Method for electrochemically treating biogas slurry after anaerobic fermentation of kitchen waste

Abstract

The invention discloses a method for electrochemically treating kitchen waste anaerobic fermentation biogas slurry, which mainly comprises the following steps: 1, removing organic matters in the kitchen waste anaerobic fermentation biogas slurry through electrochemical oxidation, and reducing the ammonia nitrogen content and COD (Chemical Oxygen Demand) value of the biogas slurry; 2, reducing residual hypochlorite in the biogas slurry subjected to electro-oxidation in the step 1 into chloride ions through a thermal decomposition method, a photolysis method or a catalytic decomposition method; 3, constructing a capacitor by using a chloride ion adsorption material and a sodium ion embedded electrode material, and adsorbing sodium chloride in the biogas slurry in the step 2 through a capacitive deionization method; 4, discharging the capacitor adsorbing the sodium chloride in the sodium chloride liquid storage tank to analyze the sodium chloride, returning the discharged capacitor to the step 3 to adsorb the sodium chloride again, and circulating for multiple times until the content of the sodium chloride in the biogas slurry reaches the discharge standard; compared with the current mainstream treatment process of the kitchen waste anaerobic fermentation biogas slurry, the method provided by the invention can greatly reduce the energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of electrochemical water treatment, in particular to a method for electrochemically treating biogas slurry after anaerobic fermentation of kitchen waste. Background Art

[0002] With the introduction of a series of environmental protection issues such as "carbon neutrality and carbon peak", garbage classification has gradually come into people's view in recent years. Due to the gradual improvement of people's living conditions, the rapid growth of the service industry, especially the rapid rise of the takeout industry, the amount of kitchen waste generated has increased year by year. As a pilot city for garbage classification, Nanjing sets an example and vigorously develops scientific treatment methods for classified garbage.

[0003] Kitchen waste refers to the excess scraps from food processing in restaurants, hotels, employee canteens and other catering industries, leftovers from the table, processing waste from fast food products, animal and plant fats that cannot be directly used, etc. Kitchen waste has a high water content and must be processed in a timely manner, otherwise it will rot and deteriorate, causing certain pollution to the nature.

[0004] At present, the mainstream food waste treatment process on the market is to first use relevant equipment to simply sort the food waste to separate plastics and other non-degradable substances, and then crush the remaining part after standing to separate the oil phase. After biochemical treatment, ultrafiltration, nanofiltration and reverse osmosis treatment, the fresh water part is directly discharged, and the concentrated water part is treated by MVR evaporation. MVR evaporation technology requires about 15kw / h to 55kw / h of electricity to evaporate one ton of water. This power consumption range takes into account different operating conditions and material properties. Compared with traditional multi-effect evaporators, MVR evaporators do have obvious advantages in energy consumption, but the MVR evaporation method for treating a large amount of and increasing food waste water still consumes the most energy in the food waste treatment process, and the solid after MVR evaporation treatment is a mixture of organic matter and salts, which is hazardous waste, which adds another processing cost. Therefore, in summary, in order to save energy, it is urgent to propose a method to replace MVR evaporation and concentration. Summary of the invention

[0005] The object of the present invention is to provide a method for electrochemically treating biogas slurry after anaerobic fermentation of food waste, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: The present invention provides a method for electrochemically treating biogas slurry after anaerobic fermentation of kitchen waste, comprising the following steps: Step 1: Remove organic matter from anaerobic fermentation slurry of food waste through electrochemical oxidation, reduce the ammonia nitrogen content and COD value of the slurry, and meet the wastewater discharge standards; Step 2: Reducing the remaining hypochlorite in the biogas slurry after the electro-oxidation in step 1 to chloride ions by a chlorate decomposition method, so as to facilitate further desalination of the biogas slurry; Step 3: construct a capacitor using chloride ion adsorption material and sodium ion embedding electrode material, and adsorb sodium chloride in the biogas slurry in step 2 at a voltage of -0.6v-0.6v by capacitive deionization method; Step 4: discharge the capacitor that absorbs sodium chloride in a sodium chloride storage tank to decompose the sodium chloride. After discharge, the capacitor returns to step 3 to absorb sodium chloride again, and the cycle is repeated multiple times until the sodium chloride content in the biogas slurry reaches the discharge standard.

[0007] Furthermore, in step 1, the electrode material of the electrochemical oxidation is ruthenium-iridium material, the temperature condition is selected to be heated in a water bath at 30-60°C, the electrolysis potential is used to test the bubble production rate of the concentrated water sample according to different water samples, different voltages are applied to the water samples respectively, the bubble generation rate is observed, and the most suitable voltage value and electrolysis time are selected. The most suitable electrolysis potential is selected, and the electrochemical power-on oxidation time and the sodium hypochlorite oxidation time of COD and ammonia nitrogen are regulated in the electrolysis time, so as to adjust the reaction balance and save electric energy.

[0008] Furthermore, in step 1, the electrochemical oxidation potential is 1.05v-1.25v (VS. SCE), and the electrolysis time is 20h.

[0009] Furthermore, in step 2, the chlorate decomposition method is a combination of one or more of thermal decomposition, photodecomposition, and catalytic decomposition.

[0010] Furthermore, the catalyst used in the catalytic decomposition method is one or more of nickel oxide, cobalt oxide, copper oxide, and iron oxide; the mass ratio of the catalyst to the electro-oxidized biogas slurry is 1:25-40. Preferably, the catalyst used in the catalytic decomposition method is nickel oxide powder doped with iron oxide powder, and the mass ratio of nickel oxide to iron oxide is 1:10-1:25 (preferably 1:19).

[0011] Furthermore, the photolysis method is carried out at 300-800W / m 2 Decomposes under light conditions.

[0012] Furthermore, the thermal decomposition method is to increase the temperature of the biogas slurry after electro-oxidation to 40-60°C; by increasing the initial temperature of the biogas slurry fermented with food waste, the ClO - break down.

[0013] Preferably, in step 2, the chlorate decomposition method is a combination of photodecomposition and catalytic decomposition.

[0014] Furthermore, in step three, the chloride ion adsorption material includes a double-layer adsorption material and a chloride ion conversion material; the sodium ion embedding electrode material includes a double-layer electrode material and a pseudocapacitor electrode material; the double-layer electrode material is one or more of activated carbon, carbon fiber, carbon gel, and carbon nanotubes; the pseudocapacitor electrode material is one or more of graphite, Prussian blue, Prussian white, and ferric ferrocyanide; the chloride ion adsorption material is one or more of an Ag composite material, a Bi composite material, and a Fe composite material.

[0015] Furthermore, in step 4, the concentration of the sodium chloride solution in the sodium chloride storage tank is a sodium chloride solution close to saturation at room temperature, that is, the sodium chloride solution in the sodium chloride storage tank has a concentration of 4.6 mol / L at 15-25°C.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) After the present invention uses an electrochemical method to treat the anaerobic fermentation slurry of food waste, the concentration of sodium chloride in the sodium chloride storage tank that needs MVR treatment is only about 10% of the reverse osmosis concentrate in the mainstream treatment process of the fermentation slurry, which greatly reduces the energy consumption of the evaporation process.

[0017] (2) In the mainstream treatment process of fermented biogas slurry, the reverse osmosis concentrate contains high concentrations of organic matter, and a certain amount of organic matter will volatilize in the MVR process; however, the wastewater after electrochemical oxidation in the present invention contains almost no organic matter, thus avoiding the risk of organic matter volatilization.

[0018] (3) In the present invention, the concentrated sodium chloride in the sodium chloride storage tank can be sold as industrial-grade sodium chloride after MVR evaporation, while the evaporation product of the mainstream sodium chloride treatment process MVR is sodium chloride with a high organic matter concentration, which is a hazardous waste.

[0019] (4) During the electrochemical oxidation process in step 1 of the present invention, hydrogen gas is produced as a byproduct at the cathode, further improving the economic efficiency of the process.

[0020] (5) In the present invention, the electric energy storage process of the sodium chloride adsorption by capacitor deionization and the discharge process of the sodium chloride desorption can recover part of the electric energy consumed by the sodium chloride adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic flow chart of a method for electrochemically treating biogas slurry after anaerobic fermentation of food waste. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, the present invention provides a technical solution: a method for electrochemically treating biogas slurry after anaerobic fermentation of food waste, comprising the following steps: Step 1: Remove organic matter from anaerobic fermentation slurry of food waste through electrochemical oxidation, reduce the ammonia nitrogen content and COD value of the slurry, and meet the wastewater discharge standards; Step 2: Reducing the remaining hypochlorite in the biogas slurry after the electro-oxidation in step 1 to chloride ions by thermal decomposition, photodecomposition or catalytic decomposition, so as to facilitate further desalination of the biogas slurry; Step 3: construct a capacitor using chloride ion adsorption material and sodium ion embedding electrode material, and adsorb sodium chloride in the biogas slurry in step 2 by capacitive deionization method; Step 4: discharge the capacitor that absorbs sodium chloride in a sodium chloride storage tank to decompose the sodium chloride. After discharge, the capacitor returns to step 3 to absorb sodium chloride again, and the cycle is repeated multiple times until the sodium chloride content in the biogas slurry reaches the discharge standard. Example 1

[0024] Step 1: Take 1L of reverse osmosis concentrated water from anaerobic fermentation of food waste (ammonia nitrogen content of 1000mg / L, COD value of 820mg / L, sodium chloride concentration of 35.4g / L), the electrode material for electrochemical oxidation is ruthenium iridium material, the temperature condition is 60℃ water bath heating, the electrochemical oxidation potential is 1.05v (VS. SCE), and the electrolysis time is 20h. The ammonia nitrogen content and COD value after electrochemical oxidation are measured by the ammonia nitrogen nanoreagent method and the COD digestion tester, and they are both 0mg / L.

[0025] Step 2: Add a mixed catalyst of NiO and Fe2O3 to the liquid after electrooxidation in step 1 at a NiO:Fe2O3 mass ratio of 1:19 and a solid-liquid mass ratio of 1:25. 2 After 10 hours of decomposition under light conditions, the sodium hypochlorite conversion rate was measured to be 98.4%.

[0026] Step 3: Use a double-layer adsorption-coated BiOCl@MC material with a mass ratio of 10:9 and ferric ferrocyanide nanocubic sodium ion embedded electrode material to construct a capacitor. After multiple adsorption / desorption (electrolysis) by capacitive deionization method, the sodium chloride concentration in the biogas slurry is reduced to 0.03g / L.

[0027] Step 4: The capacitor that absorbs sodium chloride is discharged in the sodium chloride storage tank to precipitate sodium chloride. After the capacitor is digested, the sodium chloride concentration is measured to be 0 mg / L. The capacitor after precipitation is returned to step 3 for recycling until the sodium chloride content in the solution meets the discharge standard. The sodium chloride storage tank contains a sodium chloride solution with a concentration of 4.6 mol / L at 15-25°C. The sodium chloride storage tank is evaporated and concentrated by MVR. The amount of evaporated water required is only 100 mL, which is 10% of the total amount of the original water sample.

[0028] In step three, the double-layer adsorption coated BiOCl material: agar is used as the carbon source, bismuth nitrate pentahydrate is used as the bismuth source, and calcium acetate is used as the pore-forming agent to prepare the coated bismuth-based composite material by the template method; and then K3Fe(CN)6 and Na2S2O3 are used to prepare ferric ferrocyanide nanocubes as sodium ion embedding electrode materials.

[0029] The specific preparation steps are as follows: 2 g agar powder and 1.5 g calcium acetate were added to 90 mL deionized water, placed in a 95 ℃ water bath and magnetically stirred for 30 min, and the resulting solution was recorded as solution one; 2 mmol bismuth nitrate pentahydrate was placed in a beaker, and 10 mL acetic acid solution was added and magnetically stirred to dissolve the bismuth nitrate, which was recorded as solution two; solution two was poured into solution one, stirred in a 50 ℃ water bath for 1 h, and then placed in a 50 ℃ oven for drying for 48 h; the dried precursor was carbonized under N2 atmosphere for 1 h, the carbonization temperature was 800 ℃, and the heating rate was 10 ℃ / min; the carbonized sample was then placed in a 0.03 mol / L dilute hydrochloric acid solution to remove the template, and then washed with deionized water several times to make the filtrate neutral, and finally the residue was dried at 60 ℃ to obtain the final product, which was recorded as BiOCl@MC.

[0030] The preparation steps of ferric ferrocyanide nanocubes are as follows: weigh 2 mmol K3Fe(CN)6 and 4 mmol Na2S2O3 and dissolve them in 20 mL deionized water at room temperature in turn, stir the mixture magnetically in a 60 ℃ water bath for 48 h, then centrifuge at 4000 rpm for 10 min, wash the solid phase product with deionized water several times and then vacuum dry it at 120 ℃ for 12 h to obtain FeFe(CN)6 nanocubes. Example 2

[0031] Step 1: Take 1L of fermented water from anaerobic fermentation of food waste (ammonia nitrogen content of 900mg / L, COD value of 460mg / L, sodium chloride concentration of 8.3g / L), the electrode material for electrochemical oxidation is ruthenium iridium material, the temperature condition is selected as 60℃ water bath heating, the electrochemical oxidation potential is 1.25v (VS. SCE), and the electrolysis time is 20h. The ammonia nitrogen content after electrochemical oxidation was measured by the ammonia nitrogen nanoreagent method and the COD digestion tester to be 0mg / L, the COD value was 75.4mg / L, and the COD conversion rate was 82.9%.

[0032] Step 2: Add the mixed catalyst to the liquid after electrooxidation in step 1 at a NiO:Fe2O3 mass ratio of 1:15 and a solid-liquid mass ratio of 1:25. 2 After 10 hours of decomposition under light conditions, the sodium hypochlorite conversion rate was measured to be 98.4%.

[0033] Step 3: A capacitor was constructed using a double-layer adsorption-coated BiOCl@MC material and a sodium ion embedded electrode material of ferric ferrocyanide nanocubes in a mass ratio of 10:9. After multiple adsorption / desorption by capacitive deionization, the concentration of sodium chloride in the biogas slurry was reduced to 0.03 g / L. The BiOCl@MC material and the ferric ferrocyanide nanocubes were prepared in the same manner as in Example 1.

[0034] Step 4: The capacitor that absorbs sodium chloride is discharged in the sodium chloride storage tank to precipitate sodium chloride. After the capacitor is digested, the sodium chloride concentration is measured to be 0 mg / L. The discharged capacitor is returned to step 3 for recycling until the sodium chloride content in the solution meets the emission standard. The sodium chloride storage tank contains a sodium chloride solution with a concentration of 4.6 mol / L at 15-25°C. The sodium chloride storage tank is subjected to MVR evaporation and concentration, and the amount of water required for evaporation is 11% of the total amount of the original water sample. Example 3

[0035] Step 1: Take 1L of ultrafiltration wastewater from anaerobic fermentation of food waste (ammonia nitrogen content of 790mg / L, COD value of 340mg / L, sodium chloride concentration of 11.2g / L), the electrode material for electrochemical oxidation is ruthenium iridium material, the temperature condition is 40℃ water bath heating, the electrochemical oxidation potential is 1.20v (VS. SCE), and the electrolysis time is 20h. The ammonia nitrogen content after electrochemical oxidation was measured by the ammonia nitrogen nanoreagent method and the COD digestion tester to be 0mg / L, the COD value was 20.3mg / L, and the COD conversion rate was 94.1%.

[0036] Step 2: Add the mixed catalyst to the liquid after electrooxidation in step 1 at a NiO:Fe2O3 mass ratio of 1:10 and a solid-liquid mass ratio of 1:25. 2After 10 hours of decomposition under light conditions, the sodium hypochlorite conversion rate was measured to be 95.2%.

[0037] Step 3: A capacitor was constructed using a double-layer adsorption-coated BiOCl@MC material and a sodium ion embedded electrode material of ferric ferrocyanide nanocubes in a mass ratio of 10:9. After multiple adsorption / desorption by capacitive deionization, the concentration of sodium chloride in the biogas slurry was reduced to 0.1 g / L. The BiOCl@MC material and the ferric ferrocyanide nanocubes were prepared in the same manner as in Example 1.

[0038] Step 4: The capacitor that absorbs sodium chloride is discharged in the sodium chloride storage tank to precipitate sodium chloride. After the capacitor is digested, the sodium chloride concentration is measured to be 0 mg / L. The discharged capacitor is returned to step 3 for recycling until the sodium chloride content in the solution meets the emission standard. The sodium chloride storage tank contains a sodium chloride solution with a concentration of 4.6 mol / L at 15-25°C. The sodium chloride storage tank is subjected to MVR evaporation and concentration, and the amount of water required for evaporation is 10.4% of the total amount of the original water sample. Example 4

[0039] Step 1: Take 1L of ultrafiltration wastewater from anaerobic fermentation of food waste (ammonia nitrogen content of 790mg / L, COD value of 265mg / L, sodium chloride concentration of 12.7g / L), the electrode material for electrochemical oxidation is ruthenium iridium material, the temperature condition is 50℃ water bath heating, the electrochemical oxidation potential is 1.15v (VS. SCE), and the electrolysis time is 20h. The ammonia nitrogen content after electrochemical oxidation was measured by the ammonia nitrogen nanoreagent method and the COD digestion tester to be 0mg / L, the COD content was 13.2mg / L, and the COD conversion rate was 95.0%.

[0040] Step 2: Add the mixed catalyst to the liquid after electrooxidation in step 1 at a NiO:Fe2O3 mass ratio of 1:25 and a solid-liquid mass ratio of 1:30. 2 After 10 hours of decomposition under light conditions, the sodium hypochlorite conversion rate was measured to be 97.2%.

[0041] Step 3: Use a double-layer adsorption-coated BiOCl@MC material with a mass ratio of 10:9 and a sodium ion embedded electrode material of ferric ferrocyanide nanocubes to construct a capacitor. After multiple adsorption / desorption by capacitive deionization, the sodium chloride concentration in the biogas slurry is reduced to 0.1 g / L. BiOCl@MC material and ferric ferrocyanide nanocubes are prepared in the same manner as in Example 1. Step 4: The capacitor that absorbs sodium chloride is discharged in the sodium chloride storage tank to precipitate sodium chloride. After the capacitor is digested, the sodium chloride concentration is measured to be 0 mg / L. The discharged capacitor is returned to step 3 for recycling until the sodium chloride content in the solution meets the emission standard. The sodium chloride storage tank contains a sodium chloride solution with a concentration of 4.6 mol / L at 15-25°C. The sodium chloride storage tank is subjected to MVR evaporation and concentration, and the amount of water required for evaporation is 10.7% of the total amount of the original water sample. Example 5

[0042] Step 1: Take 1L of reverse osmosis concentrated water from anaerobic fermentation of food waste (ammonia nitrogen content of 1000mg / L, COD value of 820mg / L, sodium chloride concentration of 35.4g / L), the electrode material for electrochemical oxidation is ruthenium iridium material, the temperature condition is 60℃ water bath heating, the electrochemical oxidation potential is 1.05v (VS. SCE), and the electrolysis time is 20h. The ammonia nitrogen content and COD value after electrochemical oxidation are measured by the ammonia nitrogen nanoreagent method and the COD digestion tester, and they are both 0mg / L.

[0043] Step 2: Add the mixed catalyst to the liquid after electrooxidation in step 1 at a NiO:Fe2O3 mass ratio of 1:21 and a solid-liquid mass ratio of 1:40. 2 After 5 hours of decomposition under light conditions, the sodium hypochlorite conversion rate was measured to be 83.7%.

[0044] Step 3: Use a double-layer adsorption-coated BiOCl material with a mass ratio of 10:9 and a sodium ferric ferrocyanide ion embedded electrode material to construct a capacitor. After multiple adsorption / desorption by capacitive deionization method, the sodium chloride concentration in the biogas slurry is reduced to 0.1 g / L.

[0045] Step 4: The capacitor that absorbs sodium chloride is discharged in the sodium chloride storage tank to precipitate sodium chloride. After the capacitor is digested, the sodium chloride concentration is measured to be 0 mg / L. The discharged capacitor is returned to step 3 for recycling until the sodium chloride content in the solution meets the emission standard. The sodium chloride storage tank contains a sodium chloride solution with a concentration of 4.6 mol / L at 15-25°C. The sodium chloride storage tank is subjected to MVR evaporation and concentration, and the amount of evaporated water required is 11.3% of the total amount of the original water sample. Example 6

[0046] Step 1: Take 1L of reverse osmosis concentrated water from anaerobic fermentation of food waste (ammonia nitrogen content of 1000mg / L, COD value of 820mg / L, sodium chloride concentration of 35.4g / L), the electrode material for electrochemical oxidation is ruthenium iridium material, the temperature condition is 40℃ water bath heating, the electrochemical oxidation potential is 1.05v (VS. SCE), and the electrolysis time is 20h. The ammonia nitrogen content and COD value after electrochemical oxidation are measured by ammonia nitrogen nanoreagent method and COD digestion tester, and both are 0mg / L.

[0047] Step 2: Add the mixed catalyst to the liquid after electrooxidation in step 1 at a NiO:Fe2O3 mass ratio of 1:17 and a solid-liquid mass ratio of 1:30. 2 After 10 hours of decomposition under light conditions, the sodium hypochlorite conversion rate was measured to be 91.8%.

[0048] Step 3: A capacitor was constructed using a double-layer adsorption-coated BiOCl@MC material and a Prussian blue electrode material in a mass ratio of 10:9. After multiple adsorption / desorption by capacitive deionization, the concentration of sodium chloride in the biogas slurry was reduced to 0.6 g / L. The BiOCl@MC material was prepared in the same manner as in Example 1.

[0049] Step 4: The capacitor that absorbs sodium chloride is discharged in the sodium chloride storage tank to precipitate sodium chloride. After the capacitor is digested, the sodium chloride concentration is measured to be 0 mg / L. The discharged capacitor is returned to step 3 for recycling until the sodium chloride content in the solution meets the emission standard. The sodium chloride storage tank contains a sodium chloride solution with a concentration of 4.6 mol / L at 15-25°C. The sodium chloride storage tank is subjected to MVR evaporation and concentration, and the amount of water required for evaporation is 10.5% of the total amount of the original water sample.

[0050] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0051] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A method for electrochemically treating anaerobic fermentation of food waste, characterized in that: It mainly includes the following steps: Step 1: Anaerobic fermentation of food waste by electrochemical oxidation to obtain electro-oxidized biogas slurry; Step 2: reducing the remaining hypochlorite in the biogas slurry after electro-oxidation to chloride ions by a chlorate decomposition method to obtain decomposed biogas slurry; Step 3: Use chloride ion adsorption materials and sodium ion embedding electrode materials to construct a capacitor, and use capacitive deionization method to adsorb sodium chloride in the decomposed biogas slurry; Step 4: discharge the capacitor that absorbs sodium chloride in a sodium chloride storage tank to decompose the sodium chloride. After discharge, the capacitor returns to step 3 to absorb sodium chloride again, and the cycle is repeated multiple times until the sodium chloride content in the biogas slurry reaches the discharge standard.

2. The method for electrochemically treating anaerobic fermentation of food waste according to claim 1, characterized in that: In step 1, the electrode material for electrochemical oxidation is ruthenium-iridium material, and the temperature is 30°C-60°C.

3. The method for electrochemically treating anaerobic fermentation of food waste according to claim 1, characterized in that: In step 1, the electrochemical oxidation potential is 1.05v-1.25v, and the electrolysis time is 20h.

4. The method for electrochemically treating anaerobic fermentation of food waste according to claim 1, characterized in that: In step 2, the chlorate decomposition method is one or more of thermal decomposition, photodecomposition, and catalytic decomposition.

5. The method for electrochemically treating anaerobic fermentation of food waste according to claim 4, characterized in that: The catalyst used in the catalytic decomposition method is one or more of nickel oxide, cobalt oxide, copper oxide and iron oxide; the mass ratio of the catalyst to the biogas slurry after electro-oxidation is 1:25-40.

6. The method for electrochemically treating anaerobic fermentation of food waste according to claim 4, characterized in that: The photolysis method is at 300-800W / m 2 Decomposes under light conditions.

7. The method for electrochemically treating anaerobic fermentation of food waste according to claim 4, characterized in that: The thermal decomposition method is to increase the temperature of the biogas slurry after electro-oxidation to 40-60°C.

8. The method for electrochemically treating anaerobic fermentation of food waste according to claim 1, characterized in that: In step three, the chloride ion adsorption material includes a double-layer adsorption material and a chloride ion conversion material; the sodium ion embedding electrode material includes a double-layer electrode material and a pseudocapacitor electrode material; the double-layer electrode material is one or more of activated carbon, carbon fiber, carbon gel, and carbon nanotubes; the pseudocapacitor electrode material is one or more of graphite, Prussian blue, Prussian white, and ferric ferrocyanide; the chloride ion adsorption material is one or more of an Ag composite material, a Bi composite material, and a Fe composite material.

9. The method for electrochemically treating anaerobic fermentation of food waste according to claim 1, characterized in that: In step 4, the concentration of the sodium chloride solution in the sodium chloride storage tank at 15-25° C. is 4.6 mol / L.

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