System and method for determining at least one operating parameter of a biological treatment plant for biogas production with recovery of nitrogenous nutrients

Abstract

The invention describes the coupling of a digester (110) with a bioelectrochemical system (120) in order to intensify the operation of the digester and recover the ammoniacal nitrogen contained in the digestate (3). The invention determines at least one operating parameter of the digester as a function of a value of a characteristic ratio of the digestate (3) or of the liquid fraction (3a) thereof, representative of an amount of biodegradable organic matter relative to an amount of ammonium ions. The value of this ratio is determined as a function (bi) of a target yield of ammonium ions extracted from the bioelectrochemical treatment system or of a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, and (bii) of the value of at least one operating parameter of the bioelectrochemical treatment system representative of the capacity of the electrochemical treatment system to separate the ammonium ions and of the value of at least one quality parameter of the digestate or of the liquid fraction thereof.

Description

Description Title of the invention: System and method for determining at least one operating parameter of a biological treatment plant for the production of biogas with recovery of nitrogenous nutrients Field of invention

[0001] The present invention relates to the field of effluent treatment by anaerobic digestion, and in particular the coupling of a digester with a bioelectrochemical system allowing the intensification of the operation of the digester and the recovery of the ammoniacal nitrogen contained in the digestate produced during anaerobic digestion. State of the art

[0002] Anaerobic digestion is a cascade of biochemical reactions that convert organic matter in the digester into biogas, which is primarily a mixture of carbon dioxide and methane. The remaining material is called digestate.

[0003] The primary objective of most anaerobic digestion processes is to produce energy in the form of biogas. However, the recovery of nutrients from digestate is increasingly being studied due to the rising prices of inorganic fertilizers, particularly nitrogen fertilizers, and the scarcity of resources, particularly phosphorus.

[0004] Thus, many methods for recovering nutrients from digestate have been developed in recent years. One method involves treating the digestate using an electrochemical process that allows the ammoniacal nitrogen contained in the digestate to be recovered by electrodialysis or by migration from an anode compartment to a cathode compartment. The concentrated ammoniacal nitrogen stream thus recovered can then be separated and concentrated by stripping and absorption. This method has the advantage of limiting the quantity of chemical reagents required for its implementation but requires significant electrical energy consumption due to the significant potential difference that must be applied to the system for the implementation of the electrochemical process.

[0005] It is possible to significantly reduce energy consumption by replacing the electrochemical process with a bioelectrochemical process in which at least one of the redox reactions is catalyzed by electroactive microorganisms. However, implementing this type of process is difficult to control because the electroactive microorganisms' need for biodegradable material competes with the production of biogas from the digestion stage.

[0006] There is therefore a need to couple a digester with a bioelectrochemical digestate treatment system that allows both the production of biogas and the optimization of the recovery of nitrogenous nutrients contained in the digestate at a lower cost. Summary of the invention

[0007] For this purpose, a method is proposed for determining at least one operating parameter of a biological treatment plant for an input containing carbonaceous matter and nitrogen compounds, the installation comprising: a digester adapted to produce biogas, in particular methane, and digestate by anaerobic digestion, and a bioelectrochemical treatment system receiving the digestate or a liquid fraction of the digestate, this bioelectrochemical treatment system comprising electroactive microorganisms and at least one separator capable of allowing ammonium ions to pass when a potential difference is applied.

[0008] According to the invention, the determination method comprises: (a) a step of acquiring (ai) a value of at least one, preferably at least two, parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions, and (aii) a value of at least one quality parameter of the digestate or its liquid fraction, representative of a quantity of ammonium ions relative to a total quantity of cations, (b) a step of determining a value of a characteristic ratio of the digestate or its liquid fraction, representative of a quantity of biodegradable organic matter relative to a quantity of ammonium ions, this value being determined as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, and (bii) the values ​​acquired in step (a), (c) a step of determining at least one operating parameter of the digester as a function of the value of the ratio determined in step (b), the at least one operating parameter of the digester being chosen from the temperature, the concentration of the input, the hydraulic residence time, the residence time of the solids, the mineralizable nitrogen potential of the input.

[0009] The at least one operating parameter of the digester determined by the method according to the invention then generates an inhibited operating mode of the digester. Indeed, this parameter, as determined, leads to a controlled accumulation of biodegradable organic matter and ammonium ions within the digester, this accumulation being necessary to allow the treatment of the digestate by the electroactive microorganisms of the bioelectrochemical system but requiring the digester to operate in a degraded mode.

[0010] For example, ammonium ions are known to cause an inhibitory effect on anaerobic digestion by partially blocking the biochemical reactions of methanization and thus leading to the accumulation of biodegradable organic matter.

[0011] This biodegradable organic matter typically includes organic compounds that can be oxidized by electroactive microorganisms, namely essentially volatile fatty acids (VFAs), and / or alcohols (methanol, ethanol, etc.). VFAs are fatty acids whose carbon chain contains at most 6 carbon atoms. These are mainly acetic acid or acetate, propionic acid or propionate and butyric acid or butyrate, but also isobutyric acid or isobutyrate (iC4 or isoC4), valeric acid or valerate (C5), isovaleric acid or isovalerate (iC5 or isoC5), 2-methyl butyrate (2-mb), caproic acid or caproate (C6).

[0012] Anaerobic digestion processes are usually designed and operated to maximize the degradation of biodegradable organic matter, particularly VFAs and / or alcohols. Depending on the operating conditions of the digester, the degradation of these compounds within the digester can become kinetically limiting, leading to the accumulation of these species. During optimal operation of a digester, aimed at maximizing biogas production, the operating conditions are set so that a large majority of this biodegradable organic matter is thus degraded by the biochemical reactions involved to produce methane.

[0013] In the present invention, the at least one operating parameter of the digester is determined so as to obtain a controlled accumulation of organic compounds from this biodegradable organic matter, which amounts to considering the degradation kinetics of the biodegradable organic matter as non-limiting. This makes it possible on the one hand to significantly increase the load applied to the digester, and therefore to reduce its size during dimensioning, and on the other hand to ensure sufficient operation of the bioelectrochemical system treating the digestate to obtain migration of the ammonium ions and their recovery.

[0014] The invention also provides a method for the biological treatment of an input containing carbonaceous matter and nitrogen compounds to produce biogas and recover ammonium ions, by means of a biological treatment installation as previously described, the method comprising: a step of determining at least one operating parameter of the digester implementing the determination method according to the invention, an anaerobic digestion step during which the digester is operated using the at least one operating parameter previously determined to produce biogas and a digestate or a liquid fraction of digestate comprising biodegradable organic matter and ammonium ions according to the ratio value determined in step (b) of the determination method,a bioelectrochemical treatment step during which the electroactive microorganisms oxidize the biodegradable organic matter contained in the digestate or its liquid fraction, at least a portion of the ammonium ions contained in the digestate or its liquid fraction migrates through the at least one separator and an effluent enriched in ammonium ions is extracted from the bioelectrochemical treatment system.,

[0015] This process thus makes it possible to recover a target value of ammonium ions, which can be optimized, while producing biogas. In addition, the bioelectrochemical treatment step makes it possible to treat the nitrogen present in the digestate at a lower cost since a sufficient quantity of biodegradable organic matter is introduced to migrate the ammonium ions present in the digestate or its liquid fraction. In particular, the process according to the invention makes it possible to accumulate in the digester a quantity of biodegradable organic matter sufficient or just sufficient for the bioelectrochemical treatment, the remainder being degraded to produce biogas.

[0016] The invention also relates to a system for determining at least one operating parameter of a biological treatment installation as previously described receiving an input containing carbonaceous matter and nitrogen compounds, the system comprising: means for acquiring (ai) a value of at least one, preferably at least two, parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions, and (aii) a value of at least one quality parameter of the digestate or its liquid fraction, representative of a quantity of ammonium ions relative to a total quantity of cations, first determination means adapted to determine a value of a characteristic ratio of the digestate or its liquid fraction, representative of a quantity of biodegradable organic matter relative to a quantity of ammonium ions,as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, and (bii) the values ​​received from the acquisition means, second determination means adapted to determine at least one operating parameter of the digester as a function of the value of the ratio determined by the first determination means, the at least one operating parameter of the digester being chosen from the temperature, the concentration of the input, the hydraulic residence time, the residence time of the solids, the mineralizable nitrogen potential of the input.,

[0017] This determination system typically comprises a computer, or more generally at least one processor or any other type of digital calculator. The determination system may also comprise a plurality of separate processors or digital calculators, forming different means of the system, cooperating with each other.

[0018] Finally, the invention also relates to a biological treatment plant for an input containing carbonaceous material and nitrogen compounds to produce biogas and recover ammonium ions, the plant comprising: a digester adapted to produce biogas and a digestate by anaerobic digestion, a bioelectrochemical treatment system receiving the digestate or a liquid fraction of the digestate, this bioelectrochemical treatment system comprising at least one separator capable of allowing ammonium ions to pass when a potential difference is applied.

[0019] According to the invention, the installation further comprises: a system for determining at least one operating parameter according to the invention, a system for regulating the at least one operating parameter adapted to receive the at least one operating parameter from the determination system and to modify the operating parameter(s) of the digester, and optionally of the bioelectrochemical treatment unit, using the operating parameter(s) determined by the determination system. Definitions

[0020] Electroactive microorganisms are microorganisms capable of exchanging electrons with solid, conductive surfaces.

[0021] BOD: Biological Oxygen Demand (quantity of oxygen required to oxidize all organic (biodegradable) matter biologically)

[0022] BOD5: Biological oxygen demand measured after 5 days

[0023] COD or DCOtot: Chemical oxygen demand (measurement of all oxidizable substances, whether biodegradable or not). COD can be measured according to the NFT 90-101 - February 2001 or ISO 6060-1989 standard.

[0024] The methanogenic potential (denoted BMP) corresponds to the maximum quantity of methane produced by a compound during its degradation.

[0025] The mineralizable nitrogen potential corresponds to the maximum quantity of ammoniacal nitrogen produced by a compound during its degradation. Detailed description of the invention

[0026] Other features and advantages of the invention will emerge from reading the description given below of a particular embodiment of the invention, given for information purposes, but not as a limitation, with reference to the appended drawings in which:

[0027] [Fig. 1] is a schematic representation of a biological treatment installation according to one embodiment of the invention;

[0028] [Fig. 2] is a flowchart of the determination method according to one embodiment of the invention;

[0029] [Fig. 3] is a graph representing the methane yield as a function of time during the week obtained during the methanization test of the example;

[0030] [Fig. 4] is a graph representing the concentration of AGVs in the digestate as a function of the time during the week of the methanization test of the example;

[0031] [Fig. 5] is a graph representing the total ammoniacal nitrogen concentration of the digestate as a function of the time in weeks of the methanization test of the example;

[0032] [Fig. 6] is a graph representing the hydraulic residence time of the load in the digester as a function of the time per week of the methanization test of the example.

[0033] The present invention relates to an installation and a method for the biological treatment of an input containing carbonaceous matter and nitrogen compounds in order to produce biogas, and in particular methane, while recovering the nitrogen present in the input in order to recover it.

[0034] For this purpose, the invention uses a system and a method for determining at least one operating parameter of a biological treatment installation comprising at least one digester and a bioelectrochemical treatment system coupled to the digester, directly or via a phase separation system and / or an impurity removal system. In particular, the system and the method make it possible to determine at least one operating parameter of the digester of the installation, and optionally at least one operating parameter of the bioelectrochemical treatment system.

[0035] Biological treatment plant

[0036] The system and the determination method according to the invention are suitable for determining the operating parameter(s) of an installation comprising: a digester suitable for producing biogas and digestate by anaerobic digestion, and a bioelectrochemical treatment system receiving the digestate or a liquid fraction of the digestate, this bioelectrochemical treatment system comprising electroactive microorganisms and at least one separator capable of allowing ammonium ions to pass when a potential difference is applied.

[0037] The bioelectrochemical treatment system is particularly suitable for treating digestate or a liquid fraction thereof. Thus, the electroactive microorganisms are selected from microorganisms capable of oxidizing the biodegradable organic matter of the digestate or its liquid fraction. This selection can be a selection of a pure strain added voluntarily to the system or a selection by a biological process from a mixed microbial culture.

[0038] The ammonium ions separated upon application of a potential difference can typically be extracted from the bioelectrochemical treatment system, for example by an extraction system. This extraction system comprises, for example, a pipe connected to a pump or any other device allowing the withdrawal of a fluid.

[0039] Typically, the bioelectrochemical treatment system may comprise at least one recovery compartment equipped with an extraction system, and electroactive microorganisms separated from at least one recovery compartment by the separator such that, under the application of a potential difference, the ammonium ions contained in the digestate or its liquid fraction migrate through the separator to the recovery compartment.

[0040] An example of the implementation of this installation is described below with reference to figure 1.

[0041] In the example shown in Figure 1, the treatment installation 100 comprises a digester 110, adapted to produce biogas and digestate by anaerobic digestion and a bioelectrochemical treatment system 120 adapted to treat the digestate or a liquid fraction thereof.

[0042] The digester 110 typically has an inlet 111 through which the input 1 to be treated enters, an outlet 112 for evacuating the biogas 2 produced and an outlet 113 for evacuating the digestate 3 produced.

[0043] The digester 110 may comprise one or more bioreactors mounted in parallel or in series adapted for implementing anaerobic digestion in the presence of suitable microorganisms. These may be bioreactors with continuous, semi-continuous or discontinuous feed ("batch"). For example, a sequential reactor also called an SBR reactor (Sequential Batch Reactor), a mixed culture reactor with continuous feed (Meteor™-IFAS), a fixed or free culture reactor, etc. may be used.

[0044] The digestate 3 then enters via an inlet 121 into the bioelectrochemical treatment system 120. The latter also comprises a first outlet 122 for evacuating the treated digestate 4 and a second outlet 123 for evacuating an effluent 5 enriched in ammonium ions.

[0045] In some embodiments, the facility 100 may comprise one or more optional digestate treatment systems 140, configured to separate a liquid fraction 3a from the digestate 3 before its treatment in the bioelectrochemical treatment system and / or to remove impurities from the digestate before its entry into the system 120. The optional treatment system 140 may thus be a phase separation system typically comprising one or more decanters or clarifiers or filters. The optional treatment system 140 may also be a system for removing impurities, for example by screening.

[0046] The bioelectrochemical treatment system 120 comprises at least one separator 124 capable of allowing ammonium ions to pass through. In this example, it further comprises at least one recovery compartment 125 equipped with an extraction system 126 (here comprising a pipe 126a connected to a pump 126b), and electroactive microorganisms capable of oxidizing the biodegradable organic matter of the digestate or its liquid fraction by releasing electrons and separated from the recovery compartment 125 by the separator 124 so that, under the application of a potential difference, the ammonium ions contained in the digestate or its liquid fraction migrate through the separator to the recovery compartment.

[0047] Generally speaking, the separator allows the passage of ions (cations or anions) between the anodic and cathodic compartments. It may include one or more ion exchange membranes, a porous ceramic material allowing the passage of ions, or other. When it has two ion exchange membranes, it may also include an inter-membrane compartment.

[0048] The bioelectrochemical treatment system 120 typically comprises at least one anode compartment 127 coupled to the digester 110 so as to receive the digestate or a liquid fraction thereof and in which there are electroactive microorganisms capable of oxidizing the organic matter of the digestate and its liquid fraction, at least one cathode compartment 128, at least one ammonium ion extraction system 126, and optionally at least one intermediate compartment 129 (e.g. an inter-membrane compartment), these different compartments being separated by separators. In addition, in a usual manner, it typically comprises at least one electrode 130 in each of the anode and cathode compartments as well as means 131 for applying a potential difference between the anodes and cathodes.

[0049] In a preferred embodiment shown in Figure 1, the bioelectrochemical treatment system 120 comprises an intermediate or inter-membrane compartment 129, which is located between the anode compartment 127 and the cathode compartment 128. The separator 124 capable of allowing ammonium ions to pass is then located between the anode compartment 127 and the intermediate compartment 129 which serves as a recovery compartment 125 and is equipped with the extraction system 126. Another separator 124' separates the recovery compartment 125, 129 from the cathode compartment 128. The effluent 5 rich in ammonium ions is extracted from the intermediate compartment 125, 129 via the 126 extraction system.

[0050] In another embodiment (not shown), the bioelectrochemical treatment system 120 does not include an intermediate compartment 129. In this case, the ammonium ion recovery compartment 125 serves as a cathode compartment and is equipped with the extraction system 126. The separator 124 capable of allowing ammonium ions to pass then separates the anode 127 and cathode 125 compartments. The effluent 5 rich in ammonium ions is extracted from the cathode compartment via the extraction system 126.

[0051] Regardless of the embodiment, the bioelectrochemical treatment system 120 may comprise at least one bioelectrochemical reactor - in particular a microbial electrolysis or electrosynthesis reactor.

[0052] A reactor in which only the anode compartment contains electroactive microorganisms can be used, particularly in an abiotic bio-anode / cathode configuration, to couple the treatment of organic matter from the digestate in the anode compartment (by bio-electrochemical oxidation of COD), either with the production of EE from EEO at the cathode in the case of a microbial electrolysis process, or with a reduction of CL at the cathode for a microbial cell,

[0053] Alternatively, a reactor can be used whose anode and cathode compartments contain electroactive microorganisms. By operating as a microbial electrolyzer, this type of reactor can be used in bioelectrosynthesis processes coupling digestate treatment at the anode and carbon molecule synthesis at the cathode. By operating as a microbial fuel cell, this type of reactor can be used to couple digestate treatment at the anode with denitrification treatment at the cathode of the digestate or another effluent.

[0054] In one embodiment, the bioelectrochemical treatment system can thus be used as a microbial fuel cell to produce electric current. In another embodiment, the bioelectrochemical treatment system can be used as an electrolysis system or a microbial electrosynthesis system. It can then be used to produce dihydrogen (EL) or chemical molecules of interest (methane, organic acids, alcohol, etc.). When methane is produced, the total quantity of methane produced by the installation according to the invention can be increased.In this case, the at least one cathode compartment comprising electroactive microorganisms may comprise at least one inlet for a carbon source, typically injected in the form of gas, such as CO2, biogas, or syngas, and / or introduced in solution in the form of organic carbon, for example acetate, and / or in the form of mineral carbon, in particular a bicarbonate.

[0055] In general, electroactive microorganisms are present in the form of a biofilm on the surface of the electrode. The latter can be flat, brush-shaped or in granular form, in a fixed or fluidized bed. Examples of reactors that can be used are described in documents FR3123347A1 and W02020 / 053529A1.

[0056] Regardless of the embodiment, the separator may comprise a membrane cation exchange membrane and an anion exchange membrane separated from each other by an inter-membrane compartment comprising a system for extracting molecules (typically soluble molecules) present within the compartment. The inter-membrane compartment is thus capable of collecting the ions or molecules produced in the anodic and / or cathodic compartments. The molecules recovered at this inter-membrane compartment include, for example, ammonium salts, and, depending on the composition of the digestate, other salts such as phosphate salts or others.

[0057] When such an inter-membrane compartment is present, the membranes can be positioned so that the anodic compartment is separated from the cathodic compartment by, on the way from the anodic compartment to the cathodic compartment, a cation exchange membrane and an anion exchange membrane. For example, it is then possible to recover carboxylic acids synthesized at the cathode, as well as cations (eg NH ) from the anodic compartment.

[0058] The electrochemical treatment system may comprise a multistack type structure, with a (horizontal) succession of an anodic compartment, a first intermembrane compartment, a cathodic compartment, a second intermembrane compartment, it being understood that one end of this succession is an anode, and the other is a cathode.

[0059] The biological treatment installation according to the invention may further comprise one or more treatment systems 150 for the effluent 5 rich in ammonium ions leaving the bioelectrochemical treatment system 120, making it possible in particular to separate and purify the nitrogen contained in the effluent. This system 150 may comprise one or more columns adapted to carry out stripping of the nitrogen followed by absorption, or even one or more reactors adapted to precipitate the ammonium ions in the form of struvite.

[0060] According to the invention, the installation 100 comprises a system 200 for determining at least one operating parameter configured to implement the determination method according to the invention, as well as a regulation system 300 adapted to receive the at least one operating parameter from the determination system, and to modify the corresponding operating parameter of the digester, and optionally of the bioelectrochemical treatment system, using the at least one operating parameter determined by the determination system.

[0061] The determination system 200 is described in detail below. It typically comprises one or more processors, for example microprocessors or microcontrollers. The processor(s) may have storage means which may be random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), flash memory, external memory or the like. These storage means may, among other things, store received data, a control model and one or more computer programs. The determination system also comprises communication means, optionally bidirectional, with the control system 300 and / or with sensors and / or measuring and / or determination means.

[0062] The regulation system 300 typically comprises means for adjusting the operating parameters of the installation, and in particular of the digester, and optionally of the bioelectrochemical treatment system. These adjustment means are, for example, valves, pumps, heating system, etc., in communication with the determination system.

[0063] The regulation system may thus typically comprise valves, solenoid valves, pumps, regulating the quantities of fluids entering and leaving the digester, and optionally from the bioelectrochemical treatment system, a system for maintaining the temperature of the digester, one or more sensors, chosen from a digester temperature sensor, a flow rate sensor for the flows entering and leaving the digester, and optionally from the bioelectrochemical treatment system, a sensor for measuring the nitrogen content of the input, a sensor for measuring the organic matter of the digestate or a liquid fraction thereof, a sensor for measuring the cation and / or ammonium ion content of the digestate or a liquid fraction thereof, cooperating with each other and with the determination system.

[0064] The control system may further comprise a control loop making it possible to modify the operating parameter(s) based on data received from the sensors and operating parameter(s) received from the determination system.

[0065] Method and system for determining at least one operating parameter

[0066] As shown schematically in Figure 2, the determination method according to the invention comprises: (a) a step of acquiring (ai) a value of at least one, preferably at least two, parameters representative of the capacity of the electrochemical treatment system to separate the ammonium ions, and (aii) a value of at least one quality parameter of the digestate or its liquid fraction, (b) a step of determining a value of a characteristic ratio of the digestate or its liquid fraction determined as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system, for example extracted from the recovery compartment of the latter, or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, for example in the recovery compartment of the latter, and (bii) the values ​​acquired in step (a), (c) a step of determining at least one operating parameter of the digester as a function of the value of the ratio determined in step (b).

[0067] Acquisition step (a) is used to acquire, by measurement, modeling or empirically, the values ​​of at least one parameter representative of the capacity of the electrochemical treatment system to separate ammonium ions and of at least one quality parameter of the digestate or its liquid fraction.

[0068] The at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions may in particular comprise at least one parameter representative of the capacity of the at least one separator to allow the ammonium ions to pass, and a parameter representative of a concentration gradient of the cations of on either side of at least one separator.

[0069] The parameter representing the capacity of the at least one separator to allow ammonium ions to pass typically depends on the intrinsic properties of the separator. In particular, it is typically linked to the diffusion coefficient of the separator and its thickness. The value of this parameter can be determined, in particular calculated, from diffusion coefficient values ​​and the dimensions of the separator, or else be estimated empirically or by means of a model, for example based on Fick's law. When it is estimated, it could for example be a loss parameter expressed as a percentage and representing a rate of ammonium ions that can pass through the separator.

[0070] The parameter representative of a concentration gradient of the cations on either side of the at least one separator capable of allowing ammonium ions to pass when a potential difference is applied depends on the flows entering and leaving the bioelectrochemical treatment system. The value of this parameter can thus be estimated from a model or empirically, or determined, in particular by calculation, for example as a function of an extraction rate of the ammonium ions (or of the effluent 5 enriched in ammonium ions) from the bioelectrochemical treatment system, of the residence time of the digestate or of its liquid fraction inside the bioelectrochemical treatment system.

[0071] The at least one quality parameter of the digestate or its liquid fraction is a parameter representative of a quantity of ammonium ions relative to a total quantity of cations. The value of this parameter may be estimated, in particular by means of a model or empirically, or measured as a function of the concentration of ammonium ions in the digestate or its liquid fraction, and its conductivity or its total concentration of cations. For example, the ratio of its concentration of ammonium ions to its conductivity or the ratio of its concentration of ammonium ions to its total concentration of cations, measured for example by ion chromatography, may be used as a parameter. When estimated, this parameter may be a safety coefficient taking into account the non-specificity of ion migration within the system, the value of which is for example between 0 and 1, in particular between 0.2 and 1.

[0072] Thus, the acquisition step (a) may comprise a step of receiving parameter values, and optionally a step of determining parameter values.

[0073] In step (a), other operating parameters of the bioelectrochemical treatment system may also be acquired, such as a potential difference applied or applicable to the bioelectrochemical treatment system, and / or the residence time of the digestate or its liquid fraction in the bioelectrochemical treatment system, and / or the flow rate of effluent enriched in ammonium ions extracted from the bioelectrochemical treatment system. It is then possible to carry out this determination as a function of a particular bioelectrochemical treatment system that it is desired to use, and in particular of its dimensions and the operating parameter ranges used for this particular system. In this case, it is not necessary to control the operating parameters of the bioelectrochemical treatment system to allow the desired recovery of the quantity of ammonium ions during the treatment step bioelectrochemical, because the ratio determined during this step (b) is applicable to the different possible operating conditions of the particular bioelectrochemical treatment system.

[0074] In step (a), other quality parameters of the digestate or its liquid fraction, such as its temperature and the fraction of non-hydrolyzed methanization substrate, can also be optionally acquired. The temperature will have a direct effect on the microbial kinetics of the anodic biofilm, while the fraction of non-hydrolyzed methanization substrate corresponds to a potential biodegradable substrate for the bioelectrochemical treatment system.

[0075] Step (a) can be implemented by acquisition means 210 of the determination system 200, adapted to acquire (ai) the value of the at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions, and (aii) the value of the at least one quality parameter of the digestate or its liquid fraction, representative of a quantity of ammonium ions relative to a total quantity of cations. These acquisition means 210 are optionally also adapted to implement the different embodiments of step (a) previously described.

[0076] These acquisition means 210 may comprise one or more processors and memories, in particular for storing values ​​and models, and / or means of communication, in particular with sensors and / or means of measuring and / or determining values ​​of the aforementioned parameters.

[0077] Step (b) makes it possible to determine the value of a characteristic ratio of the digestate or its liquid fraction as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system, for example from its recovery compartment, or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, for example in its recovery compartment, and (bii) the values ​​acquired in step (a). This step involves determining the quantity of biodegradable material that the microorganisms of the bioelectrochemical treatment system must degrade to release enough electrons to ensure the passage of a target quantity of ammonium ions to the other side of the separator.This quantity of biodegradable material can, for example, be estimated by material balance or determined by a kinetic model taking into account the phenomena of ionic migration and diffusion within the bioelectrochemical treatment system, these methods being well known in bioelectrochemistry.

[0078] This ratio can for example be chosen from the C / N ratio of the quantity of carbon to the quantity of nitrogen, the COD / NH / ratio of the chemical oxygen demand to the concentration of ammonium ions, the VFA / NfkC ratio of a concentration of volatile fatty acids to the concentration of ammonium ions and the BOD5 / NH / ratio of the biological oxygen demand at 5 days to the concentration of ammonium ions. The concentrations of VFAs and NH / can be determined by conventional acid-base titrations.

[0079] For example, the COD / NH ratio can be 0.25 to 10 gCOD / gN.

[0080] The target yield of extracted ammonium ions or the target concentration of separated ammonium ions can be determined according to the desired quality of effluent enriched in ammonium ions and / or according to the desired quality for the digestate or its liquid fraction, for example if the nitrogen content is required to be below a threshold.

[0081] The target yield of extracted ammonium ions or the target concentration of separated ammonium ions may also be determined based on a subsequent treatment of an effluent containing the extracted ammonium ions from the bioelectrochemical treatment system, and in particular a treatment such as struvite precipitation or stripping. Those skilled in the art will be able to determine these thresholds based on the technology used.

[0082] Step (b) can be implemented by first determination means 220 of the determination system 200, adapted, in particular programmed, to determine the value of a characteristic ratio of the digestate or of its liquid fraction, representative of a quantity of biodegradable organic matter relative to a quantity of ammonium ions, and to determine this value as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system, for example from its recovery compartment, or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, for example in its recovery compartment, and (bii) the values ​​received from the acquisition means 210. These first determination means 220 can optionally also be adapted, in particular programmed, to implement the different embodiments of step (b).These first determination means 220 may comprise one or more processors and one or more memories for storing the determined values, and optionally models.

[0083] Step (c) makes it possible to determine at least one operating parameter of the digester as a function of the value of the ratio determined in step (b). This operating parameter is chosen from the temperature, the concentration of the input, the hydraulic residence time, the residence time of the solids, the mineralizable nitrogen potential of the input.

[0084] The temperature is the operating temperature of the digester. It is typically within the digester's operating temperature range. Note that the digester can operate in a temperature range of 15 to 70°C. It can therefore be a mesophilic digester, typically operating from 15 to 45°C, or a thermophilic digester, typically operating from 45 to 70°C.

[0085] The input concentration corresponds to the concentration of the input in dry matter, also called the dryness of the digester input, and is measured in terms of percentage of dry matter. It is therefore an indicator of dehydration of the effluent used as input to the digester. For example, the concentration of the input can be modified by diluting it before entering the digester.

[0086] The mineralizable nitrogen potential of the input corresponds to the maximum quantity of nitrogen ammoniacal nitrogen obtained from the input when converted in a digester. Mineralizable nitrogen potential is typically expressed as the amount of NH produced per amount of substrate introduced. Ammoniacal nitrogen is the sum of NH and NH3 species, often denoted N-NH4. Mineralizable nitrogen potential can be measured, as described in Fisgativa, H., Marcilhac, C., Jaudoin, C. et al., Biological Nitrogen Potential (BNP): A New Methodology to Estimate Nitrogen Transformations During Anaerobic Digestion of Organic Substrates. Waste Biomass Valor (2020), or estimated by calculation, as described in Moscoviz, R., Jimenez, J. Improving anaerobic digestion mass balance calculations through stoichiometry and usual substrate characterization. Bioresource Technology (2021).

[0087] This mineralizable nitrogen potential depends on the origin of the input and can be modified by adjusting the ratio between the different methanization substrates feeding the digester, in the case of co-digestion of several methanization substrates.

[0088] The hydraulic residence time and the solids residence time may or may not be the same. When they are different, the solids residence time is generally greater than the hydraulic residence time.

[0089] In a digester, several species of microorganisms can be present such as hydrogenotrophic methanogenic archaea, acetoclastic methanogenic archaea or even syntrophic bacteria oxidizing propionate or acetate.

[0090] The species of microorganisms growing in the digester do not have the same growth rate. Thus, some species will exhibit limiting kinetics because they will have a slower growth rate than certain other species, thus limiting the speed of the overall reaction of the digester for the production of biogas.

[0091] Determining one or more operating parameters of the digester making it possible to obtain the ratio determined in step (b) amounts to favoring or disfavoring the microorganisms consuming the degradable organic matter or the by-products of their degradation, such as, for example, the syntrophic bacteria mentioned above. From models or charts predicting the kinetics of degradation of organic matter, and in particular of AGVs and / or alcohols, by the microorganisms involved, it is then possible to determine the operating parameter(s) of the digester. This or these operating parameter(s) can also be determined from measurements of the parameters of the digester and a control of the digester making it possible to achieve the ratio determined in step (b).

[0092] These charts can be produced from experimental measurements or found in the literature. There are also models for predicting kinetics, as explained below.

[0093] In a digester, the growth of microorganisms depends mainly on temperature, pH and the concentration of inhibitory compounds. Since pH itself depends on the concentration of ammonium ions and the VFAs present, the main factors include temperature and the concentration of inhibitory compounds. Among the inhibitory compounds, we can mention NH3, the concentration of which in the digester depends mainly the temperature, the concentration of the input and its mineralizable nitrogen potential. These factors will more or less slow down or accelerate the reactions. It is therefore necessary to take into account the dependence of the growth of microorganisms on these factors when choosing the operating conditions of the process, in particular the hydraulic residence time and / or the residence time of the solids.

[0094] The dependence of the growth rate on these factors can be modeled by mathematical models. They are widely described in the literature for many known microorganisms present in digesters.

[0095] We can cite for example the following article: I. Angelidaki, L. Ellegaard, and BK Ahring. A Mathematical Model for Dynamic Simulation of Anaerobic Digestion of Complex Substrates: Focusing on Ammonia Inhibition. Biotechnology and Bioengineering, 1993.

[0096] This paper presents a mathematical model of the growth rate of four groups of microorganisms (glucose-fermenting acidogens, propionate-degrading acetogens, butyrate-degrading acetogens, and acetic acid methanogens) as a function of pH, temperature, and ammonia inhibition. The model also allows for an estimation of pH based on the ionic species present in the digestate.

[0097] The following article can also be cited as an example: Batstone, DJ, Keller, J., Angelidaki, I., Kalyuzhnyi, SV, Pavlostathis, SG, Rozzi, A., Sanders, WTM, Siegrist, H., Vavilin, VA., 2002. The IWA Anaerobic Digestion Model No 1 (ADM1). Water Science and Technology, 2002.

[0098] This article, for its part, introduces the ADM1 model, an international reference in the field, which is a dynamic model allowing to simulate the phenomena governing the different stages of anaerobic digestion by integrating a large number of factors having an influence on the different kinetics in particular the growth rate of microorganisms. The model also allows an estimation of the pH according to the ionic species present in the digestate.

[0099] The ratio determined in step (b) of the method according to the invention can be determined in such a way as to allow the desired recovery of ammonium ions, regardless of the operating conditions of the bioelectrochemical treatment system. In this case, it is not necessary to control the operating parameters of the bioelectrochemical treatment system.

[0100] In some embodiments, the ratio determined in step (b) is however not determined taking into account the operating parameters of the bioelectrochemical treatment system. In this case, step (c) may also comprise the determination of at least one operating parameter of the bioelectrochemical treatment system as a function of the value of the ratio determined in step (b), of the value of at least one quality parameter of the digestate or of its liquid fraction acquired in step (a). This operating parameter may be chosen from the residence time of the digestate or of its liquid fraction in the bioelectrochemical treatment system, the effluent flow rate 5 enriched with ammonium ions extracted from the bioelectrochemical treatment system (for example from at least one recovery compartment of the latter), and a potential difference applied to the bioelectrochemical treatment system.

[0101] The applied potential difference can be changed by changing the voltage applied to the bioelectrochemical treatment system operating as an electrolyzer, or by changing the resistance applied to the bioelectrochemical treatment system operating as a battery.

[0102] The operating parameter(s) of the bioelectrochemical treatment system can then be determined using charts or models, depending on the microorganisms used in the system. Models describing the link between microbial kinetics and electric current in bioelectrochemical systems are, for example, described in the following article: Desmond-Le Quéméner, E., Moscoviz, R., Bernet, N, Marcus, A. Modeling of interspecies electron transfer in anaerobic microbial communities. Current Opinion in Biotechnology (2021).

[0103] Step (c) can be implemented by second determination means 230 of the determination system 200, adapted, in particular programmed, to determine at least one operating parameter of the digester as a function of the value of the ratio determined by the first determination means 220, this operating parameter comprising the temperature and / or the concentration of the input and / or the hydraulic residence time and / or the residence time of the solids and / or the mineralizable nitrogen potential of the input. These second determination means 230 can optionally also be adapted, in particular programmed, to implement the different embodiments of step (c).

[0104] These second determination means 230 may comprise one or more processors and one or more memories for storing the determined values, and optionally models.

[0105] The previously described determination method and system 200 can be used in a biological treatment method as described below.

[0106] Biological treatment process

[0107] The process for the biological treatment of an input containing carbonaceous matter and nitrogen compounds makes it possible to produce biogas, and in particular methane, while recovering the nitrogen present in the input, in order to recover it. The biological treatment process according to the invention can be implemented using a biological treatment installation previously described.

[0108] Input

[0109] The biological treatment method and installation according to the invention are suitable for treating an input containing carbonaceous material and nitrogen compounds. The carbonaceous material may be in dissolved, colloidal or particulate form.

[0110] This input may contain any carbonaceous material suitable for fermentation reactions, including, but not limited to, materials derived from mining, agriculture, industry or domestic sources, including virgin products or waste from any process producing carbonaceous material, including the organic fraction of municipal solid waste and sewage sludge.

[0111] The input containing carbonaceous materials may be, but is not limited to, a sludge produced in a liquid treatment line in a wastewater treatment plant or any other sludge.

[0112] Such sludge may be, but is not limited to, primary sludge from the discharge of a primary clarification process, or biological sludge from a secondary biological process in wastewater treatment, such as, but not limited to, waste activated sludge, or a combination of primary sludge and biological sludge.

[0113] The primary sludge may have been previously thickened, for example to achieve a dry matter content of 2 to 15% by mass.

[0114] The input used in the present invention may have previously been subjected to one or more sub-steps chosen from a thickening step, a filtration step (“screening”), a dehydration step, a heat treatment step and a dilution step.

[0115] This thermal treatment step may include a thermal hydrolysis process (THP) and / or a hydrothermal carbonization (HTC) process. In a THP process, the sludge, typically with a dry matter content of 12% to 25% by mass, is maintained at a temperature of 140°C to 170°C, typically for 30 to 60 minutes. The HTC process typically operates at temperatures of 180°C to 280°C for a period of minutes to several hours in a non-oxidizing atmosphere.

[0116] The input used in the present invention may have a dry matter content of 1 to 50% by mass, preferably 1 to 40% by mass or 1 to 35% by mass, for example 2 to 15% by mass or 15 to 30% by mass, or 17 to 25% by mass, or in any interval defined by two of these limits. The dry matter content may be determined gravimetrically, for example following the protocol proposed in the following report: Standard Methods for the Examination of Water and Wastewater American Public Health Association, Washington, DC (2005).

[0117] The input also contains water. Any presence of water sufficient for the implementation of biological reactions within the digester is considered suitable.

[0118] The method according to the invention can in particular make it possible to treat inputs with high nitrogen contents.

[0119] Digestion stage

[0120] The anaerobic digestion step of the process can be carried out in a digester as previously described.

[0121] The digester is operated under the operating conditions determined by the system and the method for determining at least one operating parameter.

[0122] This digestion step can be carried out under mesophilic or thermophilic temperature conditions.

[0123] The hydraulic residence time and solids residence time can be from 5 to 100 days.

[0124] By implementing the operating parameter(s) of the digester determined by the method according to the invention, the digestate has a carbonaceous matter and ammonium ion content allowing optimal recovery of the ammonium ions during its treatment in the bioelectrochemical treatment stage.

[0125] The digestate produced during the anaerobic digestion step can be sent directly to the bioelectrochemical treatment step or can be sent to a liquid-solid digestate separation step to separate the digestate into a solid fraction and a liquid fraction, such as a centrifugation or filtration step. The liquid fraction of the digestate is then sent to the bioelectrochemical treatment step.

[0126] In one embodiment, the digestate, or its liquid fraction, may in particular have a COD / Ammoniacal Nitrogen ratio of 0.25 to 10 gCOD / gN. In particular, this ratio may correspond to the ratio of the concentration of VFAs to the concentration of ammonium ions (VFA / Ammoniacal Nitrogen). The exact value of this ratio determined in step b) will generally vary depending on the desired NELC capture yield, the concentration of NELC ions in the digestate, as well as the ratio of NELC to the other cations present in the digestate.

[0127] Alternatively or in combination, the digestate, or its liquid fraction, may thus have one or more of the following characteristics: a total ammoniacal nitrogen concentration of 0.5 to 7gN / L or 0.5 to 5gN / L, or in any interval defined by two of these limits, a conductivity of 10 to 150mS / cm or 10 to 75mS / cm or in any interval defined by two of these limits, a molar ratio of the ammonium ion concentration to the total cation concentration (NELC / total cations) of 0.25 to 1mol / mol or 0.75 to 1mol / mol or in any interval defined by two of these limits.

[0128] The concentration of total ammoniacal nitrogen can be measured by colorimetric method, by acid-base titration, or by ion chromatography.

[0129] Conductivity can be measured according to standard NF EN 27888-January 1994 or ISO 7888:1985.

[0130] Such characteristics of the digestate or its liquid fraction can improve the operation of the bioelectrochemical treatment system.

[0131] Bioelectrochemical treatment step

[0132] This step is implemented in a bioelectrochemical treatment system, in particular of the type previously described with reference to the biological treatment installation.

[0133] In one embodiment, the bioelectrochemical treatment step may comprise the implementation of a reaction chosen from a reaction for reducing dioxygen or nitrate and a reaction for producing dihydrogen or organic molecules of interest chosen from organic acids, alcohols, methane. This may make it possible to improve the recovery of the digestate or its liquid fraction treated. In particular, when the molecule of interest is methane, the total quantity of methane produced during the implementation of the method according to the invention can be similar to that which would be obtained with a digester not operating in an inhibited manner. Thus, in a preferred embodiment, the bioelectrochemical treatment step comprises a methane production step. The bioelectrochemical treatment system can thus operate as a microbial fuel cell or an electrolyzer.

[0134] Whatever the embodiment, the method according to the invention may further comprise at least one step of recovering the nitrogen contained in said effluent enriched in ammonium ions chosen from (i) a stripping step followed by a step of absorbing the nitrogen, (ii) a step of precipitating the ammonium ions in the form of struvite (NLLMgPCU • 6 H2O).

[0135] The stripping step can typically be carried out in at least one column in which the effluent circulates countercurrent to a gas which may be air, or in a column containing a membrane (membrane stripping). This stripping step makes it possible to shift the chemical equilibrium of the effluent towards the gas phase (NHsgas). The adsorption step can typically be carried out in at least one column in which the gas phase leaving the stripping step is brought into contact with an absorbent, for example a sulfuric acid solution. The succession of stripping and absorption makes it possible to concentrate the nitrogen, for example in the form of ammonium sulfate in the case of sulfuric acid washing.

[0136] The ammonium ion precipitation step in the form of struvite can typically be carried out in a reactor in which a source of magnesium and / or phosphorus is generally added to the effluent, for example as described in the publication: DesmidtE, Ghyselbrecht K, Zhang Y, et al. Global phosphorus scarcity and full-scale p-recovery techniques: a review. Grit Rev Env Sci Technol. (2015). Example

[0137] Controlled accumulation test of volatile fatty acids

[0138] Food biowaste was introduced into digesters operated semi-continuously under thermophilic conditions (50°C) to produce methane. The same conditions were repeated three times; the results shown in Figures 3-6 correspond to the synthesis of the three tests. The digesters are operated so that the solids residence time is equal to the hydraulic residence time.

[0139] During the first weeks, the methanization of the biowaste was carried out under conditions that optimized methane production. The biowaste was thus treated at a low total ammonia nitrogen content (< 3 gN / L) and a high residence time (> 35 d). This allows the full methanogenic potential (BMP) to be expressed in the digester and no accumulation of volatile fatty acids was observed within the digester, as can be seen in Figures 3-6.

[0140] From week 10, the digester is artificially doped with NH4HCO3 to simulate the total ammonia nitrogen concentration resulting either from a higher biowaste concentration or from a biowaste recipe richer in nitrogen (> 4 gN / L). In addition, the hydraulic residence time is reduced to 33 days. Increasing the concentration of total ammoniacal nitrogen increases the level of inhibition of certain microbial populations, in particular the bacteria ensuring the syntrophic degradation of propionate. In addition, reducing the hydraulic residence time increases the kinetic constraint on all microbial populations in the digester. A progressive accumulation of volatile fatty acids is then observed, representing approximately 15% of the methanogenic potential and stabilizing at a value of approximately 30 g COD / L. Measurement of the composition of these volatile fatty acids by gas chromatography shows that propionate contributes more than 70% of the COD of volatile fatty acids, the other compounds corresponding to butyrate and valerate. This accumulation of acids does not prevent stable operation of the digester, whose methane production yield stabilizes around 85% of the expressed BMP.Once the steady state is reached, the digestate obtained has a COD(VFA) / N ratio of approximately 6.5 gCOD / gN, while a conductivity of 36 mS / cm is measured. A ratio of NHC / total cations is then estimated at 0.8 mol / mol.

Claims

Claims

1. Method for determining at least one operating parameter of an installation (100) for biological treatment of an input containing carbonaceous material and nitrogen compounds, the installation comprising: a digester (110) adapted to produce biogas (2) and a digestate (3) by anaerobic digestion, and a bioelectrochemical treatment system (120) receiving the digestate (3) or a liquid fraction (3a) of the digestate, this bioelectrochemical treatment system comprising electroactive microorganisms and at least one separator (124) capable of allowing ammonium ions to pass when a potential difference is applied, said method comprising: (a) a step of acquiring (ai) a value of at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions, and (aii) a value of at least one quality parameter of the digestate or its liquid fraction, representative of a quantity of ammonium ions relative to a total quantity of cations, (b) a step of determining a value of a characteristic ratio of the digestate or its liquid fraction, representative of a quantity of biodegradable organic matter relative to a quantity of ammonium ions, this value being determined as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, and (bii) the values ​​acquired in step (a), (c) a step of determining at least one operating parameter of the digester as a function of the value of the ratio determined in step (b), the at least one operating parameter of the digester being chosen from the temperature, the concentration of the input, the hydraulic residence time, the residence time of the solids, the mineralizable nitrogen potential of the input.

2. Determination method according to claim 1, characterized in that the acquisition step (a) comprises one or more of the following characteristics: the at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions is chosen from at least one parameter representative of the capacity of the at least one separator to allow the ammonium ions to pass, and a parameter representative of a concentration gradient of the cations on either side of the at least one separator, the at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions is at least one parameter representative of the capacity of the at least one separator to allow the ammonium ions to pass, and its value is estimated or determined from intrinsic characteristics of the separator, the at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions is at least one parameter representative of a concentration gradient of the cations on either side of the at least one separator, and its value is estimated or calculated, the at least one quality parameter of the digestate or its liquid fraction is chosen from the ratio of its concentration in ammonium ions to its conductivity or the ratio of its concentration in ammonium ions to its total concentration in cations, the value of at least one quality parameter of the digestate or its liquid fraction is estimated or calculated as a function of the concentration of the digestate or its liquid fraction in ammonium ions, and of its conductivity or its total concentration in cations.

3. A determination method according to any one of claims 1 or 2, characterized in that the determination step (b) comprises one or more of the following characteristics: the characteristic ratio of the digestate or its liquid fraction is chosen from the C / N ratio of the amount of carbon to the amount of nitrogen, the COD / NH ratio of the chemical oxygen demand to the concentration of ammonium ions, the VFA / NH ratio of a concentration of volatile fatty acids to the concentration of ammonium ions, the DB05 / NH ratio of the biological oxygen demand at 5 days to the concentration of ammonium ions, the target yield of extracted ammonium ions or the target concentration of separated ammonium ions are determined as a function of a subsequent treatment of an effluent containing the ammonium ions extracted from the bioelectrochemical treatment system, this treatment being chosen from struvite precipitation and stripping.

4. Method according to any one of claims 1 to 3, characterized in that step (c) further comprises: determining at least one operating parameter of the bioelectrochemical treatment system as a function of the value of the ratio determined in step (b), the value of at least one quality parameter of the digestate or its liquid fraction acquired in step (a), the at least one operating parameter of the bioelectrochemical treatment system being chosen from the residence time of the digestate or its liquid fraction in the bioelectrochemical treatment system, the flow rate of effluent enriched in ammonium ions extracted from the bioelectrochemical treatment system, a potential difference applied to the bioelectrochemical treatment system.

5. Method for biological treatment of an input containing carbonaceous material and nitrogen compounds to produce biogas and recover ammonium ions, by means of a biological treatment installation (100) comprising: a digester (110) adapted to produce biogas (2) and a digestate (3) by anaerobic digestion, and a bioelectrochemical treatment system (120) receiving the digestate (3) or a liquid fraction (3a) of the digestate, this bioelectrochemical treatment system comprising electroactive microorganisms and at least one separator (124) capable of allowing ammonium ions to pass through upon application of a potential difference, said method comprising: a step of determining at least one operating parameter of the digester implementing the determination method according to any one of claims 1 to 4, an anaerobic digestion step during which the digester is operated using the at least one operating parameter previously determined to produce biogas and a digestate or a liquid fraction of digestate comprising biodegradable organic matter and ammonium ions according to the ratio value determined in step (b) of the determination method,a bioelectrochemical treatment step during which the electroactive microorganisms oxidize the biodegradable organic matter contained in the digestate or its liquid fraction, at least a portion of the ammonium ions contained in the digestate or its liquid fraction migrates through the at least one separator and an effluent enriched in ammonium ions is extracted from the bioelectrochemical treatment system.,

6. Biological treatment method according to claim 5, characterized in that the bioelectrochemical treatment step further comprises the implementation of a reaction chosen from a reaction for reducing dioxygen or nitrate and a reaction for producing dihydrogen or organic molecules of interest chosen from organic acids, alcohols, methane.

7. Biological treatment method according to claim 5 or 6, characterized in that it further comprises at least one step of recovering the nitrogen contained in said effluent enriched in ammonium ions chosen from (i) a stripping step followed by a step of absorption of the nitrogen, (ii) a step of precipitation in the form of struvite of the ammonium ions.

8. A biological treatment method according to any one of claims 5 to 7, characterized in that: the determining step further determines at least one operating parameter of the bioelectrochemical treatment system, and during the bioelectrochemical treatment step, the bioelectrochemical treatment system is operated using the at least one operating parameter determined during the determining step.

9. System for determining (200) at least one operating parameter of a biological treatment installation for an input containing carbonaceous material and nitrogen compounds, the installation (100) comprising: a digester (110) adapted to produce biogas (2) and a digestate (3) by anaerobic digestion, and a bioelectrochemical treatment system (120) receiving the digestate (3) or a liquid fraction (3a) thereof, this bioelectrochemical treatment system comprising electroactive microorganisms and at least one separator (124) capable of allowing ammonium ions to pass through when a potential difference is applied, said system comprising: acquisition means (210) (ai) of a value of at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions, and (aii) of a value of at least one quality parameter of the digestate or its liquid fraction, representative of a quantity of ammonium ions relative to a total quantity of cations, first determination means (220) adapted to determine a value of a ratio characteristic of the digestate or its liquid fraction,representative of a quantity of biodegradable organic matter relative to a quantity of ammonium ions, as a function of (bi) a target yield of ammonium ions extracted from the bioelectrochemical treatment system or a target concentration of separated ammonium ions present in the bioelectrochemical treatment system, and (bii) the values ​​received from the acquisition means, the second determination means (230) adapted to determine at least one operating parameter of the digester as a function of the value of the ratio determined by the first determination means, the at least one operating parameter of the digester being chosen from the temperature, the concentration of the input, the hydraulic residence time, the residence time of the solids, the mineralizable nitrogen potential of the input.,

10. Determination system (200) according to claim 9, characterized in that it comprises at least one of the following characteristics: the acquisition means (210) are means for acquiring at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions chosen from at least one parameter representative of the capacity of the at least one separator to allow the ammonium ions to pass, and a parameter representative of a concentration gradient of the cations on either side of the at least one separator, the acquisition means (210) are adapted to estimate or determine from intrinsic characteristics of the at least one separator the value of at least one parameter representative of the capacity of the electrochemical treatment system to separate the ammonium ions which is at least one parameter representative of the capacity of the at least one separator to allow the ammonium ions to pass,the acquisition means (210) are adapted to estimate or calculate the value of at least one parameter representative of the capacity of the system of, electrochemical treatment to separate the ammonium ions which is at least one parameter representative of a concentration gradient of the cations on either side of the at least one separator, the acquisition means (210) are adapted to estimate or calculate the value of at least one quality parameter of the digestate or its liquid fraction as a function of the concentration of the digestate or its liquid fraction in ammonium ions, and of its conductivity or its total concentration in cations, the first determination means (220) are adapted to determine the target yield of extracted ammonium ions or the target concentration of separated ammonium ions as a function of a subsequent treatment of an effluent containing the ammonium ions extracted from the bioelectrochemical treatment system, this treatment being chosen from struvite precipitation and stripping,the first determining means (220) are adapted to determine a characteristic ratio of the digestate or its liquid fraction chosen from the C / N ratio of the quantity of carbon to the quantity of nitrogen, the COD / NH ratio of the chemical oxygen demand to the concentration of ammonium ions, the AGV / NH ratio of a concentration of volatile fatty acids to the concentration of ammonium ions, the DBO5 / NH ratio of the biological oxygen demand at 5 days to the concentration of ammonium ions.,

11. Determination system (200) according to claim 9 or 10, characterized in that the second determination means (230) are adapted to determine at least one operating parameter of the bioelectrochemical treatment system as a function of the value of the ratio determined in step (b), of the value of the at least one quality parameter of the digestate or of its liquid fraction acquired in step (a), the at least one operating parameter of the bioelectrochemical treatment system being chosen from the residence time of the digestate or of its liquid fraction in the at least one anode compartment, the flow rate of effluent enriched in ammonium ions extracted from the bioelectrochemical treatment system, a potential difference applied to the bioelectrochemical treatment system.

12. Installation (100) for biological treatment of an input containing carbonaceous matter and nitrogen compounds to produce biogas and recover ammonium ions, the installation comprising: a digester (110) adapted to produce biogas (2) and a digestate (3a) by anaerobic digestion, a bioelectrochemical treatment system (120) receiving the digestate or a liquid fraction of the digestate, this bioelectrochemical treatment system comprising electroactive microorganisms and at least one separator (124) capable of allowing ammonium ions to pass when a potential difference is applied, characterized in that it comprises: a system for determining (200) at least one operating parameter according to any one of claims 9 to 11, a regulation system (300) adapted to receive the at least one operating parameter from the determination system (200), and to modify the corresponding operating parameter of the digester, and optionally of the bioelectrochemical treatment system, using the at least one operating parameter determined by the determination system.

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