FR3013347A1 - METHOD AND STATION FOR MANAGING EFFLUENTS FROM AGRONOMIC ACTIVITIES BY HYBRID PHYTOEPURATION TREATMENT. - Google Patents

Abstract

Process for the management of raw effluents resulting from agronomic activities by hybrid phytopurification treatment, without separation of the liquid and solid phases of said effluents, this process comprising a purification step on planted filters, characterized in that it comprises a pre-treatment stage before passing them over said planted filters, said pretreatment step of subjecting the raw effluents from a slurry recovery tank to an oxygen supply and seeding of bacterial products

Description

Method and station for managing effluents resulting from agronomic activities, by hybrid phytopurification treatment. The present invention relates to a method and an effluent management station resulting from agronomic activities, in particular livestock effluents and, more particularly, pig manure. Manure management within farms is a fluctuating issue depending on the type of breeding, its geographical location and the 10 aspirations and means of the farmer. In fact, liquid waste composed of urine and feces, manure is produced and recovered in intensive livestock farms using slatted buildings (perforated soil) as a method of stabling and are, depending on the regulations, either spread or conveyed to a zone or a treatment station. This management may have impacts on the site 15 of the exploitation and the surrounding area, in terms of surface and underground water, the consequences that can be passed on to the seas and oceans (CGDD - "Evolution of pollutant fluxes to the sea" ). The manure management is therefore part of the problem of the management of aquatic environments and the preservation of good water quality and in a process of support for 20 farmers to sustainable development and accountability, this management representing, in certain regions, major issues. Slurry has a higher or lower dilution rate depending on the physiological stages of the animals, the diet chosen and the techniques of washing in piggery. Its physico-chemical characteristics are also variable within and between farms. In fact, pig manure is generally composed of 15% of a solid fraction and 85% of a liquid fraction, and has a neutral to slightly alkaline pH. The concentration of dry matter (DM) can vary from 20 kg.m-3 to 60 kg.rn-3 within the same farm, and the chemical oxygen demand can vary between 20 to 55 g 02.1-1 in function of the farms. The total nitrogen and phosphorus concentrations vary respectively from 3 to 9 kg.rn-3 and from 2 to 6 kg.rn-3 depending on the physiological stages of the pigs. The concentrations in macro (N, P, K) and micro nutrients are variable in time or depending on the farms, however the ratio N / P205 / K20 remains constant. On average, nitrogen is present as 75% as ammonia nitrogen and 10% as dissolved nitrogen. Phosphorus is mainly present in the solid phase of slurry in particulate and fine form, the organic and inorganic phosphors respectively representing 18% and 70% of the particulate and fine phase. The liquid fraction is composed of 2% organic phosphorus and 10% inorganic phosphorus. The potassium (K) is mainly present in dissolved form and can vary from 2 to 5 kg.rn-3 slurry. Depending on the diet of pigs, slurry is more or less contaminated with heavy metals and / or metalloids (TMEs) such as copper, zinc and arsenic. The microbiological composition of the slurry also varies with the farms and over time, up to 150 species of pathogenic microorganisms have been identified. Aging as well as storage also results in compositional variations such as a decrease in organic matter in favor of degassing coupled with an ammonification phenomenon as well as mild to moderate hygiene. Since manure is rich in nitrogen and phosphorus, it is traditionally applied to crops and its treatment is left to the sole "soil purifying power" provided by the export of nutrients by plants. However, the excessive spreading of slurry, given its characteristics, is at the origin of the eutrophication phenomenon of adjacent environments or green tides denounced recently by certain associations for the protection of the environment. In response to these environmental problems, the European Nitrates Directive (91/676 / EEC) nowadays regulates the quantities of nitrogen and phosphorus authorized for cultivation amendment and defines Treatment Obligation Thresholds (SOT). slurry. The fate of manure is therefore, at first, strongly linked to the geographical location of the farm. Indeed, there are areas considered in the framework of the European Nitrates Directive (91/676 / EEC) as "zones of structural surplus" (SEZs) where the spreading possibilities 30 making it possible to guarantee good purification by the soil and crops are outdated. A Treatment Obligation threshold (SOT) has been set up requiring either the treatment of excess slurry or their transfer outside the SEZs. The Nitrates Directive 91/676 / EEC also refers to "vulnerable areas" associated with monitoring programs and "action programs".

There are other areas with the status of "low production area" (where spreading is most often allowed). Coastal areas are still classified as "vulnerable areas". It is therefore important to mobilize now to develop and implement sustainable solutions to the problems posed by water contamination by nitrates and phosphorus. Moreover, in "low production areas", pig producers suffer from images of "environmental errors committed in certain vulnerable areas" as well as nuisances related to land application that lead to poor social acceptance of pig production. .

In view of the liquid nature of pig manure, it may be subjected to a treatment aimed at reducing its biological characteristics (chemical oxygen demand (COD) and biological oxygen demand (BOD)), microbiological as well as physicochemical (nitrogen, phosphorus and suspended matter (MES)). The treatment of pig manure consists of a quantitative improvement (reduction of volumes) and / or qualitative (reduction of concentrations in N, P, K, pathogenic microorganisms ...). The objective of improving the quality of manure is to reduce its environmental impact. One of the possible ways, and still can be explored, for the treatment of pig effluents is the treatment by artificial wetlands forming part of all phytoremediation processes that corresponds to the use of organic or inorganic substrate, plants and their Associated microorganisms to degrade or reduce the toxicity of organic and inorganic pollutants in the aquatic environment. In addition, these techniques offer an effective purification alternative, less expensive than conventional treatment plants, easy to implement when it is adapted and durable. However, the development of an efficient pig manure treatment system must take into account the specificities of the slurry, which are themselves related to the breeding methods and physiological stages of the animals as well as to the methods and storage times of the animal. 'effluent.

The invention relates to a method and an installation for reducing the environmental pollution associated with the spreading and contamination of water and soil by nitrates and phosphorus. It is known that in order to allow an efficient reduction of nitrogen, two diametrically opposed processes must take place: - The ammoniacal salts contained in the effluents must be oxidized (nitrification) according to the following reaction: NH4 + 1.5 02 -> H + + H20 + N0-2 - The nitrates produced must be reduced to molecular nitrogen (denitrification) according to the following reaction: N0-2 + 0.5 02 -> NO-3 The oxidation process of the ammoniacal salts is however limited by the oxygen present in the environment and in the sludge to be treated, and the denitrification can take place only in the presence of carbonaceous material, usable by the denitrifying microorganisms. Since denitrifying organisms are autotrophic and slow-growing, they can not compete with heterotrophic organisms if carbon levels are too high. The carbon abatement must intervene before that of the nitrogen, but remains necessary for the denitrification. In fact, the stoichiometric reaction of the complete nitrification is the following: NH4 + 1.83 O2 + 0.98 HCO3-> 0.021 C5H7NO2 + 1.04 H20 + 0.98 N03 + 1.88 1-12003 One-step systems and processes therefore do not allow for high degradation of total nitrogen since they can not provide alternating aerobic and anaerobic conditions, both necessary for nitrogen removal. In a constantly changing regulatory context and in the face of quality objectives for the environments to be achieved in the near future, it is important today to provide solutions, upstream, to the problems of contamination of aquatic environments by nitrogen pollutants. and phosphorous, as well as to propose innovative and ecological systems adapted to the needs of agronomy. The invention aims to develop an ecological engineering system that allows the downstream receiving environment to retain its ecological features. The purifying system according to the invention aims to bring professionals in the field of agronomy towards an eco-responsible approach presenting an alternative to the spreading, when it is possible, at lower costs and constraints. Indeed, always in an approach committed to sustainable development and support towards good environmental practices, the sizing of such a system must also be able to respond to the constraints inherent to farms such as a low land hold that can be allocated to the system purification, installation and operating costs that need to be adjusted. In addition, in accordance with the respect of the environment and the optimization of resources, ways of valorization of the by-products of purification (plant biomass, compost, effluent output ...) will be found in agreement with the needs of the breeders. The objective is therefore to propose a system whose technical and scientific reliability has been tested and tested in real conditions, while providing breeders with integrated management solutions for the plants used and elimination / recovery routes. The process according to the invention is therefore a process for managing raw effluents resulting from agronomic activities by hybrid phytopurification treatment, without separation of the liquid and solid phases of said effluents, this process comprising a pretreatment stage consisting in subjecting the raw effluents coming from a slurry recovery pit with an oxygen supply and a seeding of bacterial products, and a purification step on planted filters. More specifically, said method comprises a step of pre-treatment of the raw effluents by means of a double compartment tank, and a filtration stage by means of a vertical plant filter and / or a horizontal plant filter. This process is particularly remarkable in that the raw animal waste, that is to say the excrement directly from the slurry recovery pits, without separation of liquid and solid phases: - are first subjected to a pretreatment by passing through a unit or tank composed of two compartments, the first compartment receiving a volume equivalent to 30 days of production of raw manure for oxygenation and advantageously, though in no way limiting, seeding into bacterial products initiating nitrification NH4 +, the second compartment receiving, after a certain contact time, the product from the first compartment, which is slowly and progressively conveyed to the station of planted filters, - are then filtered and purified by means of a filtration station comprising two plant filtration systems, ie a first filtration system comprising a filter planted vertically and a second filtration system comprising a planted horizontal flow filter.

During this pretreatment step, the bacteria degrade the ammonia and transform it into nitrates according to the following reactions: NH4 + 1.5 02-> H + + H20 + NO2 N0-2 + 0.5 02 -> N0-3 The purpose of the pretreatment stage is to achieve, in a given reduced time, for example of the order of 15 days, an acceptable ammonium concentration for the implanted aquatic plants (selected specifically for their ammonium tolerances) in the filtration station, this concentration being at most of the order of 200 mg.I-1 ammonium. In order to achieve, in a lesser time, this reduction in ammonium concentration, the pretreatment unit is advantageously seeded using metering pumps with bacterial products adapted to the reactions necessary for the transformation of ammonium.

The amended bacteria correspond to the bacteria carrying out the two stages necessary for nitrification, ie: - for the oxidation of ammonium, the bacteria of the following genera: Nitrosomonas, Nitrosococcus and Nitrosospira - for the reduction of nitrates, the bacteria of the following genera : Nitrospira and Nitrobacter. In order to allow optimal phosphorus abatement (concentration reduction), mainly due to the phenomenon of physicochemical retention, it is planned to set up a trap system at the end of the purification line serving as tertiary treatment for phosphorus. This sealed container in which the effluent passes comprises a mineral substrate composed in part of aluminum allowing optimal retention of phosphorus. A waste phosphorus precipitation system, known per se, in tertiary treatment is also envisaged if the previously mentioned bin does not prove to be effective. In view of the fact that a deposition layer generally forms on the surface of vertical flow planted filters because of the slurry load contained in slurry, and more particularly in pig manure, and in order to accelerate the composting process in the upper part of the filters (surface), a lombrififtration can be put in place, in the upper part.

The effluent management facility is particularly notable in that it comprises a slurry pre-treatment unit or station disposed between the slurry recovery pit, generally located under the hog barns in the case of pig manure, and the the planted filters, this pretreatment unit or station comprising a two compartment vessel, the first of which has an inlet for the intermittent introduction of the raw effluents, means for the transfer of these into the second compartment; , and means for conveying the pretreated effluents to the planted filter (s). According to a preferred embodiment, an oxygen distributor is housed in the lower part of the first compartment. According to another embodiment, the means making it possible, on the one hand, to transport the effluents from the first compartment to the second compartment, and on the other hand, effluents from the passage in the second compartment towards the planted filters. , are constituted by pumps. According to another embodiment, the pretreatment unit 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 ammonium. The effluent management installation further includes a filtration unit or station comprising at least two successive distinct planted filters: a vertical flow plant filter: several substrate layers composed for example of gravel, gravel, sand, etc., are superimposed in a basin of a given surface, each layer having a particle size less than that of the layer disposed immediately below it, so that the filter has vertically upwardly increasing particle size ; a procession of plant species highly tolerant to ammonium and nitrates, and adapted to the station's planting climate, are sown and cultivated on the surface; A horizontal flow plant filter constituted by a single layer of substrate composed of materials of the same particle size, for example sand, on which are planted and cultivated pollotolerant plant species and adapted to the implantation climate.

In addition, the filtration station may comprise at the output of the horizontal planted filter: a leakproof filter box filled with a specific material through which the effluent passes, this material comprising a mineral substrate, for example composed, in part, of aluminum> allowing optimal retention of phosphorus, - and / or an open water zone (analysis and diffusion zone). According to an advantageous embodiment, the filtration station located immediately after the pre-treatment unit or station comprises two filtration dies which can operate in parallel, with alternation in their supply (every 1 to 7 days, for example). or as a single die, comprising the two dies connected to each other, the output of one spilling into the input of the other. Preferably, each of said filtration dies comprises: - a vertical flow filter, - a hybrid horizontal flow filter, the first third of which remains in open water, - a filter box filled with a specific material through which passes the effluent, this material comprising a mineral substrate, for example composed, in part, of aluminum, Advantageously, the effluent management installation may comprise a device for recirculation (end of die to station head), coupled water monitoring equipment. This system makes it possible to control the quality of the water leaving the station and to avoid any spill into the natural environment of polluted effluent. In addition, it allows recirculation of manure to be treated at the head of the station (if necessary) or as rinsing water pre-pits of pigsty. A retention pond is provided to cope with any hydraulic overload of the system. The foregoing and other objects, features and advantages will become more apparent from the following detailed description and accompanying drawings, in which: FIG. 1 is a schematic view illustrating an exemplary embodiment of the installation manure management system according to the invention. Figure 2 is a simplified schematic view of the station or pretreatment unit.

Figure 3 is a schematic view illustrating the operation of this preprocessing station. Figure 4 is a schematic plan view of the planted filter station.

Figure 5 is a diagrammatic view of the organization and operation of the filtration plant planted filters, illustrating the flow of effluent in said station. Figure 6 is a vertical sectional and schematic view of the station planted filters.

Referring to the drawings to describe an interesting example, although by no means limiting, realization of the phytopurification plant and implementation of the effluent management method according to the invention. It will be observed that the terms "first" and "second" used in the present description and in the claims describe certain elements of the installation according to the place they occupy in the implementation of the claimed process, considering the direction of transport of slurry during processing; they have, of course, no limiting character. The process of the invention is applicable to slurry purification plants, in particular manure from pig farms; it applies, however, generally to the treatment of manure from farms of other animals such as poultry, cattle (effluents with high organic and inorganic loads), etc., of the kind comprising minus one or more vertically-flow planted filters, or at least one or more horizontally-flow planted filters. According to the invention, the effluent management installation comprises, a pre-treatment unit or station 1 slurry, disposed between the slurry recovery tank 2 and the filtration station 6 constituted by the planted filter (s) 3 and 4 This pretreatment station comprises a sealed tank 5 with two compartments 5A and 5B, an inlet 7 opening into the first compartment 30 and connected to or connected to the slurry recovery tank 2 and an outlet 8 that the second compartment and connected to the filtration station 6. The compartments 5A and 56 communicate with each other (FIG. 2) via a pump 12.

For example, these compartments are separated by a partition 9 of height less than that of the side wall of the tank 5, so that an opening 10 establishing a communication between said compartments is formed between the upper edge of the partition 9 and the upper wall 5a of said tank.

Means known per se or within the abilities of those skilled in the art make it possible to extract the slurry from the slurry recovery tank 2 and convey it to the pre-treatment station 1. These means may, for example, be constituted by pumping devices adapted to the circulation of the products to be treated, such devices comprising for example a pipe 19 Io for conveying slurry extracted from the trough for the recovery of animal waste and a lifting pump 20 installed between the pit 2 and the pretreatment tank 5. A pump 12 is installed in the lower part of the compartment 5A and communicates with the compartment 5B by means of a pipe 12a passing through an opening in the partition 9, or reserved above the edge upper part of said partition (opening 10). According to the method of the invention, slurries from the slurry recovery tank 2 are subjected to an oxygen supply and to a seeding of bacterial products, during their passage and their stay in the first compartment 5A of the tank 5, by means of any suitable device. For example, an oxygen distributor 13 may be housed in the lower part of the first compartment 5A, into which the effluents from the slurry recovery tank 2 are introduced. In the first compartment 5A of the pre-treatment station is introduced a volume V of the raw slurry from the slurry recovery pit 2, this volume V being subjected to oxygenation for a time T, for example for a period of between 10 days and 25 days, preferably for a period of order of 15 days. Advantageously, the compartment 5A of the pretreatment unit is also inoculated during this period by addition of bacterial products having the capacity to degrade ammonium, for example by means of a seeding device 17 arranged at the plant. inlet of the tank 5A such devices being known per se or within the scope of the skilled person.

After the aforementioned contact and oxygenation time period T, this volume V is transferred to the second compartment 5B of the pre-treatment station 5, then a volume Y of the volume V transferred into the compartment 5B is sent daily, so that slow and progressive, by any appropriate means and for example by pumping, to the filtration station 6. A volume V 'can again be introduced into the compartment 5A of the pretreatment unit when the volume V has been transferred to compartment 5B. The filtration station 6 on planted filters comprises: at least one vertical flow plant filter 3 fed by the pre-treatment station 1, and at least one horizontal flow plant filter 4 fed by said vertical flow filter 3. It comprises also, preferably: a leakproof filter box 23, - a free water zone 11 (analysis and diffusion zone) The outlet 8 of the pre-treatment station is connected to the filtration station 6 and in particular to the (x) filter (s) planted 3 of the latter. The conveyance of the effluents pretreated by the pretreatment station 1 to the filtration station 6 and in particular to the (x) filter (s) planted (s) 3 of the latter, can be achieved by any means known per se or within the reach of the skilled person. These means may be constituted by a pumping system adapted to the circulation of the products to be treated or comparable products. A pump 14 is for example installed in the lower part of the compartment 58 and is connected to the outlet 8 of the tank 5 by means of a pipe 14a, said outlet being itself connected to the filtration station 6 and in particular to the x) filter (s) planted 3 of the latter, by any known means or within the reach of the skilled person. The liquids issuing from said at least one vertically-flowed filter (s) feed the at least one horizontally-flowed filter (s) 4 by any appropriate means. An open-water zone 11A, 11B is provided in the horizontal flow-planted filter tanks 4 downstream of the filter media 4a.

Vertical flow planted filters consist of layers of gravel, gravel or sand, with an increasing grain size in the direction of the bottom and are sown with plant species with a high root capacity, tolerant to ammonium and, depending on the nature of the slurry, to other pollutants, these plant species must, secondly, be adapted to the climate of the regions where the sites of implantation of phytopurification plants slurry. The filter media of the horizontal flow planted filters may be a succession of compartments containing the filter material. According to one of the preferred embodiments of the invention, the filtration station 6 comprises two filtration dies operating in parallel with an alternation in their supply. Each of the two dies is composed (FIG. 5) of a vertical flow filter 3A, 3B, of a hybrid horizontal flow filter 4A, 4B, the first third of which remains in open water, a sealed filter box 23 filled with water. a specific material, for example, a mineral substrate composed in part of aluminum, a zone of free water 11A, 11B disposed downstream of the filter media 4a (Figure 6). Advantageously, the installation according to the invention comprises a device 15 for recirculating effluents, filtering outlets to the station head, coupled to a water monitoring equipment. This device comprises a pump and a pipework suitable for the circulation of manure. These devices make it possible to control the quality of the water leaving the station and to prevent any discharge into the natural environment of polluted effluent. In addition, it allows recirculation of manure to be treated at the head of the station (if necessary). Analysis and diffusion devices can be housed in the tank. For example, an analysis and diffusion apparatus 18A, 18B may be disposed at the outlet of each horizontal flow filter 4. A retention pond (not shown) is provided to cope with any hydraulic overload of the system. One of the factors limiting the proper functioning of the planted filters being the regular watering of the plants (to ensure their proper maintenance), the design of the purification system relates to the volumes rather than the concentrations of pollutants to be cut down. This choice is made possible considering the combination of the phytopurification technique with alternation of the two dies (vertical filter (3) + horizontal filter (4)) and that of the amendment over the flow of microbial products such as enzymes or bacterial mixtures. The size 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 daily discharges produced by the animals, and the stage of rearing of the latter (post-weaning). / pre-fattening, fattening, ...).

These variants necessarily affect the concentrations of nitrogen, phosphorus, and the biological and chemical oxygen demand (BOD, COD). Plant-based treatment plants are classically sized according to the number of population equivalents (PE) to be treated. In order to dimension the pig slurry treatment plant, the daily discharge produced by the porcine stages concerned is expressed in this unit. The daily volumes and daily concentrations (N, P, BOD, COD) in pig manure ("fattening" and "post-weaning / pre-fattening" stages) and their equivalence with 1EH are given below: 1 EH Volume (effluent Nitrogen phosphorus BOD COD domestic daily 1 equivalent pork (1.1-1) (ge) (gi-1) (g.i'll (gi-1) fattening 170 (EHV) 10 2 60 120 1 equivalent pork 1, 78 90 to 180 "post-9.45 7.15 45-70 sevragelpre- is = 0.01 or = 1.5 to 3 fattening" is = 1EH or = 3.6 EF-I is = 0.4 to 0 , 6 EH EHV EH 3.69 29.15 20.30 185-370 95-150 Either = 0.02 or = 3 or = 10.2 or 3-6 or 0.8-1.3 EH EHV EH EH EH The unit of calculation is therefore the volume equivalent energy equivalent (EHV) and the volume equivalents presented above, which will then be used to calculate the optimum total surface area of the vertical and horizontal filters for 1 EHV: - vertical flow filter: 2, 6 m2 - horizontal flow filter: 5.1 m2 Po For a total useful area for a filter type (vertical filter or horizontal filter), the station will have two such filters whose sum of surfaces will be equal to the total usable area. The depths of the filters, chosen to allow an optimal flow within the filters, are fixed as follows: - a depth of the order of 75 cm for the filters with vertical flow, a depth of the order of 50 cm for the filters horizontal flow. Macrophytes planted on a filter are periodically plucked and transformed into dry matter. These plants also allow the creation of a habitat 5 favorable to purifying microorganisms, thanks to: - the oxygenation capacity of the medium by the roots, the release of carbon compounds by the roots, usable by microorganisms. Depending on the area of implantation (biogeographic zone) of the treatment station 10, a preliminary study is carried out in order to always select plant species adapted to the climate. In addition, selected plant species should not be invasive species. Slurry is a potentially limiting medium for plant growth. Indeed, the nitrogen of manure is mainly present in its ammoniacal form, a compound that can be highly toxic in plants. The use of plants identified as having root symbioses is therefore planned. The term phytoextraction is here mentioned in view of the loading of copper and zinc pig manure when these elements are integrated in the pig food supplements (consequently, varying concentrations depending on the operation). 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 layer of deposition on the surface of these planted filters, taking into account the slurry load contained in certain slurries, in particular pig manure. The installation may comprise an electrical or electronic system for controlling and managing the different 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 system control keys and the control devices can be assembled in a cabinet.10

Claims (6)

REVENDICATIONS1. Process for the management of raw effluents resulting from agronomic activities by hybrid phytopurification treatment, without separation of the liquid and solid phases of said effluents, this process comprising a purification step on planted filters, characterized in that it comprises a pre-treatment stage before passing them over said planted filters, said pretreatment step of subjecting the raw effluents from a slurry recovery tank to oxygen supply and seeding of bacterial products. 2. Method for managing effluents from agronomic activities by hybrid phytopurification treatment, according to claim 1, characterized in that the supply of oxygen and the seeding of bacterial products are operated during the stay of manure from the pit. slurry recovery, in a pretreatment tank (5). 3. A method for managing effluents resulting from agronomic activities by hybrid phytopurification treatment, according to claim 2, characterized in that the slurry is subjected to an oxygen supply and a seeding of bacterial products for a time (T). between 10 days and 25 days 4. A method for managing effluents resulting from agronomic activities by hybrid phytopurification treatment, according to claim 3, characterized in that the slurry is subjected to an oxygen supply and a seeding of bacterial products for a time (T). a duration of about 15 days 5. Process for managing effluents resulting from agronomic activities by hybrid phytopurification treatment, according to any one of claims 1 to 4, characterized in that the supply of oxygen and the seeding of bacterial products are operated during the stay. slurry from the slurry recovery pit in the firstcompartment (5A) of a two-compartment tank (5A, 5B), the slurry treated in said first compartment being transferred to the second compartment (5B) from which it is routed slowly and progressively to a station of planted filters (3, 4) 6. A method for managing effluents resulting from agronomic activities by hybrid phytopurification treatment, according to any one of claims 1 to 5, characterized in that the effluents from the pretreatment stage are purified on a vertical flow plant filter. (3), then on a horizontal flow plant filter (4) 7 A method for managing effluents resulting from agronomic activities by hybrid phytopurification treatment, according to any one of claims 1 to 6, characterized in that a lombrifiltration is placement in the upper part of the planted filters 8. Plant for the management of effluents resulting from agricultural activities, in particular slurry and, more particularly, slurry from pig farms, comprising a plant consisting of planted filters (3, 4), characterized in that it comprises a pretreatment unit or station (1) arranged upstream of said planted filters, this pre-treatment station consisting of a tank (5) with two compartments (5A, 56), or a first compartment (5A) intended to receive for a time (T) successive volumes (V) of manure from a pit for recovering manure and in which these volumes of slurry are subjected to a supply of oxygen and to a seeding of bacterial products, and a second compartment (5B) communicating with the first compartment (5A) and in which said volumes are transferred ( (V) liquid manure at the end of its treatment period, before being transported to the plant of planted filters (3, 4) 9. Installation for the management of effluents resulting from agronomic activities, in particular slurry and, more particularly porcine breeding slurry, according to claim 8, characterized in thatthe oxygen distribution device (13) is housed in the lower part of the first compartment (5A). from agricultural activities, in particular slurry and, in particular, pig manure, according to one of claims 8 or 9, characterized in that a pump (12) installed in the lower part of the first compartment (5A) makes it possible to transfer in the second compartment (5B) the volumes of manure treated in the said first compartment (5A) Plant for the management of effluents resulting from agricultural activities, in particular manure from livestock farms and, more particularly slurry pig farm, according to any one of claims 8 to 10, characterized in that a pump (14) installed in the lower part of the second compartment (5B) can convey in the direction of planted filters, liquid manure volumes treated in said first compartment (5A) 15 12. Plant for the management of effluents resulting from agronomic activities, in particular slurry and, more particularly, slurry 20 pig farm, according to any one of claims 8 to 11, characterized in that the plant filtering plant comprises successively: at least one vertical flow plant filter (3) fed by the pre-treatment station (1) and at least one horizontal flow plant filter (4) fed by said vertical flow filter (3). 13. Installation for the management of effluents resulting from agronomic activities, in particular slurry and, more particularly, manure Pig farm, according to claim 12, characterized in that it comprises: at least one sealed filter box (23) filled with a material, for example a mineral substrate composed, in part, of aluminum, and - an open-water area (11) 3514. Installation for the management of effluents resulting from agronomic activities, in particular slurry and, in particular, hog manure, according to the claim 13, characterized in that the plant of planted filters (6) comprises two filtration dies operating in parallel with an alternation in their supply, each of these two dies being composed of: a vertical flow filter (3A, 3B) ; a hybrid horizontal flow filter (4A, 4B), the first third of which remains in open water; - a filter box (23) filled with a specific material, for example a mineral substrate composed, in part, of aluminum; an open-water zone (11A, 11B) (analysis and diffusion zones) disposed downstream of the filtering media (4a). 15. Plant for the management of effluents resulting from agricultural activities, in particular farm manure and, more particularly pig slurry, according to any one of claims 8 to 14, characterized in that it comprises a device (15) recirculation of the effluents from the filtering streams to the head of the station, coupled with water monitoring equipment. 16. Installation for the management of effluents resulting from agronomic activities, in particular livestock slurry. and, more particularly pig slurry, according to any one of claims 8 to 15, characterized in that analysis and diffusion devices (18A, 186) are arranged at the outlet of the filter (s) planted at horizontal flow. 17. Plant for the management of effluents resulting from agricultural activities, in particular farm manure and, more particularly, pig slurry, according to any one of claims 8 to 16, characterized in that the total Vertical and horizontal filters for 1 EHV are 2.6 m2 for the vertical flow filter and 5.1 m2 for the horizontal flow filter.