WO2015107174A1 - Wastewater treatment device - Google Patents

Abstract

The invention relates to a device and method for treating wastewater, in particular a device for on-site wastewater treatment. Said device comprises two consecutive ponds, the first being a vertical-flow pond, the second being a horizontal-flow pond, the ponds that make up said device comprising a selection of specific filtering materials, and said ponds being planted with a selection of plant species.

Description

 DEVICE FOR TREATING WASTE WATER

The present invention relates to a device and a method for treating wastewater, in particular a non-collective sewage treatment device. This device comprises two successive basins, the first being a vertical flow basin, the second being a horizontal flow basin, the basins of which is constituted this device comprising a particular choice of filter materials, and these basins being planted by a selection of plant species. This selection of plant species combined with the layout of the pond makes it possible to obtain particularly high efficiency in the treatment of wastewater, especially in the treatment of domestic water.

 The current discharge standards in effect for the discharge of treated water into the environment are:

 Suspended matter: 30mg / l

 DB05 (biological oxygen demand during 5 days): 35 mg / l

 Phytoremediation is a known method of using plants to extract, stabilize or degrade substances present in the environment and likely to be polluting for this environment.

 Prior art is known devices for lowering organic pollution in wastewater discharged by non-collective habitats such as houses, including discharges from septic tanks.

 Such devices usually include a vertical drained filter, planted with reeds and fed by sequential sheeting. Such a device makes it possible to oxidize the organic and nitrogenous matter contained in the wastewater. The recommended dimensioning for the vertical filter is between 3 and 5 m2 per inhabitant. However, the abatement of pathogenic bacteria remains quite low in such a device. In addition, nitrogen is almost completely released as nitrates.

 In some of these devices, the vertical filtration basin is composed of two bins operating alternately. However, for the treatment of domestic effluents, this configuration is not appropriate because the daily intake of domestic effluents is not sufficient to allow the hydration and the correct survival of the plants.

Another known device is a horizontal flow filter planted with reeds. Such a filter is usually sized between 5 and 10 m2 per inhabitant in a temperate climate and operates at least partially in anaerobiosis, which limits its nitrification capacity, as well as its degradation of organic pollution. The residence time wastewater being quite high, this type of device has a fairly good efficiency of abating bacterial or pathogenic pollution.

 Sanitation devices are also known comprising two sewage filters planted with reeds placed in series, the first filter operating in vertical flow, the second in horizontal flow. The water flows vertically through the upstream filter, is drained by a duct to the downstream filter and flows horizontally in this downstream filter. Both filters are formed of particulate materials. Such a sanitation device, to provide sufficient efficiency in the purification of treated water (nitrogenous organic pollution and bacterial pollution) requires the occupation of a large floor area. Or the floor surfaces available for the implementation of the device are generally limited, especially in individual housing.

 One of the objectives of the invention is to solve this problem, that is to say to provide a satisfactory efficiency in terms of purification of treated water, while occupying a reduced floor area compared with the devices of the invention. prior art. In addition, the device and the method of the invention have controlled installation and operating costs.

 Such a result was made possible by the choice of particular materials composing the planted filters and by a selection of plant species.

 The device and the effluent treatment method according to the invention are based on proven techniques of phytopurification, ecological remediation techniques. It is based on reactions occurring in natural environments and allows a reduction of nitrogen (N), phosphorus (P), pathogens, suspended solids (SS), as well as organic matter such as chemical demand. oxygen (COD) and biological oxygen demand for 5 days (DB05).

 This purification is made possible thanks to the combined action of three main natural and complementary processes:

 o a physicochemical retention of pollutants by the substrate, reinforced by the root system of plants,

 o a biodegradation of the pollutants thanks to the microbial activity, this activity being itself stimulated by the presence of the plants,

 o phyto-assimilation of pollutants by plants and storage in their biomass.

Moreover, the interactions between the substrate, the microorganisms and the plants, such as retention, bio-stimulation, phyto-stabilization, phyto-volatilization and phyto-extraction, have significant impacts on the treatment performance. In addition, root exudates of some plant species favor the elimination of pathogens.

 To this end, the present invention proposes an effluent treatment device comprising at least:

 a vertical flow plant filter comprising at least one substrate,

 a horizontal flow planted filter comprising at least one substrate, means for distributing the wastewater in the vertical flow filter,

 effluent transfer means treated from the vertical flow filter to the horizontal flow filter,

 a means for recovering treated effluents from the horizontal flow filter,

 this device allows an abatement rate:

 MES (suspended solids)> 96%

 DB05 (biological oxygen demand for 5 days)> 96%

COD (Chemical Oxygen Demand)> 90%

 NTK (total nitrogen Kjeldahl)> 60%

 Pt (total phosphorus)> 35%

the surface of the device being less than 5m ² / EH.

 The effluents concerned are mainly domestic wastewater.

The invention relates more particularly to the treatment of domestic and assimilated wastewater consisting of blackwater and greywater of a volume evaluated in population equivalent (PE).

 For this type of effluent, the pollution streams to be treated generally amount to 250 to 450 g of DB05 per day, preferably 300 to 400 g of DB05 per day, usually around 360 g of DB05 per day.

 The sizing of the effluent management station according to the invention, and in particular filters planted from the filtration station, depends in particular on the daily volume of effluents. The unit of calculation is the population equivalent (PE) and the volume equivalents presented above.

The test protocol for carrying out these measurements is set out in Annex 2 of the Order of 7 March 2012 amending the Decree of 7 September 2009 laying down the technical requirements applicable to non-collective sewerage installations receiving a gross load of organic pollution less than or equal to 1.2 kg / day of DB05, entitled "Protocol for testing the purification performance on a test platform". The surface of the device is calculated as follows: it is equal to the sum of the surfaces of the vertical flow filter and the horizontal flow filter.

Advantageously, the total area of the device is less than or equal to 4 m ² / EH, more preferably less than or equal to 3 m ² / EH.

The effluent management installation according to the invention includes a filtration unit or station comprising at least two successive distinct planted filters:

 a vertical flow plant filter: several layers of substrates are superimposed in a basin of a given surface, each layer having a particle size smaller than that of the layer disposed immediately below it, so that the filter presents vertically up and down an increasing grain size; a collection of plant species, adapted to the domestic effluents and the climate of implantation of the station, are sown and cultivated on the surface;

 - a horizontal flow plant filter constituted by a succession of substrates arranged in a basin of a given surface, the succession meaning from upstream to downstream of the basin in the direction of the flow of water, each layer having a particle size smaller than that of the layer disposed immediately before it, so that the filter presents horizontally from upstream to downstream a decreasing particle size, on which are planted and cultivated plant species adapted to the domestic effluents and the implantation climate .

 The substrates are composed for example of gravel, gravel, sand, etc. The subject of the invention is an effluent treatment device comprising at least:

 a vertical flow plant filter comprising at least one substrate,

a horizontal flow plant filter comprising at least one substrate,

means for distributing the wastewater in the vertical flow filter,

 means for transferring treated effluents from the vertical flow filter to the horizontal flow filter,

 a means for recovering treated effluents from the horizontal flow filter,

o the substrate of the vertical flow filter comprising an upper layer with a thickness of 35 to 50 cm of pozzolan-type gravel of density ranging from 0.65 to 1.3 T / m ³ , with a porosity ranging from 10 to 50 % in vol / vol, whose pores have an average diameter ranging from 0.6 μιη to 60 μιη. o the substrate of the horizontal flow filter comprising an intermediate layer of pozzolan-type gravel with a surface representing 50 to 95% of the surface of the horizontal flow filter. The device of the invention has the advantage of providing satisfactory wastewater treatment efficiency while operating with a single rack per filter, which reduces the occupied floor area compared to some prior devices.

Advantageously, the vertical flow filter has only one rack. According to a preferred embodiment, the pozzolan type gravel implemented in the upper part of the vertical flow filter has a particle size ranging from 4 to 10 mm, a density of 0.7 to 1.1 T / m ³ , a porosity ranging from 20 to 50% in vol / vol, and pores with an average diameter ranging from 0.6 μιη to 15 μιη.

According to a preferred embodiment, the substrate of the vertical flow filter comprises:

 at least one intermediate layer of particulate material having a particle size greater than that of the pozzolan material of the upper layer and

 at least one lower layer of particulate material having a particle size greater than that of the material of the intermediate layer.

Preferably, in the substrate of the vertical flow filter:

the upper layer of pozzolan material represents 40 to 80% of the height h _v of the substrate, advantageously from 50 to 70%,

the intermediate layer of particulate material having a particle size greater than that of the pozzolan material represents 10 to 50% of the height h _v of the substrate, advantageously from 15 to 35%,

the lower layer of particulate material having a particle size greater than that of the material of the intermediate layer represents 10 to 50% of the height h _v of the substrate, preferably 15 to 35%.

 According to a preferred embodiment, the substrate of the horizontal flow filter comprises at least a first layer of particulate material having a larger particle size than the pozzolan material of the intermediate layer and at least a third layer of particulate material having a particle size smaller than that of the material of the intermediate layer.

Preferably, in the substrate of the horizontal flow filter: the upstream layer of particulate material is 30 to 70 cm long, preferably 40 to 60 cm long, more preferably about 50 cm long,

the intermediate layer of pozzolan material represents 55 to 90% of the length L _H of the substrate,

the downstream layer of particulate material is 5 to 25% of the length L _H of the substrate.

According to a preferred embodiment, in the horizontal filter, particles of particle size between 4 and 8 mm are used in the downstream part of the filter. Advantageously, the aggregates arranged in the downstream portion of the horizontal flow filter occupy a distance representing 15 to 25% of the length L _H , for a filter of length L _H less than or equal to 15 m, and from 5 to 15% of the length L _H for filters of length L _H strictly greater than 15m. It is expected that the aggregates arranged in the downstream part of the horizontal flow filter occupy a maximum length of 4m.

According to a preferred embodiment, the vertical flow filter further comprises means for the distribution of oxygen, these means being housed in the lower part of this filter.

According to a preferred embodiment, the vertical flow filter is planted with at least two plant species of different genus selected from the following families, preferably at least three species of different genus selected from the following families and preferably at least six species of different genus selected from the following families: Cyperaceae, Poaceae, Iridaceae, Juncuceae, Typhaceae, Acoraceae.

According to a preferred embodiment, the horizontal flow filter is planted with at least two species of different genus selected from the following families and preferably at least four species of different genus selected from the following families and preferably at least eight species of different genus selected from the following families: Cyperaceae, Lamiaceae, Plantaginaceae, Brassicaceae, Alismataceae, Butomaceae, Pontederiacea, Typhaceae, Ranunculaceae, Araceae, Lythraceae, Nelumbonaceae, Equisetaceae, Myrsinaceae, Marentaceae, Menyanthaceae. Depending on the biogeographic zone (biogeographic zone) of the treatment plant, a preliminary study is carried out in order to select plant species adapted to the climate.

 Preferably, the plant species selected are not invasive species such as reeds and bamboos in some countries.

According to a preferred embodiment the planting density is greater than or equal to 4 feet / m ² , preferably greater than or equal to 5 feet / m ² , even more preferably greater than or equal to 6 feet / m ² .

The devices of the invention make it possible to achieve the objectives set by the rejection standards currently in force, with a occupied area of 2m ² / EH or 3m ² / EH (EH per equivalent per inhabitant), while the installations of the prior art have equivalent efficiency with a occupied area of 5m ² / EH or more. Thus the device and the method of the invention are more economical and more effective than those of the prior art.

The transfer of effluents from the first basin to the second basin, and secondly effluents from the second basin to the recovery and evacuation zone, is preferably done by gravity by installing the filters planted on a slope. In the case where the ground is flat or has an unfavorable slope, this routing can be provided by means of pumps.

 According to one embodiment, the device according to the invention comprises means making it possible to seed the effluents treated in the latter, with bacterial products adapted to the reactions required for the transformation of the domestic effluents.

 In addition, the filtration station may comprise at the output of the horizontal planted filter an open water zone for performing analyzes and ensuring the diffusion of the effluent.

According to a first embodiment, the invention relates to effluent treatment devices with a capacity of up to 10EH.

According to this embodiment, the total dimensions of the two filters are preferably from 2.2 to 4.5 m ² / EH, advantageously from 2.6 to 3.5 m ² / EH, preferably from 2.8 to 3 , 2 m ² / EH. According to a second embodiment, the invention relates to effluent treatment devices with a capacity greater than 10EH.

According to this embodiment, the total dimensions of the two filters are preferably from 0.6 to 3.5 m ² / EH, advantageously from 0.8 to 2.5 m ² / EH, preferably from 1 to 2 m ² / EH.

Preferably the vertical flow filter is of substantially square shape, that is to say that the width l _v and the length L _v are substantially equal to + 10%.

Preferably the horizontal flow filter is of rectangular shape, the ratio of the length L _H to the width 1 _H satisfying 1 <L _H / _1H ≤ 10.

 The depths of the filters, chosen to allow an optimal flow within the filters, are fixed as follows:

a depth h _v of the order of 55 to 85 cm for the vertical flow filter, preferably 65 to 75 cm.

a depth h _H of the order of 35 to 65 cm for the horizontal flow filter, preferably 45 to 55 cm.

 The installation may comprise an electrical or electronic system for controlling and managing the various stages of operation of the filtration stations. Such systems are known per se, or within the abilities of those skilled in the art, so that it is not necessary to describe an example thereof. The control keys of the system and the control elements can be assembled in a cabinet.

The invention also relates to an effluent treatment method, this method comprising the distribution of the effluent in a device of the invention, the recovery of treated water at the device outlet.

 This recovery can consist in known manner in a distribution of treated water in the soil. Preferably, a continuous distribution of the treated water in the soil is implemented. It may include a step of storing treated water for later use, especially for watering gardens.

 Macrophytes planted on a filter are periodically plucked and transformed into dry matter. These plants also allow the creation of a habitat favorable to purifying microorganisms, thanks to:

- the oxygenation capacity of the environment by the roots,

- The release of carbon compounds by the roots, usable by microorganisms. In order to speed up the composting process in the upper part of the planted filters (surface), lombrifiltration (with for example species such as Eisenia andrei and Eisenia fetida) can be advantageously put in place, in anticipation of the formation of a deposition layer on the surface of these filters planted, taking into account the suspended matter load contained in the domestic effluents.

 The effluent treatment process may also include a microbial seeding step that accelerates the establishment of the biological equilibrium. In this way the expected purification efficiency can be achieved very quickly after the installation.

 Among the products that can be used to carry out the microbial seeding, mention may be made in particular of: Sanifosse®, Bioponil® and Bactiboost® marketed by BIOXEM.

 Advantageously, the device of the invention provides high performance in water purification, although it is small. In particular, from domestic wastewater, it makes it possible to limit the suspended matter to 30 mg / l and the DB05 (biological oxygen demand during 5 days) to 35 mg / l.

 The invention also relates to a kit for the implementation of a device as described above in a general manner and below in a detailed example.

 Such a kit includes at least:

 - A waterproof material to delimit the walls of planted filters,

 - collection, evacuation and connection pipes, preferably made of PVC,

- A collection of particulate materials, comprising at least: a pozzolan-type gravel of density ranging from 0.65 to 1.3 T / m ³ , with a porosity ranging from 10 to 50% by vol / vol, whose pores have a mean diameter ranging from 0.6 μιη to 60 μιη,

A first collection of plants, comprising at least two plant species of different genus chosen from the following families, and preferably at least three species of different genus selected from the following families and preferably at least six species of different genus selected from the following families following families: Cyperaceae, Poaceae, Iridaceae, Juncuceae, Typhaceae, Acoraceae,

A second collection of plants, comprising at least two plant species of different genus selected from the following families, and preferably at least four different genus species selected from the following families and preferably at least eight species of different genus selected from the following: families Cyperaceae, Lamiaceae, Plantaginaceae, Brassicaceae, Alismataceae, Butomaceae, Pontederiacea, Typhaceae, Ranunculaceae, Araceae, Lythraceae, Nelumbonaceae, Equisetaceae, Myrsinaceae, Marentaceae, Menyanthaceae.

 Preferred variants of the features of the device also apply to the kit of the invention.

 The kit may further include, without limitation:

 - A structure (frame) in rotproof wood,

 - Gravel, gravel, sand,

 - a distribution slab,

 - A pump.

 The composition and dimensions of the kit are calculated in EH units so that kits can be proposed for installations of all sizes.

Other features and advantages of the invention will appear on reading the following description of a preferred embodiment of the invention, given by way of example and with reference to the accompanying drawings.

 To facilitate the reading of the figures, when the same element is represented in two distinct figures, the same reference sign is used.

 FIG. 1 is a schematic vertical sectional view illustrating an exemplary embodiment of the effluent management installation according to the invention.

 FIG. 2 is a top plan view of the same effluent treatment station as FIG.

 The arrows inside the device indicate the flow direction of the water in the device.

 The plant filtering filter station shown in FIGS. 1 and 2 comprises:

 at least one vertical flow plant filter 1 supplied with effluents 7 via a feed pipe 3, and at least one horizontal flow plant filter 2 fed by said vertical flow filter 1 by means of a pipe 5. It also comprises , preferably a zone in free water 4 (analysis and diffusion zone) fed by a pipe 6.

A first basin 1 forming the vertical flow plant filter is delimited by walls 1.1 of waterproof material and filled with substrate 1.2. The walls 1.1 may be surrounded by a wooden box of rot-proof nature or any other material for creating a resistant structure, in which a waterproof cover has been placed. Such a structure is implemented in the absence of a slope allowing a digging in full dig and a gravity flow between the planted filters. The sealing of the vertical filter 1 is ensured by a flexible EPDM membrane of a thickness of 1.14 mm. The flexible EPDM membrane is protected on the underside by an anti-punching geotextile of at least 270 g / m ² providing protection against perforation of stones or roots coming from the outside. Known means (not shown in FIG. 1) at the wall penetration allow the connection between the inside and the outside of the filter 1 to be sealed.

The upper part 1.7 of the walls 1.1 of the basin 1 is flush with the surface of the ground 8. The basin 1 is filled with a succession of layers forming the substrate 1.2: an upper layer 1.3 with a thickness of about 40 cm of pozzolan type gravel of particle size 4/10 mm, density 0.9 T / m ³ , porosity 25% in vol / vol, whose pores have a diameter of 0.8 μιη; an intermediate layer 1.4 with a thickness of about 15 cm of gravel with a particle size of 16/22 mm and a lower layer 1.5 with a thickness of about 15 cm of gravel with a particle size of 20 / 31.5 mm. Other layers of particulate materials like gravel, chippings, sand may be provided. In this case, they are arranged so as to respect a growing direction of the particle size from the top of the substrate to the lower part. The bed of the vertical filter is floored in a straight slope. The depth of the bed is 1 m including 0.7 m of substrate and 0.3 m of contrast.

Plants 1.6 are installed in the substrate 1.2. The species used are Acoruscalamus, Phragmites australis, Typha latifolia, Juncuseffusus, Iris pseudaccorus. The planting density is 6 ft / m ² in the vertical filter 1. The selected plants have strong vegetative propagation capacity via their fast-growing rhizomes, which allows the formation of a dense root system in the substrate. In addition, scientific studies have shown that these plants can live well in soils rich in organic matter as is the case of the vertical filter.

 The distribution of wastewater to the facility, in particular to the vertical planted filter 1 is based on the topography of the land where the effluent treatment plant is installed. In FIG. 1, there is only one feed point 3 opening at the center of the vertical filter 1. The feed means 3 consist of a PVC pipe 3.2 having an open end 3.3 through which the effluents flow. treat. This flow is above a distribution slab 3.1 placed under the feed point 3.3, allowing the effluent to be well distributed without forming puddles of water on the surface of the substrate 1.2.

 When microbial seeding is practiced, this is done at the point of feeding 3.

A 5.1 pipe consisting of a perforated PVC pipe, DN 100 NF, passes through the basin 1: it has two branches each connected to a 5.2 chimney substantially vertical, the upper end of which is flush with the surface of the substrate 1.2. Other air vents may be placed in the substrate and connect the collection pipe 5.1, placed at the bottom of the bed, to the surface. These chimneys make it possible to aerate the bottom of the substrate. Each branch of the line 5.1 is housed in the lower part of the first basin following a slightly downward slope. The pipe 5.1 for the collection of water is perforated and placed with the slots 5.3 downwards, allowing the oxygen distribution to the substrate 1.2, the collection of filtered effluents having passed through the three levels of substrate 1.2, and their routing. via a 5.5 pipe with an end 5.4 to the horizontal planted filter 2.

 The raw wastewater 7 is poured onto the surface of the filter 1 and percolate by gravity through the substrate 1.2. A large part of the suspended solids is retained on the surface of the filter 1 by the mechanical filtration of the substrate 1.2. Organic materials are degraded and mineralized by microorganisms. Some of the soluble substances and nutrients are assimilated by the 1.6 plants to constitute biomass. The presence of plants 1.6 enhances the mechanical filtration of the substrate 1.2 via a dense root system, and stimulates biodegradation activities.

 The water from the vertical filter 1 has significantly reduced solids (MES) and organic contents (COD, DB05).

 The treated effluents from the planted vertical flow filter 1 feed the horizontal flow planted filter 2 by any appropriate means, in particular via the pipe 5.5, through its end 5.4.

 The horizontal flow planted filter 2 comprises the substrate 2.2 which may consist of a succession of vertical sections containing the chosen filtration materials 2.3, 2.4, 2.5.

The bed of the horizontal filter is floored in a straight slope. A frame of the same nature as that of the vertical filter may possibly be provided. The tightness of the filter 2 is ensured by a flexible membrane of EPDM with a thickness of 1.14 mm. The flexible EPDM membrane is protected on the underside by an anti-punching geotextile of at least 270g / m ² providing protection against perforation of stones or roots coming from the outside. The wall penetration (not shown) allows the seal between the drainage system 6 inside the filter 2 and the collection box 4.

 The depth of the bed is 0.6 m including 0.5 m of substrate and 0.1 m of contrast.

Filtration is ensured by the substrate, which consists of three slices with materials below arranged successively from upstream to downstream: - 50 cm of gravel 2.2 of 16/22 mm,

 - 250 cm of pozzolan 2.3 of 7 / 15mm,

 - 100 cm of gravel 2.4 of 4/10 mm,

 The water discharged from the vertical filter 1 is directed by a PVC drainage pipe 5.1, DN 100 mm, upstream of the horizontal filter 5.4 and circulates there by gravity from upstream to downstream. The water level 2.6, initially set during implementation in the box 4 downstream of the filter by the height of the outlet pipe, is about 5 cm below the surface of the substrate 2.2. As a result, the lower layer of the substrate is permanently saturated with water. Thus, anaerobic (deep parts of the filter) and aerobic (non-flooded surface layers, rhizosphere) zones are simultaneously in action. The anaerobic zones are largely in the majority. The residence time of the water is greater than that of the vertical filter.

 Plants 2.7 are installed in the substrate 2.2. The species used are: Juncuseffusus, Iris pseudacorus, Lythrum salicaria, Sagittariasagittifolia, Acorus calamnus, Scripuslacustris.

 The selected plants can live in soils saturated with water while developing an important root system. The association of these species promotes microbial diversity and stimulates their degradation activities in the substrate. Other properties of the plants (eg mosquito repellent) are also taken into account when choosing the species.

The planting density is 6 ft / m ² in the horizontal filter.

 The drainage system 6 is composed of the pipes 6.1 and 6.2 which are connected together. The 100 mm diameter, perforated PVC collection pipe, DN 100 NF, is placed at the bottom of the bed, perpendicular to the direction of flow and at the end close to the outlet, so as to allow the drainage of the waters. This collection pipe 6.1 is connected to a wall penetration (not shown) and then to the PVC pipe 6.2 which directs the collected water to the collection box 4.

 The collection box 4, has a water tank 4.1. A 4.2 pipe placed vertically allows to maintain a water level 4.3 of about 45 cm deep in the box. It facilitates visual monitoring of treated water and the taking of samples for qualitative checks. The box 4 is secured by a 4.4 concrete cover and does not affect the operation of the system.

By passing through the horizontal filter 2, the solids still present in the water are retained by the root system of the plants, which allows the microorganisms of the substrate 2.2 to degrade effectively. Plants 2.7 absorb soluble substances and accumulate them in their biomass. Time to longer stay allows prolonged interaction between pollutants, microorganisms and plant roots 2.7. Microbial degradation and plant assimilation are thus more complete in this step than in the vertical filter 1. Moreover, the anaerobic conditions that are predominantly present are favorable to denitrification. Therefore, the reduction of the nitrogen load is very important during this step.

 At the outlet of the horizontal filter 2, the purified water has a quality in accordance with the discharge thresholds authorized by French regulations in the natural environment.

 The zone in open water 4 is formed downstream of the horizontal flow pond 2. The sizing of the effluent management station according to the invention, and in particular filters planted from the filtration station depends in particular on the daily volume of d effluents. The unit of calculation is the volume equivalent per capita (EHV) and the volume equivalents presented above.

The station whose characteristics have been provided above is designed with a capacity of 6EH, the vertical flow filter having an area of 10m ² (3.16m in length and 3.16m in width) and the flow filter horizontal being of a surface of 8m ² (4m of length and 2m of width).

 The optimum total effective areas of vertical 1 and horizontal filters 2 illustrated for 1 EH are:

"Vertical flow filter: about 1.7 m ²

- Horizontal flow filter: approximately 1.3 m ²

The efficiency test of the purification plant described above has demonstrated the significant purification efficiencies of the device. The reduction of pathogens was also tested following the completion of 44 balances during the same efficacy trial. The test protocol was carried out in accordance with Annex 2 of the Decree of 7 March 2012 amending the Decree of 7 September 2009 laying down the technical requirements applicable to non-collective sewerage installations receiving a lower gross load of organic pollution or equal to 1.2 kg / d of DB05, entitled "Protocol for testing the purification performance on a test platform".

 These results are reported in Table 1 below:

Table 1 The maintenance of the device (weeding, plant size, raking the substrate, sludge cleaning) is relatively simple and not technical, does not require special qualification and therefore can be provided by the user.

 Of course, the present invention is not limited to the examples and to the embodiment described and shown, but it is capable of numerous variants accessible to those skilled in the art.

Claims

An effluent treatment device comprising at least:  - A planted filter (1) with vertical flow comprising at least one substrate (1 -1),  a horizontal flow plant filter (2) comprising at least one substrate (1 -2),  means for distributing the wastewater in the vertical flow filter,  means for transferring treated effluents from the vertical flow filter to the horizontal flow filter,  a means for recovering treated effluents from the horizontal flow filter,  this device allows an abatement rate:  MES (suspended solids)> 96%  DB05 (biological oxygen demand for 5 days)> 96%  COD (Chemical Oxygen Demand)> 90%  NTK (total nitrogen Kjeldahl)> 60%  Pt (total phosphorus)> 35% the surface of the device being less than 5 m ² / EH, preferably less than or equal to 3 m 2 / EH. 2. Device according to claim 1 wherein:  o the substrate (1.1) of the vertical flow filter comprises an upper layer (1.3) with a thickness of 35 to 50 cm of pozzolan-type gravel of density ranging from 0.65 to 1.3 T / m3, porosity ranging from 10 to 50% in vol / vol, whose pores have a mean diameter ranging from 0.6 μιη to 60 μιη,  o the substrate (2.2) of the horizontal flow filter comprises an intermediate layer (2.4) of pozzolan-type gravel with a surface representing 50 to 95% of the surface of the horizontal flow filter. 3. Device according to claim 2, wherein the pozzolan type gravel implemented in the upper part (1.3) of the filter (1) to vertical flow has a particle size ranging from 4 to 10 mm, a density of 0.7. at 1.1 T / m ³ , a porosity ranging from 20 to 50% in vol / vol, whose pores have a mean diameter ranging from 0.6 μιη to 15 μιη. 4. Device according to any one of the preceding claims, wherein the substrate (1.2) of the filter (1) to vertical flow comprises: - at least one intermediate layer (1.4) of particulate material of greater particle size than the pozzolan material of the upper layer (1.3) and  at least one lower layer (1.5) of particulate material having a particle size greater than that of the material of the intermediate layer. 5. Device according to any one of the preceding claims, wherein the substrate (2.2) of the horizontal flow filter comprises at least a first layer (2.3) of particulate material of greater particle size than the pozzolan material of the intermediate layer (2.4). ) and at least a third layer (2.5) of particulate material of smaller particle size than the material of the intermediate layer. 6. Device according to any one of the preceding claims, wherein the filter (1) vertical flow further comprises means (5.3) for the distribution of oxygen, these means being housed in the lower part of this filter. 7. Device according to any one of the preceding claims, wherein the filter (1) vertical flow is planted with at least two plant species (1.6) of different genus selected from the following families: Cyperaceae, Poaceae, Iridaceae, Juncuceae , Typhaceae, Acoraceae 8. Device according to any one of the preceding claims, wherein the filter (2) horizontal flow is planted with at least two species (2.6) of different genus selected from the following families: Cyperaceae, Lamiaceae, Plantaginaceae, Brassicaceae, Alismataceae, Butomaceae, Pontederiacea, Typhaceae, Ranunculaceae, Araceae, Lythraceae, Nelumbonaceae, Equisetaceae, Myrsinaceae, Marentaceae, Menyanthaceae. 9. Device according to any one of the preceding claims, wherein the planting density is greater than or equal to 4 feet / m ² . 10. Device according to any one of the preceding claims wherein the vertical flow filter has only one rack. 11. Kit for the manufacture of a device according to any one of the preceding claims, this kit comprising at least: - A waterproof material for delimiting the walls of planted filters,  - collection, evacuation and connection pipes, preferably in PVC - A collection of particulate materials, comprising at least: a pozzolan-type gravel of density ranging from 0.65 to 1.3 T / m ³ , of porosity ranging from 10 to 50% in vol / vol, whose pores have an average diameter ranging from 0.6 μιη to 60 μιη, A first collection of plants, comprising at least two plant species of different genus selected from the following families: Cyperaceae, Poaceae, Iridaceae, Juncuceae, Typhaceae, Acoraceae,  A second collection of plants, comprising at least two plant species of different genus selected from the following families: Cyperaceae, Lamiaceae, Plantaginaceae, Brassicaceae, Alismataceae, Butomaceae, Pontederiacea, Typhaceae, Ranunculaceae, Araceae, Lythraceae, Nelumbonaceae, Equisetaceae, Myrsinaceae, Marentaceae, Menyanthaceae.