Methods and systems for electrocatalytic action of urban sludge and biosolids

Abstract

Methods and systems for electrocatalytic action of urban sludge and biosolids. Such a method (and system) includes selecting a sludge source; preparing a slurry, wherein the slurry comprises a sludge source and an electrolyte; adjusting the pH of the slurry, wherein adjusting the pH of the slurry results in a slurry having an adjusted pH in the range of about (8) and (14); flowing the slurry through an electrochemical cell, wherein the electrochemical cell comprises an anode, a cathode, and a catalyst; applying a potential between the anode and the cathode, wherein applying the potential includes causing the cell voltage between the anode and the cathode to oscillate at an oscillating frequency; decomposing carbon bonds with nitrogen and phosphorus in the slurry as a result of applying the potential, releasing inorganic nitrogen and inorganic phosphorus; and obtaining electrolyzed sludge, wherein the electrolyzed sludge comprises electrolyzed solids, which contain nitrogen and phosphorus.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Application No. 63 / 506,601, filed on June 7, 2023, entitled "Methods And Systems For The Electrocatalysis Of Municipal Sludge And Biosolids", which is jointly owned by the owner of this invention. This patent application is hereby incorporated by reference in its entirety.

[0002] This disclosure relates to improved methods and systems for the electrolysis of biosolids, sludge, food waste, and manure. In particular, this disclosure relates to the electrocatalysis of sludge on transition - metal - based electrodes to produce synthetic nitrogen - based fertilizers, phosphorus - based fertilizers, and electrolyzed solid organic fertilizers from excess activated sludge, manure from concentrated animal feeding operations, and food waste.

[0003] Description of Federally Sponsored Research This invention was made with government support under National Science Foundation Center for Advancing Sustainable and Distributed Fertilizer production, CASFER, NSF 20 - 553 Gen - 4 Engineering Research Centers award number 2133576. The government has certain rights in this invention.

Background Art

[0004] There is a need to produce nitrogen - based fertilizers and phosphorus - based fertilizers from municipal sludge, sludge from concentrated animal feeding operations, food waste, and other similar sources.

[0005] The enormous amount of excess activated sludge is disposed of in landfills even after a considerable retention period during anaerobic digestion. Excess activated sludge is a major byproduct of urban wastewater treatment plants. The management and treatment of excess activated sludge presents challenges to wastewater treatment plants, such as high energy consumption and high operating costs.

[0006] Excess activated sludge contains organic materials such as lignocellulose waste, which can be converted to produce high-value chemicals such as volatile fatty acids. Therefore, the remaining activated sludge is an organic-rich material that is likely to produce high-value chemicals such as short-chain fatty acids.

[0007] Currently, urban sludge treatment is expensive. For example, about 60 percent of the operating costs of urban wastewater treatment plants are due to nitrogen costing between $220 and $1,000 per ton, and more than 1.4 million tons of nitrogen from sludge are dumped into landfills every year.

[0008] Typically, sludge cannot be used as fertilizer due to the presence of microorganisms and other organic pollutants that may be found in urban sludge.

[0009] Sludge from centralized livestock facilities such as lagoons also contains nitrogen, ranging from 5% to 10% by weight. Phosphorus is also present in these flows, making up the majority of the solid content.

[0010] Currently, centralized livestock farms in the United States generate between 16 and 22 million tons of nitrogen waste annually. This amount of nitrogen exceeds the annual domestic consumption of nitrogen-based fertilizers.

[0011] Livestock facilities in the United States generate up to 20 times more manure than humans, which amounts to 1.3 billion tons of waste. Despite this, there are no treatment plants specifically designed for these facilities. Therefore, manure management technology is also needed for centralized livestock farms, as most facilities are not located in areas where the manure can be applied to fields.

[0012] In addition, excessive direct application of untreated animal waste to fields can lead to environmental problems because nutrients exceed the soil's absorption capacity, resulting in runoff or leaching into groundwater.

[0013] Therefore, there is a need for the production of synthetic fertilizers, such as nitrogen-based and phosphorus-based fertilizers, from centralized livestock facilities, which can lead to comprehensive solutions that address food production, environmental, economic, equity, and health concerns.

[0014] Therefore, the object of this disclosure is to determine the electrochemical conversion rate of urban sludge to inorganic nitrogen and phosphorus on nickel-based electrodes and to identify sludge model compounds that can be implemented for electrocatalyst discovery in order to promote the production of synthetic nitrogen-based and phosphorus-based fertilizers from surplus activated sludge and centralized livestock facilities. [Overview of the Initiative]

[0015] This disclosure relates to improved methods and systems for the electrolysis of biosolids, sludge, food waste, and manure. In some embodiments, the methods and systems involve the electrocatalytic action of sludge on a transition electrode (e.g., nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), chromium (Cr), manganese (Mn), scandium (Sc), etc.). Thus, certain embodiments of this disclosure involve the production of synthetic nitrogen-based and phosphorus-based fertilizers from surplus activated sludge and centralized livestock facilities.

[0016] In general, in one embodiment, the present disclosure features a method for the electrocatalytic action of sludge. The method may include selecting a sludge source. The method may also include preparing a slurry. The slurry may include a sludge source and an electrolyte. The method may also include adjusting the pH of the slurry. By adjusting the pH of the slurry, a slurry having a controlled pH in the range of about 8 to 14 can be obtained. The method may also include flowing the slurry through an electrochemical cell. The electrochemical cell may include an anode, a cathode, and a catalyst. The method may also include applying a potential between the anode and the cathode. Applying a potential may include oscillating the cell voltage between the anode and the cathode at an oscillating frequency. The method may also include decomposing carbon bonds with nitrogen and phosphorus in the slurry as a result of applying a potential. The method may also include releasing inorganic nitrogen and inorganic phosphorus. The method may also include obtaining electrolyzed sludge. The electrolyzed sludge may include electrolyzed solid organic fertilizer containing nitrogen and phosphorus. The method may also include the introduction of a separator or membrane between the two electrodes.

[0017] Other advantages of this disclosure will become apparent from the following detailed description of this disclosure, in conjunction with the embodiments illustrated in the accompanying drawings. [Brief explanation of the drawing]

[0018] [Figure 1] This disclosure describes a process for the electrolysis of sludge for the production of nitrogen-based fertilizers, phosphorus-based fertilizers, and organic fertilizers / carbon sinks, according to certain embodiments of this disclosure. [Figure 2] This disclosure describes a system for the electrolysis of sludge for the production of nitrogen-based and phosphorus-based fertilizers, according to a particular embodiment of this disclosure. [Modes for carrying out the invention]

[0019] This disclosure relates to improved methods and systems for the electrolysis of biosolids, sludge, food waste, and manure. In particular, this disclosure relates to the electrocatalytic action of sludge on transition electrodes for producing synthetic nitrogen-based and phosphorus-based fertilizers from surplus activated sludge and centralized livestock facilities.

[0020] Figure 1 illustrates a process for the electrolysis of sludge for the production of nitrogen-based fertilizers, phosphorus-based fertilizers, and organic fertilizers / carbon sinks, according to a particular embodiment of the present disclosure. Figure 2 illustrates a system for the electrolysis of sludge for the production of nitrogen-based fertilizers and phosphorus-based fertilizers, according to a particular embodiment of the present disclosure.

[0021] As shown in Figure 1, this disclosure relates to a method and system for the electrolysis of biosolids, sludge, food waste, and manure. The process, as shown in Figure 1, can convert urban sludge, manure, centralized livestock facility sludge, and food waste into nitrogenous fertilizers, phosphorusous fertilizers, ammonia, slow-release organic fertilizers, and carbon sink char. The process in Figure 1 provides the conversion and valuation of urban sludge and centralized livestock facility sludge into high-value-added products such as ammonia, slow-release organic fertilizers, phosphorus, and soil-improving nutrients capable of acting as carbon sinks.

[0022] The process may yield products of inorganic nitrogen fertilizers, inorganic phosphorus fertilizers, fatty acids, hydrogen, and organic NP fertilizers. For example, in some embodiments, the inorganic nitrogen fertilizer may be ammonia, ammonium salts, calcium nitrate, or a combination thereof. For example, in some embodiments, the inorganic phosphorus fertilizer may be one or more calcium phosphates.

[0023] In some embodiments, for example, the slow-release organic fertilizer can be or can include electrolyzed biosolids. In such embodiments, the fertilizer can contain a consistent nitrogen and phosphorus content and a microstructure that enhances plant growth and increases nutrient use efficiency due to the slow-release of nitrogen. In some embodiments, the method and system for electrolysis can include a carbon sink material because the electrolyzed biosolids, such as those in the slow-release organic fertilizer, have the property of absorbing carbon dioxide.

[0024] As shown in FIG. 1, the process can start with the introduction of sludge. In some embodiments, the sludge can be sewage. In other embodiments, the sludge can be manure. In certain embodiments, the sludge can be one or more combinations of municipal sludge, manure, concentrated livestock facility sludge, and food waste.

[0025] The process can then continue with the preparation of a slurry. In such embodiments, the slurry can include sludge and an electrolyte. The sludge can contain solids between about 0.5 percent and 40 percent as a mass percentage of the solute in the solution.

[0026] In certain embodiments, the process can involve adjusting the pH of the slurry. In some embodiments, the pH of the slurry can be adjusted between 8 and 14 using potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), or other equivalent salts. These salts can also serve as electrolytes in the slurry. Although it is possible to operate the process at higher pH values, the provided range presents economic advantages.

[0027] As shown in Figure 1, the process may involve flowing a slurry through an electrochemical cell containing two electrodes, an anode and a cathode. In some embodiments, the electrochemical cell may also include a membrane or separator. In such embodiments, the addition of a separator allows for the separation of hydrogen gas, which may be released under certain applied voltages. In certain embodiments, the electrochemical cell may include an anode, a cathode, a membrane or separator for collecting hydrogen, an electrolyte, and a reference electrode.

[0028] In some embodiments, the anode may include a support that is a conductive material such as, but is not limited to, (Ni) gauze / mesh, stainless steel, Hastelloy®, graphite, nickel (Ni), nickel (Ni) foam, copper (Cu), cobalt (Co), chromium (Cr), zinc (Zn), titanium (Ti), titanium (Ti) foam, aluminum (Al), aluminum (Al) foam, vanadium (V), manganese (Mn), scandium (Sc), ruthenium (Ru), rhodium (Rh), iron (Fe), silver (Ag), gold (Au), or a combination thereof. In some embodiments, the anode may include any conductive material that is corrosion-resistant based on the system's electrolyte, cell voltage, and temperature. In some embodiments, the support may include carbon, carbon fiber, or graphene. In some embodiments, the anode may include a catalyst containing a metal such as nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), copper (Cu), zinc (Zn), ruthenium (Ru), rhodium (Rh), vanadium (V), manganese (Mn), titanium (Ti), scandium (Sc), and combinations thereof. In some embodiments, the catalyst may include a composite of graphene and a metal. The catalyst is 0.1 mg / cm³ 2 From 2 mg / cm³ 2 It may have a supported amount. The catalyst can also be used directly as a metal or support in certain embodiments.

[0029] In some embodiments, the cathode may include a support that is a conductive material such as, but is not limited to, nickel (Ni) gauze / mesh, stainless steel, Hastelloy, graphite, nickel (Ni), nickel (Ni) foam, copper (Cu), cobalt (Co), chromium (Cr), zinc (Zn), titanium (Ti), titanium (Ti) foam, aluminum (Al), aluminum (Al) foam, vanadium (V), manganese (Mn), scandium (Sc), ruthenium (Ru), rhodium (Rh), iron (Fe), silver (Ag), gold (Au), or a combination thereof. In some embodiments, the anode may include any conductive material that is corrosion-resistant based on the system's electrolyte, cell voltage, and temperature. In some embodiments, the support may include carbon, carbon fiber, or graphene. In some embodiments, the anode may include a catalyst containing a metal such as nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), copper (Cu), zinc (Zn), ruthenium (Ru), rhodium (Rh), vanadium (V), manganese (Mn), titanium (Ti), scandium (Sc), and combinations thereof. In some embodiments, the catalyst may include a composite of graphene and a metal. The catalyst is 0.1 mg / cm³ 2 From 2 mg / cm³ 2 It may have a supported amount. The catalyst can also be used directly as a metal or support in certain embodiments.

[0030] In some embodiments, a membrane and / or separator may be included in the electrochemical cell. Specifically, in some embodiments, the electrochemical cell may include, for example, a membrane such as Nafion, frit glass, and / or a separator, such as, for example, polyethylene.

[0031] In some embodiments, the electrolyte may contain both strong and weak bases. For example, the electrolyte may include potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), or a combination thereof. The electrolyte may be present at a concentration such that the pH is maintained between approximately 8 and 14.

[0032] The process may also involve applying an oscillation of potential between two electrodes. For example, the cell voltage can be applied between the anode and cathode of the cell. In some embodiments, current is applied instead of voltage. In some embodiments, the voltage can be oscillated at frequencies of 1, 10, 30, 60 seconds, and 15, 30 minutes. In some embodiments, the effective cell voltage can be up to 2.0V (subtracted by ohm resistance, counter, wire, etc.), depending on the type of electrolyte used and the temperature. The cell voltage of an electrochemical cell can vary from 0.8V to 2.0V, excluding the ohm resistance. The applied cell voltage can prevent the oxidation of water at the anode of the cell, and the oxidation potential is a function of the electrolyte used and the temperature.

[0033] During oscillation, in some embodiments, the temperature is controlled. For example, the temperature may be controlled between approximately 20°C and 80°C.

[0034] In some embodiments, the applied potential breaks the carbon bonds between nitrogen and phosphorus. As a result, in such embodiments, the process may include releasing nitrogen and phosphorus as inorganic phosphorus and nitrogen. For example, inorganic phosphorus may include phosphates. For example, inorganic nitrogen may be ammonia, nitrates, or a combination thereof.

[0035] The process products may include electrolyzed solids containing fractions of nitrogen and phosphorus in organic forms that can be applied as organic fertilizer. In some embodiments, the microstructure of the electrolyzed sludge can serve as a sink for absorbing carbon dioxide (CO2) from the atmosphere.

[0036] Therefore, in some embodiments, the process in Figure 1 can reduce the time required to produce organic fertilizer. In some embodiments, the fertilizer may contain carbon, nitrogen, and phosphorus. For example, a biological process takes 30 to 45 days to digest organic waste into fertilizer. In contrast, the process in Figure 1, by electrolysis of sludge, reduces the digestion time to less than 6 hours. The residence time for conversion in the process in Figure 1 can be 2 hours. This residence time for conversion in the process in Figure 1 is significantly shorter than that of processes using anaerobic digesters, which typically take about 10 to 20 days.

[0037] The process shown in Figure 1 can result in a 24.85 percent reduction in total solids and a 46.42 percent reduction in volatile solids, which represents a reduction of approximately 25 percent in sludge disposal costs compared to conventional treatment methods.

[0038] In some embodiments, this process can result in the conversion of 68% of organic nitrogen into inorganic nitrogen. [Examples]

[0039] Example 1 Slow-release fertilizer (electrolyzed sludge) was produced using a process for electrolysis of sludge, which includes nitrogen-based and phosphorus-based fertilizers, as well as for the production of organic fertilizers / carbon sinks. In the examples, the electrolyzed sludge (solid matter after electrolysis) showed a 20 to 40% reduction in carbon content and the destruction of pathogens. In addition, the microstructure of the material was altered, with the surface formed of microparticles and nanoparticles. This material contained nitrogen and phosphorus at compost-like concentrations. The altered microstructure enabled the slow release of the fertilizer, resulting in advantages in the soil. The altered microstructure can minimize the release of inorganic fertilizer when mixed with synthetic inorganic fertilizers in the soil.

[0040] Example 2 Using processes for the electrolysis of sludge for nitrogen-based and phosphorus-based fertilizers, as well as for the production of organic fertilizers / carbon sinks, electrolyzed sludge was produced as a carbon sink material. The electrolyzed sludge released volatile carbon. Due to changes in microstructure, the product behaves similarly to activated carbon, enabling the absorption of carbon dioxide (CO2) and other pollutants. Other pollutants may include methane, benzene, toluene, or combinations thereof.

[0041] In accordance with the above disclosures, the systems and methods listed in the following clauses are specifically contemplated and intended as a non-limiting set of examples.

[0042] Clause 1. A method for the electrocatalytic action of sludge, comprising: selecting a sludge source; preparing a slurry, wherein the slurry comprises the sludge source and an electrolyte; adjusting the pH of the slurry, wherein the adjustment of the pH of the slurry results in the slurry having an adjusted pH in the range of about 8 to 14; and flowing the slurry through an electrochemical cell, wherein the electrochemical cell comprises an anode, a cathode, and a catalyst. A method comprising: applying a potential between the anode and the cathode, wherein the application of the potential includes causing the cell voltage between the anode and the cathode to vibrate at an oscillation frequency; severing carbon bonds with nitrogen and phosphorus in the slurry as a result of the application of the potential; releasing inorganic nitrogen and inorganic phosphorus; and obtaining electrolyzed sludge, wherein the electrolyzed sludge contains electrolyzed solids that contain nitrogen and phosphorus.

[0043] Clause 2. The method according to any of the preceding clauses, wherein the sludge source includes one or more of the following: urban sludge, manure, centralized livestock facility sludge, and food waste.

[0044] Clause 3. The method according to any of the preceding clauses, wherein the sludge source contains solids in a mass percentage in the range of about 0.5 percent to 40 percent.

[0045] Clause 4. The method according to any of the preceding clauses, further comprising adjusting the pH of the slurry by adding a salt to the slurry.

[0046] Clause 5. The method according to any of the preceding clauses, wherein the salt is potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), or a combination thereof.

[0047] Clause 6. The method according to any of the preceding clauses, wherein the electrochemical cell further comprises a membrane.

[0048] Clause 7. The method according to any of the preceding clauses, wherein the film comprises Nafion, frit glass, or a combination thereof.

[0049] Clause 8. The method according to any of the preceding clauses, wherein the electrochemical cell further comprises a separator, the separator separating hydrogen gas.

[0050] Clause 9. The method according to any of the preceding clauses, wherein the separator is polyethylene.

[0051] Clause 10. The method according to any of the preceding clauses, wherein the electrochemical cell further includes a reference electrode.

[0052] Clause 11. The method according to any of the preceding Clauses, wherein the anode includes (Ni) gauze / mesh, stainless steel, Hastelloy, graphite, nickel (Ni), nickel (Ni) foam, copper (Cu), cobalt (Co), chromium (Cr), zinc (Zn), titanium (Ti), titanium (Ti) foam, aluminum (Al), aluminum (Al) foam, vanadium (V), manganese (Mn), scandium (Sc), ruthenium (Ru), rhodium (Rh), iron (Fe), silver (Ag), gold (Au), or a combination thereof.

[0053] Clause 12. The method according to any of the preceding Clauses, wherein the cathode includes nickel (Ni) gauze / mesh, stainless steel, Hastelloy, graphite, nickel (Ni), nickel (Ni) foam, copper (Cu), cobalt (Co), chromium (Cr), zinc (Zn), titanium (Ti), titanium (Ti) foam, aluminum (Al), aluminum (Al) foam, vanadium (V), manganese (Mn), scandium (Sc), ruthenium (Ru), rhodium (Rh), iron (Fe), silver (Ag), gold (Au), or a combination thereof.

[0054] Clause 13. The method according to any of the preceding clauses, wherein the catalyst comprises a composite of a combination of graphene and a metal.

[0055] The method according to any of the preceding clauses, wherein the vibration frequencies of 10, 30, 60 seconds, and 15, 30 minutes are applied.

[0056] Clause 15. The method according to any of the preceding clauses, further comprising applying the oscillating cell voltage between the anode and the cathode to maintain a controlled temperature, wherein the controlled temperature is in the range of about 20°C to about 80°C.

[0057] Clause 16. The method according to any of the preceding clauses, wherein the inorganic nitrogen comprises ammonia, nitrates, or a combination thereof.

[0058] Clause 17. The method according to any of the preceding clauses, wherein the inorganic phosphorus comprises a phosphate salt.

[0059] Clause 18. The method according to any of the preceding clauses, wherein the electrolyzed sludge contains organic fertilizer.

[0060] Clause 19. The method according to any of the preceding Clauses, wherein the electrolyzed sludge contains microstructures, and the microstructures of the electrolyzed sludge serve as a sink for the absorption of carbon dioxide (CO2).

[0061] Clause 20. The method according to any of the preceding clauses, wherein the cell voltage, excluding resistive losses, varies from approximately 0.8V to approximately 2.0V.

[0062] Clause 21. The method of any of the preceding clauses, further comprising applying the potential between the anode and the cathode to prevent oxidation of water at the anode.

[0063] Clause 22. The method according to any of the preceding clauses, wherein the organic fertilizer comprises carbon, nitrogen, and phosphorus.

[0064] Clause 23. Electrolyzed solid organic fertilizer containing nitrogen, carbon, and phosphorus.

[0065] Article 24. The electrolyzed solid organic fertilizer described in any of the preceding articles promotes a nitrogen cycle economy.

[0066] Clause 25. The electrolyzed solid organic fertilizer described in any of the preceding clauses, which facilitates runoff reduction.

[0067] The preceding description uses specific nomenclature for illustrative purposes and to provide a complete understanding of the embodiments described. However, it should be apparent to those skilled in the art that specific details are not required to practice the embodiments described. Therefore, the preceding description of specific embodiments is presented for illustrative and explanatory purposes only. They are not intended to be exhaustive or to limit the embodiments described to the exact forms disclosed. Given the above teachings, it should be apparent to those skilled in the art that many modifications and variations are possible.

[0068] While embodiments of the Disclosure have been shown and described, modifications thereof can be made by those skilled in the art without departing from the spirit and teachings of the Disclosure. The embodiments described herein and the examples provided herein are illustrative and not intended to limit the scope of the Disclosure. Many variations and modifications of the Disclosure disclosed herein are possible and within the scope of the Disclosure. The scope of protection is not limited by the foregoing description but is limited only by the following claims, which include all equivalents of the subject matter of the claims.

[0069] Quantitative and other numerical data may be presented herein in range form. Such range forms are used solely for convenience and brevity and should be understood to be interpreted flexibly to include all individual numbers or subranges contained within that range, as if each number and subrange were explicitly listed, rather than just the numbers explicitly enumerated as the limits of the range. For example, the numerical range from approximately 1 to approximately 4.5 should be interpreted to include not only the explicitly enumerated limits of 1 to approximately 4.5, but also individual numbers such as 2, 3, 4, and subranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges enumerating only one number, such as "less than approximately 4.5," which should be interpreted to include all the values ​​and ranges enumerated above. Furthermore, such interpretations should apply regardless of the breadth of the range or the characteristics described. The symbol "~" is equivalent to "approximately."

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the subject matter of this disclosure pertains. Any methods, devices, and materials similar or equivalent to those described herein may be used in the practice or testing of the subject matter of this disclosure, but representative methods, devices, and materials are described herein.

[0071] In accordance with long-standing patent law convention, the terms “a” and “an,” when used in this application, including in the claims, mean “one or more.”

[0072] Unless otherwise indicated, all numbers used herein to represent quantities of raw materials, reaction conditions, etc., should be understood in all cases to be modified by the term "approximately." Therefore, unless otherwise indicated, numerical parameters described herein are approximations that may vary depending on the desired properties to be obtained by the subject matter of this disclosure.

[0073] As used herein, the term "and / or," when used in the context of listing entities, means that the entities exist individually or in combination. Thus, for example, the phrase "A, B, C, and / or D" includes A, B, C, and D individually, but also any and all combinations of A, B, C, and D, as well as partial combinations of A, B, C, and D.

[0074] The above discussion is intended to illustrate the principles and various embodiments of this disclosure. Once the above disclosure is fully understood, numerous variations and modifications will become apparent to those skilled in the art. The following claims are intended to be construed to encompass all such variations and modifications.

[0075] References Environmental Protection Agency. Detecting and mitigating the environmental impact of fecal pathogens originating from confined animal feeding operations: Review (2005). (Obtained from http: / / www.farmweb.org / Articles / Detecting%20and%20Mitigating%20the%20Environmental%20Impact%20of%20Fecal%20Pathogens%20Originating%20from%20Confined%20Animal%20Feeding%20Operations.pdf).

[0076] Jafari, M., Botte G.G. Electrochemical valorization of waste activated sludge for short-chain fatty acids production. Frontiers in Chemistry 10:974223 (2022).

[0077] Jafari, M., Botte, G.G. Electrochemical treatment of sewage sludge and pathogen inactivation. J Appl Electrochem 51, 119 - 130 (2021).

[0078] Liu, H. et al. Phosphorus recovery from municipal sludge-derived ash and hydrochar through wet-chemical technology: A review towards sustainable waste management, Chemical Engineering Journal 417, 129300 (2021).

[0079] Lu, F., Botte G.G. Understanding the electrochemically induces conversion of urea to ammonia using nickel-based catalysts, Electrochimica Acta, 246, 564 - 571(2017).

[0080] Schmalzried, H.D. & Fallon, L.F., Jr. Large-scale dairy operations: Assessing concerns of neighbors about quality-of-life issues. J. of Dairy Science, 90(4), 2047 - 2051(2007)(http: / / jds.fass.org / cgi / reprint / 90 / 4 / 2047?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=large-scale&searchid=1&FIRSTINDEX=0&volume=90&issue=4&resourcetype=HWCから取得).

[0081] Zhuang, X. et al. The transformation pathways of nitrogen in sewage sludge during hydrothermal treatment, Bioresource Technology 245, 463 - 470(2017).

Claims

1. A method for the electrocatalytic action of sludge, (a) Selecting a sludge source, (b) Preparing a slurry, wherein the slurry contains the sludge source and the electrolyte, (c) Adjusting the pH of the slurry such that adjusting the pH of the slurry results in the slurry having an adjusted pH in the range of about 8 and 14. (d) Flowing the slurry through an electrochemical cell, wherein the electrochemical cell is (i) Anode, (ii) Cathode, and (iii) Catalyst The slurry is flowed through an electrochemical cell, which includes the following: (e) Applying a potential between the anode and the cathode, wherein applying the potential includes causing the cell voltage between the anode and the cathode to vibrate at an oscillation frequency, (f) The application of the potential causes the carbon bonds between nitrogen and phosphorus in the slurry to be broken, (g) Releasing inorganic nitrogen and inorganic phosphorus, (h) Obtaining electrolyzed sludge, wherein the electrolyzed sludge contains electrolyzed solids that contain nitrogen and phosphorus, Methods that include...

2. The method according to claim 1, wherein the sludge source includes one or more of the following: urban sludge, human waste, centralized livestock facility sludge, and food waste.

3. The method according to claim 1, wherein the sludge source contains solid matter in a mass percentage in the range of about 0.5 percent to 40 percent.

4. The method according to claim 1, further comprising adjusting the pH of the slurry by adding a salt to the slurry.

5. The method according to claim 4, wherein the salt is potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), or a combination thereof.

6. The method according to claim 1, wherein the electrochemical cell further comprises a membrane.

7. The method according to claim 6, wherein the film comprises Nafion, frit glass, or a combination thereof.

8. The method according to claim 1, wherein the electrochemical cell further includes a separator, the separator separates hydrogen gas.

9. The method according to claim 1, wherein the separator is polyethylene.

10. The method according to claim 1, wherein the electrochemical cell further includes a reference electrode.

11. The method according to claim 1, wherein the anode comprises nickel (Ni) gauze / mesh, stainless steel, Hastelloy, graphite, nickel (Ni), nickel (Ni) foam, copper (Cu), cobalt (Co), chromium (Cr), zinc (Zn), titanium (Ti), titanium (Ti) foam, aluminum (Al), aluminum (Al) foam, vanadium (V), manganese (Mn), scandium (Sc), ruthenium (Ru), rhodium (Rh), iron (Fe), silver (Ag), gold (Au), or a combination thereof.

12. The method according to claim 1, wherein the cathode comprises nickel (Ni) gauze / mesh, stainless steel, Hastelloy, graphite, nickel (Ni), nickel (Ni) foam, copper (Cu), cobalt (Co), chromium (Cr), zinc (Zn), titanium (Ti), titanium (Ti) foam, aluminum (Al), aluminum (Al) foam, vanadium (V), manganese (Mn), scandium (Sc), ruthenium (Ru), rhodium (Rh), iron (Fe), silver (Ag), gold (Au), or a combination thereof.

13. The method according to claim 1, wherein the catalyst comprises a composite of graphene and a metal.

14. The method according to claim 1, further comprising applying the oscillating cell voltage between the anode and the cathode to maintain a controlled temperature, wherein the controlled temperature is in the range of about 20°C to 80°C.

15. The method according to claim 1, wherein the inorganic nitrogen comprises ammonia, a nitrate, or a combination thereof.

16. The method according to claim 1, wherein the inorganic phosphorus comprises a phosphate salt.

17. The method according to claim 1, wherein the electrolyzed sludge contains organic fertilizer.

18. The electrolyzed sludge contains microstructures, and these microstructures of the electrolyzed sludge contain carbon dioxide (CO2). ２ The method according to claim 1, wherein it serves as a sink for absorbing )

19. The method according to claim 1, wherein the cell voltage, excluding resistance losses, fluctuates between approximately 0.8V and approximately 2.0V.

20. The method according to claim 1, further comprising applying the potential between the anode and the cathode to prevent oxidation of water at the anode.

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