Device for bioelectrochemically treating soy sauce wastewater

Abstract

The invention relates to a device for bioelectrochemically treating soy sauce wastewater and a preparation method thereof, the device for bioelectrochemically treating soy sauce wastewater comprises an anode chamber and a cathode chamber, the center of the anode chamber is provided with a columnar anode; a columnar cathode is arranged in the center of the cathode chamber; a space between the columnar anode and the anode chamber is filled with a modified conductive oxidation filler; electroactive bacteria grow on the columnar anode and the modified conductive oxidation filler, and the modified conductive oxidation filler is metal-doped activated carbon. The activated carbon is mixed with a mixed solution of zinc sulfate and potassium sulfate, the zinc sulfate and the potassium sulfate are adsorbed on the activated carbon, and corresponding metal oxides are formed on the surface of the activated carbon through calcination, so that the metal-doped activated carbon is formed; the metal potassium and the metal zinc have electronic interaction and synergistic effect, so that the electronic conductivity can be improved, and the degradation treatment of the soy sauce wastewater is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a device for bio-electrochemical treatment of soy sauce wastewater. Background Art

[0002] Among the technologies for treating soy sauce wastewater, bioelectrochemical treatment methods have gradually attracted attention. Traditional soy sauce wastewater treatment technologies mainly include physical and chemical methods and biological methods. Among them, physical and chemical methods such as flocculation, precipitation and activated carbon adsorption can effectively remove organic matter and pigments in wastewater, but these methods often require high operating costs and treatment costs. Biological methods, such as activated sludge method and biofilter method, can use microorganisms to decompose organic pollutants in wastewater, with lower operating costs and higher treatment efficiency, but the degradation rate and treatment effect of wastewater are limited by the metabolic capacity of microorganisms and the complexity of wastewater.

[0003] In recent years, bioelectrochemical treatment technology has shown good prospects as an emerging wastewater treatment method. This technology combines electrochemical processes and biological treatment processes, using electric current to drive biological reactions, thereby improving the degradation efficiency of wastewater. A typical bioelectrochemical treatment device includes an anode chamber and a cathode chamber, wherein an anode is arranged in the anode chamber and a cathode is arranged in the cathode chamber. A current is generated between the anode and the cathode through a power supply, driving the electroactive bacteria in the anode chamber to perform a biodegradation reaction, while a reduction reaction also occurs in the cathode chamber.

[0004] However, existing bioelectrochemical treatment devices still have some problems when treating soy sauce wastewater. The fillers in traditional devices, such as activated carbon, have insufficient performance. These fillers have limitations in terms of conductivity, specific surface area and adsorption capacity, resulting in uneven growth of electroactive bacteria and low electron transfer efficiency, affecting the stability and operation of the device, thereby affecting the overall degradation effect.

[0005] Therefore, it is necessary to develop a new technical solution to address the deficiencies in the prior art and improve the efficiency of soy sauce wastewater treatment. Summary of the invention

[0006] Based on this, the present invention provides a device for bioelectrochemical treatment of soy sauce wastewater. The present invention uses biochar formed by calcining fruit shells and silicon dioxide, and combines it with modified conductive oxidative fillers to improve the attachment and growth effect of electroactive bacteria, thereby effectively improving the degradation efficiency of soy sauce wastewater. These improvements are intended to solve the deficiencies in the prior art, improve the overall performance of the treatment system, and overcome the problems existing in the prior art.

[0007] One object of the present invention is to provide a device for treating soy sauce wastewater by bioelectrochemical treatment, wherein the device comprises an anode chamber and a cathode chamber, wherein

[0008] A columnar anode is disposed at the center of the anode chamber; a columnar cathode is disposed at the center of the cathode chamber;

[0009] The space between the columnar anode and the anode chamber is filled with a modified conductive oxide filler;

[0010] Electroactive bacteria grow on the columnar anode and the modified conductive oxidizing filler;

[0011] The space between the columnar cathode and the cathode chamber is filled with a conductive reducing filler;

[0012] The columnar anode and the columnar cathode are externally connected to a power source;

[0013] The anode chamber and the cathode chamber are separated by a partition, and a water outlet A is provided at the lower end of the partition;

[0014] The soy sauce wastewater enters from the water inlet at the lower end of the anode chamber, passes through the water outlet A, and flows out from the water outlet B arranged at the upper end of the cathode chamber;

[0015] Wherein, the modified conductive oxide filler is metal-doped activated carbon.

[0016] Specifically, the soy sauce wastewater enters from the water inlet at the lower end of the anode chamber, and the wastewater fills the left side of the anode chamber and overflows to the right side of the anode chamber. The electroactive bacteria attached and grown on the anode and the modified conductive oxidizing filler oxidize the organic matter to generate carbon dioxide, hydrogen ions, etc., and then enters the cathode chamber through the water outlet A. The wastewater fills the left side of the cathode chamber and overflows to the right side of the cathode chamber, and then flows out from the water outlet B arranged at the upper end of the cathode chamber; when the sewage flows through the cathode chamber, the organic matter ions oxidized in the anode chamber are attached to the cathode and the conductive reducing filler, and the generated gases such as water, hydrogen or methane are discharged, thereby achieving the effect of sewage purification.

[0017] Furthermore, the preparation method of the modified conductive oxide filler comprises the following steps:

[0018] S1, mixing silica particles with fruit shells, adding water to disperse, then filtering, and calcining the solid at high temperature to obtain activated carbon;

[0019] S2. Grind the activated carbon into particles, add the particles into a mixed solution of zinc sulfate and potassium sulfate, stir and dry the solid, and then heat and cool the solid in a tubular furnace protected by an inert gas to obtain the metal-doped activated carbon.

[0020] Furthermore, in step S1, the calcination conditions are: 450-600° C., calcination for 60-90 min.

[0021] Furthermore, in step S2, the particle size of the activated carbon is 2-5 mm.

[0022] Furthermore, in step S2, the heating temperature is 800-900°C.

[0023] Furthermore, in step S1, the mass ratio of the silicon dioxide particles to the fruit shell is 2:1-1:0.5.

[0024] Furthermore, in step S2, the concentration of the zinc sulfate solution is 0.03-0.07 mol / L.

[0025] Furthermore, in step S2, the concentration of the potassium sulfate solution is 0.05-0.07 mol / L.

[0026] Furthermore, the conductive reducing filler is selected from graphite.

[0027] Furthermore, the electroactive bacteria are selected from one or more of the genus Geobacter, the genus Proteiniphilum, the genus Pseudomonas and the anaerobic ammonia-oxidizing bacteria Cloacamonas.

[0028] The present invention has the following beneficial effects:

[0029] The filler of the anode chamber in the bioelectrochemical treatment device for soy sauce wastewater provided by the present invention is a modified conductive oxide filler; the modified conductive oxide filler first calcines and carbonizes silicon dioxide particles and fruit shells to form activated carbon, so that the silicon dioxide forms a dense, uniform and numerous porous structure on the fruit shell, thereby effectively increasing the specific surface area of ​​the activated carbon, thereby increasing the growth space of electroactive bacteria, and being more conducive to the attachment and reproduction of electroactive bacteria; secondly, by mixing the activated carbon with a mixed solution of zinc sulfate and potassium sulfate, the zinc sulfate and potassium sulfate are first adsorbed on the activated carbon, and then calcined to form corresponding metal oxides on the surface of the activated carbon, thereby forming metal-doped activated carbon; because metallic potassium and metallic zinc are introduced into the activated carbon, there is electronic interaction and synergistic effect between the metallic potassium and metallic zinc, which can improve electronic conductivity and promote the degradation treatment of soy sauce wastewater; in addition, because a large amount of metal oxide crystals are loaded on the activated carbon, the specific surface area of ​​the activated carbon can be further increased, so that the electroactive bacteria have a better living environment, which is more conducive to the reproduction of the electroactive bacteria, thereby effectively improving the treatment capacity of soy sauce wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of the device for bioelectrochemical treatment of soy sauce wastewater according to the present invention.

[0031] In the figure: 1, anode chamber; 2, cathode chamber; 3, columnar anode; 4, columnar cathode; 5, modified conductive oxidation filler; 6, conductive reducing filler; 7, power supply; 8, partition; 9, water outlet A; 10, water outlet B; 11, water inlet. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0033] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0034] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0035] Example 1

[0036] A bioelectrochemical device for treating soy sauce wastewater, the bioelectrochemical device for treating soy sauce wastewater comprising an anode chamber 1 and a cathode chamber 2, wherein

[0037] A columnar anode 3 is disposed at the center of the anode chamber 1; a columnar cathode 4 is disposed at the center of the cathode chamber 2;

[0038] The space between the columnar anode 3 and the anode chamber 1 is filled with a modified conductive oxide filler 5, and the height of the modified conductive oxide filler 5 is enough to immerse the columnar anode 3;

[0039] Electroactive bacteria grow on the columnar anode 3 and the modified conductive oxide filler 5;

[0040] The space between the columnar cathode 4 and the cathode chamber 2 is filled with a conductive reducing filler 6, and the height of the conductive reducing filler 6 is enough to immerse the columnar cathode 4;

[0041] The columnar anode 3 and the columnar cathode 4 are externally connected to a power supply 7, and the power supply 7 connects the columnar anode 3 to the positive electrode through an anode wire, and the power supply 7 connects the columnar cathode 4 to the negative electrode through a cathode wire;

[0042] The anode chamber 1 and the cathode chamber 2 are separated by a partition 8, and a water outlet A9 is provided at the lower end of the partition 8;

[0043] The soy sauce wastewater enters from the water inlet 11 at the lower end of the anode chamber 1, and overflows to the right side of the anode chamber 1 after filling the left side of the anode chamber 1. The electroactive bacteria attached and grown on the columnar anode 3 and the modified conductive oxidizing filler 5 oxidize the organic matter in the soy sauce wastewater to generate carbon dioxide, hydrogen ions, etc., and then enters the cathode chamber 2 through the water outlet A9. The wastewater fills the left side of the cathode chamber 2 and overflows to the right side of the cathode chamber 2, and then flows out from the water outlet B10 arranged at the upper end of the cathode chamber 2; when the sewage flows through the cathode chamber 2, the organic matter ions oxidized in the anode chamber 1 are attached to the cathode and the conductive reducing filler 6, and the generated water, hydrogen or methane and other gases are discharged;

[0044] Wherein, the modified conductive oxide filler 5 is metal-doped activated carbon;

[0045] The volume of the anode chamber 1 and the cathode chamber 2 is 7L, the material of the columnar anode 3 is a titanium anode plate, the material of the columnar cathode 4 is a stainless steel film electrode cathode plate, the material of the conductive reducing filler 6 is graphite, the electroactive bacteria is Geobacter sp. (CGMCC accession number No. 1.12536), the partition 8 is an insulating plastic plate, and the water outlet A9 and the water outlet B10 are provided with a water-permeable non-woven fabric;

[0046] The preparation method of the metal-doped activated carbon is as follows:

[0047] S1-1, drying almond shells at 250°C, crushing them, passing them through a 20-mesh sieve, immersing them in a 2wt% KOH solution at 70°C for 20h, and filtering them;

[0048] S1-2, the filtered almond shells were mixed with silicon dioxide (1:1, m / m), then added to a sufficient amount of deionized water, stirred and dispersed, then filtered, dried at 100°C for 24 hours, then calcined at 500°C for 60 minutes, washed after cooling, dried, then soaked in 0.5 mol / L sodium hydroxide solution for 12 hours and washed until neutral, then soaked in 1 mol / L hydrochloric acid solution for 12 hours and washed until neutral, and dried to obtain activated carbon;

[0049] S2. Mix 0.05 mol / L zinc sulfate solution and 0.05 mol / L potassium sulfate solution (1:1, v / v) to obtain a mixed solution, grind the activated carbon into 5 mm particles, soak the activated carbon in the mixed solution for 12 h at room temperature (solid-liquid ratio of 1 g / mL), filter and dry the solid, and then place it in a nitrogen-protected tubular furnace at 10 °C / min -1The mixture is heated to 850° C. at a heating rate of , and maintained for 3 h, and then cooled to obtain the metal-doped activated carbon.

[0050] Example 2

[0051] A bioelectrochemical device for treating soy sauce wastewater, the bioelectrochemical device for treating soy sauce wastewater comprising an anode chamber 1 and a cathode chamber 2, wherein

[0052] A columnar anode 3 is disposed at the center of the anode chamber 1; a columnar cathode 4 is disposed at the center of the cathode chamber 2;

[0053] The space between the columnar anode 3 and the anode chamber 1 is filled with a modified conductive oxide filler 5, and the height of the modified conductive oxide filler 5 is enough to immerse the columnar anode 3;

[0054] Electroactive bacteria grow on the columnar anode 3 and the modified conductive oxide filler 5;

[0055] The space between the columnar cathode 4 and the cathode chamber 2 is filled with a conductive reducing filler 6, and the height of the conductive reducing filler 6 is enough to immerse the columnar cathode 4;

[0056] The columnar anode 3 and the columnar cathode 4 are externally connected to a power supply 7, and the power supply 7 connects the columnar anode 3 to the positive electrode through an anode wire, and the power supply 7 connects the columnar cathode 4 to the negative electrode through a cathode wire;

[0057] The anode chamber 1 and the cathode chamber 2 are separated by a partition 8, and a water outlet A9 is provided at the lower end of the partition 8;

[0058] The soy sauce wastewater enters from the water inlet 11 at the lower end of the anode chamber 1, and the wastewater overflows to the right side of the anode chamber 1 after filling the left side of the anode chamber 1. The electroactive bacteria attached and grown on the columnar anode 3 and the modified conductive oxidation filler 5 oxidize the organic matter to generate carbon dioxide, hydrogen ions, etc., and then enter the cathode chamber 2 through the water outlet A9. The wastewater overflows to the right side of the cathode chamber 2 after filling the left side of the cathode chamber 2, and then flows out from the water outlet B10 set at the upper end of the cathode chamber 2; when the sewage flows through the cathode chamber 2, the organic ions oxidized in the anode chamber 1 are attached to the cathode and the conductive reducing filler 6, and the generated water, hydrogen or methane and other gases are discharged;

[0059] Wherein, the modified conductive oxide filler 5 is metal-doped activated carbon;

[0060] The volume of the anode chamber 1 and the cathode chamber 2 is 7L, the material of the columnar anode 3 is a Fe thin film electrode anode plate, the material of the columnar cathode 4 is a stainless steel thin film electrode cathode plate, the material of the conductive reducing filler 6 is graphite, the electroactive bacteria is Geobacter sp. (CGMCC accession number No. 1.12536), the partition 8 is an insulating plastic plate, and the water outlet A9 and the water outlet B10 are provided with a water-permeable non-woven fabric;

[0061] The preparation method of the metal-doped activated carbon is as follows:

[0062] S1-1, drying almond shells at 250°C, crushing them, passing them through a 20-mesh sieve, immersing them in a 2wt% KOH solution at 70°C for 20h, and filtering them;

[0063] S1-2, the filtered almond shells were mixed with silicon dioxide (1:1, m / m), then added to a sufficient amount of deionized water, stirred and dispersed, then filtered, dried at 100°C for 24 hours, then calcined at 500°C for 60 minutes, washed after cooling, dried, then soaked in 0.5 mol / L sodium hydroxide solution for 12 hours and washed until neutral, then soaked in 1 mol / L hydrochloric acid solution for 12 hours and washed until neutral, and dried to obtain activated carbon;

[0064] S2. Mix 0.05 mol / L zinc sulfate solution and 0.05 mol / L potassium sulfate solution (1:1, v / v) to obtain a mixed solution, grind the activated carbon into 5 mm particles, soak the activated carbon in the mixed solution for 12 h at room temperature (solid-liquid ratio of 1 g / mL), filter and dry the solid, and then place it in a nitrogen-protected tubular furnace at 10 °C / min -1 The mixture is heated to 850° C. at a heating rate of , and maintained for 3 h, and then cooled to obtain the metal-doped activated carbon.

[0065] Example 3

[0066] A bioelectrochemical device for treating soy sauce wastewater, the bioelectrochemical device for treating soy sauce wastewater comprising an anode chamber 1 and a cathode chamber 2, wherein

[0067] A columnar anode 3 is disposed at the center of the anode chamber 1; a columnar cathode 4 is disposed at the center of the cathode chamber 2;

[0068] The space between the columnar anode 3 and the anode chamber 1 is filled with a modified conductive oxide filler 5, and the height of the modified conductive oxide filler 5 is enough to immerse the columnar anode 3;

[0069] Electroactive bacteria grow on the columnar anode 3 and the modified conductive oxide filler 5;

[0070] The space between the columnar cathode 4 and the cathode chamber 2 is filled with a conductive reducing filler 6, and the height of the conductive reducing filler 6 is enough to immerse the columnar cathode 4;

[0071] The columnar anode 3 and the columnar cathode 4 are externally connected to a power supply 7, and the power supply 7 connects the columnar anode 3 to the positive electrode through an anode wire, and the power supply 7 connects the columnar cathode 4 to the negative electrode through a cathode wire;

[0072] The anode chamber 1 and the cathode chamber 2 are separated by a partition 8, and a water outlet A9 is provided at the lower end of the partition 8;

[0073] The soy sauce wastewater enters from the water inlet 11 at the lower end of the anode chamber 1, and the wastewater overflows to the right side of the anode chamber 1 after filling the left side of the anode chamber 1. The electroactive bacteria attached and grown on the columnar anode 3 and the modified conductive oxidation filler 5 oxidize the organic matter to generate carbon dioxide, hydrogen ions, etc., and then enter the cathode chamber 2 through the water outlet A9. The wastewater overflows to the right side of the cathode chamber 2 after filling the left side of the cathode chamber 2, and then flows out from the water outlet B10 set at the upper end of the cathode chamber 2; when the sewage flows through the cathode chamber 2, the organic ions oxidized in the anode chamber 1 are attached to the cathode and the conductive reducing filler 6, and the generated water, hydrogen or methane and other gases are discharged;

[0074] Wherein, the modified conductive oxide filler 5 is metal-doped activated carbon;

[0075] The volume of the anode chamber 1 and the cathode chamber 2 is 7L, the material of the columnar anode 3 is a Fe thin film electrode anode plate, the material of the columnar cathode 4 is a stainless steel thin film electrode cathode plate, the material of the conductive reducing filler 6 is graphite, the electroactive bacteria is Pseudomonas sp. (CCTCC AB 2012838), the partition 8 is an insulating plastic plate, and the water outlet A9 and the water outlet B10 are provided with a water-permeable non-woven fabric;

[0076] The preparation method of the metal-doped activated carbon is as follows:

[0077] S1-1, drying almond shells at 250°C, crushing them, passing them through a 20-mesh sieve, immersing them in a 2wt% KOH solution at 70°C for 20h, and filtering them;

[0078] S1-2, the filtered almond shells were mixed with silicon dioxide (1:1, m / m), then added to a sufficient amount of deionized water, stirred and dispersed, then filtered, dried at 100°C for 24 hours, then calcined at 500°C for 60 minutes, washed after cooling, dried, then soaked in 0.5 mol / L sodium hydroxide solution for 12 hours and washed until neutral, then soaked in 1 mol / L hydrochloric acid solution for 12 hours and washed until neutral, and dried to obtain activated carbon;

[0079] S2. Mix 0.05 mol / L zinc sulfate solution and 0.05 mol / L potassium sulfate solution (1:1, v / v) to obtain a mixed solution, grind the activated carbon into 5 mm particles, soak the activated carbon in the mixed solution for 12 h at room temperature (solid-liquid ratio of 1 g / mL), filter and dry the solid, and then place it in a nitrogen-protected tubular furnace at 10 °C / min -1 The mixture is heated to 850° C. at a heating rate of , and maintained for 3 h, and then cooled to obtain the metal-doped activated carbon.

[0080] Comparative Example 1

[0081] A device for bioelectrochemical treatment of soy sauce wastewater. The difference between this comparative example and Example 1 is that the silicon dioxide in step S1-2 is removed and replaced by almond shells of equal mass. Other components and preparation methods are the same as those in Example 1.

[0082] Comparative Example 2

[0083] A device for bioelectrochemical treatment of soy sauce wastewater. The difference between this comparative example and Example 1 is that in step S2, an equal volume of 0.05 mol / L zinc sulfate solution is used to replace 0.05 mol / L potassium sulfate solution, and other components and preparation methods are the same as those in Example 1.

[0084] Test Case

[0085] The performance test was carried out on the bioelectrochemical treatment device for soy sauce wastewater prepared in Example 1 and Comparative Examples 1-2.

[0086] The test method is as follows:

[0087] Soy sauce wastewater with a COD value of 1230 mg / L, an ammonia nitrogen concentration of 140 mg / L, and a pH of 7 was added from the water inlet to the bioelectrochemical treatment device for soy sauce wastewater prepared in Example 1 and Comparative Example 1-2, respectively. The output voltage of the power supply was 1.2-1.6 V, and the current density was controlled to be 0.03 mA / cm 2 , control the hydraulic retention time to 5h, and measure the COD and ammonia nitrogen concentrations of the treated soy sauce wastewater.

[0088] The test results are shown in Table 1.

[0089] Table 1 Performance test results

[0090] project Example 1 Comparative Example 1 Comparative Example 2 COD(mg / L) 88 192 137 Ammonia nitrogen concentration (mg / L) 7 23 18

[0091] It can be seen from Table 1 that the bioelectrochemical treatment device for soy sauce wastewater of the present invention has excellent wastewater treatment capacity and good performance, and solves the defects existing in the prior art.

[0092] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0093] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A device for bioelectrochemical treatment of soy sauce wastewater, characterized in that: The bioelectrochemical treatment device for soy sauce wastewater comprises an anode chamber and a cathode chamber, wherein A columnar anode is disposed at the center of the anode chamber; a columnar cathode is disposed at the center of the cathode chamber; The space between the columnar anode and the anode chamber is filled with a modified conductive oxide filler; Electroactive bacteria grow on the columnar anode and the modified conductive oxidizing filler; The space between the columnar cathode and the cathode chamber is filled with a conductive reducing filler; The columnar anode and the columnar cathode are externally connected to a power source; The anode chamber and the cathode chamber are separated by a partition, and a water outlet A is provided at the lower end of the partition; The soy sauce wastewater enters from the water inlet at the lower end of the anode chamber, passes through the water outlet A, and flows out from the water outlet B arranged at the upper end of the cathode chamber; Wherein, the modified conductive oxide filler is metal-doped activated carbon.

2. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 1, characterized in that: The preparation method of the modified conductive oxide filler comprises the following steps: S1, mixing silica particles with fruit shells, adding water to disperse, then filtering, and calcining the solid at high temperature to obtain activated carbon; S2. Grind the activated carbon into particles, add the particles into a mixed solution of zinc sulfate and potassium sulfate, stir and dry the solid, and then heat and cool the solid in a tubular furnace protected by an inert gas to obtain the metal-doped activated carbon.

3. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 2, characterized in that: In step S1, the calcination conditions are: 450-600° C., calcination for 60-90 min.

4. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 2, characterized in that: In step S1, the mass ratio of the silicon dioxide particles to the fruit shell is 2:1-1:0.

5.

5. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 2, characterized in that: In step S2, the particle size of the activated carbon is 2-5 mm.

6. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 2, characterized in that: In step S2, the heating temperature is 800-900°C.

7. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 2, characterized in that: In step S2, the concentration of the zinc sulfate solution is 0.03-0.07 mol / L.

8. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 2, characterized in that: In step S2, the concentration of the potassium sulfate solution is 0.05-0.07 mol / L.

9. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 1, characterized in that: The conductive reducing filler is selected from graphite.

10. The device for bioelectrochemical treatment of soy sauce wastewater according to claim 1, characterized in that: The electroactive bacteria are selected from one or more of the genus Geobacter, Proteophilic Bacteria, Pseudomonas and anaerobic ammonia oxidizing bacteria.

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