Method and system for electrocatalysis of municipal sludge and biological solids

Abstract

The invention relates to a method and a system for electrocatalyzing municipal sludge and biological solids. Such methods (and systems thereof) include 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 adjusting the pH of the slurry is such that the slurry has an adjusted pH in a range between about (8) and (14); flowing the slurry through an electrochemical cell, wherein the electrochemical cell includes an anode, a cathode, and a catalyst; applying a potential between the anode and the cathode, wherein applying the potential includes oscillating a cell voltage between the anode and the cathode at an oscillation frequency; breaking carbon bonds with nitrogen and phosphorus in the slurry due to the application of the potential; inorganic nitrogen and inorganic phosphorus are released; and obtaining an electrolyzed sludge, wherein the electrolyzed sludge comprises an electrolyzed solid comprising nitrogen and phosphorus.

Description

[0001] Cross-referencing of related patent applications

[0002] This application claims the benefit of U.S. Application Serial No. 63 / 506,601, filed June 7, 2023, entitled “Methods and Systems For The Electrocatalysis Of Municipal Sludge and Biosolids,” which is jointly owned by the owners of this invention. This patent application is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to improved methods and systems for the electrolysis of biological solids, sludge, food waste, and manure. Specifically, 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 waste activated sludge, manure from centralized animal husbandry operations, and food waste.

[0004] Statement on federally funded research

[0005] This invention was funded by the National Science Foundation Center for the Advancement of Sustainable and Distributed Fertilizer Production (CASFER) NSF 20-553 Gen-4 Engineering Research Center, grant number 2133576. The government holds certain rights to this invention. Background Technology

[0006] Nitrogen-based and phosphorus-based fertilizers need to be produced from municipal sludge, sludge from centralized animal husbandry operations, food waste, and other similar sources.

[0007] Even after a considerable retention time during anaerobic digestion, large quantities of waste activated sludge eventually end up in landfills. Waste activated sludge is a major byproduct of municipal wastewater treatment plants. The management and disposal of waste activated sludge presents challenges to wastewater treatment plants, such as high energy consumption and operating costs.

[0008] Waste activated sludge contains organic materials (such as lignocellulose waste), which can be converted to produce high-value chemicals, such as volatile fatty acids. Therefore, residual activated sludge is a material rich in organic matter with great potential for producing value-added chemicals such as short-chain fatty acids.

[0009] Currently, urban sludge disposal is expensive. For example, nearly 60 percent of the operating costs of urban wastewater treatment plants are spent on nitrogen, ranging from $220 to $1,000 per tonne, and more than 1.4 million tons of nitrogen from sludge are disposed of in the land each year.

[0010] Sludge is typically not used as fertilizer because of the presence of microorganisms and other organic pollutants that can be found in urban sludge.

[0011] Sludge from concentrated animal husbandry operations (such as lagoons) also contains nitrogen ranging from 5% to 10% by weight. Phosphorus is also present in these streams, with most of its concentration existing in solid form.

[0012] Currently, intensive animal husbandry operations in the United States generate the equivalent of 16 to 22 million tons of nitrogen waste annually. This amount of nitrogen exceeds the country's annual consumption of nitrogen-based fertilizers.

[0013] Livestock facilities in the United States produce 20 times more manure than human manure, equivalent to 1.3 billion tons of waste. Despite this, these facilities lack treatment plants. Therefore, centralized animal husbandry operations also require manure management techniques, as most facilities are not located in places where manure can be applied to the fields.

[0014] In addition, excessive direct application of untreated manure to the field poses environmental challenges because nutrients exceed the soil's absorption capacity and are lost or leach into groundwater.

[0015] Therefore, there is a need to produce synthetic fertilizers, such as nitrogen-based and phosphorus-based fertilizers, from centralized animal husbandry operations, which could generate holistic solutions to address food production, environmental, economic, equity, and health issues.

[0016] Therefore, the purpose of this disclosure is to determine the electrochemical conversion rate of municipal sludge to inorganic nitrogen and phosphorus on a nickel-based electrode and to identify sludge model compounds that can be implemented for electrocatalyst discovery to facilitate the production of synthetic nitrogen-based and phosphorus-based fertilizers from waste activated sludge and centralized animal husbandry operations. Summary of the Invention

[0017] This disclosure relates to improved methods and systems for the electrolysis of biological solids, sludge, food waste, and manure. In some embodiments, the methods and systems involve the electrocatalysis of sludge on transition-based electrodes, such as, for example, nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), chromium (Cr), manganese (Mn), scandium (Sc), etc. Thus, certain embodiments of this disclosure relate to the production of synthetic nitrogen-based and phosphorus-based fertilizers from waste activated sludge and centralized animal husbandry operations.

[0018] Generally, in one embodiment, this disclosure features a method for electrocatalytically processing 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 further include adjusting the pH of the slurry. Adjusting the pH of the slurry may result in an adjusted pH in the range of approximately 8 to 14. The method may further include flowing the slurry through an electrochemical cell. The electrochemical cell may include an anode, a cathode, and a catalyst. The method may further include applying a potential between the anode and the cathode. Applying the potential may include oscillating the cell voltage between the anode and the cathode at an oscillating frequency. The method may further include breaking carbon bonds with nitrogen and phosphorus in the slurry due to the applied potential. The method may further include releasing inorganic nitrogen and inorganic phosphorus. The method may further include obtaining electrolyzed sludge. The electrolyzed sludge may include an electrolyzed solid organic fertilizer containing nitrogen and phosphorus. The method may further include introducing a diaphragm or membrane between two electrodes. Attached Figure Description

[0019] Other advantages of this disclosure will become apparent from the following detailed description of the embodiments illustrated in conjunction with the accompanying drawings, in which:

[0020] Figure 1 The present disclosure describes a process for electrolyzing sludge to produce nitrogen-based fertilizers, phosphorus-based fertilizers, and organic fertilizers / carbon sinks, according to certain embodiments of the present disclosure.

[0021] Figure 2 Systems for electrolyzing sludge to produce nitrogen-based and phosphorus-based fertilizers according to certain embodiments of the present disclosure are described. Detailed Implementation

[0022] This disclosure relates to improved methods and systems for the electrolysis of biological solids, sludge, food waste, and manure. Specifically, this disclosure relates to the electrocatalysis of sludge on transition-based electrodes to produce synthetic nitrogen-based and phosphorus-based fertilizers from waste activated sludge and centralized animal husbandry operations.

[0023] Figure 1 The present disclosure describes a process for electrolyzing sludge to produce nitrogen-based fertilizers, phosphorus-based fertilizers, and organic fertilizers / carbon sinks, according to certain embodiments of the present disclosure. Figure 2 Systems for electrolyzing sludge to produce nitrogen-based and phosphorus-based fertilizers according to certain embodiments of the present disclosure are described.

[0024] like Figure 1 As shown, this disclosure relates to a method and system for electrolyzing biological solids, sludge, food waste, and manure. The process is as follows: Figure 1As shown, this process can convert urban sludge, manure, sludge from centralized animal husbandry operations, and food waste into nitrogen-based fertilizers, phosphorus-based fertilizers, ammonia, slow-release organic fertilizers, and carbon sinks. Figure 1 The process transforms and adds value to sludge from urban and centralized animal husbandry operations into valuable products with the ability to be used as carbon sinks, such as ammonia, slow-release organic fertilizers, phosphorus, and soil-enhancing nutrients.

[0025] This process can produce products of inorganic nitrogen-based fertilizers, inorganic phosphorus-based fertilizers, fatty acids, hydrogen, and organic NP fertilizers. For example, in some embodiments, the inorganic nitrogen-based fertilizer may be ammonia, ammonium salts, calcium nitrate, or combinations thereof. For example, in some embodiments, the inorganic phosphorus-based fertilizer may be one or more types of calcium phosphate.

[0026] In some embodiments, for example, slow-release organic fertilizers may be or include electrolyzed biosolids. In such embodiments, the fertilizer may contain consistent nitrogen and phosphorus content and microstructure to enhance plant growth due to the slow release of nitrogen, thereby improving nutrient use efficiency. In some embodiments, the methods and systems for electrolysis may include carbon sink materials, since electrolyzed biosolids (such as those in slow-release organic fertilizers) have the property of absorbing carbon dioxide.

[0027] like Figure 1 As shown, the process can begin with the introduction of sludge. In some embodiments, the sludge can be wastewater. In other embodiments, the sludge can be manure. In some embodiments, the sludge can be one or a combination of the following: municipal sludge, manure, sludge from centralized animal husbandry operations, and food waste.

[0028] The process can continue to prepare a slurry. In such embodiments, the slurry may include sludge and electrolytes. The sludge may include approximately 0.5% to 40% solids by mass percentage of the solute in the solution.

[0029] In some embodiments, the process may involve adjusting the pH of the slurry. In some embodiments, potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), or other equivalent salts can be used to adjust the pH of the slurry between 8 and 14. These salts can also be used as electrolytes in the slurry. Operating the process at higher pH values ​​is feasible, but the range offered presents an economic advantage.

[0030] like Figure 1As shown, the process may include 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 blocking of hydrogen gas that may be released at certain applied voltages. In some embodiments, the electrochemical cell may contain an anode, a cathode, a membrane or separator for collecting hydrogen gas, an electrolyte, and a reference electrode.

[0031] In some embodiments, the anode may include a conductive material and a support, such as, but not limited to, Ni mesh / wire 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 combinations thereof. In some embodiments, the anode may include any conductive material that is corrosion-resistant based on the system's electrolyte, battery voltage, and temperature. In some embodiments, the support may include carbon, carbon fibers, or graphene. In some embodiments, the anode may include a catalyst comprising metals 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 material of graphene and metal combinations. The catalyst can have a concentration of 0.1 mg / cm³. 2 Up to 2 mg / cm 2 The loading amount. In some embodiments, the catalyst may also be used as a direct metal or support.

[0032] In some embodiments, the cathode may include a conductive material and a support, such as, but not limited to, nickel (Ni) mesh / wire 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 combinations thereof. In some embodiments, the anode may include any conductive material that is corrosion-resistant based on the system's electrolyte, battery voltage, and temperature. In some embodiments, the support may include carbon, carbon fibers, or graphene. In some embodiments, the anode may include a catalyst comprising metals 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), or combinations thereof. In some embodiments, the catalyst may include a composite material of graphene and metal combinations. The catalyst can have a concentration of 0.1 mg / cm³. 2 Up to 2 mg / cm 2 The loading amount. In some embodiments, the catalyst may also be used as a direct metal or support.

[0033] In some embodiments, membranes and / or separators may be included in the electrochemical cell. Specifically, in some embodiments, the electrochemical cell may contain membranes, such as, but not limited to, Nafion, sintered glass, and / or separators, such as, but not limited to, polyethylene.

[0034] In some embodiments, the electrolyte may be a strong base or a weak base. 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 that maintains the pH between approximately 8 and 14.

[0035] The process may also include applying a potential oscillation between the two electrodes. For example, a battery voltage may be applied between the anode and cathode of the battery. In some embodiments, a current is applied instead of a voltage. In some embodiments, the voltage may oscillate at frequencies of 1, 10, 30, 60 seconds and 15, 30 minutes. In some embodiments, the effective battery voltage can be as high as 2.0V (minus ohmic resistance, counters, wires, etc.), depending on the type of electrolyte used and the temperature. Excluding ohmic resistance, the battery voltage of an electrochemical cell can vary from 0.8V to 2.0V. The applied battery voltage prevents water oxidation at the battery anode, and the oxidation potential is a function of the electrolyte used and the temperature.

[0036] In some embodiments, the temperature is controlled during oscillation. For example, the temperature may be controlled at approximately 20°C. Up to 80℃ between.

[0037] In doing so, in some embodiments, the applied potential causes the carbon bonds with nitrogen and phosphorus to break. Therefore, in such embodiments, the process may include releasing nitrogen and phosphorus into inorganic phosphorus and nitrogen. For example, inorganic phosphorus may include phosphates. For example, inorganic nitrogen may be ammonia, nitrates, or combinations thereof.

[0038] The product of this process may include an electrolyzed solid containing a portion of nitrogen and phosphorus in organic form, which can be applied as an organic fertilizer. In some embodiments, the microstructure of the electrolyzed sludge can be used as a sink for absorbing carbon dioxide (CO2) from the atmosphere.

[0039] Therefore, in some embodiments... Figure 1 The process can reduce the time required to produce organic fertilizer. In some embodiments, the fertilizer may include carbon, nitrogen, and phosphorus. For example, biological processes require 30 to 45 days to digest organic waste into fertilizer. However, in... Figure 1 During the process, sludge electrolysis reduces the digestion time to less than six hours. Figure 1 The time allotted for the conversion process can be two hours. Figure 1 The residence time used for conversion during the process is significantly shorter than that used for conversion during the process of using an anaerobic digester, which typically requires about 10 to 20 days.

[0040] Figure 1 The process can reduce total solids by 24.85% and volatile solids by 46.42%, which means that sludge disposal costs are reduced by about 25% compared to conventional treatment methods.

[0041] In some embodiments, the process can convert 68% of organic nitrogen into inorganic nitrogen.

[0042] Work Example 1

[0043] Slow-release fertilizers (from electrolyzed sludge) are produced using methods employed for electrolyzing sludge to generate nitrogen-based and phosphorus-based fertilizers along with organic fertilizers / carbon sinks. In working examples, the electrolyzed sludge (the solid after electrolysis) reduces carbon content by 20-40%, while pathogens are eliminated. Furthermore, changes in the material's microstructure create a surface with micron and nanoparticles. This material contains nitrogen and phosphorus at concentrations similar to compost. These microstructural changes allow for slow fertilizer release, providing an advantage in the soil. When mixed with synthetic inorganic fertilizers in the soil, these microstructural changes minimize the release of the inorganic fertilizers.

[0044] Work Example 2

[0045] Carbon sink materials (i.e., electrolyzed sludge) are produced using methods for electrolyzing sludge to generate nitrogen-based and phosphorus-based fertilizers and organic fertilizers / carbon sinks. Electrolyzed sludge releases volatile carbon. Due to changes in its microstructure, the product behaves similarly to activated carbon, enabling it to absorb carbon dioxide (CO2) and other pollutants. Other pollutants may include methane, benzene, toluene, or combinations thereof.

[0046] Consistent with the foregoing disclosure, the examples of systems and methods enumerated in the following clauses are specifically considered and are intended as a set of non-limiting examples.

[0047] Clause 1. A method for electrocatalytically processing sludge, the method comprising: selecting a sludge source; preparing a slurry, wherein the slurry includes the sludge source and an electrolyte; adjusting the pH of the slurry, wherein adjusting the pH of the slurry results in the slurry having an adjusted pH in the range of approximately 8 to 14; passing the slurry through an electrochemical cell, wherein the electrochemical cell includes an anode, a cathode, and a catalyst; applying a potential between the anode and the cathode, wherein applying the potential includes causing a cell voltage between the anode and the cathode to oscillate at an oscillating frequency; breaking carbon bonds with nitrogen and phosphorus in the slurry due to the applied potential; releasing inorganic nitrogen and inorganic phosphorus; and obtaining electrolyzed sludge, wherein the electrolyzed sludge comprises electrolyzed solids containing nitrogen and phosphorus.

[0048] Clause 2. The method described under any of the foregoing clauses, wherein the sludge source includes one or more of the following: municipal sludge, manure, sludge from centralized animal husbandry operations, and food waste.

[0049] Clause 3. The method described under any of the foregoing clauses, wherein the sludge source comprises solids in the range of approximately 0.5% to 40% by mass.

[0050] Clause 4. The method according to any of the foregoing clauses, wherein adjusting the pH of the slurry further comprises adding salt to the slurry.

[0051] Clause 5. The method described under any of the preceding clauses, wherein the salt comprises the use of potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium oxide (CaO), or a combination thereof.

[0052] Clause 6. The method according to any of the foregoing clauses, wherein the electrochemical cell further comprises a membrane.

[0053] Clause 7. The method described under any of the foregoing clauses, wherein the membrane comprises Nafion, sintered glass, or a combination thereof.

[0054] Clause 8. The method according to any of the foregoing clauses, wherein the electrochemical cell further comprises a separator, wherein the separator blocks hydrogen gas.

[0055] Clause 9. The method described under any of the foregoing clauses, wherein the diaphragm is polyethylene.

[0056] Clause 10. The method according to any of the foregoing clauses, wherein the electrochemical cell further includes a reference electrode.

[0057] Clause 11. The method according to any of the preceding clauses, wherein the anode comprises (Ni) mesh / wire 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 combinations thereof.

[0058] Clause 12. The method according to any of the preceding clauses, wherein the cathode comprises nickel (Ni) mesh / wire 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 combinations thereof.

[0059] Clause 13. The method according to any of the preceding clauses, wherein the catalyst comprises a composite material of graphene and metal combination.

[0060] Clause 14. The method according to any of the preceding clauses, wherein the oscillation frequency is applied for 1, 10, 30, 60 seconds and 15, 30 minutes.

[0061] Clause 15. The method according to any of the foregoing clauses, wherein applying an oscillating cell voltage between the anode and the cathode further comprises maintaining a controlled temperature, wherein the controlled temperature is at approximately 20°C. with 80℃ Within the range.

[0062] Clause 16. The method described under any of the foregoing clauses, wherein the inorganic nitrogen comprises ammonia, nitrates, or combinations thereof.

[0063] Clause 17. The method described under any of the foregoing clauses, wherein the inorganic phosphorus comprises phosphate.

[0064] Clause 18. The method described under any of the foregoing clauses, wherein the electrolyzed sludge includes organic fertilizer.

[0065] Clause 19. The method according to any of the preceding clauses, wherein the electrolyzed sludge comprises microstructures, wherein the microstructures of the electrolyzed sludge serve as sinks for absorbing carbon dioxide (CO2).

[0066] Clause 20. The method described in accordance with any of the preceding clauses, wherein ohmic losses are excluded, and the battery voltage varies from approximately 0.8V to approximately 2.0V.

[0067] Clause 21. The method according to any of the preceding clauses, wherein the application of the potential between the anode and the cathode further comprises preventing water oxidation at the anode.

[0068] Clause 22. The method described under any of the foregoing clauses, wherein the organic fertilizer comprises carbon, nitrogen and phosphorus.

[0069] Clause 23. An electrolyzed solid organic fertilizer comprising nitrogen, carbon, and phosphorus.

[0070] Clause 24. Electrolyzed solid organic fertilizers as described in any of the preceding clauses, wherein the electrolyzed solid organic fertilizers promote a nitrogen cycle economy.

[0071] Clause 25. Electrolyzed solid organic fertilizer as described in any of the preceding clauses, wherein the electrolyzed solid organic fertilizer promotes runoff reduction.

[0072] For purposes of explanation, the foregoing description uses specific terminology to provide a thorough understanding of the described embodiments. However, it will be apparent to those skilled in the art that specific details are not required to practice the described embodiments. Therefore, the above description of specific embodiments is presented for purposes of illustration and description. The description is not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to those skilled in the art that many modifications and variations are possible in light of the above teachings.

[0073] Although embodiments of this disclosure have been shown and described, modifications can be made to them by those skilled in the art without departing from the spirit and teachings of this disclosure. The embodiments and examples provided herein are merely illustrative and not intended to be limiting. Many variations and modifications of this disclosure are possible and are within the scope of this disclosure. The scope of protection is not limited by the description set forth above, but only by the following claims, which include all equivalents of the subject matter of the claims.

[0074] Quantities and other numerical data may be presented in range format throughout this document. It should be understood that this range format is used solely for convenience and brevity and should be flexibly interpreted to include not only the numerical values ​​explicitly stated as the limits of the range, but also all individual numerical values ​​or subranges encompassing that range, as if each numerical value and subrange were explicitly stated. For example, a numerical range of approximately 1 to approximately 4.5 should be interpreted not only to include the explicitly listed limits of 1 to approximately 4.5, but also to include individual numerical values ​​such as 2, 3, and 4, and subranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges listing only a single numerical value, such as “less than approximately 4.5,” which should be interpreted to include all the aforementioned values ​​and ranges. Furthermore, this interpretation should apply regardless of the breadth of the range or characteristic described. The symbol “~” is equivalent to “approximately.”

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter of this disclosure pertains. Although any methods, apparatus, and materials similar or equivalent to those described herein may be used in the practice or testing of the subject matter of this disclosure, representative methods, apparatus, and materials are described here.

[0076] According to long-standing patent law practice, the terms “a” and “an” are used in this application (including the claims) to mean “one or more”.

[0077] Unless otherwise specified, all figures used in the specification to indicate quantities of ingredients, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters set forth in the specification are approximations that can vary depending on the desired properties sought to be obtained through the subject matter currently disclosed.

[0078] As used herein, the term “and / or” in the context of a list of entities means that the entities exist individually or in combination. Thus, for example, the phrase “A, B, C and / or D” includes not only A, B, C, and D individually, but also any and all combinations and sub-combinations of A, B, C, and D.

[0079] The foregoing discussion is intended to illustrate the principles and various embodiments of this disclosure. Once the foregoing disclosure is fully understood, many changes and modifications will become apparent to those skilled in the art. The following claims are intended to cover all such variations and modifications.

[0080] References

[0081] Environmental Protection Agency. Detecting and mitigating the environmental impact of fecal pathogens originating from confined animal feeding operations: Review (2005). (Retrieved from http: / / www.farmweb.org / Articles / Detecting%20and%20Mitigating%20the%20 Environmental%20Impact%20of%20Fecal%20Pathogens%20Originating%20from%20Confined%20Animal%20Feeding%20Operations.pdf).

[0082] Jafari, M., Botte G.G. Electrochemical valorization of waste activated sludge for short-chain fatty acids production. Frontiers in Chemistry 10:974223 (2022).

[0083] Jafari, M., Botte, G.G. Electrochemical treatment of sewage sludge and pathogen inactivation. J Appl Electrochem 51, 119–130 (2021).

[0084] 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).

[0085] Lu, F., Botte G. G. Understanding the electrochemically induces conversion of urea to ammonia using nickel-based catalysts, Electrochimica Acta, 246, 564-571 (2017).

[0086] 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) (retrieved from http: / / jds.fass.org / cgi / reprint / 90 / 4 / 2047?maxtoshow=&hits=10&RESULTFOR MAT=&fulltext=large-scale&searchid=1&FIRSTINDEX=0&volume=90&issue=4&resource type=HWC).

[0087] 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 electrocatalytic treatment of sludge, the method comprising: (a) Selecting sludge sources; (b) Preparing a slurry, wherein the slurry comprises the sludge source and the electrolyte; (c) 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 approximately 8 to 14; (d) passing the slurry through an electrochemical cell, wherein the electrochemical cell comprises: (i) Anode, (ii) Cathode, and (iii) Catalyst; (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 oscillate at an oscillation frequency; (f) The carbon bonds to nitrogen and phosphorus in the slurry are broken due to the application of the electric potential; (g) Release of inorganic nitrogen and inorganic phosphorus; and (h) Obtaining electrolyzed sludge, wherein the electrolyzed sludge comprises electrolyzed solids containing nitrogen and phosphorus.

2. The method according to claim 1, wherein the sludge source includes one or more of the following: municipal sludge, manure, sludge from centralized animal husbandry operations, and food waste.

3. The method of claim 1, wherein the sludge source comprises solids in the range of approximately 0.5% to 40% by mass.

4. The method of claim 1, wherein adjusting the pH of the slurry further comprises adding salt to the slurry.

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

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

7. The method of claim 6, wherein the membrane comprises Nafion, sintered glass, or a combination thereof.

8. The method of claim 1, wherein the electrochemical cell further comprises a separator, wherein the separator blocks hydrogen gas.

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

10. The method of claim 1, wherein the electrochemical cell further comprises a reference electrode.

11. The method according to claim 1, wherein the anode comprises nickel (Ni) mesh / wire 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 combinations thereof.

12. The method according to claim 1, wherein the cathode comprises nickel (Ni) mesh / wire 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 combinations thereof.

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

14. The method of claim 1, wherein applying an oscillating cell voltage between the anode and the cathode further comprises maintaining a controlled temperature, wherein the controlled temperature is in the range of approximately 20°C to 80°C.

15. The method of claim 1, wherein the inorganic nitrogen comprises ammonia, nitrates, or combinations thereof.

16. The method of claim 1, wherein the inorganic phosphorus comprises phosphate.

17. The method of claim 1, wherein the electrolyzed sludge comprises organic fertilizer.

18. The method of claim 1, wherein the electrolyzed sludge comprises a microstructure, wherein the microstructure of the electrolyzed sludge serves as a sink for absorbing carbon dioxide (CO2).

19. The method of claim 1, wherein ohmic losses are excluded, and the battery voltage varies from about 0.8V to about 2.0V.

20. The method of claim 1, wherein applying the potential between the anode and the cathode further comprises preventing water oxidation at the anode.

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