Device and method for reducing ammonium ions in a liquid effluent

Abstract

The invention relates to a method for treating ammonium ions present in a liquid fraction of an input material comprising carbonaceous organic matter and nitrogenous compounds, by means of at least one bioelectrochemical treatment unit (14, 16, 22) comprising electroactive microorganisms and configured to receive a liquid fraction of the input material having undergone at least one preliminary treatment step, the method comprising a step of degrading at least a portion of the ammonium ions present in the liquid fraction under anaerobic conditions.

Description

Device and method for removing ammonium ions from a liquid effluent

[0001] The invention relates to the field of treatment of liquid effluents comprising carbonaceous matter (in particular wastewater), and in particular the coupling of a treatment process with a bioelectrochemical system enabling the handling of ammoniacal nitrogen contained in the effluent.

[0002] The current objective of most processes deployed to manage nitrogen-laden streams is not the recovery of ammonium but only its treatment. These processes are generally characterized by significant treatment and / or infrastructure costs.

[0003] One approach involves treating ammonium by nitrification / denitrification in activated sludge. This is the process most commonly used for ammonium treatment in wastewater treatment plants. It consists of a first nitrification stage where ammonium is successively oxidized to nitrite and then to nitrate under aerobic conditions. The nitrate is then reduced to nitrite and then to nitrogen gas by a denitrification process under anoxic conditions and with the presence of biodegradable carbon. This process therefore requires a repeated aeration stage of the effluent to ensure the presence of oxygen in the environment. However, effluent treatment requires significant infrastructure and incurs high energy costs, particularly for aerating the basin.Furthermore, this aerobic process produces sludge, the treatment of which is also costly, as well as the potential emission of nitrous oxide, a gas with a global warming potential up to 300 times greater than carbon dioxide. Finally, in the event of a shortage of biodegradable carbon, the addition of external carbon is necessary to achieve denitrification.

[0004] A second approach involves treating ammonium by nitrification / denitrification using biofiltration. This technology operates on the same principle as the one described previously, but with attached bacteria (or biofilms). These biofilters allow for a smaller footprint by offering much more compact reactors. However, treating ammonium with biofilters also requires oxygen injection and therefore results in significant energy consumption. Similarly, aerobic conditions can lead to the production of nitrous oxide. Furthermore, the denitrification of oxidized nitrogen often requires the addition of an external carbon source, such as methanol, which generates additional operating costs.

[0005] A third approach involves treating ammonium by nitrification / denitrification in membrane bioreactors. This is another aerobic treatment of ammonium. This type of reactor also allows for a smaller footprint due to its compact design, while ensuring superior performance in terms of nitrogen and suspended solids removal. However, like the previous treatments, this process relies on the nitrification of ammonium and therefore requires oxygen, resulting in significant energy consumption. Furthermore, a large amount of energy is also needed to maintain the pressure difference across the membranes for water filtration. These aerobic conditions can also lead to the production of nitrous oxide. In addition, the membranes must be regularly cleaned and replaced due to clogging and breakage.Finally, in the event of a deficiency in biodegradable carbon, the addition of external carbon is necessary for denitrification.

[0006] A fourth approach involves treating ammonium by nitrate shunting. Nitrate shunting is similar to nitrification / denitrification, except that ammonium oxidation is stopped at the nitrite stage and does not proceed to the nitrate stage. The nitrites are then denitrified under anoxic conditions in the presence of biodegradable carbon. This process reduces sludge production, the energy required for aeration, and requires less carbon to treat the nitrogen. It can optionally be coupled with a downstream Anammox reaction (see description below). However, although less energy-intensive than the previous processes, nitrate shunting still requires 75% of the aeration needs of conventional nitrification. Since denitrification is heterotrophic, the carbon requirement remains, and sludge production is still significant.Finally, this process places nitrites at the heart of the treatment, which has two environmental impacts: it is more prone to nitrous oxide emissions and the discharged water may contain low concentrations of nitrites, which still need to be treated downstream.

[0007] A fifth approach involves treating ammonium by partial nitritation followed by the Anammox reaction. This process first oxidizes ammonium to nitrite under aerobic conditions while retaining a fraction of ammoniacal nitrogen. The Anammox reaction then oxidizes the ammonium to nitrogen gas using nitrite as an electron acceptor. As a partially anaerobic process, it helps to limit energy costs. It also reduces sludge production and eliminates the need for carbon to treat the nitrogen. However, the growth of Anammox bacteria is sensitive to physicochemical variations in the environment (particularly temperature variations), and maintaining the population within the reactor requires specific material or operational precautions (media, strainer, plug flow management, sludge age management).As described previously, this type of process requires significant infrastructure and therefore high construction costs. Furthermore, this process produces approximately 10% of the input nitrogen load as nitrate, thus negatively impacting the overall efficiency. Finally, this process places nitrites at the heart of the treatment, which has two environmental impacts: it is more prone to nitrous oxide emissions, and the discharged water may contain low concentrations of nitrites, which then require further treatment downstream.

[0008] A sixth approach involves the electrochemical oxidation of ammonium. The ammonium in the effluent can be oxidized to nitrogen gas at the anode of an electrochemical system (non-biological catalysis). The electrochemical system can be operated in fuel cell mode, for example, by supplying oxygen to the cathode. Alternatively, the process can be operated as an electrolyzer to produce value-added molecules at the cathode, such as dihydrogen. These processes can be compact, and this technology is applicable to various effluents: wastewater, digester effluent, return flows, etc. However, this type of electrochemical process requires the use of expensive electrodes, such as platinum electrodes. Furthermore, it is often necessary to add metallic catalysts to the effluent, which must then be recovered.In the case of a fuel cell operation, oxygen must be actively supplied to the cathode, which represents an operating cost. In the case of an electrolyzer operation, a high potential difference must be imposed to maintain the reaction (depending on the catalysts, the process design, and the electron acceptor at the cathode), which results in a high energy cost.

[0009] Today, ammonium treatment is overwhelmingly carried out through nitrification / denitrification reactions. While these processes are efficient, they are energy-intensive (primarily due to oxygen diffusion during the nitrification phase). They involve significant infrastructure costs and produce large quantities of sludge that subsequently require treatment. Biofilters and / or membrane bioreactors allow for a smaller land footprint thanks to more compact reactors. However, they also require substantial electricity consumption and can emit nitrous oxide, a greenhouse gas. Finally, all of these processes involve a coupling between nitrogen and carbon treatment, particularly for denitrification.Nitrogen treatment is constrained by the amount of available carbon, which implies either the costly addition of external carbon or limiting carbon capture in upstream processes, which is detrimental to the energy balance of the sector. The uncaptured carbon cannot not only be used for energy production through anaerobic digestion processes, as is often the case, but must also be oxidized.

[0010] Thus, anaerobic or partially anaerobic processes, as described in the fifth and sixth approaches, appear promising, not only for reducing energy consumption by eliminating the need for oxygen injection, but also for limiting sludge production, bypassing the carbon / nitrogen balance of the effluent, and, in the case of the sixth approach, limiting nitrous oxide production. However, they do present the aforementioned drawbacks. The partial nitritation / Anammox process is a partially anaerobic process where nitrites serve as the final electron acceptor for the electrons released from ammonium oxidation. This process, however, requires significant infrastructure, potential management of discharges (containing nitrite and nitrate), and the need for aeration remains.

[0011] The invention aims in particular to provide a process for treating a liquid carbonaceous effluent containing ammonium ions while limiting its energy cost, economic cost, environmental impact and land footprint.

[0012] To this end, the invention relates to a process for treating ammonium ions present in a liquid fraction of an input comprising carbonaceous organic matter and nitrogen compounds, by means of at least one bioelectrochemical treatment unit comprising electroactive microorganisms and configured to receive a liquid fraction of the input having undergone at least one preliminary treatment step, the process comprising a step of degradation of at least a part of the ammonium ions present in the liquid fraction under anaerobic conditions.

[0013] Thus, the process according to the invention can be carried out in a more compact installation (particularly thanks to the fixation of biomass at the anode) and this technology is applicable to several types of effluent: municipal wastewater, industrial wastewater, digester effluent, etc. Furthermore, depending on the implementation, it is possible to eliminate the need for organic carbon for nitrogen treatment. The degradation of ammonium by a bioelectrochemical system also helps to limit electricity consumption. In addition, if the process is used as an electrolyzer, it is possible to limit net energy consumption by producing dihydrogen or methane at the cathode.

[0014] The operation of the bioelectrochemical unit does not require the supply of oxygen for the treatment of ammonium ions, which reduces the net energy consumption of the process and also reduces the emission of nitrous oxide.

[0015] Furthermore, and compared to ammonium treatment by nitrate shunting, the process according to the invention does not require stopping nitrification at the nitrite stage, and does not require, as may be the case when implementing an Anammox type process, the production or addition of nitrites.

[0016] Finally, and compared to an electrochemical oxidation process of ammonium, the process according to the invention does not require expensive catalysts or metallic reagents.

[0017] Depending on other optional features of the ammonium ion treatment process, taken alone or in combination: the bioelectrochemical treatment unit comprises a single compartment; at least one bioelectrochemical treatment unit performs ammonium ion oxidation for the production of nitrogen gas at an anode of the bioelectrochemical treatment unit; and: carbon dioxide reduction for the production of methane or HCO3 ion reduction +For the production of dihydrogen at a cathode of the bioelectrochemical treatment unit, and / or the reduction of nitrates or nitrites for the production of nitrogen gas at a cathode of the bioelectrochemical treatment unit, the process employs several bioelectrochemical treatment units in series, at least one first bioelectrochemical treatment unit carrying out the oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the first bioelectrochemical treatment unit, at least one second bioelectrochemical treatment unit carrying out the oxidation of ammonium ions to nitrogen gas at an anode of the second bioelectrochemical treatment unit, the first and second bioelectrochemical treatment units carrying out the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions +For the production of dihydrogen at a cathode of the bioelectrochemical treatment unit, at least one bioelectrochemical treatment unit performs an oxidation of ammonium ions for the production of nitrates or nitrites at an anode of the bioelectrochemical treatment unit, and: a reduction of nitrates or nitrites for the production of nitrogen gas at a cathode of the bioelectrochemical treatment unit, and / or a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions +For the production of dihydrogen at a cathode of the bioelectrochemical treatment unit, at least one bioelectrochemical treatment unit performs an oxidation of ammonium ions for the production of nitrates or nitrites and an oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the bioelectrochemical treatment unit, and a reduction of nitrates or nitrites for the production of nitrogen gas and a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions +for the production of dihydrogen at the level of a cathode of the bioelectrochemical processing unit, and at least one bioelectrochemical processing unit carries out a reduction of carbon dioxide for the production of fatty acid, for example acetate, or ethanol at the level of a cathode of the bioelectrochemical processing unit, the bioelectrochemical processing unit comprising a cation exchange membrane.

[0018] The invention also relates to a process for treating an input comprising carbonaceous organic matter and nitrogen compounds in a treatment line, the process comprising the following steps: at least one preliminary treatment step of the input separating the input into a liquid fraction and a second fraction, for example sludge, sand or grease, the process for treating ammonium ions according to the invention.

[0019] Depending on other optional characteristics of the input treatment process taken alone or in combination: the preliminary treatment step includes a step chosen from primary settling, filtration, rhizofiltration, primary biofiltration, biosorption, primary flotation, sieving or micro-sieving separating the liquid fraction sent to the bioelectrochemical treatment unit from a second fraction directed to another treatment step, for example anaerobic digestion; the process includes upstream of the ammonium ion treatment process a step for degrading ammonium ions remaining in the liquid fraction, for example by a nitrification and denitrification process; the process includes upstream of the ammonium ion treatment process a step for degrading carbonaceous organic matter, for example by biofiltration, via a membrane bioreactor, biodisc contactors, trickling filters,of a methanization unit, by a high-load activated sludge process, at least one bioelectrochemical treatment unit carrying out an oxidation of ammonium ions into nitrates or nitrites, or into gaseous dinitrogen, at the level of an anode of the bioelectrochemical treatment unit, the process includes upstream of the bioelectrochemical treatment unit a pre-denitrification step, at least one bioelectrochemical treatment unit carrying out an oxidation of ammonium ions into nitrates or nitrites at the level of an anode of the bioelectrochemical treatment unit, at least a part of the nitrates or nitrites produced being returned to the pre-denitrification step, and the process includes downstream of the ammonium ion treatment process a depollution step of the liquid fraction chosen from electrocoagulation, tertiary filtration, reed beds, ozonation, treatment by use of activated carbon,Ultraviolet treatment, or treatment using formic acid or ferrates.

[0020] The invention also relates to a device for treating ammonium ions present in a liquid fraction of an input comprising carbonaceous organic matter and nitrogen compounds, the input having undergone at least one preliminary treatment step producing the liquid fraction, the device comprising at least one bioelectrochemical treatment unit comprising electroactive microorganisms and arranged to receive the liquid fraction, the bioelectrochemical treatment unit comprising means configured to degrade at least a portion of the ammonium ions present in the liquid fraction under anaerobic conditions.

[0021] Depending on other optional features of the ammonium ion treatment device, taken alone or in combination: the bioelectrochemical treatment unit comprises a single compartment; at least one bioelectrochemical treatment unit is configured to perform ammonium ion oxidation for the production of nitrogen gas at an anode of the bioelectrochemical treatment unit; and: carbon dioxide reduction for the production of methane or HCO3 ion reduction +for the production of dihydrogen at a cathode of the bioelectrochemical treatment unit, and / or a reduction of nitrates or nitrites for the production of nitrogen gas at a cathode of the bioelectrochemical treatment unit. The device comprises several bioelectrochemical treatment units in series, at least one first bioelectrochemical treatment unit being configured to carry out an oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the first bioelectrochemical treatment unit, at least one second bioelectrochemical treatment unit being configured to carry out an oxidation of ammonium ions for the production of nitrogen gas at an anode of the second bioelectrochemical treatment unit.the first and second bioelectrochemical treatment units being configured to achieve either a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions, + For the production of dihydrogen at a cathode of the bioelectrochemical treatment unit, at least one bioelectrochemical treatment unit is configured to perform an oxidation of ammonium ions for the production of nitrates or nitrites at an anode of the bioelectrochemical treatment unit, and: a reduction of nitrates or nitrites for the production of nitrogen gas at a cathode of the bioelectrochemical treatment unit, and / or a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions +For the production of dihydrogen at a cathode of the bioelectrochemical treatment unit, at least one bioelectrochemical treatment unit is configured to carry out the oxidation of ammonium ions for the production of nitrates or nitrites and the oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the bioelectrochemical treatment unit, and the reduction of nitrates or nitrites for the production of nitrogen gas and the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions +for the production of dihydrogen at a cathode of the bioelectrochemical processing unit, and at least one bioelectrochemical processing unit is configured to carry out a reduction of carbon dioxide for the production of fatty acid, for example acetate, or ethanol at a cathode of the bioelectrochemical processing unit, the bioelectrochemical processing unit comprising a cation exchange membrane.

[0022] The invention also relates to an installation for the treatment of an input comprising carbonaceous organic matter and nitrogen compounds in a treatment line, the device comprising: at least one preliminary treatment unit of the input configured to separate the input into a liquid fraction and a second fraction, for example sludge, sand or grease, and a device for the treatment of ammonium ions present according to the invention.

[0023] Depending on other optional characteristics of the input treatment installation, taken alone or in combination: the installation includes, upstream of the ammonium ion treatment device, a primary input treatment unit chosen from among a primary settling tank, a filtration or rhizofiltration or primary biofiltration module, a primary flotation module, a bio-sorption module, a screening module or a micro-screening module and configured to separate the input into a liquid fraction and a second fraction, the second fraction preferably being redirected to an anaerobic digester; the installation includes, upstream of the ammonium ion treatment device, a biological treatment module for carbonaceous matter, for example, a unit for the degradation of organic carbonaceous matter by biofiltration, by a membrane bioreactor, by a methanizer, by biodisc contactors,by trickling filters or by a high-load activated sludge unit, at least one bioelectrochemical treatment unit being configured to carry out an oxidation of ammonium ions into nitrates or nitrites, or into gaseous dinitrogen, at the level of an anode of the bioelectrochemical treatment unit, the installation includes upstream of the bioelectrochemical treatment unit a pre-denitrification module, at least one bioelectrochemical treatment unit being configured to carry out an oxidation of ammonium ions into nitrates or nitrites at the level of an anode of the bioelectrochemical treatment unit, the bioelectrochemical treatment unit including means of returning at least part of the nitrates or nitrites produced to the pre-denitrification module, and the installation includes downstream of the ammonium ion treatment device an additional liquid fraction depollution module chosen from an electrocoagulation module,a tertiary filtration module, reed beds, an ozonation module, an activated carbon treatment module, an ultraviolet treatment module, or a formic acid treatment module. Brief description of the figures

[0024] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0025] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a first embodiment of the invention,

[0026] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a first variant of a second embodiment of the invention,

[0027] is a representation of a device for processing an input comprising carbonaceous organic matter and nitrogen compounds according to a second variant of the second embodiment of the invention,

[0028] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a third variant of the second embodiment of the invention,

[0029] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a first variant of a third embodiment of the invention,

[0030] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a second variant of the third embodiment of the invention,

[0031] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a fourth embodiment of the invention,

[0032] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a first variant of a fifth embodiment of the invention,

[0033] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a second variant of the fifth embodiment of the invention,

[0034] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a first variant of a sixth embodiment of the invention,

[0035] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a second variant of the sixth embodiment of the invention,

[0036] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a first variant of a seventh embodiment of the invention, and

[0037] is a representation of a device for treating an input comprising carbonaceous organic matter and nitrogen compounds according to a second variant of the seventh embodiment of the invention. Detailed description

[0038] The present invention relates to an installation 2 and a biological treatment process for an input containing carbonaceous organic matter and nitrogen compounds, for example, wastewater delivered to a wastewater treatment plant. The examples below describe a wastewater treatment plant as an input treatment installation 2. More broadly, the input can be any type of input comprising carbonaceous organic matter, including, but not limited to, materials derived from mining, agriculture, industry, or domestic sources, including virgin products or waste from any process producing carbonaceous organic matter, including the organic fraction of municipal solid waste and sewage sludge.

[0039] Several embodiments will be described subsequently, all relating to wastewater treatment. A plant 2 and a process for treating an input will be described concurrently for each embodiment.

[0040] The illustration shows a first embodiment of the invention. In this embodiment, an input, here municipal wastewater as well as raw water, enters through a wastewater inlet pipe 4.

[0041] Wastewater first passes through a pretreatment module 6. This module protects the pipes from blockages and other treatment equipment from abrasion, and more generally removes anything that could hinder subsequent treatment. The pretreatment operations are as follows (a treatment plant may include one or more of these operations, depending on its size and the quality of the raw water): screening; sieving; maceration; grit removal; grease removal, frequently combined with grit removal; oil removal; treatment of by-products: sand and grease; combined treatment of sewer cleaning products and treatment plant sand.

[0042] The water exiting the pretreatment module 6 is then conveyed to a primary treatment unit 8. This unit separates the incoming water into two streams: a liquid fraction and a second fraction, typically composed of sludge, sand, grease, etc. If the second fraction consists of sludge, this sludge can be conveyed to an anaerobic digester 10. The primary treatment unit can be selected from a primary settling tank, a primary filtration or biofiltration module, a primary flotation module, a screening module, or a micro-screening module.

[0043] The anaerobic digester 10 enables a cascade of biochemical reactions that convert organic matter into biogas, primarily a mixture of carbon dioxide and methane. Primary settling can be achieved using a circular clarifier.

[0044] The remaining material at the outlet of the anaerobic digester 10, or digestate, can be conveyed to a dewatering module 12. The latter separates the digestate into a liquid fraction which can be recirculated within the wastewater treatment plant, for example upstream of the primary treatment unit 8, and into a solid residue, or cake, discharged from the wastewater treatment plant 2.

[0045] The liquid fraction from the primary treatment unit 8 is conveyed to an ammonium ion treatment device comprising, firstly, a bioelectrochemical treatment unit 14. This bioelectrochemical treatment unit 14 contains electroactive microorganisms. Electroactive microorganisms are defined as microorganisms capable of exchanging electrons with solid, conductive surfaces. The bioelectrochemical treatment unit 14 is specifically designed to treat the liquid fraction exiting the primary settling tank. Thus, the electroactive microorganisms are selected from among those capable, under anaerobic conditions (thus eliminating the need for oxygen supply), of carrying out oxidation and reduction reactions on compounds present in the liquid fraction.This selection can be a selection of a pure strain intentionally added to the bioelectrochemical treatment unit 14 or a selection by a biological process from a mixed microbial culture. All embodiments of the invention describe bioelectrochemical treatment units operating under anaerobic conditions and for which nitrogen treatment does not require the presence of organic carbon.

[0046] The bioelectrochemical treatment unit 14 functions as an electrolyzer by applying a potential difference. Unlike a microbial fuel cell, an electrolyzer results in a net expenditure of electrical energy. This allows for the production of value-added molecules at the cathode (as described later), limits sludge production, and avoids the production of N2O, a greenhouse gas 100 to 300 times more potent than CO2.

[0047] In addition to these advantages, the treatment plant 2 and the treatment process according to the invention make it possible to separate nitrogen treatment from carbon treatment. This gives it a wide range of applications and, above all, allows for a change in the overall treatment approach. This approach almost always consists of preserving biodegradable carbon in order to reduce oxidized nitrogen (as in nitrification / denitrification). The ability to treat nitrogen independently of carbon makes it possible to use the latter for energy purposes. This is called carbon redirection. Until now, this redirection has been hampered by the inability to treat nitrogen. The process according to the invention removes this obstacle to the energy recovery of biodegradable carbon through anaerobic digestion.

[0048] It should be noted that nitrate shunting and partial nitritation / Anammox provide the same advantages on carbon redirection but do not benefit, or not to the same extent, from the advantages mentioned above (limitation of N2O, reduced sludge production, reduction of energy requirements, possibility of producing value-added molecules).

[0049] The generic operating principle of a bioelectrochemical treatment unit according to the invention is described below.

[0050] Reactor description

[0051] The various bioelectrochemical steps described in the patent application (|NH4_ox N2| for the oxidation of ammonium ions to nitrogen gas, |NH4_ox NOx| for the oxidation of ammonium ions to nitrates or nitrites, |BOD_ox| for the oxidation of carbonaceous organic matter, |NOx_red| for the reduction of nitrates or nitrites and |CO2_red| for the reduction of carbon dioxide) can be carried out on a laboratory scale in a bioelectrochemical pilot plant in H. Thus, for the cases |NH4_ox N2|, |NH4_ox NOx|, the anodic compartment is filled by any effluent containing ammonium ions (synthetic solution of ammonium ions, wastewater, upstream returns) while the cathodic compartment is filled by a solution containing either nitrates for the case |NOx_red| (synthetic solution or real effluent) or an electrolyte containing carbon dioxide for the case |CO2_red| (carbonate solution, wastewater).The anodic and cathodic compartments are separated by a cation exchange membrane when a soluble carbon molecule (e.g., acetate) is produced at the cathode by the reduction of carbon dioxide (CO2). In all other cases, separation of the compartments by an ion exchange membrane is possible but not necessary. The electrodes can be made of fabric or graphite brushes, activated carbon granules, or stainless steel grids.

[0052] Nature of microorganisms

[0053] The nature and choice of inoculum for forming electroactive biofilms will directly depend on the oxidation or reduction reaction that must be carried out on the electrode. The types of microorganisms required and their sources are listed in the following table:

[0054] Reaction Electrode Microorganisms Possible Inoculum|NH4_ox N2|Anode Electrogenic nitrifying bacteria Nitrification / denitrification sludge Anammox sludge|NH4_ox NOx|Anode Electrogenic nitrifying bacteria Nitrification / denitrification sludge Anammox sludge|BOD_ox|Anode Electrogenic bacteria Wastewater, Digested sludge|NOx_red|Cathode Electrotrophic denitrifying bacteria Denitrification sludge|CO2_red|Cathode Hydrogenotrophic archaea (CH4) Homoacetogenic bacteria (Acetate) Digested sludge

[0055] Anodic and cathodic reactions

[0056] The different equations for oxidation and reduction reactions are detailed in the following table:

[0057] Reaction Electrode Reaction Equation |NH4_ox N2|Anode NH4 + -> ½ N2+ 4H + + 3rd - |NH4_ox NOx|NH4 Anode + + 2H2O -> NO2 - + 8H + + 6th - or NH4 + + 3H2O -> NO3 - + 10 AM + + 8th -|BOD_ox|AnodeCH3COOH + 2H2O -> 2CO2+ 8H + + 8th - (acetate oxidation)|NOx_red|CathodeNO2 - + 4H + + 3rd - -> ½ N2 + 2H2O or NO3 - + 6 hours + + 5th - -> ½ N2 + 3H2O|CO2_red|CathodeCO2+ 8H + + 8th - -> CH4 + 2H2O (methane production) 2CO2 + 8H + + 8th - -> CH3COOH + 2H2O (acetate production)

[0058] Origins and fates of the different molecules

[0059] For each of the redox reactions listed above, the origin of the molecule destroyed and the fate of the one produced are listed in the following table:

[0060] Reaction Electrode Origin Fate of the compound produced|NH4_ox N2|Anode Ammonium ions present in the effluent to be treated Nitrogen gas released to the atmosphere|NH4_ox NOx|Anode Ammonium ions present in the effluent to be treated Nitrates or nitrites reduced at the cathode|BOD_ox|Anode Carbonaceous organic matter present in the effluent to be treated Carbon dioxide released to the atmosphere or reduced at the cathode|NOx_red|Cathode Nitrates or nitrites present in the effluent to be treated Nitrogen gas released to the atmosphere|CO2_red|Cathode Carbon dioxide present in the effluent or from the anode Methane recovered from the gas network Acetate recovered from the cathode compartment

[0061] Operating conditions

[0062] For each configuration listed in the patent application, each experiment must be performed under anaerobic conditions. This prevents any unwanted reactions at the anode (where oxygen can act as an electron acceptor instead of the electrode) or at the cathode (where the electron can act as the final electron acceptor instead of the compound to be reduced). Experiments can be performed using batch feeding, which allows for the formation of electroactive biofilms, followed by continuous feeding, enabling the measurement of treatment kinetics and biofilm aging. Experiments can be conducted at room temperature. Advantageously, it is preferable to maintain the anodic and cathodic pH between 7 and 8. Applying a potential difference is necessary for configurations with the |CO2_red| step.In cases where the |NH4_ox N2| or |NH4_ox NOx| steps occur at the anode and the |CO2_red| step occurs at the cathode, a potential difference of 1.4–1.5 V is required. For configurations with the |NH4_ox NOx| step at the anode and the |NOx_red| step at the cathode, it is worth noting that applying a potential difference is not necessary because the reaction is spontaneous; however, applying a small potential difference (e.g., approximately 0.3 V) allows for lower nitrate or nitrite concentrations.

[0063] Performance calculation

[0064] The performance of these bioelectrochemical processes is evaluated to determine their suitability. Treatment performance is calculated by measuring the removal of various pollutants (carbonaceous organic matter, ammonium ions, nitrates / nitrites) as well as their treatment kinetics. Electrochemical performance is assessed by current densities and anodic and cathodic faradaic efficiencies. Performance in terms of compound production is measured by the concentrations and productivities of the targeted molecules.

[0065] Processing performance

[0066] The reduction of compound A is calculated using the following equation:

[0067]

[0068] With ΔA the change in concentration of compound A between two times and A i the initial concentration of compound A.

[0069] Compound A can be carbonaceous organic matter (in the case |BOD_ox|), ammonium ions (in the case |NH4_ox N2| and |NH4_ox NOx|) and nitrates / nitrites (in the case |NOx_red|)

[0070] The surface degradation flux of compound A is calculated using the following equation:

[0071]

[0072] With Δt the time variation, ΔA the change in concentration of compound A during Δt, and S the anode or cathode surface area

[0073] Compound A can be carbonaceous organic matter (in the case |BOD_ox|), ammonium ions (in the case |NH4_ox N2| and |NH4_ox NOx|) and nitrates / nitrites (in the case |NOx_red|).

[0074] Production performance

[0075] The surface productivity of compound A is calculated using the following equation:

[0076]

[0077] With Δt the time variation, ΔA the change in concentration of compound A during Δt and S cath the cathode surface

[0078] Compound A can be methane or soluble carbon compounds (e.g., acetate) in the case |CO2_red|.

[0079] Electrochemical performance

[0080] The current density is calculated using the following equation. This quantity is calculated for all possible configurations.

[0081]

[0082] With I being the current intensity (in A) and S the anode or cathode surface area (m²)

[0083] Production fluxes, abatement rates, and current densities are converted to electrode surface area for comparability. Furthermore, in this type of process, it is the electrode surface area that is working, not the volume of each compartment; therefore, the values ​​must be expressed in electrode meters, not cubic meters. 3of reactor.

[0084] The anodic faradaic yield for the oxidation of compound A is calculated by the following equation:

[0085]

[0086] With M A the molar mass of compound A (in g / mol), I the current intensity (in A), n the number of electrons exchanged (in mol of electrons), F the Faraday constant (96500 C / mol), V the reactor volume (in L), ΔA the change in concentration of compound A (in g / L).

[0087] The possible values ​​of A, and therefore of MA and n, are listed in the following table and associated with the different possible configurations.

[0088] ConfigurationReactionAM Compound A (g / mol)n (mol of electrons)|NH4_ox N2|NH4 + -> N2NH4 + 183|NH4_ox NOx|NH4 + -> NO2 - NH4 + 186|NH4_ox NOx|NH4 + -> NO3 - NH4 + 188|BOD_ox|BOD -> CO2BOD324

[0089] The cathodic faradaic yield for the reduction or production of compound A is calculated by the following equation:

[0090]

[0091] With M A the molar mass of compound A (in g / mol), I the current intensity (in A), n the number of electrons exchanged (in mol of electrons), F the Faraday constant (96500 C / mol), V the reactor volume (in L), ΔA the change in concentration of compound A (in g / L).

[0092] The possible values ​​of A, and therefore of MA and n, are listed in the following table and associated with the different possible configurations:

[0093] ConfigurationReactionAM Compound A (g / mol)n (mol of electrons)|NOx_red|NO2 - -> N2NO2 - 463|NOx_red|NO3 - -> N2NO3 - 625|CO2_red|CO2-> CH4CH4168|CO2_red|CO2-> CH3COOHCH3COOH608

[0094] In the example shown, the first bioelectrochemical processing unit 14 comprises a single compartment. A "single compartment" is defined as a configuration in which the bioelectrochemical processing unit does not include an ion-exchange membrane, a simple membrane, or any other physical separator. This configuration eliminates the need for a membrane by simultaneously controlling the bioelectrochemical processing unit at both the anode and cathode. This is the case for all the bioelectrochemical processing units described subsequently.

[0095] It should be noted, however, that according to the invention and depending on the molecules to be produced at the cathode of the bioelectrochemical treatment unit 14, the latter may be equipped with an ion-exchange membrane. For example, the process according to the invention can enable the production at the cathode of soluble carbon-based molecules such as fatty acids or ethanol. In the case of fatty acid production, this could involve the production of acetate, which is achieved by reducing carbon dioxide at the cathode, with the acetate remaining trapped in the cathodic compartment. In this example, the membrane is therefore a cation-exchange membrane.

[0096] The first bioelectrochemical treatment unit 14 comprises electroactive microorganisms that oxidize carbonaceous organic matter to produce carbon dioxide at its anode, and reduce carbon dioxide to produce methane at its cathode. This results in the degradation of non-redirected carbonaceous organic matter upstream of the first bioelectrochemical treatment unit 14 towards the anaerobic digester 10, and the production of a molecule of interest, in this case methane. This description focuses on the production of methane at the cathode as the molecule of interest. It was specified above that other molecules of interest can be produced at the cathode. In the first embodiment of the invention, as well as in subsequent ones, it is possible to produce dihydrogen instead of methane at the cathode whenever a methane production method is described.

[0097] The water exiting the first bioelectrochemical treatment unit 14 is sent to a second bioelectrochemical treatment unit 16. This second unit is configured to oxidize ammonium ions to nitrogen gas at its anode and reduce carbon dioxide to produce methane at its cathode. This process thus degrades ammonium ions without the need for oxygen or organic carbonaceous matter, producing a molecule of interest, in this case methane (or dihydrogen).

[0098] The treated water leaves the ammonium ion treatment device, more specifically the second bioelectrochemical treatment unit 16, through a treated water outlet pipe 18.

[0099] The treatment plant 2 and the process for treating an input, and more particularly ammonium ions, according to the invention, provide the following advantages: A reduction in sludge production thanks to the redirection of carbonaceous organic matter to the anaerobic digester 10 during primary treatment, a redirection made possible by the absence of a carbon requirement for the degradation of ammonium ions. Carbon redirection is therefore maximized. No need for external carbon input, even though a greater quantity of nitrogen would need to be removed, due to the absence of a carbon requirement for the degradation of ammonium ions. A reduction in energy requirements due to the absence of a need for oxygen input for the degradation of ammonium ions and carbon. A reduction in the size of the infrastructure required for the treatment of the input. A reduction in nitrous oxide emissions.A production of valuable molecules.

[0100] Laillustrates a first variant of a second embodiment of the invention. Only the differences between this embodiment and the first will be described.

[0101] In the second embodiment of the invention, an aerobic biological treatment module for carbonaceous matter 20 is arranged between the primary treatment unit 8 and a single bioelectrochemical treatment unit 22. There is therefore a biological treatment step for carbonaceous organic matter, as in the previous configuration, but by aerobic oxidation.

[0102] In other words, the liquid fraction exiting the primary treatment unit 8 and containing carbonaceous organic matter not redirected to the anaerobic digester 10 from the primary treatment unit 8 has the carbonaceous matter degraded in the biological treatment module, aerobic or anaerobic, of the carbonaceous matter 20. The latter can be formed by: A unit for the degradation of carbonaceous organic matter by biofiltration (the water to be treated arrives continuously in an aerobic biological reactor called a “biofilter” and passes through materials which ensure the retention of suspended matter), A membrane bioreactor (a reactor allowing the implementation of an aerobic biological process in which the degradation of organic matter is carried out by aerobic bacteria inside a moving bed biological reactor).Anaerobic digestion or methanation, for example in a UASB (Upflow Anaerobic Sludge Blanket) or AnMBR (Anaerobic Membrane Bioreactor) type reactor. A high-load activated sludge unit (a unit allowing activated sludge treatment with a short sludge retention time). An RBC (Rotating Biofilm Contactor or Rotating Discs) type treatment unit (the presence of rotating plastic or metal discs immersed in the wastewater, where they rotate slowly and supply oxygen to the biological treatment process). A reed bed filter (the presence of one or more filter layers made of granular materials (sand, gravel, pebbles) in which reeds are planted and grow).

[0103] The water exiting the aerobic biological treatment module for carbonaceous matter 20 (i.e., the liquid fraction) is conveyed to the bioelectrochemical treatment unit 22. This unit contains electroactive microorganisms that oxidize ammonium ions to nitrogen gas at its anode and reduce carbon dioxide to produce methane at its cathode. This process thus results in the degradation of nitrogen without oxygen or organic carbon (which is redirected to the anaerobic digester 10 and further degraded by the bioelectrochemical treatment unit 22), producing a molecule of interest, in this case, methane.

[0104] The treatment installation 2 and the process for treating an input, and more particularly ammonium ions, according to the invention confers the same advantages as the first embodiment of the invention.

[0105] Figure 22 illustrates a second variant of the second embodiment of the invention. In this latter variant, the only difference between it and the previous one lies in the nature of the reduction reaction occurring at the cathode (the same oxidation takes place at the anode). The bioelectrochemical treatment unit 22 is configured to perform, at its cathode, a reduction of nitrates or nitrites (possibly produced unintentionally upstream) in order to produce nitrogen gas, in addition to that produced at the anode by the oxidation of ammonium ions. The advantages of this variant are the same as the previous one.

[0106] Figure 22 illustrates a third variant of the second embodiment of the invention. In this latter variant, the only difference between it and the second variant lies in the nature of the oxidation reaction occurring at the anode (the same reduction takes place at the cathode). The bioelectrochemical treatment unit 22 is configured to perform, at its anode, the oxidation of ammonium ions to produce nitrates or nitrites, which are then reduced at the cathode to produce nitrogen gas. The advantages of this variant are the same as the two preceding ones.

[0107] Laillustrates a first variant of a third embodiment of the invention. Only the specific features of this embodiment will be described.

[0108] In the third embodiment of the invention, a biological treatment reactor 24 for carbonaceous organic matter and for the partial treatment of nitrogenous matter into activated sludge is located downstream of the primary treatment unit 8. The latter, whose operation is conventional and known, ensures, among other things, the degradation of carbonaceous organic matter and the partial treatment of ammonium ions into nitrate ions under aerobic conditions. A denitrification module 26 is located downstream of the biological treatment reactor 24. The latter consists of a denitrification biofiltration module using media to support attached bacteria. This module ensures the reduction of nitrate ions generated in the biological treatment reactor 24. External carbon, for example methanol, is injected as part of the denitrification process, which leads to the production of nitrites.

[0109] In other words, the liquid fraction exiting the primary treatment unit 8 and comprising carbonaceous organic matter not redirected to the anaerobic digester 10 from the primary treatment unit 8 has its carbonaceous organic matter and a fraction of its ammonium ions degraded in the biological treatment reactor 24. The denitrification module 26 begins the nitrogen degradation process.

[0110] The water exiting the denitrification module 26, containing ammonium ions and nitrites or even nitrates, is sent to the bioelectrochemical treatment unit 22, the latter being configured to: carry out an oxidation of remaining ammonium ions into nitrogen gas at the level of an anode of the bioelectrochemical treatment unit 22, and carry out a reduction of nitrates or nitrites produced upstream, in particular nitrites produced by the denitrification module 26, into nitrogen gas.

[0111] In this embodiment, similar to the PDN / A process for "Partial Denitrification / Anammox", the Anammox step is replaced by a bioelectrochemical treatment unit 22, which allows for a gain in terms of compactness and overall nitrogen reduction.

[0112] This illustrates a second variant of the third embodiment of the invention. In this latter embodiment, the only difference between this variant and the previous one lies in the nature of the reduction reaction occurring at the anode (the same reduction takes place at the cathode). The bioelectrochemical treatment unit 22 is configured to perform, at its anode, the oxidation of ammonium nitrate or nitrite ions, which are then reduced at the cathode (along with those produced upstream of the bioelectrochemical treatment unit 22) to produce nitrogen gas. The advantages of this variant are the same as the two preceding ones.

[0113] Figure 1 illustrates a fourth embodiment of the invention. In this latter embodiment, and downstream of the primary treatment unit 8, a single bioelectrochemical treatment unit 22 is configured to: Carry out, at its anode, an oxidation of carbonaceous organic matter for the production of carbon dioxide as well as an oxidation of ammonium ions for the production of nitrates or nitrites. Carry out, at its cathode, a reduction of nitrates or nitrites for the production of nitrogen gas as well as a reduction of carbon dioxide for the production of methane.

[0114] The advantages of this embodiment are the same as those of the first two embodiments of the invention.

[0115] Figure 32 illustrates a first variant of a fifth embodiment of the invention. In this embodiment, a pre-denitrification module 32 is located downstream of the primary treatment unit 8 and upstream of the bioelectrochemical treatment unit 22. This pre-denitrification module 32 is typically used after primary treatment, with or without the addition of chemical reagents, to perform denitrification using the organic carbon in the settled water. In other words, the pre-denitrification module 32 enables the denitrification of nitrates produced downstream while simultaneously consuming the carbonaceous organic matter present in the water exiting the primary treatment unit 8 that has not been redirected to the anaerobic digester 10.

[0116] To achieve this, the bioelectrochemical treatment unit 22 is configured to oxidize ammonium ions at its anode into nitrates or nitrites, which are then returned to the pre-denitrification module 32 for degradation, while simultaneously allowing the consumption of carbonaceous organic matter. The bioelectrochemical treatment unit 22 thus replaces a conventional nitrate production module using ammonia nitrogen oxidation, for example, under aerobic conditions.

[0117] The bioelectrochemical treatment unit 22 is configured to achieve, at its cathode, a reduction of carbon dioxide for the production of methane.

[0118] The advantages of this embodiment are the same as those of the first two embodiments of the invention, except that the possibilities of redirecting carbon are conditioned by the amount of nitrogen to be degraded, and it is possible that a need to increase nitrogen degradation may require an external carbon input or redirecting less carbon.

[0119] Laillumer illustrates a second variant of the fifth embodiment of the invention. The latter is similar to the first, except that the bioelectrochemical treatment unit 22 is configured, in addition to the reduction of carbon dioxide, so as to reduce nitrates or nitrites (in excess and therefore not returned to the pre-denitrification module 32) for the production of nitrogen gas.

[0120] The advantage of this variant is that the bioelectrochemical treatment unit 22 ensures the degradation of nitrates not having been redirected to the pre-denitrification module 32. This makes it possible, compared to the first variant, to maximize the redirection of carbon and to do without an external supply of carbon in case of need for increased nitrogen degradation because the degradation of nitrates does not rely solely on the pre-denitrification module 32 but is also carried out by the bioelectrochemical treatment unit 22 which makes nitrogen degradation independent of the presence of carbon.

[0121] This illustrates a first variant of a sixth embodiment of the invention. In this embodiment, a nitrate bypass module 38 is positioned between the primary treatment unit 8 and the bioelectrochemical treatment unit 22. This module is used as an anoxic / aerobic biological treatment downstream of a carbon redirection system. By operating with aeration cycles, it enables the aerobic oxidation of ammonium ions to nitrite ions. These nitrites are reduced to nitrogen gas during the anoxic phases. Excess microorganisms, or biological sludge, are conventionally sent to the anaerobic digester 10.

[0122] The water at the outlet of the nitrate shunt module 38, which may contain ammonium, nitrite or nitrate ions, is sent to the bioelectrochemical treatment unit 22 which is configured to: Carry out, at its anode, an oxidation of ammonium ions for the production of nitrogen gas. Carry out, at its cathode, a reduction of nitrates or nitrites for the production of nitrogen gas.

[0123] Figure 22 illustrates a second variant of the sixth embodiment of the invention. In this latter embodiment, the only difference between this variant and the first variant lies in the nature of the oxidation reaction occurring at the anode (the same reduction takes place at the cathode). The bioelectrochemical treatment unit 22 is configured to carry out, at its anode, the oxidation of ammonium ions to produce nitrates or nitrites, which are then reduced at the cathode to produce nitrogen gas. The advantages of this variant are the same as the two preceding ones. Furthermore, a bioelectrochemical treatment unit that oxidizes ammonium at the anode and reduces nitrates or nitrites at the cathode can operate as a battery (without energy input, as the reactions are spontaneous).By applying even a small potential difference, it would be possible to reduce more nitrates or nitrites and achieve lower discharge concentrations (by applying a potential difference, it is possible to oxidize water at the anode).

[0124] According to an embodiment not shown in the figures, the water exiting the bioelectrochemical treatment unit could be sent to an additional pollution control module, for example, an electrocoagulation module. This module could, for instance, treat soluble metals that may be present in the rinse water from surface treatment baths. Electrocoagulation is a process that coagulates micropollutants using electrolysis with a consumable anode (aluminum or iron). Alternatively, the module could be a tertiary filtration unit, an ozonation unit, a treatment unit using activated carbon, an ultraviolet treatment unit, or a treatment unit using formic acid.

[0125] This illustrates a first variant of a seventh embodiment of the invention. In this latter embodiment, a bioelectrochemical treatment unit is arranged downstream of the dehydration module 12 and is configured to: Carry out, at its anode, an oxidation of ammonium ions for the production of nitrogen gas. Carry out, at its cathode, a reduction of carbon dioxide for the production of methane.

[0126] Such a configuration allows the ammonium ions generated in the anaerobic digester 10 from the sludge produced by the primary treatment unit 8 and / or by the aerobic biological treatment module of carbonaceous matter 20 and present in the liquid fraction at the outlet of the dewatering module 12 to be degraded, which reduces the quantity of ammonium ions returned to the main treatment process, for example upstream of the primary treatment unit 8.

[0127] Figure 1 illustrates a second variant of the seventh embodiment of the invention. This latter embodiment is similar to the first variant except for the nature of the reactions occurring at the anode and cathode. Specifically, the bioelectrochemical treatment unit is located downstream of the dehydration module 12 and is configured to: At its anode, oxidize ammonium ions to produce nitrates or nitrites; and at its cathode, reduce nitrates or nitrites to produce nitrogen gas.

[0128] The advantages of this variant are the same as for the first variant of this embodiment. List of references

[0129] 2: Processing Plant

[0130] 4: Wastewater inlet pipe

[0131] 6: Preprocessing module

[0132] 8: Primary treatment unit

[0133] 10: anaerobic digester

[0134] 12: Dehydration module

[0135] 14: First bioelectrochemical treatment unit

[0136] 16: Second bioelectrochemical treatment unit

[0137] 18: Treated water outlet pipe

[0138] 20: Biological carbonaceous matter processing module

[0139] 22: Bioelectrochemical treatment unit

[0140] 24: Biological treatment reactor

[0141] 26: denitrification module

[0142] 32: Pre-denitrification module

[0143] 34: Primary filtration module

[0144] 38: nitrate shunt module

Claims

Process for treating ammonium ions present in a liquid fraction of an input comprising carbonaceous organic matter and nitrogen compounds, by means of at least one bioelectrochemical treatment unit (14, 16, 22,) comprising electroactive microorganisms and configured to receive a liquid fraction of the input having undergone at least one preliminary treatment step, the process comprising a step of degradation of at least a portion of ammonium ions present in the liquid fraction under anaerobic conditions. Ammonium ion treatment process according to claim 1, wherein the bioelectrochemical treatment unit (14, 16, 22) comprises a single compartment. A process for treating ammonium ions according to any one of the preceding claims, wherein at least one bioelectrochemical treatment unit (14, 16, 22) carries out the oxidation of ammonium ions for the production of nitrogen gas at an anode of the bioelectrochemical treatment unit (14, 16, 22), and: a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (14, 16, 22), and / or a reduction of nitrates or nitrites for the production of gaseous dinitrogen at the level of a cathode of the bioelectrochemical treatment unit (14, 16, 22). A process for treating ammonium ions according to claim 3, comprising several bioelectrochemical treatment units in series (14, 16), at least one first bioelectrochemical treatment unit (14) carrying out the oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the first bioelectrochemical treatment unit (14), at least one second bioelectrochemical treatment unit (16) carrying out the oxidation of ammonium ions to nitrogen gas at an anode of the second bioelectrochemical treatment unit (16), the first and second bioelectrochemical treatment units (14, 16) carrying out the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (14, 16). A process for treating ammonium ions according to any one of the preceding claims, wherein at least one bioelectrochemical treatment unit (22) carries out the oxidation of ammonium ions for the production of nitrates or nitrites at an anode of the bioelectrochemical treatment unit (22), and: the reduction of nitrates or nitrites for the production of nitrogen gas at a cathode of the bioelectrochemical treatment unit (22), and / or the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (22). A process for treating ammonium ions according to any one of the preceding claims, wherein at least one bioelectrochemical treatment unit (22) carries out the oxidation of ammonium ions for the production of nitrates or nitrites and the oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the bioelectrochemical treatment unit (22), and the reduction of nitrates or nitrites for the production of nitrogen gas and the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions. + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (22). Ammonium ion treatment process according to claim 1, wherein at least one bioelectrochemical treatment unit carries out a reduction of carbon dioxide for the production of fatty acid, for example acetate, or ethanol at a cathode of the bioelectrochemical treatment unit, the bioelectrochemical treatment unit comprising a cation exchange membrane. A process for treating an input comprising carbonaceous organic matter and nitrogen compounds in a treatment line, the process comprising the following steps: at least one preliminary treatment step of the input separating the input into a liquid fraction and a second fraction, for example sludge, sand or grease, the process for treating ammonium ions according to any one of the preceding claims. A process for treating an input according to the preceding claim, wherein the preliminary treatment step comprises a step selected from primary decantation, filtration, rhizofiltration, primary biofiltration, bio-sorption, primary flotation, sieving or micro-sieving separating the liquid fraction sent to the bioelectrochemical treatment unit (14, 16, 22) from a second fraction directed to another treatment step, for example anaerobic digestion. Process for treating an input according to any one of claims 8 or 9, comprising upstream of the ammonium ion treatment process a step of degrading ammonium ions remaining in the liquid fraction, for example by a nitrification and denitrification process. Process for treating an input according to any one of claims 8 to 10, comprising upstream of the ammonium ion treatment process a step of degradation of carbonaceous organic matter, for example by biofiltration, via a membrane bioreactor, biodisc contactors, bacterial beds, by a methanization step, by a high-load activated sludge process, at least one bioelectrochemical treatment unit carrying out an oxidation of ammonium ions into nitrates or nitrites, or into gaseous dinitrogen, at the level of an anode of the bioelectrochemical treatment unit (14, 16, 22). A process for treating an input according to any one of claims 8 to 11, comprising upstream of the bioelectrochemical treatment unit (22) a pre-denitrification step, at least one bioelectrochemical treatment unit (22) carrying out an oxidation of ammonium ions into nitrates or nitrites at an anode of the bioelectrochemical treatment unit (22), at least a portion of the nitrates or nitrites produced being returned to the pre-denitrification step. Process for treating an input according to any one of claims 8 to 12, comprising downstream of the ammonium ion treatment process a depollution step of the liquid fraction selected from electrocoagulation, tertiary filtration, reed beds, ozonation, treatment using activated carbon, ultraviolet treatment or treatment using formic acid or ferrates. Device for treating ammonium ions present in a liquid fraction of an input comprising carbonaceous organic matter and nitrogen compounds, the input having undergone at least one preliminary treatment step producing the liquid fraction, the device comprising at least one bioelectrochemical treatment unit (14, 16, 22) comprising electroactive microorganisms and arranged to receive the liquid fraction, the bioelectrochemical treatment unit (14, 16, 22) comprising means configured to degrade at least a portion of the ammonium ions present in the liquid fraction under anaerobic conditions. Ammonium ion treatment device according to claim 14, wherein the bioelectrochemical treatment unit (14, 16, 22) comprises a single compartment. Ammonium ion processing device according to any one of claims 14 or 15, wherein at least one bioelectrochemical processing unit (14, 16, 22) is configured to carry out an oxidation of ammonium ions for the production of nitrogen gas at an anode of the bioelectrochemical processing unit, and: a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (14, 16, 22), and / or a reduction of nitrates or nitrites for the production of gaseous dinitrogen at the level of a cathode of the bioelectrochemical treatment unit (14, 16, 22). An ammonium ion treatment device according to claim 16, comprising several bioelectrochemical treatment units (14, 16) in series, at least one first bioelectrochemical treatment unit (14) being configured to carry out the oxidation of carbonaceous organic matter for the production of carbon dioxide at an anode of the first bioelectrochemical treatment unit (14), at least one second bioelectrochemical treatment unit (16) being configured to carry out the oxidation of ammonium ions for the production of nitrogen gas at an anode of the second bioelectrochemical treatment unit (16), the first and second bioelectrochemical treatment units (14, 16) being configured to carry out the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (14, 16). An ammonium ion treatment device according to any one of claims 14 to 17, wherein at least one bioelectrochemical treatment unit (22) is configured to carry out the oxidation of ammonium ions for the production of nitrates or nitrites at an anode of the bioelectrochemical treatment unit (22), and: the reduction of nitrates or nitrites for the production of nitrogen gas at a cathode of the bioelectrochemical treatment unit (22), and / or the reduction of carbon dioxide for the production of methane or the reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (22). An ammonium ion treatment device according to any one of claims 14 to 18, wherein at least one bioelectrochemical treatment unit (22) is configured to carry out ammonium ion oxidation for the production of nitrates or nitrites and carbonaceous organic matter oxidation for the production of carbon dioxide at an anode of the bioelectrochemical treatment unit (22), and a reduction of nitrates or nitrites for the production of nitrogen gas and a reduction of carbon dioxide for the production of methane or a reduction of HCO3 ions + for the production of dihydrogen at the level of a cathode of the bioelectrochemical treatment unit (22). Ammonium ion processing device according to claim 14, wherein at least one bioelectrochemical processing unit is configured to carry out carbon dioxide reduction for the production of fatty acid, for example acetate, or ethanol at a cathode of the bioelectrochemical processing unit, the bioelectrochemical processing unit comprising a cation exchange membrane. Installation for the treatment (2) of an input comprising carbonaceous organic matter and nitrogen compounds in a treatment line, the device comprising: at least one preliminary treatment unit (6, 8, 20, 24, 26, 32, 34, 38) of the input configured to separate the input into a liquid fraction and a second fraction, for example sludge, sand or grease, a device for the treatment of ammonium ions present according to any one of claims 14 to 20. A processing installation (2) for an input according to claim 21, comprising upstream of the ammonium ion treatment device a primary processing unit (8) for the input selected from a primary settling tank, a primary filtration or rhizofiltration or biofiltration module, a bio-sorption, a primary flotation module, a screening module or a micro-screening module and configured to separate the input into a liquid fraction and a second fraction, the second fraction being preferably redirected to an anaerobic digester (10). A treatment installation (2) for an input according to any one of claims 21 or 22, comprising upstream of the ammonium ion treatment device a biological treatment module for carbonaceous matter (20), for example a unit for the degradation of carbonaceous organic matter by biofiltration, a membrane bioreactor, a methanizer, biodisc contactors, bacterial beds or a high-load activated sludge unit, at least one bioelectrochemical treatment unit (22) being configured to carry out an oxidation of ammonium ions into nitrates or nitrites, or into gaseous dinitrogen, at the level of an anode of the bioelectrochemical treatment unit (22). A processing installation (2) for an input according to any one of claims 21 to 23, comprising upstream of the bioelectrochemical processing unit (22) a pre-denitrification module (32), at least one bioelectrochemical processing unit (22) being configured to carry out an oxidation of ammonium ions into nitrates or nitrites at an anode of the bioelectrochemical processing unit (22), the bioelectrochemical processing unit (22) comprising means for returning at least a portion of the nitrates or nitrites produced to the pre-denitrification module (32). Installation for processing (2) an input according to any one of claims 21 to 24, comprising downstream of the ammonium ion treatment device an additional liquid fraction depollution module selected from an electrocoagulation module, a tertiary filtration module, reed beds, an ozonation module, an activated carbon treatment module, an ultraviolet treatment module or a formic acid treatment module.

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