Organic solid waste composting process utilizing electric field-microorganism synergistic fermentation

Abstract

The invention relates to the technical field of organic solid waste composting, in particular to an organic solid waste composting process utilizing electric field-microorganism synergistic fermentation. The conventional composting process for organic solid wastes is low in composting efficiency, and the content of humus in the obtained organic fertilizer is difficult to reach 140 g / kg or above. In order to solve the technical problems, the invention provides the organic solid waste composting process by utilizing electric field-microorganism synergistic fermentation, various organic solid wastes are mainly adopted for co-fermentation, the reasonable carbon-nitrogen ratio of compost is ensured, fermentation composting is performed under the synergistic effect of the electric field and microorganisms, the activity and metabolic rate of the microorganisms are promoted by the electric field, and the organic solid waste composting effect is improved. The method promotes the oxygenolysis and humus of organic matters, facilitates the generation of more humus in a short time, improves the composting efficiency, and guarantees the quality of the obtained organic fertilizer.

Description

Technical Field

[0001] The invention relates to the technical field of organic solid waste composting, and in particular to an organic solid waste composting process utilizing electric field-microorganism synergistic fermentation. Background Art

[0002] With the acceleration of urbanization and the large-scale development of agriculture, the annual output of organic solid waste (including kitchen waste, livestock and poultry manure, rural straw, sludge and food processing waste, etc.) continues to rise. Traditional treatment methods such as landfill have hidden dangers such as high land resource occupation rate and leachate contamination of groundwater; although incineration can achieve reduction, it is easy to produce toxic gases such as dioxins, and the carbon resource utilization rate is insufficient. In comparison, aerobic composting technology has become an important development direction for organic solid waste treatment because of its harmlessness and resource utilization characteristics.

[0003] At present, the mainstream composting process mainly relies on microbial degradation, and achieves organic matter decomposition and pathogen inactivation by building a high-temperature fermentation environment. However, the existing technology has significant defects: (1) In order to maintain the temperature of the pile, it needs to be highly densely stacked, resulting in insufficient ventilation porosity and low oxygen transmission efficiency, which reduces the organic matter degradation rate by 30%-50% and extends the fermentation cycle to 40-60 days; (2) The increase in the proportion of anaerobic areas causes NH 3 , H 2 The emission of harmful gases such as S increases. Monitoring data show that the emission of ammonia in traditional windrow composting can reach 15%-30% of the total nitrogen content; (3) The high temperature duration is insufficient (usually <55°C), resulting in an inactivation rate of heat-resistant pathogenic microorganisms such as Bacillus less than 70%, posing a biosafety risk; (4) The passivation ability of heavy metal ions (such as Cu, Zn, and Cd) in solid waste is limited. Microbial metabolism can only achieve 10%-20% ion state conversion. The final product may still cause heavy metal enrichment after being applied to the soil.

[0004] Existing improvement technologies mostly focus on optimizing a single link, such as adding exogenous bacterial agents to improve degradation efficiency, or adding bulking agents to improve aeration, but they fail to systematically solve the imbalance problem of mass transfer-reaction coupling mechanism. In addition, late-stage chemical passivation treatment is often used for heavy metal pollution, which leads to increased costs and the risk of secondary pollution. Therefore, it is urgent to develop an integrated composting technology that can simultaneously improve the conversion efficiency of organic matter, enhance the inactivation effect of pathogens, and achieve in-situ passivation of heavy metals. Summary of the invention

[0005] The problem in the prior art is that the composting efficiency of conventional composting processes for organic solid waste is low, and the humus content in the obtained organic fertilizer is difficult to reach more than 140g / kg. In view of the above technical problems, the present invention provides an organic solid waste composting process using electric field-microorganism synergistic fermentation, which comprises the following steps:

[0006] The organic solid waste mixture is dehydrated to a water content of no more than 50%, and then microbial agents are added to the organic solid waste mixture. After stirring evenly, the mixture is piled on the surface of the cathode plate, and the anode rod is vertically inserted into the top of the pile body, and then fermentation begins. The cathode plate is connected to the negative pole of the external power supply, and the anode rod is connected to the positive pole of the external power supply. The bottom end of the anode rod does not contact the surface of the cathode plate. During the fermentation process, a voltage U is applied once every 7-8 hours through the external power supply, and then the pile is turned once. The fermentation time is 20-22 days. After the compost fermentation is completed, organic fertilizer is obtained.

[0007] Preferably, the organic solid waste mixture includes one or more of crop straw, livestock manure, and sewage plant sludge.

[0008] Preferably, the organic solid waste mixture is a mixture of crop straw, livestock manure, and sewage sludge in a mass ratio of 1-2:0.8-1.2:4-5.

[0009] Preferably, the microbial agent includes one or more of Thiobacillus ferrooxidans, Saccharomyces cerevisiae, Bacillus licheniformis, Rhodopseudomonas, Trichoderma harzianum, and Aspergillus niger.

[0010] Preferably, the microbial agent is composed of Thiobacillus ferrooxidans cells, Saccharomyces cerevisiae cells, Bacillus licheniformis cells, Rhodopseudomonas cells, Trichoderma harzianum cells, and Aspergillus niger cells in a mass ratio of 12:9:23:18:8:4.

[0011] Preferably, the voltage applied during the composting fermentation process is calculated according to the following formula:

[0012] Un=U0+ΔU|k-2n|,

[0013] In the above formula, Un represents the voltage value corresponding to the nth turning of the compost, U0 represents the initial voltage value, the value range of ΔU is 0.8-1V, K and n are both integers greater than 0, K=8-12, n≥1.

[0014] Preferably, the vertical distance between the bottom end of the anode rod and the cathode plate is 30-50 cm.

[0015] Preferably, a conditioner is added during the compost turning process, and the amount of the conditioner added is 0.06-0.1% of the total mass of the compost. The conditioner includes bentonite, chitosan and disodium hydrogen phosphate. After the compost turning is completed, the compost is aerated, and the aeration volume is 0.1-0.2L / kg·min and the aeration time is 5-10min. Adding a conditioner to the compost each time the compost is turned can effectively improve the air permeability of the compost.

[0016] Preferably, the conditioning agent consists of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 30-45:10-15:3-6.

[0017] Preferably, the conditioning agent consists of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 38:12:5.

[0018] The present invention has the following beneficial effects:

[0019] (1) The present invention uses multiple organic solid wastes for co-fermentation, which ensures that the compost has a reasonable carbon-nitrogen ratio. The electric field and microorganisms work together to ferment and compost. The electric field promotes the activity and metabolic rate of the microorganisms, promotes the oxidative decomposition and humification of organic matter, and is conducive to the generation of more humus in a short time, thereby improving the composting efficiency and ensuring the quality of the compost. At the same time, the electric field promotes the complexation of heavy metals with humus, so that the heavy metals are effectively fixed, and the heavy metals are effectively prevented from causing greater pollution to the soil during the composting fermentation process.

[0020] (2) The microbial agent used in the present invention can effectively decompose organic matter in the compost to form humus, and increase the activity of the microbial colony under the action of the electric field, effectively ensuring the composting effect and the quality of the organic fertilizer. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present invention, and are not intended to limit the scope of the present invention.

[0022] The raw materials used in the following examples of the present invention are described as follows:

[0023] Microbial agents were all commercially available products.

[0024] Thiobacillus ferrooxidans (ATCC 33020), Supplier: American Type Culture Collection.

[0025] Saccharomyces cerevisiae (CCTCC AY2019004), supplier: China Center for Type Culture Collection.

[0026] Rhodopseudomonas (CCTCC DB20082542), supplier: China Center for Type Culture Collection.

[0027] Bacillus licheniformis (CICC 10087), supplier: China Industrial Microbiological Culture Collection Center.

[0028] Trichoderma harzianum (CCTCC HF2008541), supplier: China Center for Type Culture Collection.

[0029] Aspergillus niger (CCTCC AF2016003), supplier: China Center for Type Culture Collection.

[0030] The thiobacillus ferrooxidans was cultured by a conventional microbial culture method (9K culture medium, temperature 30°C) to obtain a thiobacillus ferrooxidans bacterial liquid, and the obtained thiobacillus ferrooxidans bacterial liquid was centrifuged and freeze-dried to obtain bacterial cells.

[0031] The saccharomyces cerevisiae is cultured by a conventional microbial culture method (YPD medium, temperature 28-30° C.) to obtain a saccharomyces cerevisiae bacterial liquid, and the obtained saccharomyces cerevisiae bacterial liquid is centrifuged and freeze-dried to obtain bacterial bodies.

[0032] The Rhodopseudomonas is cultured by a conventional microbial culture method (liquid culture medium, temperature 25-34° C.) to obtain a Rhodopseudomonas bacterial liquid, and the obtained Rhodopseudomonas bacterial liquid is centrifuged and freeze-dried to obtain bacterial bodies.

[0033] Bacillus licheniformis is cultured by a conventional microbial culture method (agar culture medium, temperature 30-37° C.) to obtain a Bacillus licheniformis bacterial liquid, and the obtained Bacillus licheniformis bacterial liquid is centrifuged and freeze-dried to obtain bacterial bodies.

[0034] The Trichoderma harzianum is cultured by a conventional microbial culture method (potato culture medium, temperature 28-30° C.) to obtain a Trichoderma harzianum bacterial liquid, and the obtained Trichoderma harzianum bacterial liquid is centrifuged and freeze-dried to obtain bacterial bodies.

[0035] Aspergillus niger is cultured by a conventional microbial culture method (Czapek medium, temperature 37°C) to obtain Aspergillus niger bacterial liquid, and the obtained Aspergillus niger bacterial liquid is centrifuged and freeze-dried to obtain bacterial bodies.

[0036] The organic solid waste mixture (C / N ratio is 24.5:1) used in the following Example 1 of the present invention is a mixture of corn stalks, livestock manure, and sewage sludge in a mass ratio of 1.5:1:4.5, wherein the livestock manure is a mixture of chicken manure, cow manure, and pig manure in a mass ratio of 4:3:3, and the particle size range of the corn stalks is 2-4 mm.

[0037] Sewage plant sludge is the sludge formed by treating domestic sewage.

[0038] Example 1

[0039] An organic solid waste composting process using electric field-microorganism synergistic fermentation, the steps are as follows:

[0040] The organic solid waste mixture is dehydrated to a water content of 50%, and then a microbial agent is added to the organic solid waste mixture, the amount of the microbial agent added is 0.8% of the total mass of the organic solid waste mixture, and after stirring evenly, the mixture is piled on the surface of the cathode plate, and the anode rod is vertically inserted into the top of the pile body, and then fermentation begins. The cathode plate is connected to the negative electrode of the external power supply, and the anode rod is connected to the positive electrode of the external power supply. The vertical spacing between the bottom end of the anode rod and the cathode plate is 40 cm. During the fermentation process, a voltage U is applied once by the external power supply every 7.5 hours, and then the pile is turned once. The fermentation time is 21 days. After the compost fermentation is completed, organic fertilizer is obtained. A conditioner is added during the turning process. The amount of the conditioner added is 0.08% of the total mass of the compost. The conditioner consists of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 38:12:5. After the turning is completed, aeration is performed in the compost, and the aeration amount is 0.15L / kg·min and the aeration time is 8min.

[0041] The microbial agent is composed of Thiobacillus ferrooxidans cells, Saccharomyces cerevisiae cells, Bacillus licheniformis cells, Rhodopseudomonas cells, Trichoderma harzianum cells, and Aspergillus niger cells in a mass ratio of 12:9:23:18:8:4.

[0042] The voltage U applied during composting is calculated according to the following formula:

[0043] Un=U0+ΔU|k-2n|,

[0044] In the above formula, Un represents the voltage value corresponding to the nth turning of the compost, U0 represents the initial voltage value, U0=13V, ΔU=0.9V, K and n are both integers greater than 0, K=10, n≥1.

[0045] Example 2 is the same as Example 1, except that the organic solid waste mixture in Example 2 is a mixture of corn straw, livestock manure, and sewage sludge in a mass ratio of 1:0.8:4, and the C / N ratio of the organic solid waste mixture is 20.1:1.

[0046] Example 3 is the same as Example 1, except that the organic solid waste mixture in Example 3 is a mixture of corn straw, livestock manure, and sewage sludge in a mass ratio of 2:1.2:5, and the C / N ratio of the organic solid waste mixture is 28:1.

[0047] Example 4 is the same as Example 1, except that the microbial agent in Example 4 is composed of Thiobacillus ferrooxidans cells, Saccharomyces cerevisiae cells, Bacillus licheniformis cells, Rhodopseudomonas cells, Trichoderma harzianum cells, and Aspergillus niger cells in a mass ratio of 10:6:20:15:5:2.

[0048] Example 5 is the same as Example 1, except that the microbial agent in Example 5 is composed of Thiobacillus ferrooxidans cells, Saccharomyces cerevisiae cells, Bacillus licheniformis cells, Rhodopseudomonas cells, Trichoderma harzianum cells, and Aspergillus niger cells in a mass ratio of 15:12:25:20:10:6.

[0049] Example 6 is the same as Example 1, except that the amount of microbial agent added in Example 6 is 0.5% of the total mass of the organic solid waste mixture.

[0050] Example 7 is the same as Example 1, except that the amount of microbial agent added in Example 7 is 1% of the total mass of the organic solid waste mixture.

[0051] Example 8 is the same as Example 1, except that in Example 8, voltage is applied once every 7 hours through an external power supply during the fermentation process.

[0052] Example 9 is the same as Example 1, except that in Example 9, a voltage is applied once every 8 hours through an external power supply during the fermentation process.

[0053] Embodiment 10 is the same as Embodiment 1, except that in Embodiment 10, U0=12V.

[0054] Example 11 is the same as Example 1, except that in Example 11, U0=14V.

[0055] Example 12 is the same as Example 1, except that in Example 12, ΔU=0.8V.

[0056] Example 13 is the same as Example 1, except that in Example 13, ΔU=1V.

[0057] Example 14 is the same as Example 1, except that in Example 14, K=8.

[0058] Example 15 is the same as Example 1, except that in Example 15, K=12.

[0059] Example 16 is the same as Example 1, except that the conditioning agent in Example 16 consists of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 30:10:3.

[0060] Example 17 is the same as Example 1, except that the conditioning agent in Example 17 consists of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 45:15:6.

[0061] Example 18 is the same as Example 1, except that the amount of conditioner added in Example 18 is 0.06% of the total mass of the compost.

[0062] Example 19 is the same as Example 1, except that the amount of conditioner added in Example 19 is 0.1% of the total mass of the compost.

[0063] Example 20 is the same as Example 1, except that the aeration volume in Example 20 is 0.1 L / kg·min and the aeration time is 5 min.

[0064] Example 21 is the same as Example 1, except that the aeration volume in Example 21 is 0.2 L / kg·min and the aeration time is 10 min.

[0065] Example 22 is the same as Example 1, except that the fermentation days of Example 22 is 20 days.

[0066] Example 23 is the same as Example 1, except that the fermentation days of Example 23 are 22 days.

[0067] Comparative Example 1 is the same as Example 1, except that no voltage is applied during the composting fermentation process in Comparative Example 1.

[0068] Comparative Example 2 is the same as Example 1, except that the voltage applied during the composting fermentation process in Comparative Example 2 is always kept at 13V.

[0069] Comparative Example 3 is the same as Example 1, except that no conditioner is added during the composting fermentation process in Comparative Example 3.

[0070] Comparative Example 4 is the same as Example 1, except that no aeration is performed during the composting fermentation process in Comparative Example 4.

[0071] Performance Testing

[0072] 1. Explore the influence of mixture composition on the performance of organic fertilizer

[0073] Taking Examples 1-3 as experimental comparison, the performance of organic fertilizers under different components of the mixture is shown in Table 1 below:

[0074] Table 1

[0075] Group Lignin degradation rate (%) Humus content (g / kg) Example 1 69.52 152.37 Example 2 68.72 149.63 Example 3 68.19 146.35

[0076] In Table 1, humus content (g / kg) refers to the mass of humus produced by fermentation of organic solid waste mixture dehydrated to 50% per kilogram. It can be seen from the data in Table 1 that compared with Examples 1, 2, and 3, the organic fertilizer lignin degradation rate and humus content of Example 1 are both the highest, indicating that the organic fertilizer performance of Example 1 is the best, so the mixture composition selected in Example 1 is the best.

[0077] 2. Explore the effects of the composition and addition amount of microbial agents on the performance of organic fertilizers

[0078] Taking Example 1 and Examples 4-7 as experimental comparison, the organic fertilizer performance under different components and addition amounts of microbial agents is shown in Table 2 below:

[0079] Table 2

[0080] Group Lignin degradation rate Humus content (g / kg) Example 1 69.52 152.37 Example 4 67.93 140.88 Example 5 67.25 138.65 Example 6 68.14 146.38 Example 7 69.61 152.86

[0081] It can be seen from the data in Table 2 that, compared with Examples 1, 4, and 5, the organic fertilizer lignin degradation rate and humus content of Example 1 are the highest, indicating that the organic fertilizer performance of Example 1 is the best. This may be because the organic matter in the pile is most fully decomposed under the microbial agent component of Example 1, so the microbial agent component selected in Example 1 is the best.

[0082] Compared with Examples 1, 6 and 7: As the amount of microbial agent added increases, the lignin degradation rate and humus content of the organic fertilizer both increase, until the lignin degradation rate and humus content of the organic fertilizer in Example 1 reach the highest. As the amount of microbial agent added continues to increase, the lignin degradation rate and humus content of the organic fertilizer begin to have no obvious changes. Therefore, from a cost perspective, the amount of microbial agent added selected in Example 1 is optimal.

[0083] 3. Investigate the influence of electric field parameters on the performance of organic fertilizer

[0084] Using Example 1 and Examples 8-15 as experimental comparisons, the performance of the organic fertilizer under different electric field parameters is shown in Table 3 below:

[0085] Table 3

[0086] Group Lignin degradation rate Humus content (g / kg) Example 1 69.52 152.37 Example 8 68.12 143.58 Example 9 67.87 141.25 Example 10 69.12 148.71 Embodiment 11 68.54 145.23 Example 12 68.63 146.11 Example 13 68.13 144.32 Embodiment 14 67.15 140.12 Embodiment 15 67.98 142.53 Comparative Example 1 62.31 125.49 Comparative Example 2 65.29 133.70

[0087] It can be seen from the data in Table 3 that, compared with Examples 8-15, Example 1: the interval time of applying the electric field is too short or too long, the initial voltage of the electric field is too low or too high, the single increase in voltage is too low or too high, and the value of k is too small or too large, which will lead to a decrease in the lignin degradation rate and humus content of the organic fertilizer. This may be because under the electric field parameters of Example 1, the internal environment of the pile is the most suitable and the microbial activity is the best, so the electric field parameters selected in Example 1 are optimal.

[0088] In Example 1, compared with Comparative Examples 1 and 2, after no electric field is applied to the pile or the electric field voltage is kept constant, the lignin degradation rate and humus content of the organic fertilizer are significantly reduced. This may be because after no electric field is applied to the pile or the electric field voltage is kept constant, the fermentation temperature and gas flowability in the pile are changed. Therefore, the electric field application method selected in Example 1 is optimal.

[0089] 4. Explore the effects of the composition and amount of conditioners on the performance of organic fertilizers

[0090] Using Example 1, Examples 16-19 and Comparative Example 3 as experimental comparisons, the performance of organic fertilizers under different components and addition amounts of the conditioning agent is shown in Table 4 below:

[0091] Table 4

[0092] Group Lignin degradation rate Humus content (g / kg) Example 1 69.52 152.37 Example 16 68.95 148.77 Embodiment 17 68.52 146.35 Embodiment 18 68.66 146.98 Embodiment 19 67.89 144.82 Comparative Example 3 66.21 136.26

[0093] It can be seen from the data in Table 4 that, compared with Examples 1, 16, and 17, the organic fertilizer lignin degradation rate and humus content of Example 1 are both the highest, indicating that the organic fertilizer performance of Example 1 is the best. This may be because under the conditioner component of Example 1, the air permeability in the pile is the best, so the conditioner component selected in Example 1 is the best;

[0094] Compared with Examples 1, 18 and 19: the organic fertilizer lignin degradation rate and humus content of Example 1 are the highest, indicating that the organic fertilizer performance of Example 1 is the best. This may be because under the amount of conditioner added in Example 1, the environment in the pile is most suitable, so the amount of conditioner added selected in Example 1 is optimal.

[0095] 5. Investigate the influence of aeration parameters on the performance of organic fertilizer

[0096] Using Example 1, Examples 20-21 and Comparative Example 4 as experimental comparisons, the performance of the organic fertilizer under different aeration parameters is shown in Table 5 below:

[0097] Table 5

[0098] Group Lignin degradation rate Humus content (g / kg) Example 1 69.52 152.37 Embodiment 20 68.31 146.25 Embodiment 21 67.97 145.86 Comparative Example 4 66.54 136.74

[0099] It can be seen from the data in Table 5 that compared with Examples 1, 20 and 21, the organic fertilizer lignin degradation rate and humus content of Example 1 are the highest, indicating that the organic fertilizer performance of Example 1 is the best. This may be because under the aeration parameters of Example 1, the temperature and oxygen content in the pile are most suitable, so the aeration parameters selected in Example 1 are optimal.

[0100] 6. Explore the effect of fermentation time on the performance of organic fertilizer

[0101] Using Example 1 and Examples 22-23 as experimental comparisons, the performance of the organic fertilizer under different fermentation times is shown in Table 6 below:

[0102] Table 6

[0103] Group Lignin degradation rate Humus content (g / kg) Example 1 69.52 152.37 Embodiment 22 68.24 147.55 Embodiment 23 69.55 152.96

[0104] It can be seen from the data in Table 6 that, compared with Examples 1, 22 and 23, as the fermentation time increases, the lignin degradation rate and humus content of the organic fertilizer both increase, until the lignin degradation rate and humus content of the organic fertilizer in Example 1 reach the highest, and as the fermentation time continues to increase, the lignin degradation rate and humus content of the organic fertilizer begin to have no obvious changes. Therefore, from a cost perspective, the fermentation time selected in Example 1 is optimal.

[0105] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An organic solid waste composting process using electric field-microorganism synergistic fermentation, characterized in that: The following steps are involved: The organic solid waste mixture is dehydrated to a water content of no more than 50%, and then microbial agents are added to the organic solid waste mixture. After stirring evenly, the mixture is piled on the surface of the cathode plate, and the anode rod is vertically inserted into the top of the pile body, and then fermentation begins. The cathode plate is connected to the negative pole of the external power supply, and the anode rod is connected to the positive pole of the external power supply. The bottom end of the anode rod does not contact the surface of the cathode plate. During the fermentation process, a voltage U is applied once every 7-8 hours through the external power supply, and then the pile is turned once. The fermentation time is 20-22 days. After the compost fermentation is completed, organic fertilizer is obtained.

2. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 1, characterized in that: The organic solid waste mixture includes one or more of crop straw, livestock excrement, and sewage plant sludge.

3. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 1, characterized in that: The organic solid waste mixture is a mixture of crop straw, livestock excrement, and sewage plant sludge in a mass ratio of 1-2:0.8-1.2:4-5.

4. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 1, characterized in that: The microbial agent includes one or more of Thiobacillus ferrooxidans, Saccharomyces cerevisiae, Bacillus licheniformis, Rhodopseudomonas, Trichoderma harzianum and Aspergillus niger.

5. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 4, characterized in that: The microbial agent is composed of Thiobacillus ferrooxidans cells, Saccharomyces cerevisiae cells, Bacillus licheniformis cells, Rhodopseudomonas cells, Trichoderma harzianum cells, and Aspergillus niger cells in a mass ratio of 12:9:23:18:8:

4.

6. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 1, characterized in that: The voltage applied during composting is calculated according to the following formula: Un=U0+ΔU|k-2n|, In the above formula, Un represents the voltage value corresponding to the nth turning of the compost, U0 represents the initial voltage value, the value range of ΔU is 0.8-1V, K and n are both integers greater than 0, K=8-12, n≥1.

7. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 1, characterized in that: The vertical distance between the bottom end of the anode rod and the cathode plate is 30-50 cm.

8. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 1, characterized in that: A conditioner is added during the compost turning process, wherein the added amount of the conditioner is 0.06-0.1% of the total mass of the compost, and the conditioner includes bentonite, chitosan and disodium hydrogen phosphate. After the compost turning is completed, the compost is aerated, and the aeration volume is 0.1-0.2L / kg·min and the aeration time is 5-10min.

9. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 8, characterized in that: The conditioning agent is composed of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 30-45:10-15:3-6.

10. The organic solid waste composting process using electric field-microorganism synergistic fermentation according to claim 9, characterized in that: The conditioning agent is composed of bentonite, chitosan and disodium hydrogen phosphate in a mass ratio of 38:12:5.