collection, treatment, storage and reuse of household water

[0001] The present invention relates to the field of water resource management, in particular at the level of individual houses, and in particular by the recovery of wastewater, such as household water or grey water for irrigation and watering purposes. The wastewater concerned is typically that coming in particular from the kitchen (sink, wash basin, dishwasher, etc.) and the bathroom (shower, bathtub, sinks, bidet, etc.), excluding that coming from the toilets.

[0002] It relates more particularly to a device or module for the collection, sanitizing treatment, temporary storage and reuse for the purposes of watering and / or irrigation of household or gray water from a dwelling.

[0003] Several devices for treating wastewater from homes are already known.

[0004] Most existing solutions are of complex and sophisticated construction and implement electronic management means and consume energy continuously or at least intermittently.

[0005] There are also passive solutions which, in order to provide satisfactory performance in terms of volume treated, require large dimensions which are incompatible with urban housing. In addition, the quality of the treatment carried out is difficult to control and cannot be guaranteed.

[0006] Indeed, in retention systems, a lack of regular evacuation of treated water can lead to a significant reduction in sanitary quality and a proliferation of harmful microorganisms.

[0007] In permanent gravity flow systems, the total absence of regulation makes the treatment quality variable depending on the quantity of water to be treated.

[0008] The applicant markets a product called “Phytotiny” intended for the treatment of household wastewater from non-permanent dwellings, such as cabins, caravans, small houses or the like.

[0009] The latter device comprises a sealed container open on top, a bed of filter materials planted on the surface and at least one means for removing and / or evacuating the treated water for its flow to the outside, the bed of filter materials comprising two layers of different filter media (an upper layer of sand and a lower layer of wood chips) which are arranged in a vertically superimposed manner in the container. The upper layer is planted and the household water is discharged onto the surface of the upper layer and the treated water is extracted, after percolation through the mass of filter materials, at a bottom region of the container.

[0010] This permanent flow device naturally has limited treatment properties (short residence time, corresponding to the through travel time), and does not allow positive control of the flow, nor to constitute a water reserve for periods without production of household wastewater.

[0011] The present invention aims to overcome these drawbacks.

[0012] To this end, it relates to a device of the aforementioned type, characterized in that the or one of the means for evacuating and / or removing the treated water constitutes an overflow device and is configured to automatically and passively, in normal operation of said device, evacuate a controlled quantity of treated water when the level of liquid present in the container exceeds a preset maximum level, so as to bring this level back to a minimum level determining the volume of liquid currently present in the container.

[0013] The invention will be better understood, thanks to the following description, which relates to a preferred embodiment, given by way of non-limiting example, and explained with reference to the appended schematic drawing, the single figure of which:

[0014] [Fig-1] corresponds to a sectional view of a device in accordance with an advantageous embodiment of the invention, according to a plane comprising the vertical axis of symmetry of the container forming part of the device.

[0015] The attached figure illustrates a device (1) for the collection, sanitizing treatment, temporary storage and reuse for the purposes of watering and irrigation of household or gray water (EM), where appropriate raw.

[0016] This device (1) comprises a sealed container (2) open on top, a bed of filtering materials (3) planted with macrophytes (6) on the surface and at least one means (4, 4') for extracting and / or discharging the treated water (ET) for its flow to the outside. The bed of filtering materials (3) comprises at least two layers of different filter media (5, 5', 5”) which are arranged in a vertically superimposed manner in the container (2) and incorporate at least one planted upper layer (5), the household water (EM) being poured onto the surface of the upper layer (5) and the treated water (ET) being extracted, after percolation of the liquids through the bed of filtering materials (3), from a bottom region (2') of the container (2).

[0017] According to the invention, the or one of the means (4, 4') for evacuating and / or removing the treated water (ET) constitutes an overflow device and is configured to automatically and passively carry out, in normal operation of said device (1), the evacuation of a controlled quantity of treated water (ET) when the level of liquid present in the container (2) exceeds a preset maximum level (CMax), so as to bring this level back to a minimum level (Cmin) determining the volume (normally minimal) of liquid currently present in the container (2).

[0018] Thus, the invention provides a device (1) which is completely passive and self-regulating, guaranteeing sufficient residence time for treatment of minimum quality (for the intended use), automatically delivering batches of treated water which have percolated through the entire filter bed and also making it possible to have a permanent reserve of treated water available.

[0019] In accordance with a preferred embodiment of the invention, the mass of filtering materials (3) comprises, in current operation, three superimposed functional zones for the liquids present in the container (2), namely: i) a lower zone (ZI) of permanent storage, continuously saturated with treated water (ET) and subject to extractions by tanks, ii) a middle zone (ZM) of dynamic storage, variably saturated with liquids and subject to sequential emptying towards the lower zone (ZI), and iii) an upper zone (ZS) dedicated to the root development of the plants (6) present on the surface, unsaturated and allowing the vertical passage of the liquids contained in the household water (EM) discharged towards the middle zone (ZM), following a first treatment.

[0020] Thanks to these arrangements, the invention makes it possible to positively control the circulation of liquids in the filter mass in association with gravitation, by a phenomenon of forced transition of the liquids through the filter mass, induced by an extraction in the lower part of the container.

[0021] As shown in [Fig.l], and in accordance with a constructive arrangement of the invention, it can advantageously be provided that in the container (2), the horizontal plane associated with the maximum dimension (CMax) corresponds substantially to an interface (II) between the middle zone (ZM) and the upper zone (ZS) and that the horizontal plane associated with the dimension (Cmin) corresponds substantially to an interface (12) between the middle zone (ZM) and the lower zone (ZI).

[0022] According to a preferred embodiment variant, making it possible to have water treatment of sufficient quality for the intended uses and simultaneously to have a device with limited bulk, the mass of filtering materials (3) is structurally composed of at least three different granular filtering layers (5, 5', 5”) superimposed vertically, namely, from top to bottom, a first filtering layer (5) formed of sand and receiving the root systems of plants (6), advantageously macrophytes, a second filtering layer (5') formed of a mixture of natural materials and a third layer (5”) formed of charcoal, the first filtering layer (5) being, preferably, covered with a surface layer of mulch (5'”) capable of carrying out mechanical filtration of household or gray water (EM) directly discharged onto it.

[0023] In relation to a possible optimized exploitation of the constructive variant aforementioned, in particular in terms of efficiency and quality of treatment, it may advantageously be provided that the lower permanent storage zone (ZI) corresponds to the majority of the third filter layer (5”), that the middle dynamic storage zone (ZM) comprises the second filter layer (5') and an upper section of limited thickness (el) of the third filter layer (5”), adjoining the second filter layer (5'), and that the unsaturated upper zone (ZS) corresponds to the first filter layer (5) plus the mulch layer (5”').

[0024] According to a simple and effective embodiment of the means (4) for discharging the treated water (ET) constituting an overflow, and as shown in the attached figure, this means (4) comprises a drainage conduit (7) which is open at the bottom region (2') of the container (2), which extends into the mass of filtering materials (3) from this bottom region (2') at least up to the level of the minimum level (Cmin) and which is connected to an arrangement (8) of external discharge conduit, comprising a siphon (8') fixing the maximum level (CMax) and configured to carry out with self-priming a discharge of a controlled quantity of treated water (ET) when the liquid level in the container (2) reaches this maximum level (Cmax).

[0025] This siphon (8') installed at a certain height relative to the bottom of the container (2) fixes the maximum volume of water stored in current operation in the latter and draws by a siphoning effect exclusively treated water (ET) residing at the bottom of the container (2), that is to say a liquid having percolated through all the filter layers of the massif.

[0026] In an economical and practical construction variant to be implemented by an individual, the siphon (8') is constituted by a portion of flexible pipe, for example a portion of small diameter garden hose, forming an inverted U, this siphon (8') being attached to the container (2), for example by means of a fixing site (9) of the hook type, possibly adjustable in height. The position of the elbow of the siphon (8) is preferably such that it is substantially level with the interface zone between the first and second filter layers (5 and 5').

[0027] In combination with the minimum level (Cmin), it is thus also possible to adjust and fix the volume of the tarpaulins evacuated automatically each time the level of the liquids in the container (2) exceeds the maximum level (CMax), which causes the flow to start.

[0028] The siphon (8') may correspond to the connection end (by clipping or watertight screwing) of different types of watering and irrigation means, and supply for example either a watering hose handled by a user (the container 2 is then advantageously placed at a certain height from the ground), or a drip watering hose placed on the ground or even a hose supplying a watering system automatic.

[0029] Advantageously, it may be provided that the drainage duct (7) extends upwards beyond the level of the minimum height (Cmin), up to above the surface of the upper layer (5), and where appropriate above a possible layer of mulch (5'”), to form a ventilation chimney (7'), the connection between the drainage duct (7) and the external discharge duct arrangement (8) being in the form of a lateral tapping (10) in said drainage duct (7) at the height of the minimum height (Cmin).

[0030] At its lower opening, this drainage duct (7) can advantageously be provided with a protective grid (11) preventing obstruction by pieces of coal. At its upper opening, this same duct can be provided with a ventilation cap (12) with a mosquito net.

[0031] In order to be able, for example, to fill a watering can (14) (see figure) or to be able to completely empty the container (2) of all liquid (period of non-use or winter emptying), the device (1) may comprise a second means (4') for evacuating the treated water (ET) from the bottom region (2') of the container (2) and allowing controlled withdrawal of the treated water (ET), up to a possible complete emptying of the liquids from the container (2), for example in the form of a tap-type withdrawal nozzle.

[0032] Those skilled in the art understand that the device (1) must be sized to the needs of each application. It is of course also possible to produce a module of standard dimensions and to associate several of them in parallel to increase the processing capacity.

[0033] Upstream of the device (1), the household wastewater may have possibly undergone pre-treatment (mechanical filtering, decantation, etc.) and its discharge, preferably with a substantially homogeneous distribution on the surface (by means of a plurality of outlets distributed on the surface), may advantageously be carried out by simple gravity, but also if necessary by pumping (lift pump), this depending on its installation (possibly at a certain height as indicated in the figure, buried or placed on the ground) and the arrangement of the wastewater evacuation pipes of the dwelling concerned.

[0034] Downstream of the device (1), the water treated by the latter can, as an alternative to direct use, also supply an additional filtration or treatment means to further improve its sanitary quality and diversify its possible uses.

[0035] As a non-limiting example of dimensioning a device according to the invention, it may be provided that, for the treatment of household water (HM) from a single-family house, the mass of filtering materials (3) with a stratified structure is made up of a substantially cylindrical volume, possibly slightly tapered into a truncated shape. downwards, with a diameter of approximately 1 m and a height of between approximately 70 cm and 120 cm, preferably of the order of approximately 80 cm, and comprising the following filter layers, superimposed from top to bottom: i) a surface layer of mulch (5'”) with a thickness of between approximately 5 cm and 15 cm, for example formed of wood chips, sawdust and / or bark, ii) a first granular filter layer (5) formed of sand and with a thickness of between approximately 10 cm and 40 cm, iii) a second granular filter layer (5') formed of a mixture of oyster shells, charcoal and terracotta or expanded clay, and with a thickness of between approximately 5 cm and 15 cm, and iiii) a third layer (5”) formed of charcoal, of the activated carbon or biochar type, and with a thickness of between approximately 30 cm and 60 cm. cm.

[0036] The macrophytes (6) planted on the surface can for example be types: marsh iris, loosestrife or even carex.

[0037] The second granular filter layer (5') formed from a mixture of natural materials is for example composed, in volume percentages, of 20% to 40% of the following three materials: 1) oyster shell fragments, 2) biochar or activated carbon and 3) crushed brick or expanded clay. Preferably, the three components are each present at a level of approximately 33%.

[0038] It may be noted that the shape of the container (2) may advantageously resemble that of a giant flower pot, but other shapes, for example parallelepiped, spherical or ovoid, are possible. It is advantageously made of a waterproof, mechanically resistant and substantially rot-proof material, for example a hard plastic material of the polyethylene or polypropylene type.

[0039] The operation of the device (1) in relation to the illustrated embodiment and the path of the liquids within it can be summarized as described below. The household wastewater (EW) is fed in the upper part onto the filter bed (3) present in the container (2), is mechanically filtered by the surface mulch layer (5'”), percolates vertically by gravity through the various superimposed layers (5, 5', 5”) of different filter media, where it is freed from a large part of the solid and dissolved pollution. The flow of water is unsaturated in the upper part of the container (2), in the upper functional zone (ZS). The biological treatment of the water by means of the microorganisms developing in the filter media (sand) of this zone (ZS), as well as around the roots of the macrophyte plants (6), is then aerobic.Then, these pre-treated waters pass towards a saturated functional zone (ZI) in the lower part or bottom zone (2') of the container (2). However, before reaching this lower saturated functional zone (ZI), these waters will have stayed temporarily (the time to form a tank by accumulation) in the middle functional zone (ZM) to undergo a second phase of . treatment, essentially adsorption of pollutants on the materials of the second filter layer (5') and aerobic / anaerobic biodegradation. Due to the space freed up following the evacuation of a tarpaulin taken from the bottom of the container (2), the water present in the middle functional zone (MZ) will percolate towards the lower functional zone (LZ) to remain there for an extended period. The permanent saturation state of the latter not only increases the residence time and therefore the final treatment, but also promotes biological treatment processes in aerobic / anaerobic conditions, as well as pollutant adsorption phenomena. In addition, saturation ensures storage of the treated water (ET) which is thus available for reuse in irrigation / watering in the garden.The container (2) is advantageously sized to provide a reserve of approximately 80 to 100 L per day and per person for watering (average consumption common in European countries).

[0040] A more detailed additional description is given below, by way of example and with reference to the attached figure.

[0041] The container (2) in the form of a pot, with its bed of filtering materials (3) planted on the surface, is fed from above by the distribution device for raw household wastewater (EM) from a home. The latter consists, for example, of a pipe connected to the pot using a rubber seal or a wall pass-through, in order to ensure the sealing of the assembly. The discharged household water arriving at the filter is distributed on the surface of the filtering medium, first undergoes mechanical filtration by passing through the surface mulch layer (5'”), then flows vertically through a first filtering layer (5) formed of sand whose role is to retain suspended matter and treat the dissolved pollution contained in the water. The sand layer is planted with macrophytes (6) serving as a support for the purifying biomass as well as unclogging agents.This layer of sand is covered with a layer of organic material such as wood chips and / or wood bark forming a mulch and allowing to maintain a satisfactory hygrometry in the sand, conducive to the development of plants and purifying microorganisms. Then, the water percolates vertically in a second filter layer (5') formed of a mixture of several natural materials which together increase the treatment capacity provided by the device (1), for example a homogeneous mixture of oyster shells, activated carbon or biochar and terracotta or expanded clay. The water is finally treated in a layer of charcoal (5”) which represents the last stage of filtration of household water and constitutes the storage medium for the treated water (ET) awaiting extraction for use.

[0042] As shown in the figure, the treated water (ET) can be discharged at two points in the pot: a high outlet (4) for automatic passive watering and a low outlet (4') for example to feed a watering can (14) or to empty the pot (2). The upper outlet (4) is fed by a drainage pipe or conduit (7), mounted in the filter bed (3), open in the bottom region (2') of the pot and provided with strainers or grids (11) to prevent it from clogging. This drainage pipe or conduit (7) also allows the aeration of the filter material bed (3). For this purpose, it extends upwards through the filter bed (3), and is provided with an aeration chimney with a cap (12) projecting above the surface of this bed and connected to the atmosphere. By its construction and arrangement, the assembly [drainage conduit (7) + conduit arrangement (8)] with its lateral tapping (10) at the lower level (Cmin) and its siphon (8') defining the upper level (CMax) forms a means of evacuation or outlet from the top (4) which serves both as an overflow and as a passive watering point, without human intervention.A garden hose can be connected to it in order to direct the treated water to the areas of the garden or green space requiring watering. The supply to this upper outlet is made from the bottom of the pot (2) and the filter bed (3) in order to optimize the residence time of the liquids and to guarantee that each drop of water evacuated has undergone all the above filtration stages before leaving the device (1). The means of evacuation or outlet from the bottom (4') consists in the figure of a tap installed for example 2-3 cm from the bottom of the pot. This outlet at the bottom part allows water to be collected with a watering can when the pot (2) is raised, for example at a minimum height of approximately 0.33 m, thanks to a suitable support (13). The lower outlet also allows for a complete emptying of the device (1), which can be recommended approximately once a year at least, in order to regenerate the purifying properties of the planted bed of filter materials (3).

[0043] As already indicated, within the planted bed of filter materials (3) there are three distinct functional zones: saturated, semi-saturated (or beating zone) and unsaturated. The first saturated zone, the permanent storage zone (ZI), is located at the bottom of the pot (2) and is designed to keep a constant and always available volume of treated water (ET) in order to be able to manually fill a watering can via the tap. This constant volume is regulated by the level of the high outlet tap (Cmin, 12). Below this high outlet, the only way to empty the pot (2) is to open this low outlet tap (4').

[0044] The second semi-saturated zone, i.e. the dynamic storage middle zone (ZM) or beat zone, is designed to allow passive watering, i.e. in an autonomous and advantageously self-priming manner. During the day, this middle zone (ZM) fills and empties alternately, through the high outlet (4). The quantity of water available in this zone is defined by the maximum height of the inverted U-shaped pipe portion on the fixing hook (9) and the height of the lateral outlet of the drainage conduit (Cmin). The small diameter of the pipe forming the U allows a siphon effect and the emptying of this temporary storage zone (ZM). Thus, the device (1) makes it possible to obtain autonomous watering without the need for electricity by tarpaulin effect.

[0045] The upper unsaturated functional zone (ZS) is reserved for the root development of macrophytes and the first stage of aerobic biological treatment of raw household water (EM).

[0046] Of course, the invention is not limited to the embodiment described and shown in the attached drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. Device (1) for the collection, sanitizing treatment, temporary storage and reuse for the purposes of watering and irrigation of household or gray water (EM), where appropriate raw, this device (1) comprising a sealed container (2) open on top, a bed of filter materials (3) planted with macrophytes (6) on the surface and at least one means (4, 4') for extracting and / or discharging the treated water (ET) for its flow to the outside, the bed of filter materials (3) comprising at least two layers of different filter media (5, 5', 5”) which are arranged in a vertically superimposed manner in the container (2) and incorporate at least one planted upper layer (5), the household water (EM) being poured onto the surface of the upper layer (5) and the treated water (ET) being extracted, after percolation of the liquids through the bed of filter materials (3), from a bottom region (2') of the container (2),one of the means (4, 4') for discharging and / or extracting the treated water (ET) constitutes an overflow device and is configured to automatically and passively, in normal operation of said device (1), discharge a controlled quantity of treated water (ET) when the level of liquid present in the container (2) exceeds a preset maximum level (CMax), this means (4) for discharging the treated water (ET) constituting an overflow comprising a drainage conduit (7) which is connected to an arrangement (8) of external discharge conduit, comprising a siphon (8') setting the maximum level (CMax) and configured to self-prime discharge the treated water (ET) when the level of liquid in the container (2) reaches this maximum level (Cmax), device (1) characterized in that the mass of filtering materials (3) comprises, in normal operation, three superimposed functional zones for the liquids present in the container (2),namely: i) a lower zone (ZI) of permanent storage, continuously saturated with treated water (ET) and subject to extractions by tanks, ii) a middle zone (ZM) of dynamic storage, variably saturated with liquids and subject to sequential emptying towards the lower zone (ZI), and iii) an upper zone (ZS) dedicated to the root development of plants (6), present on the surface, unsaturated and allowing the vertical passage of liquids contained in the household water (EM) discharged towards the middle zone (ZM), following a first treatment, in that the drainage conduit (7) is open at the bottom region (2') of the container (2) and extends into the mass of filtering materials (3) from this bottom region (2') at least up to the level of a minimum or lower level (Cmin), in that the assembly [drainage conduit (7) + conduit arrangement (8)] has a lateral tapping (10) at the level of said lower level (Cmin), and in that the permanent storage zone (ZI) located at the bottom of the container (2) is designed to keep a constant and always available volume of treated water (ET),this constant volume being regulated by the level or the dimension (Cmin) of said tapping (10) of the high outlet and the controlled and automatic evacuation of treated water (ET) being carried out by tanks whose volume is regulated by combination of the minimum dimension (Cmin) and the maximum dimension (Cmax).,

2. Device according to claim 1, characterized in that, in the container (2), the horizontal plane associated with the maximum dimension (CMax) corresponds substantially to an interface (II) between the middle zone (ZM) and the upper zone (ZS) and in that the horizontal plane associated with the dimension (Cmin) corresponds substantially to an interface (12) between the middle zone (ZM) and the lower zone (ZI).

3. Device according to one of claims 1 and 2, characterized in that the mass of filtering materials (3) is structurally composed of at least three different granular filtering layers (5, 5', 5”) superimposed vertically, namely, from top to bottom, a first filtering layer (5) formed of sand and receiving the root systems of plants (6), advantageously macrophytes, a second filtering layer (5') formed of a mixture of natural materials and a third layer (5”) formed of charcoal, the first filtering layer (5) being, preferably, covered with a surface layer of mulch (5'”) capable of carrying out mechanical filtration of the household or gray water (EM) directly discharged onto it.

4. Device according to claims 1 and 3, characterized in that the lower zone (ZI) of permanent storage corresponds to the major part of the third filter layer (5”), in that the middle zone (ZM) of dynamic storage comprises the second filter layer (5') and a upper slice of limited thickness (el) of the third filter layer (5”), adjoining the second filter layer (5'), and in that the unsaturated upper zone (ZS) corresponds to the first filter layer (5) plus the mulch layer (5”').

5. Device according to any one of claims 1 to 4, characterized in that the siphon (8') is constituted by a portion of flexible pipe forming an inverted U, this siphon (8') being attached to the container (2), for example by means of a fixing site (9) of the hook type, possibly adjustable in height.

6. Device according to any one of claims 1 to 5, characterized in that the drainage duct (7) extends upwards beyond the level of the minimum dimension (Cmin), up to above the surface of the upper layer (5), and where appropriate above a possible layer of mulch (5”), to form a ventilation chimney (7’), the connection between the drainage duct (7) and the external discharge duct arrangement (8) being in the form of a lateral tapping (10) in said drainage duct (7) at the height of the minimum dimension (Cmin).

7. Device according to any one of claims 1 to 6, characterized in that it comprises a second means (4') for discharging the treated water (ET) from the bottom region (2') of the container (2) and allowing controlled withdrawal of the treated water (ET), until possible complete emptying of the liquids from the container (2), for example in the form of a tap withdrawal nozzle.

8. Device according to any one of claims 1 to 7, characterized in that the container (2) is installed at a certain height from the ground or placed on the ground and is in the form of a pot.

9. Device according to any one of claims 1 to 8, characterized in that, for the treatment of household water (EM) from a single-family house, the mass of filtering materials (3) with a stratified structure consists of a substantially cylindrical volume, possibly slightly tapering in a frustoconical direction towards the bottom, with a diameter of approximately 1 m and a height of between approximately 70 cm and 120 cm, preferably of the order of approximately 80 cm, and comprising the following filtering layers, superimposed from top to bottom: i) a surface layer of mulch (5”) with a thickness of between approximately 5 cm and 15 cm, for example formed of wood chips, sawdust and / or bark, ii) a first granular filtering layer (5) formed of sand and of thickness between approximately 10 cm and 40 cm, iii) a second granular filter layer (5') formed from a mixture of oyster shells, charcoal and terracotta or expanded clay, and of thickness between approximately 5 cm and 15 cm, and iiii) a third layer (5”) formed from charcoal, of the activated carbon or biochar type, and of thickness between approximately 30 cm and 60 cm.

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