EP1838628A1 - Method for treating and reaction for decomposition of organic material in a fluid and/or for decontamination of liquid loaded with metals - Google Patents

Abstract

The invention relates to a method for decomposition of organic material in a liquid and/or for decontamination of liquid loaded with metals, comprising the treatment of the liquid by passage over a bed of a fungal biomass, fixed on a solid support in a treatment reactor. The biomass bed is preferably in fluidised form or in the form of a mobile bed and, furthermore, the microfungi are cultivated in parallel in a separate bioreactor. The invention further relates to a decomposition plant for organic material in a liquid and/or for decontamination of a liquid loaded with metals using the above method.

Description

PROCESSING METHOD AND REACTOR FOR DEGRADATION OF ORGANIC FLUID MATERIAL AND / OR DETOXIFICATION OF CHARGED METAL FLUID

The present invention relates to the general technical field of the treatment of fluids, such as sludge or effluent, especially fluids loaded with metals. More specifically, the present invention is particularly suitable for the treatment of effluents or sludge predominantly urban.

In particular, the present invention relates to a method of degradation of organic fluid material and / or detoxification of metal loaded fluid comprising treating the fluid on a bed of mycelial biomass fixed on a solid support in a treatment reactor. Mycelial biomass consists of micromycetes that are filamentous fungi that can include molds and yeasts. The method according to the present invention thus makes it possible to treat fluids by using micromycetes in fixed culture, which make it possible to degrade at least a portion of the organic material of the fluids and / or which make it possible to detoxify the fluids polluted by metals. The invention also relates to a degradation plant of the fluid organic material and / or detoxification fluid loaded with metals suitable for the implementation of said method.

Metals, especially heavy metals of the chromium, cadmium, nickel, copper, zinc, lead or mercury type represent a particularly important source of pollution, both in terms of quantity and in terms of environmental risks, particularly when Sludge is intended for agricultural application or composting.

In order to reduce the metal concentrations in solution below the standards in force, various processes have been developed. In addition to physicochemical processes such as basic precipitation, adsorption on resin and desorption, and ultrafiltration or nano filtration membrane techniques, and electrochemical processes such as cementation, electrolysis or electrodialysis, biological processes have been developed.

The latter are based on the capabilities of certain biomasses to fix the metals in solution, thus ensuring a depollution of effluents polluted by metal ions. The diversity of the biological world, linked to an important activity research, leads to very wide possibilities. The biomasses studied come from various origins: marine (algae), fungal (fungi), vegetable (leaves, bark, sawdust ...), and bacterial.

Nevertheless, the processes aimed at reducing the metal concentrations of effluents or sludge developed up to now do not have satisfactory depollution efficiencies under acceptable economic conditions, and generally do not make it possible to act on different types of metals presenting disparities in concentrations. In addition, such processes are particularly limited when it comes to treating high effluent flows low concentration. In addition, the treatments of the prior art for the depollution of effluents concentrated in metals using biomasses of various kinds often require a complete and permanent regeneration of the biomass, in particular by the use of regular inoculations of biological additives. or chemical, in order to effectively fix toxic metals, and the use of techniques such as solid / liquid separation (centrifugation, decantation) to separate metals from the treated fluid.

Moreover, certain techniques of the prior art such as physico-chemical processes denature the sludge or effluent to be treated, while other processes such as membrane filtrations have particularly high operating costs. Therefore, there was thus a need to develop a method and an installation for the treatment of fluids, such as effluents or sludges, not having the disadvantages of the methods and devices of the prior art, and allowing in particular to perform an efficient cleanup of fluids within a single structure of adsorption / desorption of metals, in particular by avoiding the need to completely and permanently regenerate the biomass in the reactor.

The present invention fills this need. The Applicant has thus discovered a new process and an installation making it possible to effectively treat and depollute metal-concentrated fluids, such as raw effluents, wastewater before treatment, sewage sludge, sludge or effluent emanating from volume reduction methods; the sludge or effluent at the outlet of the digester or aeration (various charges), in a compact treatment reactor, very simple operation and implementation, and in which is effectively carried out the adsorption and desorption of the metals to be eliminated.

The process which is the subject of the present invention thus makes it possible to degrade a large fraction of the metals in solution with a metal retention efficiency ranging from 20 to 99%, in particular from 30 to 95%, in particular from 45 to 85%, for a wide range. range of metal ions in varying concentrations.

Furthermore, the method according to the present invention makes it possible to get rid of a substantial part of the toxic pollutions, while still preserving in the treatment reactor at least a part of the biomass that will then be able to be reused for subsequent processing operations . In addition, during the detoxification of metal-loaded fluids, the process according to the present invention makes it possible to drive a concentrate of toxic pollutions (washing effluents: desorption stage) out of the treatment reactor in a very small volume of fluid, which we will then be able to get rid very easily, for example by incineration, drying or a specific treatment. Finally, the process according to the present invention makes it possible to work almost continuously for one to several days, and therefore to treat a large volume of fluid to be detoxified.

In addition, the Applicant has found that, in addition to detoxifying the metal-laden fluids, the process according to the present invention was able to degrade some of the organic matter of the fluids to be treated and to reduce their volume in part. Thus, the process according to the present invention is able either to detoxify the fluids loaded with metals, or to degrade a part of the organic matter of the fluids to be treated, or at the same time to carry out the detoxification of the fluids loaded with metals and the degradation of a part of the organic matter of these fluids. During the degradation of the organic matter of the fluids, the metals trapped in this organic matter are released and solubilized. Thus, by virtue of this degradation, the metals are made more accessible, and the detoxification of the fluids is then facilitated. Thus, the degradation process is intimately related to the detoxification process, and the performances of these two types of processes are thus potentiated, exerting a synergistic action.

The process for the degradation of the organic material of fluids according to the present invention, which makes it possible to treat the fluids using micromycetes in culture fixed, is particularly advantageous compared to the fluid treatment process using micromycetes in free culture, as described in the patent application WO 03/076351.

Indeed, the degradation method according to the present invention constitutes an improvement over the method of the application WO 03/076351, since the method according to the present invention makes it possible to significantly improve the biological degradation of the organic material by the mycelial route, and reduce the volume of sludge by the same amount.

The method which is the subject of the present invention thus makes it possible to degrade a large fraction of the organic material of the fluid in a range of from 20 to 80%, advantageously from 40 to 50%, on average of the amount of dry matter (material

Organic and mineral matter) fluids such as sludge, and thus generate a high reduction in the volume of sewage sludge.

The degradation performances are improved, insofar as the micromycetes which are fixed on a support make it possible to obtain a favorable intimate contact between the fluids to be treated and the mycelial biomass. In addition, the growth rate of mycelial species in fixed culture is accelerated compared to the growth rate of mycelial species in free culture. Thus, the growth rate μ of the micromycetes in the fixed culture is advantageously between 0.1 and 0.2 μ- ¹ according to the mycelial species, whereas the growth rate μ of the micromycetes in free culture (without solid support) is typically of the order of 0.05 j- ¹ . In addition, the residence time of the sludge or effluent in the treatment reactor is decreased when using micromycetes fixed on a solid support according to the process according to the invention (fixed culture), compared to the processes in which are placed micromycetes in free culture. Typically, the residence time is from 10 to

20 days in free culture. Advantageously, the residence time of the sludge or effluents to be treated in the treatment reactor is of the order of 1 to 5 days, typically 3 to 4 days, in the context of the present invention.

The method of degradation of the organic material is also advantageous since it makes it possible to minimize the supply of micromycetes into the treatment reactor for renewal purposes. Advantageously, the supply into the reactor of treatment of micromycetes grown in parallel continuously in a bioreactor associated on site, ensuring the in situ bioaugmentation of micromycetes in the treatment reactor, is thus reduced.

In a particularly advantageous embodiment according to the present invention, the micromycetes are in a dynamic fixed culture. The treatment reactor then contains a bed of mycelial biomass fixed on a solid support, and the bed is in the form of a fluidized bed or in the form of a moving bed (MBBR).

The subject of the present invention is thus a process for the degradation of the organic fluid material and / or the detoxification of metal-laden fluid, comprising the treatment of the fluid by passage over a bed of mycelial biomass fixed on a solid support in a reactor of treatment, the fluid being selected from effluents or sludge treatment plant predominantly urban.

Advantageously according to the present invention, the mycelial biomass is produced from micromycetes, or a mixture of micromycetes consisting of molds and yeasts.

In a particular embodiment of the present invention, the micromycetes of the mycelial biomass are selected from the genera Penicillium, Trichoderma, Mucor, Galactomyces, Streptillus, Fusarium, Geotricum, Phoma, Botrytis, Geomyces, Saccharomyces, and mixtures thereof. In particular, the micromycetes are chosen from: Penicillium roqueforti,

Penicillium chrysogenum, Penicillium atramenlosum, Trichoderma viride, Trichoderma reesei, Trichoderma harΣianum, Mucor hiemalis, Mucor racemosus, Mucor fuscus, Mucor plumheus, Galactomyces geotricum, Aspergillus phoenicis, Aspergillus niger, Geotricum candidum, Phoma glomerata, Botrytis Cinerea, Geomyces pannorum, and their mixtures.

In one embodiment, a single strain of micromycetes is used. According to another embodiment, several different strains are combined, forming a mycelial mixture, possibly with a synergistic effect.

According to one particular characteristic of the present invention, the mycelial yeasts are chosen from the genera Candida, Saccharomyces, Rhodotorula, Aureobasidium, Endomycopsis and Pichia, and their mixtures. Yeasts are typically fungi or filamentous fungi. In particular, the yeasts are chosen from: Candida sake, Saccharomyces cerevisiae, Rhodotorula rubra, Aureobasidium pullulans, Endomycopsis capsularis, Pichia membranifaciens, and mixtures thereof.

In a particular embodiment of the present invention, the solid support is an inert support, such as an inert granular support, advantageously made of pozzolana, limestone, sand, pumice, basalt, clay, quartz, anthracite, activated alumina, zeolite, or mixtures thereof, or a plastic support or lining.

Advantageously according to the present invention, the particle size of the solid support is between 1 and 5 mm, more advantageously between 1 and 3 mm.

The solid support according to the present invention can also be loose or structured packing, such as plastic packing or the like, or mineral packing.

Advantageously, the degradation and / or detoxification process according to the present invention is carried out at least partially aerobically in the treatment reactor. The method can thus be implemented in syncopage mode. In a preferred embodiment of the present invention, the degradation and / or detoxification process according to the present invention is carried out aerobically in the treatment reactor. In a particular embodiment of the present invention, the micromycetes are grown in parallel continuously in a separate bioreactor.

In a particular embodiment of the present invention, the method further comprises a preliminary step of ultrasonic fluid treatment. Ultrasonic treatment of fluids such as sludge has already been described in various articles, such as: Shimizu et al., Biotechnology and Bioengineering, 1993, Vol. 41, 1082-1091; Yoon et al., Water Research, 2005, 39, 3738-3754; and Vera et al., IWA-Sludge South Africa Conference, 2005.

The ultrasonic treatment of fluids, upstream of the biological treatment by micromycetes in fixed culture, is particularly advantageous according to the present invention, since it makes it possible to achieve increased degradation yields, and the possibilities of dissolution of the metals, and therefore metal retention, more important. Indeed, ultrasonic pretreatment aims to disintegrate fluids such as sludge, by transforming particulate organic matter into soluble organic matter. Ultrasound allows lysing fluid cells, and releasing some of the interstitial fluid contained in cell membranes. This allows an ease of accessibility of organic matter (COD rendered soluble), and an acceleration of degradation of organic matter and release of metals.

Advantageously, in the degradation process of the organic fluid material according to the present invention, the contact time of the fluid with the bed of mycelial biomass is between 1 and 7 days, advantageously between 1 and 5 days, even more advantageously between 2 and 5 days. and 4 days.

In a particular embodiment, the mycelial biomass bed is in the form of a fluidized bed or in the form of a moving bed in the degradation method according to the present invention. In an exemplary embodiment of the present invention, the bed of mycelial biomass is in the form of a fluidized bed. The degradation process then advantageously comprises: feeding the fluid to be treated in the lower part of the reactor, the reactor being an upflow treatment reactor containing a bed of mycelial biomass fixed on a solid support, the recirculation of the fluid having passed through the reactor; bed, from the upper part of the reactor to the lower part of the reactor, so as to create an expansion of the bed and maintain an expansion rate sufficient to prevent clogging of the bed, and recovery of the cleaned fluid. Advantageously according to the present invention, the expansion rate of the bed is maintained between 5 and 50%, advantageously between 10 and 40%, even more advantageously between 20 and 30%.

According to a particular characteristic, the recovery of the depolluted fluid is carried out by overflow or by pumping the decontaminated fluid located in the upper part of the reactor overcoming the bed of mycelial biomass.

In another embodiment of the present invention, the bed of mycelial biomass is in the form of a moving bed. The treatment reactor is then a moving bed reactor (Moving Bed Bioreactor: MBBR = Bioreactor moving bed). MBBR-type reactors have already been described in various articles such as Water Sci Technol 2004; 49 (1): 61-8, or Water Sci Technol. 2003; 47 (12): 155-61. However, no MBBR of the prior art has implemented a biomass bed of micromycetes in culture fixed on a solid support. In addition, the method which is the subject of the present invention aims to degrade the organic matter and / or to detoxify the fluids loaded with metals, whereas the mobile beds conventionally used until now have been used for the treatment of carbon and carbon. nitrogen.

In this embodiment of the present invention, the micromycetes are fixed on a plastic lining, advantageously having different specific surfaces. The plastic lining on which the biomass is fixed can be extracted from the reactor for washing.

During the degradation of the material, it is possible to wash the treatment reactor by injection of a washing fluid such as water, when the bed of biomass becomes clogged. This clogging can be detected if the concentration of MES in the reactor (1) is too high. Typically, the concentration is too high when at the outlet of the reactor (1), the concentration is 20 to 50% higher than the initial MES concentration of the fluid to be treated.

The washing fluid may be an aqueous solution, such as water, an acid, a base, or mixtures thereof. The washing fluid may for example be treated or purified water, water leaving the purification plant, water upgraded using membrane techniques (superior bacteriological qualities), or water network.

Advantageously, the sludge resulting from the washing is then reinjected into the treatment reactor during the degradation of the organic material of the fluids, when the fluids are not loaded with metal pollutants.

According to a particular characteristic of the present invention, the method which is the subject of the present invention relates to a method for detoxifying metal-loaded fluid by adsorbing metals by passing on the bed of solid-supported mycelial biomass in the treatment reactor, comprising contacting the fluid to be treated with the bed of mycelial biomass, and the recovery of the fluid detoxified, characterized in that, intermittently, the flow of the fluid is interrupted on the biomass bed and the bed of biomass is washed by circulating a washing fluid in the reactor under hydraulic conditions allowing desorption metals by driving at least a portion of the biomass loaded with metals.

Typically, the metals are selected from the group consisting of chromium, cadmium, nickel, copper, zinc, lead, mercury, aluminum, arsenic, selenium, cobalt, and mixtures thereof.

Advantageously according to the present invention, the washing fluid is an aqueous solution, such as water, an acid, a base, or mixtures thereof. In a particularly advantageous manner, the washing fluid is water. The washing fluid may for example be treated or purified water, water leaving the purification plant, water upgraded using membrane techniques (superior bacteriological qualities), or water network. Advantageously according to the present invention, during the detoxification, the bed of biomass is washed after having reached a threshold value of pressure drop in the reactor and / or a threshold value of the ratio of the content of MES of the fluid output by relative to the MES content of the fluid entering the reactor.

Advantageously according to the present invention, the hydraulic conditions for desorbing the metals are obtained with a flow rate of the washing fluid which is 5 to 30 times, advantageously 5 to 25 times, in particular 20 to 25 times, greater than the speed of the washing fluid. passage of the fluid on the biomass bed during adsorption.

By the term "fluid velocity" is meant in the sense of the present invention the ratio: hydraulic flow rate of the fluid on the ground surface of the treatment reactor.

Furthermore, the hydraulic conditions, such as the type of flow (laminar, turbulent, etc.), during the washing operation may advantageously be chosen so as to desorb the metals by driving at least a part of the biomass loaded with metals out of the treatment reactor (1). In a particular embodiment of the present invention, the bed of mycelial biomass is in the form of a fixed bed, in particular when the fluids to be treated are effluents, and not sludges. Advantageously in this case, Hydraulic conditions for desorbing the metals are obtained with a flow rate of the washing fluid of between 40 and 60 m / h, advantageously of the order of 50 m / h, for a fluid flow rate on the bed of biomass during adsorption of between 2 and 5 m / h, advantageously between 2 and 3 m / h.

In another particular embodiment of the present invention, the bed of mycelial biomass is in the form of a fluidized bed during detoxification. Advantageously in this case, the hydraulic conditions for desorbing the metals are obtained with a bed expansion rate of between 25 and 60%, advantageously between 30 and 50%, during the washing operation, for a rate of expansion. of the bed of between 15 and 35%, advantageously of the order of 20%, during the adsorption of metals, provided that the rate of expansion of the bed during washing is always greater than the rate of expansion of the bed during adsorption.

In another particular embodiment of the present invention, the bed of mycelial biomass is in the form of a moving bed during detoxification. The treatment reactor is then a moving bed reactor (MBBR).

In this embodiment of the present invention, the micromycetes are fixed on a plastic lining (3), advantageously having different specific surfaces. The plastic lining (3) on which the biomass is fixed can be extracted from the reactor (1) for washing in a washing tank (11). Advantageously, the washing tank (1 1) may be a decanter or a reactor promoting settling.

The washing is advantageously carried out as follows:

The packings and sludge fluid of the process reactor (1) are pumped (16) to a wash tank (11) by means of pumping means. The floating power of the plastic packings (3) which rise to the surface in the washing tub (11) is used, and the sludge is allowed to settle in the tub (11), which is preferably a decanter. Preferably, the settling of the sludge is a summary settling

(That is to say, there is always a little sludge and effluent loaded into the tank (11) that have not decanted). The sludge at the bottom of the tank (11) is then withdrawn by means of recirculation means (15), for reintroduction into the main treatment reactor (1). Advantageously, a grid (13) is used in the washing tub for retain the packings in the tank (11) during the reintroduction of the fluid from the tank (1 1) to the reactor (1).

The operation of washing the packings in the tank (11) is then carried out.

The objective of the washing operation is to unhook the linings (solid supports) metals or toxic pollutants intimately attached to the micromycetes since fixed in their cell wall. Advantageously, the washing is carried out with stirred water or water at high pressure, or with reagent baths (acid, base).

The washing can also be carried out with any disintegration technique such as mechanical shear-type disintegration, or by using ultrasound to disintegrate the material and pick up this fixed biomass on the packings.

At the end of the washing, the settling is advantageously allowed to take place again in the tank (1 1), then the concentrate (the decantate) (17) is withdrawn from the bottom of the tank.

(11) using pumping means. The concentrate (17) is a polluted concentrate

(loaded with metals and toxic pollutants, and loaded with dissolved and organic matter), which is driven out of the tank (11).

Floating packings supernatant in the tank (11) are then re-introduced into the reactor using pumps (16) or any other system for conducting these packings to the main treatment reactor (1).

In a particularly advantageous manner according to the present invention, it is possible to seed the supports or packings (3) at the end of the washing step in the tank (1 1) using micromycetes. Typically, the micromycetes are grown in a separate bioreactor (8), in parallel with the treatment reactor (1) and the wash tank (11). Advantageously, the micromycetes are injected from the bioreactor (8) to the washing tub (11). This embodiment is advantageous since the micromycetes injected into the tank (1 1) are then in a medium adapted to mycelial growth, which accelerates and promotes the formation of biomass on the packings (3). The packings (3) are then already re-seeded when they are then reintroduced into the treatment reactor (1).

In a particular embodiment of the present invention, the method further comprises a preliminary step of solubilizing the metals of the fluids to be treated. The subject of the present invention is also a plant for the degradation of the fluid organic material and / or the detoxification of a fluid loaded with metals, comprising at least one treatment reactor (1) containing: injection means (2) for the fluid treating, - a bed of biomass (3) mycelium fixed on a solid support, a gas injection device (4) such as air, extraction means (5) of the treated fluid, optionally means for extraction and reinjection of the solid support, optionally injection means (6) of the washing fluid, and - optionally extraction means (7) of the washing fluid.

Advantageously according to the present invention, the treatment reactor (1) further contains means for regulating the temperature, pH and / or oxygenation. The treatment reactor (1) may also comprise means for regulating the flow rates for injection and extraction of the fluid to be treated and / or the washing fluid.

This installation is suitable for implementing the method according to the present invention.

Advantageously according to the present invention, the plant further comprises, in parallel with the treatment reactor (1), a bioreactor (8) for continuous culture of micromycetes.

In a particular embodiment of the present invention, the micromycete continuous culture bioreactor (8) comprises: means for injecting nutrients, trace elements, diluted substrate and an inoculum to be cultivated; means for homogeneous distribution of the micromycetes in the bioreactor, transfer means (9) of the micromycetes grown to the treatment reactor (1), and filtration of the air circulating in the bioreactor.

The transfer means (9) may be of the type of solenoid valves or pumps. The sizing of the bioreactor (8) allows a monthly injection in a range of 1/5 to 2/3 of its reserve capacity. Advantageously according to the present invention, the installation further comprises, upstream of the treatment reactor (1), means for treating the fluid to be treated ultrasonically.

In a particular embodiment of the present invention, the plant further contains, upstream of the treatment reactor (1), means for solubilizing the metals of the fluids to be treated, such as anaerobic reactors, and / or means acidification (14).

The plant according to the present invention may contain a single treatment reactor or several associated processing reactors in parallel (flow sharing) or in series, especially in industrial applications. If the plant according to the present invention contains several treatment reactors, it is possible to selectively dimension each of the structures constituting the pathway by selecting a particular bed of mycelial biomass (specific mycelial cocktail), specific treatment conditions (pH, temperature). , and by adjusting the hydraulic and / or rheological operating parameters (climbing speed and useful height of material in particular).

Typically, the installation can comprise two treatment reactors within each of which is carried out a detoxification of the fluid. The first treatment reactor can then be a roughing work where the majority of the metal pollution is clipped, and the second processing reactor can be a refining work to remove the remaining metals. In a particular embodiment of the present invention, each of the reactors may be specific according to a concentration range and the type of metals to be decontaminated.

Various objects and advantages of the present invention will become apparent to those skilled in the art by way of reference to the following illustrative drawing: FIG. 1 is a schematic sectional view of a fluid treatment reactor (1) which comprises means injecting (2) fluid to be treated, a sand layer (12) surmounted by a fluidized bed of biomass (3) mycelium fixed on a solid support pozzolan type, an air injection device (4) in the form of bubbles of different diameters such as a booster supplying an air diffusion system, means for extracting (5) the detoxified fluid, means for injecting (6) the washing fluid, means for extraction (7) of the washing fluid containing at least a part biomass loaded with metals, and, in parallel with the treatment reactor (1), a continuous micromycete culture bioreactor (8) equipped with transfer means (9) for micromycetes grown to the treatment reactor (1). Figure 2 is a schematic sectional view of a fluid treatment reactor (1) containing a fixed culture of micromycetes moving bed. The treatment reactor (1) comprises fluid injection means (2) to be treated, a mobile bed of mycelial biomass fixed on a solid support (3) of the plastic packing type, an air injection device (4). ), extraction means (5) of the detoxified fluid, a grid (13) for retaining the packings (solid supports) when extracting the fluid from the reactor. In parallel with the treatment reactor (1), there is a washing tank (11) containing the packings (3) floating in the tank, a grid (13) for retaining the packings (solid supports) when the fluid of the tank. The washing tub (1 1) also contains means for extracting the concentrates (17) loaded with metals. Recirculation means (15) is used to return fluids such as sludge from the wash tank to the treatment reactor (1). A means (16) for extracting and reintroducing the packings makes it possible to send the packings into the washing tub (11) for the purpose of being washed, and then to reintroduce the packings freed from the majority of the metal pollutions in the reactor. treatment (1). Advantageously, the treatment reactor (1) and the washing tank (1 1) may contain stirring means.

FIG. 1 corresponds to an embodiment of the method that is the subject of the present invention, in which the treatment reactor is in fluidized form. The fluid extraction means (5) and the extraction means (7) of the washing fluid containing at least a portion of the metal-loaded biomass may be merged at the outlet of the reactor (1) in the context of the present invention. invention, as shown in Figure 1, and each of the extracted fluids can then be directed to an extraction circuit of its own, for example using a valve system. Advantageously, the fluid to be treated can be previously stored in a storage tank (10) or supply, before being transferred, for example by means of pumps, to the treatment reactor (1). The fluid to be treated can undergo a pretreatment using acidification means (14) to promote the solubilization of metals.

The treatment reactor (1) is advantageously provided with a fluid recirculation circuit to be treated, of the effluent or sludge type, in order to promote fluidization and expansion of the bed of mycelial biomass (3). A recirculation pump is then advantageously installed on a recovery tank (1 1), which is preferably equipped with stirring means to prevent sludge or effluent settling. The recovery tank allows in particular to eliminate the surplus air before the recovery of the fluid to be treated by the recirculation pump. The treated fluids can be recovered overflow from the recovery tank (11), and can be transferred, for example by gravity, into a sludge or effluent extraction tank.

The air injection (4) can be carried out directly in the treatment reactor

(1), or can be performed in the recirculation line, preferably downstream of the recirculation pump. The injection of air (4) into the recirculation pipe makes it possible to promote the dispersion of the air within the fluids to be treated, and to limit the preferential passages that can cause a gas injection at a point in the reactor.

The process according to the present invention can effectively treat various types of fluids, such as sludge or raw urban or industrial effluents, concentrated in toxic metals. The method according to the present invention is advantageously used to treat effluents or sludge predominantly urban, including sludge from a biological treatment anacrobic or aerobic, or a so-called primary or physicochemical treatment. The fluids which can be treated in the context of the present invention may be more or less loaded with MES, and may have contents of between 5 and 30 g / l, advantageously between 5 and 15 g / l, in particular between 8 and 10 g / l. g / L.

The metals that can be treated by the present invention are of various types, and may be in varying concentrations in the fluid to be treated.

The treatment of fluids according to the present invention can be carried out continuously or discontinuously (batch type). When the treatment is carried out continuously, the treatment reactor is continuously fed with the fluid to be cleaned and the fluid is extracted partially or completely detoxified. The treatment is simply interrupted for a short period of time during which washing the biomass bed with a washing fluid to entrain at least a portion of the biomass loaded with metals.

When the bed is in fluidized form, the fluid to be treated is advantageously recirculated in the treatment reactor. The treatment reactor (1) according to the present invention is advantageously a cylindrical reactor of vertical axis, with a height generally of between 1 and 5 meters, typically about 2 to 4 meters. In one embodiment, it is possible to envisage a civil engineering design of the treatment reactor (1). By the term "cylindrical" is meant in the sense of the present invention a surface generated by a generator that moves parallel to a fixed direction based on a fixed plane profile perpendicular to the given direction. Thus, the perimeter of the base of the treatment reactor (1) can be in various forms, such as the square or rectangular shape.

The introduction of fluid to be treated in the treatment reactor (1) can be performed by an injection manifold (2) equipped with orifices of adjusted diameter. The introduction of fluid can also be carried out using a strainer floor, preferably provided with several strainers distributed over the section of the treatment reactor (1). The strainers have orifices preferably between 0.5 and 5 mm, even more preferably between 1 and 2 mm. In an exemplary embodiment of the present invention, as shown in FIG. 1, a layer of sand or a similar material is placed in the treatment reactor (1) under the biomass bed (3) in fixed culture. , advantageously above the injection means of the fluid to be treated, the floor type strainer. The sand may be coarse sand with a particle size of between 4 and 5 mm. The layer of sand or similar granular material used makes it possible to support and maintain the biomass bed (3) in culture fixed in the treatment reactor (1), and to improve the dispersion of sludge or effluent in the biomass bed .

The biomass bed (3) according to the present invention can be fixed or mobile. When the fluid to be treated is water or an effluent having MES contents of less than 5 g / l, a fixed bed is advantageously used.

When the biomass bed (3) is fixed, the treatment reactor (1) can be upflow or downflow. The fluid to be treated can thus be introduced in part upper reactor and this fluid is advantageously brought into contact with the bed of mycelial biomass by percolation, over the entire height of the reactor, preferably from one end to the other of the reactor. The detoxified fluid is then advantageously recovered using a recovery device (5), such as a set of crenellated chutes.

When the biomass bed (3) is in moving or fluidized form, the treatment reactor (1) is preferably upflow. The biomass bed is then no longer compacted, but is in the expanded state. When the support of the biomass bed is an inert granular support such as pozzolan, the bed can not be suspended by mechanical stirring, because of the friable nature of the support material. The bed is then advantageously put in fluidized form by recirculation of the effluents or sludge in the treatment column (1). The recirculation flow rate, which is preferably 10 to 100 times greater than the supply flow rate of the fluids to be treated, makes it possible, in addition to the feed rate, to reach within the biomass bed the minimum fluidization speed, the speed beyond which the bed becomes expanded. Once the bed is expanded, suspended solids can pass through it, preventing clogging of the treatment reactor (1).

When a bed of biomass (3) is used in fluidized form, the fluid to be treated is advantageously introduced into the lower part of the reactor, preferably at the base of the reactor. The detoxified fluid is then advantageously recovered in the upper part of the reactor, for example by overflow, with the aid of a recovery device (5), such as a set of crenellated chutes. The detoxified fluid, partially or almost completely, may also be recovered from a fluid recirculation line (as shown in Figure 1). Advantageously according to the invention, the biomass is fixed on an inert solid support allowing to favor its development. The support thus makes it possible to facilitate the concentration of the biomass. Indeed, it has been validated that the growth of micromycetes and the efficient retention of metals from the fluids to be treated were improved by the presence of an inert solid support on the surface of which the micromycetes and therefore the metals retained in their chitin can to stare. Typically, the solid support is an inert granular support, with a particle size of between 1 and 3 mm, preferably of the order of 2 mm. The solid support can sieved before being injected into the reactor. In a particularly advantageous manner according to the present invention, the support used is a support based on pozzolan, preferably having a particle size of between 1 and 3 millimeters. Preferably, a support having a distribution distribution the least dispersed possible.

Biomass used can be isolated from the ground or various pre-existing ecological systems. Micromycetes for generating mycelial biomass can be of various kinds. Micromycetes are microorganisms particularly adapted for the retention of various metals, and are advantageously used in the context of the present invention in the form of a mycelial consortium. Typically, one proceeds to the simultaneous development of a set of synergistic species of micromycetes. The type of micromycetes injected into the treatment reactor is determined according to the nature of the fluids to be treated and the types of metals that are to be fixed. Advantageously according to the invention, the metals to be eliminated are fixed by adsorption in the cell walls of the fungi, more particularly at the level of the predominant constituents of the cell wall, i.e. in the chitin of the fungi.

By the term "micromycetes", reference is made to microorganisms, as opposed to higher fungi. We understand at the same time the notion of mycelium which is the vegetative apparatus, and the spores (reproductive apparatus). In addition, any lower fungus, used in an amount sufficient to contribute to the detoxification of sludge or effluents, this detoxification is evaluated by techniques appropriate to the scope of the skilled person. Thus, the species cited in the context of the present invention are to be considered as non-limiting examples, the invention covering the use of species whose metal retention activity is demonstrated. In the following description, the term micromycete or mycelium (plural mycelia) will be used interchangeably for the sake of simplicity.

Preferably, for micromycetes, particularly suitable are species that can be selected by appropriate selection protocols. This selection of strains then cultured facilitates the production in large quantities of an active mycelial preparation for adsorbing the toxic pollutants of the solutions to be treated. Once the selection of strains has been made, a preparation of at least one of these strains will be administered to the fluids to be treated at the implementation of the installation.

Among the micromycetes that are effective in cleaning up fluids, some species can be found in sewage sludge. We speak of endogenous micromycetes. But, in general, these micromycetes are present in insufficient quantities in these sludges to detoxify them sufficiently. And, they are not implanted under conditions favoring the mode of metabolism sought for optimal fixation of metal pollution. Some species can also be obtained from other biological sources. Advantageously according to the present invention, the fluid that one wants to detoxify is brought into contact with the biomass over the entire height selected in the core of the treatment reactor, for example by means of iluidization. Recirculation ensures almost permanent contact during the defined residence time.

The detoxification of the fluids can be carried out within the aerobic or anaerobic treatment reactor. The treatment reactor (1) thus advantageously contains a device for injecting gas (4) in the form of bubbles, which are advantageously of different diameters. The gas injection device (4) is preferably arranged in the immediate vicinity of the lower part of the reactor, in particular when using a fluidized bed of biomass. The gas injection device (4) is advantageously in the form of a booster, preferably provided with a non-return valve to prevent the rise of sludge or effluent at the booster.

In a particular embodiment of the present invention, the treatment reactor (1) is aerobic. A venturi system can then be used to allow the direct introduction of atmospheric air into the reactor (1). The introduction of air by a compressor or a blower into the flow of the liquid to be treated can also be used with or without venturi. The air injection device (4) makes it possible both to supply the oxygen necessary for the development of the biomass and to suspend the carrier particles of microorganisms when a fluidized bed of biomass is used. In a particularly preferred manner according to the present invention, the detoxification is carried out with an oxygenation of the order of 0.2 to 2 mg / l of oxygen. dissolved, even more advantageously between 0.5 and 1.5 mg / L, for example of the order of

1 mg / L.

In another particular embodiment of the present invention, the treatment reactor (1) is anaerobic. A cocktail of fungi developing under strict anaerobic or anaerobic conditions is then advantageously used. The gas injected into the reactor (1) can then be hydrogen or methane. This gas can be recirculated in the reactor (1), especially when using a fluidized bed of biomass.

The detoxification can be carried out in temperature ranges ranging from 20 to 50 ^° C., advantageously at room temperature. The detoxification of fluids, such as sludge, in the reactor can be carried out at neutral pH, advantageously at a pH of the order of 6 to 8. It can also be carried out at acidic pH, for example at a pH of order of 4 to 6, in order to increase the purification performance of micromycetes.

The pH of the treatment reactor can then be regulated using a mineral acid such as sulfuric acid, nitric or hydrochloric acid, or an organic acid of the acetic acid type.

Advantageously according to the present invention, the MES contents are measured at the inlet and at the outlet of the reactor in order to ensure that the fluids such as the sludge are not retained in the bed of mycelial biomass, and that the biomass is able to exercise its adsorbent power. The measurement of the MES contents at the inlet and the outlet of the reactor is a good indicator of the clogging of the column.

Advantageously according to the present invention, the nature and / or the particle size of the solid support, the height of the bed, the speed and the flow rate of the fluid to be treated or recirculated, the rate of expansion of the bed when using a bed of biomass in mobile form, or the contact time of the fluid to be treated in the reactor, are chosen so as to exert effective adsorption of metals, preferably of the order of 20 to 99%, in particular 45 to 85% .

According to an exemplary embodiment of the present invention, an effluent or sludge contains, at the inlet, zinc contents of the order of 1000 mg / kg of solids, copper contents of the order of 600 mg / kg of materials. dry matter, and chromium contents of the order of 6180 mg / kg of solids. On leaving the reactor after having used the process according to the present invention for at least 1 day (24h), the effluent or the sludge may contain zinc contents of the order of 150 mg / kg of solids, copper of the order of 96 mg / kg of dry matter, and levels of undetectable chromium. The metal retention rates are then respectively of the order of 85% for zinc, 84% for copper, and about 100% for chromium. Following the washing operation, at least 75 to 85% of the metal pollution is found in the metal pollution concentrate entrained out of the treatment reactor. This percentage changes over time. Advantageously according to the present invention, the washing operation is a partial wash, aiming at detaching 50 to 80% of the biomass that has developed on the grains. The metallic pollution is recovered as time goes by in the metal pollution concentrate entrained out of the treatment reactor, following the various washes performed. Typically, the contact time in the treatment reactor (1) is of the order of a few hours to a few days, preferably 1 to 2 days. The height of the biomass bed at rest can be determined as a function of the contact time and the velocity of the fluid in the treatment reactor.

Typically, the treatment reactor (1) is filled with 30 to 70%, advantageously 50 to 60%, of granular material of the pozzolan type which will constitute the solid support of the biomass bed.

In a particular embodiment according to the present invention, the biomass bed is in fluidized form and the injection of fluid to be treated, as well as the injection of gas such as air, into the reactor lead to an expansion of the material. adsorbent by creating a mobile bed of mycelial biomass. Advantageously, the fluid is recirculated in the treatment reactor (1), preferably with a recirculation rate 10 to 100 times greater than the feed rate of the fluids in the reactor, in order to promote fluidization and expansion of the reactor. bed.

Typically, the speed of the fluid in the reactor is chosen as a function of the retention rate of the metals that one wishes to obtain, and / or as a function of the contact time. Advantageously according to the present invention, after having circulated the fluid to be treated on the bed of mycelial biomass in fixed culture for a certain time, thus leading to the retention of toxic metals by adsorption, at least one washing of the biomass bed is carried out. using a washing fluid, such as water, which is injected into the treatment reactor (1). The nature of the washing fluid used depends on the medium and the selected mycelial species, as well as the operating constraints and the characteristics that one wants to give to the concentrate of metallic pollutions (pH of the concentrate).

Typically, the washing of the bed is carried out every 1 to 3 days. The frequency of the washing depends in particular on the nature and the concentration of the sludge or effluent to be treated, the volume of the treatment reactor and the Montasse bed, the operating constraints and the level of depollution required. Washing frequencies may be periodic, but not necessarily. Periodic washing frequencies are generally used when the process according to the present invention is carried out in an automated manner.

Advantageously according to the present invention, the bed washing operations are triggered when a rise in pressure drop in the reactor (1) is observed and / or an increase in the ratio of the content of the MES of the fluid leaving the reactor by relative to the MES content of the reactor inlet fluid (1). Indeed, an increase in pressure drop in the treatment reactor, typically of the order of 20 to 50%, advantageously 40 to 50%, or an increase in the content of

MES output fluid, typically of the order of 10 to 20%, relative to the initial MES content of the fluid to be treated, are reliable indicators of clogging of the bed, and the obstruction of the passage of fluid in the reactor. The flexibility of the process depends on the concentration and quality of the sludge being treated.

Thus, the monitoring of the MES content of the fluid entering and leaving the treatment reactor, as well as the monitoring of the pressure measurement at a point in the reactor (to determine the pressure drop) make it possible to determine when the washing bed must be done and how often. Typically, digital pressure sensors can be used to determine when the wash should be started. Instead of monitoring the SS content of the fluid entering and leaving the reactor, it is also possible to monitor the content of the fluid in MS (dry matter), in MV (Materials Volatiles), or in MVS (Dry Volatile Matter), or use diverted indicators.

In general, the bed of biomass is washed after having reached a threshold value of pressure drop in the treatment reactor (1) and / or a threshold value of the ratio of the content of MES of the outlet fluid with respect to the MES content of the fluid entering the reactor (1).

In a very particular embodiment according to the present invention, when the fluids to be treated are particularly rich in metals and then have metal contents of the order of g / L, the monitoring of the saturation rate of the adsorption sites of the bed and metal content of the input-output fluids can be used as limiting factors to determine when should be triggered bed washing operations. Advantageously, it is possible to implement an analysis of the metals in line, thus obtaining an accurate indication of the needs of the washing sequences. In general, when the metal contents of the fluids to be treated are of the order of one hundred mg / L, it is advantageous to use limiting factors for monitoring the content of MES of the fluid entering and leaving the treatment reactor. , as well as the monitoring of the pressure drop in the reactor, to determine when to wash the bed of biomass. Fluid turbidity monitoring can also be used as a limiting factor.

The hydraulic conditions of the washing fluid, such as the flow rate or the flow rate of the washing fluid, are chosen so as to obtain an effective desorption of the metals by driving at least a portion of the biomass loaded with metals, advantageously by entrainment of at least 50%, still more preferably at least 70%, in particular at least 80%, of the biomass loaded with metals. Advantageously according to the present invention, the washing is carried out under faster flow conditions than during the adsorption phase, in order to unhook at least part of the grain biomass of the support, and to drive out of the reactor a concentrated toxic metal pollution. The detoxification process according to the present invention makes it possible to separate and remove from the treatment reactor (1) a metal pollution concentrate having a very small volume relative to the volume of fluid to be treated at the inlet of the reactor. Advantageously, the process makes it possible to concentrate the metals in a volume of 10 to 1000 times, preferably of the order of 100 times, smaller than the volume of sludge or effluent to be treated. One of the great interests of the process according to the present invention is that the volume of waste to be disposed of can be effectively reduced.

The washing according to the present invention makes it possible to unclog the bed of biomass and to continue the treatment of the fluids to be detoxified. Advantageously according to the present invention, the flow rate or the flow rate of the washing fluid in the reactor are chosen so as to return to the end of the washing at the initial conditions of the MES content of the fluids and pressure drop in the reactor. . In an exemplary embodiment of the present invention, the washing is carried out until the MES contents of the fluid entering and leaving the reactor do not differ by more than 10%, and / or the pressure drop in the reactor. reactor is not increased by more than 10%.

In a particular embodiment of the present invention, the bed of mycelial biomass is in the form of a fixed bed. The washing can then be carried out countercurrently or co-currently in the treatment reactor (1). In a particular embodiment, the flow rate of the washing fluid is 20 to 25 times greater than the flow rate of the fluid during the adsorption phase.

Typically, the flow rate of the washing fluid is about 50 m / h during the desorption phase, for a fluid flow rate on the biomass bed of about 2 m / h during the phase of desulfurization. 'adsorption.

In another particular embodiment of the present invention, the bed of mycelial biomass is in the form of an expanded bed. The washing fluid is then injected into the lower part of the reactor. In a particular embodiment, the expansion rate of the bed is of the order of 50% during the washing operation for a sludge having a MES content of the order of 10%, whereas the rate of Expansion of the bed is of the order of 20% during the adsorption phase of the metals. In another exemplary embodiment of the present invention, the expansion rate of the bed is of the order of 35% during the washing operation for a water that is slightly loaded with MES, whereas the rate of expansion of the bed is of the order of 15% during the adsorption phase of the metals. Advantageously according to the present invention, the process according to the present invention makes it possible always to leave in the reactor part of the fixed culture mycelial biomass, thus making it possible to reuse the remaining biomass and to renew mycelial biology much more easily for the treatment operations. later. Advantageously, a partial or partial washing of the bed of mycelial biomass is carried out in the context of the present invention.

Without being limited to such an interpretation, the Applicant has observed that the more the support was colonized and the more the mycelial biomass had exerted its power of adsorption and metabolization of metals, the easier it was to unhook part of the charged biomass. in metals and the training out of the reactor of a concentrate of toxic pollutions. Thus, the simple injection of the washing fluid into the reactor under fast flow conditions makes it possible to unhook part of the biomass concentrated in metals.

The washing fluid loaded with metals is recovered, after having circulated on the biomass bed, using an extraction device (7) of the washing fluid. It may for example be collected by overflow in the upper part of the reactor using a recovery device, such as a set of crenellated chutes, when the injection of the washing fluid is in the lower part of the reactor. The metal loaded wash fluid can also be recovered from a fluid recirculation line (Figure 1).

In an exemplary embodiment of the present invention, it is possible to use an intermediate tank (1 1) which is located on a recirculation loop between the injection means (6) of the washing fluid and the extraction means (5). fluid.

The washing sequence can thus take place as follows. The passage of the fluid to be treated is temporarily interrupted on the bed of biomass, and the intermediate tank (11) is emptied, which is then filled with wash water, for example effluents leaving the outlet. sewage treatment plant that are lightly loaded. Then, the washing water is circulated in the reactor (1) by passing it over the bed of biomass (3), for example at a rate of 350 L / h (40% of the pump) for 15 minutes. . Then, it is proceeded to the emptying of the intermediate tank (11), which is then filled with washing water, and the toxic pollution concentrate is recovered in an auxiliary tank. Then, the washing water is circulated again in the reactor (1) by passing it over the biomass bed (3) at a higher rate than during the first washing sequence, for example at a rate of about 435 L / h (50% of the pump) for 15 minutes. Then, the intermediate tank (11) is emptied again, which is then filled with water, and the toxic pollution concentrate is recovered in an auxiliary tank.

Several passages of the washing fluid on the biomass bed can thus be carried out within the scope of the present invention, before resuming the treatment of fluids to be detoxified by adsorption of the metals in the reactor.

Advantageously according to the present invention, the micromycetes are cultivated in parallel continuously in a micromycete continuous culture bioreactor (8), separated from the treatment reactor (1), and the micromycetes are injected into the treatment reactor (1). from said bioreactor (8), advantageously using transfer means (9). The injection of the micromycetes into the reactor (1) is preferably carried out by gravity, or by means of valves that are opened and closed with a fixed flow rate or, failing this, the pumping technology makes it possible to preserve the microorganisms injected into a favorable metabolism. The continuous culture of micromycetes in a bioreactor makes it possible to ensure the continuous and permanent renewal of the mycelial biomass by bio-increase in the reactor (1). This favors reproduction of mycelial species in situ and anabolic growth of mycelia without external inoculation by adding bioadditives to the reactor. Preferably, it is desired to generate self-stabilization of the mycelial species in the treatment reactor (1). Advantageously, the treatment reactor (1) and the bioreactor (8) are inoculated as soon as they are put into service. Preferably, the treatment reactor is inoculated as soon as it is put into service using micromycetes produced under specific conditions. Typically, the reactor (1) is inoculated with 0.5 to 15%, advantageously from 3 to 6%, in particular from 4 to 6%, of micromycetes, preferably in the form of a mycelial cocktail, relative to the volume of the mixture. sludge or effluent and granular material of the pozzolan type present in the reactor (1). Injections of micromycetes into the treatment reactor (1) from the bioreactor (8) are preferably carried out periodically, for example every 2 months. The biomass in the treatment reactor (1) is thus regularly regenerated.

The fluids to be treated are advantageously enriched with nutrients (source of carbon, nitrogen, etc.) or carbonaceous substrates of the molasses type, preferably molasses of the sugar industry, starch, or malt extracts. The nutrients or carbon substrates are advantageously injected into the bioreactor (8), and can also be injected directly into the treatment reactor (1).

The amount of micromycetes injected into the treatment reactor from the bioreactor (8) is determined so as to always have a concentration of species sufficient to ensure the retention of metallic pollutions by adsorption. New species are thus regularly injected into the treatment reactor (1) in order to constantly regenerate the mycelia, especially in order to replace fungi which have assimilated too many metals and which are therefore lysed. Indeed, it was discovered that there was a lethal dose of metals for fungi, and that the fungi generally underwent intoxication and lysis after having assimilated a dose in metals higher than this lethal dose.

In one embodiment, repetitive inputs of biocatalysts may be automatically performed during the process. In this case, fluids, such as sludge, loaded with micromycetes (application of inoculation to the first day) serve as inoculum themselves. However, in some cases, given the richness and natural complexity of the sludge or microorganism effluent, micromycete cultures may not be specific enough (uncontrolled development in the presence of nutrients from non-specific and non-specific flora). repetitive).

A mixture of a selected "exogenous" fungi and other "endogenous" amplified and nutrient regulated flora will preferably be used. The process then makes it possible to constantly overdose the "active ingredient" and to maintain the technical performance despite variations in the flow or the composition of the fluids to be detoxified. The bioreactor (8), allowing on-site production and / or continuous injection of microorganisms into the reactor (1), allows permanent and optimal colonization of the sludge. Compared to the definition of the chemostat mode (a culture in a renewed environment) which involves a single inoculation in the first day and then self-sufficiency, this is an additional security. At the start of the installation, the system is inoculated with a cocktail selected and adapted to the type of fluid to be detoxified. This step allows the start of the installation because it generates the autonomous operation of the whole.

The continuous culture of micromycetes in the bioreactor (8) is preferably carried out aerobically. The bioreactor (8) is specially configured for continuous micromycete culture. The bioreactor (8) operates according to the principle similar to the "trickle bed", preferably using a preferably lamellar lined support, or a plastic support in the form of a strip, allowing the development of a mycelial biology. This bioreactor, which could be called "mycelial bed", is used to grow aerated mycelial cocktail after being selected for each type of fluid to be treated.

The size of the bioreactor (8) is dependent on the flow to be treated, but also on the quality and / or the composition of the effluents to be treated. The bioreactor (8) is generally of small volume relative to the treatment reactor (1). Typically, the bioreactor (8) occupies a useful volume 50 to 500 times, advantageously 50 to 100 times, smaller than the main treatment reactor (1). For example, the useful volume of the bioreactor (8) may be of the order of 1 m ³ , for a reactor volume (1) of the order of 50 m ³ . An appropriate amount of mycelial preparation is transferred via line (9) to the treatment reactor (1). The mycelial preparation produced in the bioreactor (8) comprises spores and mycelia.

The volume of fluid treated in the treatment reactor corresponds to a determined residence time, and is seeded by spores and mycelium produced in situ.

The continuous mycelia production bioreactor (8) must be capable of supplying the biomass it contains and growing there with the amount of oxygen it needs. It involves mixing three phases: an aqueous phase (the culture medium), a gaseous phase (the oxygenation gas of the mycelia, typically air), a biotic phase consisting of the majority of mycelium biomass.

The smooth progress of the process is related to the transfer phenomena between the cells (mycelia and spores) and the culture medium. It is first of all a transfer of matter from the external medium to the cell as regards the substrate and the compounds of the culture medium necessary for cell growth, in the opposite direction for the products of the metabolism of the cells in culture. . So that transfers can correctly, the distribution of the cells in the culture medium must be the best possible. In aerobic mycelia culture, it is the oxygenation gas that creates turbulence and allows the maintenance of cells in homogeneous suspension. The geometry of the bioreactor is designed so that oxygen transfer is as efficient as possible. The supply of nutrients makes it possible to promote the development of micromycetes microorganisms and thus has an influence on the kinetic behavior of the present mycelial population.

In order for the microorganisms to be homogeneously distributed, the necessary oxygen to be supplied and the temperature maintained, appropriate transfer means are used. As the mycelial development continues, the cell concentration increases, the concentration of products synthesized by the microorganisms too, while the medium becomes depleted in substrate. Regardless of the microorganism, the bioreactor (8) is designed to allow as good contact as possible between the two biotic and abiotic phases of the system. The bioreactor (8) typically comprises, at the air inlet, an air filtration system, designed to avoid unwanted contamination by microorganisms. This filtration is performed for aerial bacterial microorganisms greater than or equal to 0.22 microns, or microorganisms of the aerial yeast type greater than or equal to 0.44 microns. During the treatment of the fluids in the treatment reactor (1), the rheological and chemical characteristics of the medium change, which leads to changes in operation, the transfers being made in the same way. It is therefore recommended to act on the operating modes to ensure that the mycelial population is at all times in the best conditions and that its kinetic behavior is optimal within the treatment reactor (1): air flow, and / or addition of substrates, or addition of reagents, and / or regulation of the temperature and pH (all these operations being easily automated). The treatment reactor (1) is designed according to the type of process that must take place there.

The bioreactor establishes the established regime of the process described. When the established regime is reached (expected level of metal adsorption performance), the regular supply of a sufficient quantity of fluids such as sludge (substrate for the flora) makes it possible to maintain the mycelial population to a degree of performance. constant. The bioreactor (8) can be in a variety of forms, such as a cylindrical column, of variable height depending on the sizing flows: air, surface of the contact lining. It comprises, for example, three parts: a lower part making it possible to collect a liquid loaded with mycelium, pumped and then poured back into the upper part of the column which forms a spraying system (spray boom designed in such a way that the mycelia are not fragmented). The central portion contains a structured type of packing or other, to optimize the implantation of the cultivated population, its fixation and development in favorable conditions. This packing can be of different types and different materials, the main thing being to allow the attachment of mycelia.

This spraying generated by a recirculation of the liquid (via a pump) allows its runoff on the lining of the tower and thus moistens the mycelia which adsorb the components of the liquid.

This bioreactor (8) is preferably surmounted by a roof-type cover allowing free passage of airflow but preventing rain falls.

The exchanges are favored by a countercurrent between the air and the concentrated liquid percolating on the lining. A thermoregulation may be necessary in the case where the bioreactor (8) would not be protected from freezing. Advantageously according to the present invention, the bioreactor (8) is heated and insulated. The bioreactor (8) is designed to obtain a very limited consumption of inoculum to be implanted, because of the autonomy of the system which operates in recirculation peπnanente, this recirculation ensuring optimal contact for the mycelial population with the constituents promoting its development.

A biological punctual analytical follow-up makes it possible to check the growth of the different species of mycelia constituting the selected cocktail.

A chemical analytical monitoring, existing on the treatment stations with high metal contents, makes it possible to be located on the performances of the system. The detoxification time is predefined according to the initial characteristics, but may vary according to the variations of flow treated upstream. It is a system that adapts perfectly to this kind of fluctuation: the analytical follow-ups make it possible to ensure the good performance of detoxification. Advantageously, the performance of the degradation system of the organic material is quantified by performing analyzes of materials at the inlet and outlet of the treatment reactor: analysis of the MES (suspended matter) or MVS (volatile organic material (at about 555 ^° C. )), representative of organic matter. The same flow gap is an accurate reflection of the degradation of organic matter. In this, typically, the performance of the technology is subtracted from the volume of concentrate extracted from the process.

In a particular embodiment of the present invention, the method further comprises a preliminary step of solubilizing the metals of the fluids to be treated. Indeed, depending on the shape of the metals in the fluids to be treated, it will be necessary to transport these metals to the soluble phase. Studies have already shown that release of the constitutive metals from the soil in the form of leachate (concentrated soluble phase) is caused in anaerobic media. Also, in pre-treatment of the detoxification plant, it may be necessary in some cases (depending on the complexed form of the metal in the fluid such as sludge) to treat the fluid on an anaerobic stage with variable kinetics that can go from minutes to hours or more. In this stage, mycelial species or yeasts usually encountered in digesters can be implanted to target a decontamination of a metal or micro organic pollutant. Such pretreatment can make it possible to dissolve said metal and to treat the dissolved part (more accessible substrate) on the detoxification stage. The implementation of this technology can only be carried out in cases where physico-chemical dephosphatation has been implemented in the water sector. In the case where biological dephosphatation exists on the water chain, this anaerobiosis step can not be implemented without preventing the release of phosphorus.

It will also be envisaged according to the performances achieved with the metal dissolution stage of treating only the supernatant (metal concentrate) having previously separated via a complementary step the pellet and the supernatant (to be considered in the case for example where 50 to 90% of the initially concentrated metal in fluids such as sludge pass into the phase called "aqueous"). Pretreatment by acidification can also be envisaged in order to improve the solubilization of the metals of the fluids to be treated.

The following examples are given without limitation and illustrate the present invention.

Examples of embodiment of the invention:

Example 1

General operating conditions

The test was carried out in a laboratory woman (working volume, 4 L). Pozzolan represents 60% of the height of the reactor or "column". This support is configured as a filter between two pierced plates. The system is continuous: feeding and sludge disposal are provided by pumps. The input / output flow rates are set at 2 mL / min. Aeration is provided by bubbling (unquantified aeration).

Fungal strains

The inoculum consists of 3 micromycetes. These are the genera Mucor and Aspergillus.

Design

To _date , the sludge is enriched with 5% molasses (molasses at 80 g / L). This sludge is inoculated with 3% of micromycetes (stock). The system then runs in batch mode for 3 days. Afterwards, the continuous system is put in place for 25 hours. This can treat about 3 L of sludge.

Analyzes

_Daily sludge (untreated) and at 25 _hours are sent to the laboratory for Ni and Cr assays. Results

The dosages of Ni and Cr (in mg / L) are shown in Table 1 below: Board

In this operating configuration, the capture yields on the bed of mycelial biomass fixed on the support based on pozzolan are shown in Table 2 below:

Table 2:

These results clearly indicate that detoxification with the method according to the present invention is very effective.

Example 2

An installation according to the present invention contains a treatment reactor (1) of the order of 60 L, having a height of 1.60 m for 150 mm in diameter, comprising a floor strainer provided with 3 strainers distributed over the entire section of the reactor, the strainers having orifices of the order of 1 mm. The strainer floor is surmounted by a layer of sand having a particle size of the order of 5 mm, surmounted by a bed of biomass in culture fixed on pozzolan of particle size of the order of 2 mm. The pozzolan height in the reactor is about 1 m at rest. Micromycetes of genus Mucor and Geotricum and Candida yeasts are injected into the reactor. The treatment column is provided with a recirculation circuit for expanding and fluidizing the biomass bed. The recirculation pump operates in a range between 0 and 700 L / h, and advantageously operates at a rate of about 300 L / h. The feed pump, which feeds the sludge to be treated in the column, operates in a range between 0 and 100 L / h. The sludge to be treated, which has MES contents of 8 to 10 g / L, is first admitted to a stirred feed tank, preferably having an acidic pH, and is then fed to the treatment reactor via the feed pump. Sludge is enriched with malt extracts. For 20 liters of pozzolan, a feed rate of the order of 20 L / day can be used. The residence time is then about 24 hours in the treatment reactor. Advantageously, the pump runs a few minutes (about 5 minutes) every 3-4 hours.

The installation is equipped with a booster (range 4 to 6 m ³ / h) to inject into the air recirculation line necessary for the biological functioning of the aerobic cocktail of micromycetes.

The treated sludge can be recovered by overflow, at the upper end of the treatment reactor, or overflow from a recovery tank placed on the recirculation loop. The biomass bed is in fluidized form. The expansion rate of the bed is of the order of 35% during the treatment of sludge by adsorption of metals. After a certain time, the passage of the sludge on the bed of biomass is interrupted and the bed is washed with water, with a bed expansion rate of the order of 50%.

The retention efficiencies are of the order of 73% for cadmium, 72% for nickel and 77% for chromium.

Example 3

The following example is an example of continuous degradation of the urban sludge wastewater treatment plant organic matter. A mycelial cocktail is injected into a treatment reactor to form a bed of mycelial biomass fixed on a solid support. The residence time of the sludge with the bed of mycelial biomass is between 4 and 5 days.

Two tests were carried out using sludge of different origin. For each type of sludge, a suitable cocktail was used. The first test was carried out using micromycetes of the genera Mucor, Galactomyces, and Penicillium. The results are shown in the following Table 3. The degradation yield of the organic material is of the order of 60%. The second trial was carried out using a mixture of micromycetes and mycelial yeasts of the genera Mucor, Candida, and Pichia.

In this test, the recirculation volume is 35 1. The results are shown in the following Table 4.

The meaning of the abbreviations used in Tables 3 and 4 is as follows: MS = dry matter, rec = recirculation, food = feed, V = volume, ext = extraction, I / O = input / output, cum = cumulated ie over the entire period, Delta m = mass variation.

Table 3

O O

O \

O -4 K)

O \ κ>

Abatement yields

Daily mass balance Cumulative mass balance sludge

MS [rec] V alim MS [alim] V ext MS [ext] m alim m ext mol Δ m rec Σm alim Σm ext Δm rec I / O day I / O cum g / l I g / 1 1 g g%

7.5 7.1

4.7

4.6 6.7 0

3.8 6 6.8 5.5 2.7 40.8 14.85 28 40.8 14.85 -28 63.6 63.6

2.5 6 6.8 5.5 2.5 40.8 13.75 45.5 81.6 28.6 -73.5 66.3 65.0

1, 9 6 6.7 6.5 2 40.2 13 21 121.8 41.6 -94.5 67.7 65.8

1.7 6 6.6 6 1, 8 39.6 10.8 7 161.4 52.4 -101.5 72.7 67.5

O H W κ>

O o ⁽ Jy

OO ~ 4

Table 4

Daily mass balance Cumulative mass balance Yield% m I / O

MS date [rec] V alum MSfalim] V ext MS [ext] alim m ext mol Δ m rec Σm alim Σm ext Δm rec I / S eu m cum g / i / g / i / g / ι ggggggg% + rec%

3/11 6

7/11 4,4 6.3

8/11 5,7 6 6.3 6 6.3 37.8 37.8 45.5 37.8 37.8 -10.5 0.0 27.8

9/11 5.5 6 6.2 5 5.9 37.2 29.5 -7 75 67.3 -17.5 10.3 33.6

10/11 5 5 7.6 5 5.2 38 26 -17.5 113 93.3 -35 17.4 48.4

14/11 6.3 22 7.6 22 6.4 167.2 140.8 77 45.5 357.2 234.1 10.5 34.5 31.5

15/11 6.4 6 7 5.5 9.9 42 54.45 3.5 399.2 288.55 14 27.7 24.2

16/11 5.8 6 7.8 6 9.2 46.8 55.2 -21 446 343.75 -7 22.9 24.5

17/11 5.3 5 7.6 5 8.4 38 42 -17.5 484 385.75 -24.5 20.3 25.4

18/11 5.2 5 7.5 5 7.4 37.5 37 -3.5 521, 5 422.75 -28 18.9 24.3

21/11 6.2 27 7 26 7 189 182 77 35 787.5 604.75 7 23.2 22.3

22/11 8.9 7.5 7.2 7.5 9.9 54 74.25 94.5 841, 5 679 101, 5 19.3 7.2

23/11 7.1 6 7.3 5.5 9.4 43.8 51, 7 -63 885.3 730.7 38.5 17.5 13.1

24/11 7.3 6 7.1 5.5 7.1 42.6 39.05 7 927.9 769.75 45.5 17.0 12.1

25/11 6.9 7 7.9 7 7.6 55.3 53.2 -14 983.2 822.95 31, 5 16.3 13.1

28/11 6.8 6 7.7 5.5 6 46.2 33 77 -3.5 1106.4 855.95 28 22.6 20.1

29/11 9.7 6 7.9 6 9.7 47.4 58.2 101, 5 1153.8 914.15 129.5 20.8 9.5

1/12 5.8 7.5 7.7 7.5 7.4 57.75 55.5 -136.5 1211, 55 969.65 -7 20.0 20.5

2/12 7,1 6 7,7 5,5 7 46,2 38,5 45,5 1257,75 1008,15 38,5 19,8 16,8

5/12 4.7 18 7.2 17 4.6 129.6 78.2 77 -84 1464.35 1086.35 -45.5 25.8 28.9

6/12 6 6 7.1 6 8.1 42.6 48.6 45.5 1506.95 1134.95 0 24.7 24.7

7/12 5.8 6 6.8 6 7.5 40.8 45 -7 1547.75 1179.95 -7 23.8 24.2

8/12 6 6 7.1 6 6.1 42.6 36.6 7 1590.35 1216.55 0 23.5 23.5

9/12 5.1 8 6.6.8 6.1 52.8 48.8 -31, 5 1643.15 1265.35 -31, 5 23.0 24.9

12/12 7 7 0 0 77 -178.5 1720,15 1265.35 -210 26.4 38.6

Claims

A method of degradation of organic fluid material and / or detoxification of metal-laden fluid comprising treating the fluid by passage over a bed of mycelial biomass fixed on a solid support in a treatment reactor, the fluid being selected from effluents or sludge from urban wastewater treatment plants.

2. Method according to claim 1, characterized in that the micromycetes of the mycelial biomass are selected from the genera Penicillium, Trichoderma, Mucor, Galactomyces, Aspergillus, Fusarium, Geolricum, Phoma, Botrytis, Geomyces, Saccharomyces, and mixtures thereof.

3. Process according to claim 2, characterized in that the micromycetes are chosen from: Penicillium roqueforti, Penicillium chrysogenum, Penicillium atramenlosum, Trichoderma viride, Trichoderma reesei, Trichoderma harzianum, Mucor hiemalis, Mucor racemosus, Mucor fuseus, Mucor plumbeus, Galactomyces geotricum, Aspergillus phoenicis, Aspergillus niger, Geotricum candidum, Phoma glomerata, Botrytis Cinerea, Geomyces pannorum, and mixtures thereof.

4. Method according to any one of claims 1 to 3, characterized in that the solid support is an inert support, such as an inert granular support, preferably consisting of pozzolana, limestone, sand, pumice, basalt, clay, quartz, anthracite, activated alumina, zeolite, or mixtures thereof, or a plastic support or lining.

5. Method according to any one of the preceding claims, characterized in that the micromycetes are grown in parallel continuously in a separate bioreactor.

6. Method according to any one of the preceding claims, characterized in that it further comprises a preliminary step of ultrasonic fluid treatment.

Process for the degradation of the organic fluid material according to one of the preceding claims, characterized in that the contact time fluid with the bed of mycelial biomass is between 1 and 7 days, preferably between 2 and 4 days.

8. degradation process according to claim 7, characterized in that the bed of mycelial biomass is in the form of fluidized bed or moving bed.

9. Process for detoxifying metal-loaded fluid according to any one of claims 1 to 6 by metal adsorption by passage on the bed of solid-supported mycelial biomass in the treatment reactor, comprising contacting the fluid. to be treated with the bed of mycelial biomass, and the recovery of the detoxified fluid, characterized in that, intermittently, the passage of the fluid on the bed of biomass is interrupted and the bed of biomass is washed by circulating in the reactor of a washing fluid under hydraulic conditions for desorbing the metals by driving at least a portion of the biomass loaded with metals.

10. detoxification process according to claim 9, characterized in that the metals are selected from the group consisting of chromium, cadmium, nickel, copper, zinc, lead, mercury, aluminum, arsenic, selenium, cobalt, and mixtures thereof.

1. A detoxification process according to claim 9 or 10, characterized in that the washing fluid is water.

12. Detoxification process according to any one of claims 9 to

11, characterized in that the bed of biomass is washed after reaching a threshold value of pressure drop in the reactor and / or a threshold value of the ratio of the content of MES of the outlet fluid relative to the MES content of the fluid entering the reactor.

13. A detoxification process according to any one of claims 9 to

12, characterized in that the hydraulic conditions for desorbing the metals are obtained with a flow rate of the washing fluid which is 5 to 30 times, advantageously 20 to 25 times, greater than the rate of passage of the fluid on the bed of biomass during adsorption.

14. A method of detoxification according to any one of claims 9 to

13, characterized in that the bed of mycelial biomass is in the form of a fluidized bed or moving bed.

15. The method of detoxification according to claim 14, characterized in that the hydraulic conditions for desorbing the metals are obtained with a bed expansion rate of between 25 and 60%, preferably between 30 and 50%, during the operation. washing, for a bed expansion rate of between 15 and 35%, advantageously of the order of 20%, during the adsorption of metals, provided that the rate of expansion of the bed during washing is always higher than the rate of expansion of the bed during adsorption.

16. Installation for degradation of the fluid organic material and / or detoxification of metal-laden fluid comprising at least one treatment reactor (1) containing: injection means (2) for the fluid to be treated, a bed of biomass (3) mycelium fixed on a solid support, an air injection device (4), extraction means (5) of the treated fluid, - optionally extraction and reinjection means of the solid support, optionally injection means (6) for the washing fluid, and possibly extraction means (7) for the washing fluid.

17. Installation according to claim 16, characterized in that it further comprises, in parallel with the treatment reactor (1), a bioreactor (8) continuous culture of micromycetes.

18. Installation according to claim 16 or 17, characterized in that it further contains, upstream of the treatment reactor (1), means for treating the fluid to be treated by ultrasound.