Method for processing liquid manure, preferably agricultural liquid manure, dicarboxylic-acid-containing and / or dicarboxylic-acid-salt-containing agent for said purpose, and use of said agent

Abstract

The invention relates to a method for processing liquid manure, preferably agricultural liquid manure, in particular for producing biomass fertilizer; to a dicarboxylic-acid-containing and / or dicarboxylic-acid-salt-containing agent for said purpose; and to the use of said dicarboxylic-acid-containing and / or dicarboxylic-acid-salt-containing agent.

Description

[0001] Method for processing, preferably agricultural, manure, an agent containing dicarboxylic acid and / or dicarboxylic acid salts for this purpose and its use

[0002] Technical field

[0003] The invention relates to a method for processing, preferably agricultural, liquid manure, in particular for the production of biomass fertilizer, as well as a dicarboxylic acid and / or dicarboxylic acid salt-containing agent for this purpose and the use of this dicarboxylic acid and / or dicarboxylic acid salt-containing agent.

[0004] State of the art

[0005] Spreading liquid manure in agriculture can cause various problems. Ammonia and other volatile substances such as hydrogen sulfide cause unpleasant odors. Furthermore, ammonia can lead to acidification or nutrient enrichment of soils and water bodies. Therefore, it is advisable to treat liquid manure before spreading to prevent the formation of ammonia, i.e., to convert nitrogen into other compounds, such as ammonium nitrogen. Additionally, liquid manure can be problematic for application due to its content of pathogenic germs, such as Escherichia coli (E. coli), as contamination of the soil or groundwater is a potential risk.

[0006] Various methods for processing agricultural manure are known from the state of the art.

[0007] In W080 / 02282, a fermentation process is proposed to preserve the potential nutritional value of the fertilizer. Furthermore, a goal is to reduce pathogenic bacteria in these materials to ensure safe handling, transport, and disposal. To this end, the addition of Lactobacillus and the mixing of a carbohydrate into the fertilizer are proposed to lower the fertilizer's pH value to below 4.5. EP3162784A1 also addresses a process for processing agricultural manure to produce biomass fertilizer. This involves the addition of carbon-containing substances such as mono-, di-, and oligo-carbons.Polysaccharides, pyruvic acids and glucono-delta-lactone and the like to the liquid phase, as well as the introduction of molds and / or yeasts and / or bacteria, in order to metabolize in particular ammonium ions, potassium ions and phosphate ions by the molds and yeasts and / or bacteria in a microbiological endergonic reaction.

[0008] In EP3587381A1, one of the process steps for the processing of agricultural manure is proposed, in which a biogenic semi-aerobic fermentation without the supply of air or O2 is carried out for acidification by adding bacteria to a pH value of approximately 6.0–5.8. A further process step involves aerobic dissimilation and / or fermentation and further acidification to a pH value of approximately 4.8 with the addition of molds and / or yeasts and / or bacteria with the supply of air or oxygen.

[0009] Description of the invention

[0010] The object of the invention is therefore to provide a method for processing agricultural manure, in particular for the production of biomass fertilizer, by which at least approximately odorless manure with a minimal content of E. coli - in particular so low that the content is "undeterminable" - is obtained in order to subsequently produce the processed manure for the production of biomass fertilizer or liquid compost.

[0011] The invention solves this problem by means of the features of claim 1.

[0012] The acidification process step involves lowering the pH value, thereby shifting the ammonium / ammonia equilibrium towards ammonium. This reduces ammonia emissions and can be achieved, for example, by adding acids such as sulfuric acid, acetic acid, and / or glacial acetic acid. Another method of acidification is the addition of carbon-containing nutrients and / or Lactobacillus species or other microorganisms to the liquid manure or homogenized manure mixture.

[0013] The aim of reducing ammonia emissions is twofold: firstly, to reduce the environmentally harmful effects of ammonia, and secondly, to increase fertilizer efficiency throughout the entire nutrient cycle. The acidification of the slurry to reduce its pH value can be adjusted to match the pH value of the slurry supplied for treatment.

[0014] The process according to the invention is characterized, among other things, by the addition of an agent containing a dicarboxylic acid salt and / or a dicarboxylic acid salt. While the acidification step reduces ammonia emissions and can reduce the number of E. coli bacteria or inhibit their activity, the specific use of a dicarboxylic acid and / or a dicarboxylic acid salt leads to unexpectedly pronounced effects with regard to a particularly effective and prolonged reduction of bacteria – specifically, even over two weeks. Dicarboxylic acids and dicarboxylic acid salts not only act as pH lowerers and as agents for maintaining a constant acidic pH range, but it has also been shown that dicarboxylic acids and dicarboxylic acid salts – according to the invention and especially after prior acidification – exhibit antimicrobial effects and effectively inhibit the growth of E. coli over an extended period.

[0015] The combination of the process steps of acidification and the addition of an agent containing dicarboxylic acids and / or dicarboxylic acid salts can prove crucial – specifically, the effect of the agent containing dicarboxylic acids and / or dicarboxylic acid salts can be optimal if the pH of the slurry is precisely adjusted during acidification. The higher the pH of the slurry before the treatment according to the invention, the higher the expected microbial load, particularly with E. coli. Therefore, in the case of slurry with a pH above 12, acidification may be necessary to adjust the pH to below 6.0, approximately to or below 4.5. In general, it may be found that acidifying the slurry to a pH of at least 6.0, preferably at least 6.5, and more preferably to or exactly 6.5, is sufficient or optimal for the subsequent process steps.

[0016] The aerobic treatment step further enhances the antimicrobial effects and the aforementioned reduction in ammonia emissions by promoting the degradation of organic substances and the destruction of pathogenic structures. Stirring and aerating the mixture of slurry and the agent containing dicarboxylic acids and / or dicarboxylic acid salts can also ensure a more homogeneous distribution of oxygen and the agent, further improving the process and stabilizing the treated slurry—for example, until it is further processed and / or applied. This step also makes it possible to raise the pH value of the treated slurry. The aerobic treatment of the mixture of slurry and the agent containing dicarboxylic acids and / or dicarboxylic acid salts preferably takes place over a period of approximately 10–12 days.A period of 13 to 15 days may also prove advantageous, depending on the temperature of the slurry during this period and / or the desired pH value of the slurry treated according to the invention, which, depending on the composition and pH value of the soil onto which this treated slurry is applied, may even be alkaline. This ensures complete stabilization of the environment of the slurry treated according to the invention until its application, as organic substances are effectively broken down, pathogenic germs are reduced, and ammonia emissions are minimized within this timeframe. These treatment periods ensure optimal development of the microbial population and provide slurry for a high-quality biomass fertilizer with virtually odorless properties and such a low E. coli content that it is "undetectable."

[0017] In particular, it was found that these process steps according to the invention, or the combination of said process steps according to the invention, can produce virtually odorless slurry in which the E. coli content falls below the detection limit – a result that cannot be achieved with previous methods, or only through comparatively complex and / or costly process steps. Furthermore, the choice of a water-based or aqueous solution of the agent containing dicarboxylic acid and / or dicarboxylic acid salts allows for simple and cost-effective dosing into the processing process.

[0018] If the agent containing dicarboxylic acids and / or dicarboxylic acid salts includes dicarboxylic acids from the group consisting of citric acid, fumaric acid, malic acid, oxalic acid, and succinic acid, and / or their salts, this can, for example, allow for flexible adaptation of the process to the specific properties of the slurry. These acids are characterized by their high efficacy in lowering pH and their antimicrobial effect. The selection of the appropriate dicarboxylic acid or combination can be tailored to the starting material to ensure maximum odor reduction and pathogenic germ control.

[0019] For example, the agent containing dicarboxylic acid and / or dicarboxylic acid salts consists of one of these ingredients or of a combination of these predominantly or entirely.

[0020] Preferably, the agent containing dicarboxylic acids and / or dicarboxylic acid salts includes short-chain peptide chains. The content of short-chain peptide chains can significantly enhance the agent's effectiveness, particularly with regard to its E. coli reduction activity. The peptides can be selected from the bacteriocin group. It is also possible to add short-chain peptide chains as an additional nutrient source for aerobic stabilization, which can contribute to more efficient decomposition of organic substances and thus to a further reduction of odors and pathogenic germs.

[0021] For example, the mixture of slurry and a product containing dicarboxylic acids and / or dicarboxylic acid salts has a content of 0.6 to 10 wt.% or 0.6 to 6 wt.%. It may be necessary to adjust the dicarboxylic acid and / or dicarboxylic acid salt content to the upper limit of this range, especially if the slurry used in the process has a particularly high pH value, for example, 12 – perhaps because in such cases the bacterial load or E. coli content of the slurry used as feedstock may also be comparatively high. If necessary, under such conditions, a reduction to a lower pH value, for example below 6.0, may be required in the preceding process step of acidification.

[0022] In general, it may be sufficient if the mixture of slurry and dicarboxylic acid-containing agent contains 0.6 to 4% by weight of dicarboxylic acid and / or dicarboxylic acid salt.

[0023] In general, a dicarboxylic acid and / or dicarboxylic acid salt content of 0.80 to 2.2 wt.% in the mixture of slurry and product containing dicarboxylic acid and / or dicarboxylic acid salts can prove effective and / or sufficient – ​​particularly if the slurry provided for the process has a pH of 10 to 11. A content of 0.8 to 2.0 wt.% or 1.0 to 1.5 wt.% may prove sufficient if the slurry provided for the process has a pH of approximately 10 – specifically, if acidification to a pH of 6.5 or in the range of 6.5 has been achieved during the process step – which is advantageous in terms of cost. A content of 2 to 3%, particularly 2 to 3 wt.%, may also be sufficient.-%, of dicarboxylic acid and / or dicarboxylic acid salt in the mixture of slurry and agent containing dicarboxylic acid and / or dicarboxylic acid salt can prove particularly effective with slurry provided for the process with a pH value of 11 or higher.

[0024] The formulation, tailored to the specific slurry supplied for the process, ensures – in addition to the aforementioned acidification step – an effective and consistent reduction in pH value as well as a sustained antimicrobial effect, without impairing the microbial activity required for subsequent aerobic stabilization. Excessively high concentrations can negatively impact the treatment process, while excessively low concentrations may prevent the desired results in terms of odor reduction and pathogen control.In general, the addition of a dicarboxylic acid-containing agent according to the invention is characterized by its positive effects with regard to a particularly pronounced reduction of germs, since dicarboxylic acids not only act as a pH reducer and ensure a constant acidic pH range, but also do so for a period of > 10 days, for example 10-12 days or 13 to 15 days, specifically for the subsequent aerobic treatment in the process according to the invention.Preferably, the aerobic treatment is carried out by stirring and aerating the mixture of slurry and agent containing dicarboxylic acids and / or dicarboxylic acid salts with the supply of oxygen, for example by means of an agitator. This supply of oxygen preferably occurs in alternating intervals of 10 to 30 minutes, particularly 20 minutes, of continuous aeration, followed by a period of 20 to 40 minutes, particularly 30 minutes, without aeration. Air and / or enriched / pure oxygen can be used for this purpose. This intermittent oxygen supply optimizes the aerobic treatment of the mixture of slurry and agent containing dicarboxylic acids and / or dicarboxylic acid salts. This promotes the growth of a diverse microorganism population and maximizes the degradation of organic substances, while preventing the environment from becoming degraded, for example, towards putrefaction.This cyclical approach can ensure efficient odor reduction and pathogenic germ control as well as stabilization of the slurry treated according to the invention, while simultaneously avoiding an overload of the mixture with oxygen.

[0025] This process step can advantageously be carried out at a temperature substantially above 10 degrees Celsius. In particular, the process according to the invention is characterized by the fact that a temperature of 12 to 13 degrees is suitable, which offers cost advantages in cool ambient conditions. It can also be carried out, for example, at a temperature above 18 degrees Celsius, particularly between 20 and 21 degrees Celsius. A temperature between 20 and 21 °C may also be suitable. Adjusting the temperature range can promote the activity of the microorganism population and accelerate the degradation of organic substances. A higher temperature may be suitable for increasing the efficiency of the process with regard to odor reduction and pathogen control.

[0026] Preferably, after the stirring and aeration step of the mixture of slurry and agent containing dicarboxylic acids and / or dicarboxylic acid salts, its consistency is modified by adding additives, particularly its viscosity. This can be achieved, for example, by adding plant biomass such as beet pulp and / or beet molasses and / or cereal flour and / or cereal meal, hay and / or straw meal, and / or by adding natural clay materials. This adjustment of the material's viscosity can, for example, ensure improved handling and storability, or adapt it to the properties of the soil onto which the slurry is applied. The addition of solids can also positively influence the structure of the final product, i.e., the biomass fertilizer or liquid compost, and optimize its application properties—especially with regard to ensuring stable soil structures.

[0027] The acidification step can be achieved by adding organic acid or can include such an addition – preferably by stirring. To reduce costs, acetic acid and / or glacial acetic acid are particularly suitable for this purpose. Preferably, the acidification of the slurry is stopped when the pH value specified in claim 1 is reached. The acidification step is carried out in a controlled manner until the desired / required pH value (e.g., 5.5–7.0 or at least 6.0, preferably 6.5) is reached and then stopped. This can optimize the reduction of ammonia formation – without unnecessary acid addition or extreme pH values ​​that could adversely affect desired microbial activity. The precise adjustment of the pH value – for example, to a lower pH value according to claim 1 – is possible.Claim 1: The higher the pH value of the slurry as starting material for the process according to the invention, the more crucial it is for the subsequent effectiveness of the dicarboxylic acid and / or the dicarboxylic acid salt, or for maintaining a constant pH value through the dicarboxylic acid and / or the dicarboxylic acid salt, as well as for aerobic stabilization.

[0028] Additionally or alternatively, acidification can be carried out as biogenic acidification. This can include the following process steps, particularly in the order mentioned:

[0029] Addition of carbon-containing nutrients for bacteria present in the slurry, for example mono-, di-, oligo- or polysaccharides or beet sugar cane molasses or vinasse and / or supply of oxygen, in particular air and / or enriched / pure oxygen, to inhibit methanogenic bacteria, preferably by means of an agitator in the slurry.

[0030] For example, a combination of nutrient supply and aeration can support an optimal pH drop and prepare the slurry for subsequent processing steps. These substances serve as an additional energy source for the microorganism population and promote their growth and activity, which can contribute to accelerated decomposition of organic matter and improve the efficiency of the process in terms of odor reduction and microbial control.

[0031] For example, acidification essentially ensures an oxygen content of > 2%, particularly an average oxygen content of > 2%, in the slurry. This prevents the processes in the slurry from becoming anaerobic. This oxygen content effectively inhibits methanogenic bacteria and promotes aerobic processes. Ensuring this oxygen level can prove crucial for efficient pH reduction and preparing the slurry for subsequent treatment steps aimed at reducing odor emissions and pathogenic germs – especially with regard to the effects of dicarboxylic acids and / or dicarboxylic acid salts, as this results in slurry that is not only more pH-stable but also more stable in other properties such as consistency.In this context, or more generally during acidification, oxygen can be added every 2 to 4 hours or every 2 to 6 hours for approximately 15 to 20 seconds each time. This procedure ensures a constant, but not excessive, oxygen content in the slurry, which effectively supports the inhibition of methane-producing bacteria while simultaneously avoiding unnecessary energy consumption.

[0032] For example, acidification takes place over a period of up to 4 days, particularly 2 to 3 days. This timeframe can prove sufficient for an efficient yet constant reduction in pH. It is conceivable that the following parameters, individually or in combination, could be determined and / or adjusted before acidifying the slurry:

[0033] Set the temperature to > 10 degrees Celsius, ideally 12 to 13 degrees Celsius. If necessary, a temperature above 18 degrees, especially 20-21 degrees, is also acceptable. This optimal temperature promotes the activity of the microorganisms involved and thus accelerates the fermentation process and the reduction of the pH value.

[0034] Determining the pH value of the slurry: The initial pH measurement serves as a reference value for monitoring the acidification process and enables precise control of the acid addition.

[0035] Determination of total nitrogen in slurry: Knowledge of the nitrogen content allows for the estimation of the ammonia potential and optimizes the dosage of emission reduction measures.

[0036] Determination of the content of ammonium, potassium, and phosphate: This analysis of these nutrients allows for an assessment of the fertilizer value of the slurry and serves as a basis for an adapted application after processing.

[0037] Determination of the content of Enterobacteriaceae and E. coli: The initial measurement provides a reference value for the subsequent assessment of the effectiveness of pathogenic germ reduction during the process - but can also prove crucial for the choice of the amount of dicarboxylic acid and / or dicarboxylic acid salt-containing agent to be added to the slurry.

[0038] Determining the viscosity of the slurry: Knowing the viscosity allows for a more optimal dosage of additives.

[0039] Testing for antibacterial inhibitors, especially antibiotics: The presence of such substances can impair the effectiveness of acidification; their identification may allow for adjustments to the procedure.

[0040] It is conceivable that carbon-containing nutrients are added to the slurry according to the specific pH value for the bacteria present in the slurry.

[0041] For example, at a pH of < 8, molasses can be added to the slurry at a rate of 2% by volume, particularly with a sugar content of 60% by weight. At a pH of > 8, molasses can be added at a rate of 3% by volume, particularly with a sugar content of 60% by weight. Such adjustments can optimize the nutrient supply for existing bacteria and thus support efficient fermentation to lower the pH, regardless of the initial state of the slurry.

[0042] The invention also aims to provide a means by which at least approximately odorless slurry with such a low E. coli content can be produced reproducibly that E. coli is classified as "undetermined".

[0043] The invention solves the stated problem through the features of claim 13.

[0044] The dicarboxylic acid and / or dicarboxylic acid salt-containing agent for processing liquid manure according to the invention comprises, individually or in combination, citric acid, fumaric acid, malic acid, oxalic acid, succinic acid, and / or their salts. It may be provided that the dicarboxylic acid and / or dicarboxylic acid salt-containing agent is an aqueous solution of the aforementioned acids and / or their salts—and / or consists predominantly or exclusively of them. Furthermore, the invention may be particularly distinguished if this dicarboxylic acid and / or dicarboxylic acid salt-containing agent is used for processing agricultural liquid manure, especially for the production of biomass fertilizer.

[0045] The dicarboxylic acids not only offer pH-lowering effects, or the dicarboxylic acids and / or the dicarboxylic acid salt can have pH-stabilizing properties in the acidic range – they are also suitable for adjusting a constant pH value in the acidic range over a longer period of time, for example > 10 days, such as 10-12 days or 13 to 15 days, specifically for the subsequent aerobic treatment in the process according to the invention.

[0046] This makes it possible to reduce pathogenic germs, especially the E. coli content, below the detection limit. In this way, it is possible to reproducibly obtain at least nearly odorless slurry with such a low E. coli content that it is classified as undetectable.

[0047] For the reasons stated above with regard to the corresponding process features, the agent according to the invention, comprising dicarboxylic acids and / or dicarboxylic acid salts, can prove to be particularly suitable for processing, preferably agricultural, liquid manure that has been acidified to reduce its pH value, in particular by fermentation and / or by the addition of organic acid, such as glacial acetic acid and / or acetic acid, for example to adjust the pH value of the liquid manure to below 6.5, in particular 4.5 to 6.0, or acidified to a pH value of the liquid manure in the range of 5.5 to 7.0 or of at least 6.0, preferably at least 6.5, more preferably in the range of or exactly 6.5. Glacial acetic acid and / or acetic acid can be particularly well suited for acidification – also with regard to keeping costs low.

[0048] The agent containing dicarboxylic acids and / or dicarboxylic acid salts can be distinguished in its use, for the reasons stated in the corresponding process characteristics, by being added to, preferably agricultural, manure for its processing, in particular to reduce Escherichia coli bacteria and / or at least to approximately neutralize odors. It is particularly suitable for the production of biomass fertilizer. Preferably, the agent containing dicarboxylic acids and / or dicarboxylic acid salts is water-based or exists as an aqueous solution.

[0049] Furthermore, the use of the agent containing dicarboxylic acid and / or dicarboxylic acid salts may be particularly advantageous for the reasons mentioned above in relation to the corresponding process characteristics, if it contains fumaric acid, malic acid, oxalic acid, succinic acid and / or their salts, either individually or in combination, and in particular consists predominantly or exclusively of these.

[0050] Furthermore, when using a product containing dicarboxylic acids and / or dicarboxylic acid salts, it can prove advantageous if it contains short-chain peptide chains. This is particularly relevant with regard to enhancing its effect on reducing E. coli. The peptides for this purpose can be selected from the group of bacteriocins.

[0051] For the reasons stated in connection with the corresponding process characteristics, the use of the agent containing dicarboxylic acid and / or dicarboxylic acid salts by addition to a slurry can be characterized if the slurry has previously been acidified to reduce its pH value, in particular by fermentation - and / or by the addition of organic acid, such as glacial acetic acid and / or acetic acid, for example to adjust the pH value of the slurry to be in the range of 5.5 to 7.0 or to adjust it to a pH value of at least 6.0, preferably at least 6.5, more preferably in the range of or exactly 6.5.

[0052] For the reasons stated in connection with the corresponding process features, the use of the dicarboxylic acid-containing agent is suitable if, by adding it to the slurry, a mixture of slurry and dicarboxylic acid- and / or dicarboxylic acid salt-containing agent is produced with a content of 0.6 to 10 wt.% or 0.6 to 6 wt.%, in particular 0.6 to 4 wt.%, preferably 0.8 to 2.2 wt.%, more preferably 0.8 to 2.0 wt.%, more preferably 1.0 to 1.5 wt.%, or 2 to 3% adjusted to dicarboxylic acid and / or its salt.

[0053] Method for implementing the invention

[0054] To demonstrate the effects achieved, agricultural manure was treated according to the invention.

[0055] The starting material for the process was 10 m of untreated material. 3Cattle slurry with a pH of 10 – which is a comparatively high pH – and the following bacterial population was provided: Escherichia coli (kFU / ml): 79,000. The slurry was adjusted to a pH of 6.5 by adding an aqueous dilution of 98% glacial acetic acid. No biogenic acidification, as described in claim 8, was performed in this treatment. a. Subsequently, an aqueous solution of a dicarboxylic acid-containing agent – ​​in this exemplary embodiment – ​​namely an aqueous solution of 10 wt% oxalic acid, was added to obtain a mixture of the slurry and the dicarboxylic acid-containing agent comprising 1 wt% oxalic acid of the dicarboxylic acid-containing agent. In this exemplary embodiment, the dicarboxylic acid-containing agent consisted of water and 10 wt% oxalic acid. b.Subsequently, the slurry underwent aerobic treatment over a period of 14 days, with continuous stirring using a propeller stirrer and aeration by means of a beam aerator at the bottom of the container at a temperature of 12 °C.

[0056] The oxygen supply was 20 - 40 g O2 / m² 3 h by fine-bubble aeration of the beam fan. This resulted in a pH value of 7.6, which was desirable for the specific composition and pH value of the soil on which the liquid manure according to the invention was applied.

[0057] The treated slurry was examined using a culture method (plate counting method Biomerieux Coli-ID Agar). The following results were obtained:

[0058] • Escherichia coli (E. coli): not detectable in 1 ml

[0059] • Coliform bacteria: not detectable in 1 ml

[0060] The study confirms successful treatment. Neither E. coli nor coliform bacteria could be detected in the manure.

[0061] It should be noted that in other cases, the inventive method has been used with manure as starting material which contained 100 times the amount of E. coli compared to the aforementioned embodiment. In such cases, acidification to a pH value of 5.5 to 6.0, as well as adjusting the mixture of manure and a dicarboxylic acid-containing agent with 4 wt% oxalic acid of the dicarboxylic acid-containing agent, may be necessary.

Claims

Patent claims:

1. A process for processing, preferably agricultural, liquid manure, in particular for the production of biomass fertilizer, characterized by the following process steps: Acidification of the slurry to reduce the pH value of the slurry, in particular by fermentation, for example to adjust the pH value of the slurry to a value below 6.5, in particular 4.5 to 6.0, or to adjust the pH value of the slurry to a value in the range of 5.5 to 7.0 or to adjust the pH value to at least 6.0, preferably at least 6.5, more preferably in the range of or exactly 6.5, hereinafter, preferably in the following order, Addition of an agent containing dicarboxylic acid and / or dicarboxylic acid salts, in particular a water-based or aqueous solution containing dicarboxylic acid and / or dicarboxylic acid salts, to slurry and aerobic treatment, in particular aerobic stabilization, while stirring and aerating the mixture of slurry and agent containing dicarboxylic acid and / or dicarboxylic acid salts, preferably over a period of approximately 10-12 days or over a period of approximately 13 to 15 days.

2. Method according to claim 1, characterized in that the agent comprising dicarboxylic acid and / or dicarboxylic acid salt comprises dicarboxylic acid from the group consisting of citric acid, fumaric acid, malic acid, oxalic acid and succinic acid and / or their salts individually or in combination, and in particular consists predominantly or entirely of these substances.

3. Method according to one of the preceding claims, characterized in that the agent comprising dicarboxylic acid and / or dicarboxylic acid salt comprises short-chain peptide chains, in particular bacteriocins.

4. Method according to one of the preceding claims, characterized in that a mixture of slurry and an agent containing dicarboxylic acid and / or dicarboxylic acid salts is produced, which contains 0.6 to 10 wt.% or 0.6 to 6 wt.%, in particular 0.6 to 4 wt.%, preferably 0.8 to 2.2 wt.%, more preferably 0.8 to 2.0 wt.%, more preferably 1.0 to 1.5 wt.%, or 2 to 3% of dicarboxylic acid and / or dicarboxylic acid salts.

5. Method according to one of the preceding claims, characterized in that the aerobic treatment is carried out by stirring and aerating the mixture of slurry and agent containing dicarboxylic acid and / or dicarboxylic acid salts. • with the supply of oxygen, in particular air and / or enriched / pure oxygen, the supply of oxygen being carried out in particular by means of an agitator in the mixture of slurry and agent containing dicarboxylic acid and / or dicarboxylic acid salts, preferably in alternating successive intervals of 10 to 30 minutes, in particular 20 minutes, of aeration lasting long, followed by a period of 20 to 40 minutes, in particular 30 minutes, without aeration, • optionally at a temperature of substantially > 10 degrees Celsius, in particular 12 to 13 degrees Celsius, or substantially > 18 degrees Celsius, in particular between 20 and 21 degrees Celsius.

6. Method according to one of the preceding claims, characterized in that, after the process step of stirring and aerating the mixture of slurry and agent containing dicarboxylic acid and / or dicarboxylic acid salts, its consistency is changed by adding additives, in particular the viscosity - for example by adding plant biomass such as beet pulp and / or beet molasses and / or cereal flour and / or cereal flour and / or hay and / or straw meal, and / or by adding natural clay materials.

7. Method according to one of the preceding claims, characterized in that the acidification of the slurry is carried out upon reaching the value specified in claim 1. pH value is reduced and / or that the acidification is carried out by adding organic acid, in particular glacial acetic acid and / or acetic acid, preferably by stirring into the slurry, or includes such an addition.

8. Method according to one of the preceding claims, characterized in that the acidification comprises the following process steps, in particular in the order mentioned: • Addition of carbon-containing nutrients for bacteria present in the slurry, for example mono-, di-, oligo- or polysaccharides or beet / sugar cane molasses or vinasse, and / or • Supply of oxygen, in particular air and / or enriched / pure oxygen, to inhibit methanogenic bacteria, preferably by means of an agitator in the slurry.

9. Method according to one of the preceding claims, characterized in that during acidification an oxygen content of > 2% in the slurry is essentially ensured and / or that the supply of oxygen takes place every 2 to 4 hours or every 2 to 6 hours for approximately 15 to 20 seconds each time.

10. Method according to one of the preceding claims, characterized in that the acidification preferably takes place over a period of up to 4 days, in particular 2 to 3 days.

11. Method according to one of the preceding claims, characterized in that the following parameters are determined and / or adjusted before acidification of the slurry: • Setting the temperature to > 10 degrees Celsius, in particular 12 to 13 degrees Celsius or to > 18 degrees Celsius, in particular 20-21 degrees Celsius, and / or • Determination of the pH value of the slurry and / or • Determination of total nitrogen in slurry, and / or • Determination of the content of ammonium, potassium, phosphate and / or • Determination of the content of Enterobacteriaceae and E. coli and / or • Determination of the viscosity of the slurry and / or • Testing for antibacterial inhibitors, especially antibiotics.

12. Method according to claim 11, characterized in that carbon-containing nutrients for bacteria present in the slurry are added to the slurry according to the determined pH value, in particular • at a pH value of < 8: molasses in an amount of 2 vol.% of the slurry, in particular with a sugar content of 60 wt.%, or • at a pH value of > 8: molasses in an amount of 3 vol.% of the slurry, in particular with a sugar content of 60 wt.%.

13. A dicarboxylic acid and / or dicarboxylic acid salt-containing agent, in particular as a water-based or aqueous solution, for the processing of, preferably agricultural, manure, in particular for the production of biomass fertilizer, comprising individually or in combination citric acid, fumaric acid, malic acid, oxalic acid, succinic acid and / or their salts, in particular consisting predominantly or exclusively thereof.

14. Use of an agent containing a dicarboxylic acid and / or dicarboxylic acid salt, in particular water-based or present as an aqueous solution, for the processing of, in particular, agricultural, manure, especially for the production of biomass fertilizer, with a reduction in Escherichia coli bacteria and / or at least approximately neutralizing odors.

15. Use of an agent comprising a dicarboxylic acid and / or dicarboxylic acid salt according to claim 14, characterized in that the agent comprising a dicarboxylic acid and / or dicarboxylic acid salt comprises, individually or in combination, citric acid, fumaric acid, malic acid, oxalic acid, succinic acid and / or their salts, in particular consisting predominantly or exclusively of these.

16. Use of an agent comprising a dicarboxylic acid and / or dicarboxylic acid salt according to claim 14 or 15, wherein this agent comprises short-chain peptide chains, in particular bacteriocins.

17. Use of an agent comprising a dicarboxylic acid and / or dicarboxylic acid salt according to claim 14, 15 or 16, characterized in that it is added to a slurry which has previously been acidified to reduce its pH value, in particular by fermentation and / or by the addition of organic acid, such as glacial acetic acid and / or acetic acid, for example to adjust the pH value of the slurry to a value below 6.5, in particular 4.5 to 6.0, or to adjust the pH value of the slurry to a value in the range of 5.5 to 7.0 or to adjust the pH value to at least 6.0, preferably at least 6.5, more preferably in the range of or exactly 6.

5.

18. Use of an agent containing dicarboxylic acids and / or dicarboxylic acid salts according to claim 14, 15, 16 or 17, characterized in that by adding it to the slurry a mixture of slurry and agent containing dicarboxylic acids and / or dicarboxylic acid salts is produced with a content of dicarboxylic acids and / or their salts adjusted to 0.6 to 10 wt.% or 0.6 to 6 wt.%, in particular 0.6 to 4 wt.%, preferably 0.8 to 2.2 wt.%, more preferably 0.8 to 2.0 wt.%, more preferably 1.0 to 1.5 wt.%, or 2 to 3%.