Composite electroactive microbial agent of mineral powder and application thereof

Abstract

The present application belongs to the technical field of waste biological treatment, and relates to a composite electroactive microbial agent containing mineral powder and application thereof. In the prior art, when agricultural organic waste is recycled, the composite degradation microbial agent added in the reaction system cannot be efficiently transported, resulting in low fermentation efficiency and poor stability. The microbial agent provided in the present application contains 10-20 wt% of a microbial mixture and 80-90 wt% of mineral powder. The microbial mixture contains metal-reducing Geobacter, Clostridium butyricum and Shewanella, and the mass ratio of the three is 3-6:1-4:3-5. By coupling the composite electroactive microorganism and the porous conductive mineral carrier, the system serves as an electron express pipeline, effectively enhances the electron transfer between the microorganism and the reaction material, guarantees the transmission rate and effect, realizes the recycling of waste tailings, effectively shortens the fermentation time, and increases the anaerobic fermentation gas production.

Description

Technical Field

[0001] This invention relates to the field of waste biological treatment technology, specifically to mineral powder composite electroactive microbial agents and their applications. Background Technology

[0002] With my country's rapid economic development, the total amount of solid organic waste in urban and rural areas nationwide is enormous. More than 90% of this organic waste comes from agricultural and rural planting or breeding waste. Approximately 700 million tons of crop straw and 1.8 billion tons of livestock manure are not effectively and scientifically utilized annually, resulting in serious resource waste. Currently, the core of agricultural organic waste resource utilization methods is microbial action. Microbial treatment has the following advantages: it can decompose organic matter into inorganic matter, transforming manure into fertilizer and clean water through anaerobic and aerobic treatment stages; treating manure not only reduces environmental pollution but also converts it into organic fertilizer, improving agricultural planting efficiency; during the treatment process, microbial communities continuously multiply, rapidly decomposing organic matter, eliminating odors, and killing pathogens, thereby improving treatment efficiency and reducing treatment time. However, in the process of agricultural organic waste resource utilization, the inherent microorganisms in the material cannot efficiently complete the degradation of organic matter in complex systems. Therefore, existing technologies mainly improve the fermentation efficiency of the system by adding highly efficient degrading bacteria or mixed microbial agents.

[0003] For example, Chinese patent application publication number CN106916767A, filed on March 29, 2017, entitled "A Compound Microbial Agent and Its Application in Degrading Cellulose in Poultry and Livestock Manure," discloses a compound microbial agent composed of bacterial strains cultured in beef extract peptone medium and fungal strains cultured in PDA medium at a 1:1 volume ratio. The bacterial strains consist of enzyme-producing bacteria adapted to low temperatures, ambient temperatures, and high temperatures, with a ratio of 1 to 1.5:1:1. Similarly, the fungal strains also consist of enzyme-producing bacteria adapted to low temperatures, ambient temperatures, and high temperatures, with a ratio of 1 to 1.5:1:1. This scheme achieves continuous enzyme production through the synergistic growth of various bacterial strains, creating a relatively stable cellulase-producing environment with stable enzyme activity. However, the composite microbial strains added to the reaction system of this scheme cannot efficiently transport to organic matter, resulting in low fermentation efficiency and poor stability.

[0004] For example, Chinese patent application publication number CN114874936A, filed on April 28, 2022, entitled "A Composite Microbial Agent for the Treatment of Domestic Sludge, Preparation Method and Application," discloses a composite microbial agent comprising 10-15 parts Bacillus, 5-10 parts Lactic Acid Bacteria, 5-10 parts Yeast, 5-10 parts Bacillus natto, 10-15 parts Photosynthetic Bacteria, 10-15 parts Nitrifying Bacteria, 20-30 parts Sulfur-Reducing Bacteria, 5-7 parts Zeolite Powder, 5-10 parts Glucose, and 2-3 parts Dicalcium Phosphate. This scheme adds a carrier for the microbial agent, making the agent more evenly dispersed in the waste. However, the system still suffers from the problem of limited adsorption and transport rates between highly efficient functional microorganisms and the reaction medium, resulting in low degradation efficiency, a long fermentation cycle, and the degradation effect still needs improvement. Summary of the Invention

[0005] 1. The technical problem that the invention aims to solve

[0006] In existing technologies for the resource utilization of agricultural organic waste through microbial treatment, the addition of composite degradation agents to the reaction system often results in inefficient reaction transport, leading to low fermentation efficiency and poor stability. This application provides a mineral powder composite electroactive microbial agent. By combining electroactive microorganisms with a porous conductive mineral carrier, this agent acts as an electron transport corridor within the system, effectively enhancing the electron transfer performance between fermenting microorganisms and reactants, ensuring transport rate and effectiveness. This achieves resource utilization of waste tailings while effectively shortening fermentation time and increasing anaerobic gas production.

[0007] 2. Technical Solution

[0008] To achieve the above objectives, the provided technical solution is as follows:

[0009] The mineral powder composite electroactive microbial agent of the present invention, calculated by total mass of 100wt%, comprises 10-20wt% of a microbial mixture and 80-90wt% of conductive mineral powder;

[0010] The bacterial mixture contains metalloretic bacteria, clostridium butyricum, and Shewanella, and the ratio of metalloretic bacteria, clostridium butyricum, and Shewanella is 3-6:1-4:3-5 by mass.

[0011] Preferred,

[0012] (1) The culture conditions for Geobacter metallireducens are as follows:

[0013] Microbial strain and culture medium composition: Metal-reducing Geobacterium strain (0.5–1 wt%, optimal 1 wt%), distilled or deionized water (60–70 wt%, optimal 65 wt%), ferric citrate (10–20 wt%, optimal 15 wt%), tryptone (10–15 wt%, optimal 10 wt%), yeast extract (1–5 wt%, optimal 5 wt%), and sodium chloride (2–5 wt%, optimal 4 wt%).

[0014] (2) The culture conditions for Clostridium butyricum are as follows:

[0015] Inoculum and culture medium composition: Clostridium butyricum strain (0.5–1 wt%, preferably 1 wt%), distilled or deionized water (40–60 wt%, preferably 50 wt%), tryptone (10–20 wt%, preferably 15 wt%), agar powder (10–30 wt%, preferably 20 wt%), yeast extract (1–10 wt%, preferably 6 wt%), soybean peptone (1–5 wt%, preferably 5 wt%), and sodium chloride (1–3 wt%, preferably 3 wt%).

[0016] (3) The culture conditions for Shewanella (Shewanella oneidensis MR-1) are the same as those for Clostridium butyricum.

[0017] Furthermore, the microbial agent comprises 15 wt% of a microbial mixture and 85 wt% of conductive mineral powder;

[0018] The ratio of metalloretinobacillus, butyric acid bacillus, and Shewanella is 4.5:2:4.

[0019] Furthermore, the conductive mineral powder is pyrite or magnetite.

[0020] Furthermore, the particle size of the conductive mineral powder is 100-120 mesh.

[0021] Furthermore, the particle size of the bacterial agent is 1–3 mm.

[0022] The application of mineral powder composite electroactive microbial agents involves applying these agents to the treatment of agricultural organic waste.

[0023] Furthermore, the amount of the microbial agent used is 1 to 3 wt‰ of the amount of agricultural organic waste.

[0024] Preferably, the amount of sludge added is 1 wt% of the agricultural organic waste.

[0025] Furthermore, sludge is also added to the agricultural organic waste.

[0026] Furthermore, the amount of sludge added is 20-30 wt% of the agricultural organic waste.

[0027] Preferably, the amount of sludge added is 20 wt% of the agricultural organic waste.

[0028] Furthermore, the agricultural organic waste refers to livestock and poultry manure, agricultural straw, or fruit peels and residues.

[0029] Preferably, the agricultural organic waste is duck manure.

[0030] 3. Beneficial effects

[0031] Compared with existing known technologies, the technical solution provided by this invention has the following beneficial effects:

[0032] (1) The mineral powder composite electroactive microbial agent of the present invention comprises 10-20 wt% of a microbial mixture and 80-90 wt% of mineral powder; the microbial mixture comprises metallo-reducing bacillus, butyric acid bacillus and Shewanella, and the ratio of metallo-reducing bacillus, butyric acid bacillus and Shewanella by mass is 3-6:1-4:3-5. The agricultural organic waste treatment agent is prepared by composite electroactive microorganisms coupled with porous conductive mineral carrier. In the system, it can act as an electron fast-pass corridor, which can effectively enhance the electron transfer performance between fermentation microorganisms and reactants in the system, ensure the transmission rate and effect, and effectively shorten the fermentation time and increase the anaerobic fermentation gas production while realizing the resource utilization of waste tailings. The composite electroactive microbial strain possesses long and flexible conductive pili, providing channels for electrical contact between microorganisms. Furthermore, the use of pyrite, a material with good conductivity, as a carrier ensures the treatment agent has sufficient specific surface area and conductivity to meet the needs of microbial interaction and electron transfer, promoting the enrichment of functional microorganisms, accelerating the degradation of plastics by organic acids in the system, and thus increasing methane production. This invention features rapid fermentation speed, high gas production, continuous generation, low investment and operating costs, and simple operation throughout the anaerobic fermentation process of organic waste, significantly improving economic efficiency.

[0033] The microorganisms selected were *Geobacterium metalloreticum*, *Clostridium butyricum*, and *Shewanella*. These three bacteria possess good electrochemical activity, long and flexible conductive pili and C-type cytochromes (C-Cyts), providing channels for electrical contact between microorganisms. They also have sufficient conductivity to meet the electron transfer requirements between functional microorganisms. Furthermore, the three bacteria exhibit good symbiotic relationship within the system, effectively reducing acid accumulation and improving gas production efficiency. Simultaneously, conductive mineral powder (such as pyrite) has excellent conductivity; its addition can effectively replace C-Cyts and the conductive pili of the microorganisms as an electron connection device, saving energy for cell movement, enabling long-distance electron transport, accelerating electron transfer, and thus speeding up the reaction rate.

[0034] (2) The application of the mineral powder composite electroactive microbial agent of the present invention, when applied to the treatment of agricultural organic waste, can shorten the anaerobic fermentation time cycle by more than 50% compared with the anaerobic fermentation system of agricultural organic waste without the addition of the treatment agent; effectively improve the methane production of anaerobic fermentation, with an average methane production rate more than twice that of the anaerobic fermentation system without the addition of the treatment agent, which can effectively improve economic benefits. Detailed Implementation

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] The metal-reducing *Geobacterium metalloreticum*, *Clostridium butyricum*, *Shewanella*, and *Geobacterium thioreticum* used in this application were all purchased from Beijing BioBio Biotechnology Co., Ltd., with model numbers ATCC 53774, Bio 58285, ATCC 700550, and ATCC 2815, respectively.

[0037] Example 1

[0038] The mineral powder composite electroactive microbial agent of this embodiment includes: a mixture of microbial strains composed of metal-reducing Gastrobacterium, Clostridium butyricum, and Shewanella, as well as conductive mineral powder.

[0039] The ratio of metal-reducing *Geobacterium metallurgum*, *Clostridium butyricum*, and *Shewanella* by weight is 3:1:3. The treatment agent contains 10 wt% of the bacterial mixture and 90 wt% of the mineral powder.

[0040] The preparation method is as follows:

[0041] (1) Culture of Geobacter metallireducens

[0042] Microbial strain and culture medium composition: Metal-reducing Geobacterium strain (0.5–1 wt%, optimal 1 wt%), distilled or deionized water (60–70 wt%, optimal 65 wt%), ferric citrate (10–20 wt%, optimal 15 wt%), tryptone (10–15 wt%, optimal 10 wt%), yeast extract (1–5 wt%, optimal 5 wt%), and sodium chloride (2–5 wt%, optimal 4 wt%).

[0043] In this embodiment, the above-mentioned bacterial strains and culture medium are mixed according to a total weight ratio of 100wt% (the optimal value), and then anaerobically cultured at 25-35℃ for about 10-12 hours until the logarithmic growth phase before being freeze-dried for later use.

[0044] (2) Cultivation of Clostridium butyricum

[0045] Inoculum and culture medium composition: Clostridium butyricum strain (0.5–1 wt%, preferably 1 wt%), distilled or deionized water (40–60 wt%, preferably 50 wt%), tryptone (10–20 wt%, preferably 15 wt%), agar powder (10–30 wt%, preferably 20 wt%), yeast extract (1–10 wt%, preferably 6 wt%), soybean peptone (1–5 wt%, preferably 5 wt%), and sodium chloride (1–3 wt%, preferably 3 wt%).

[0046] In this embodiment, the above-mentioned bacterial strains and culture medium are mixed according to a total weight ratio of 100wt% (the optimal value), and then kept at 30-35℃ for 18-24 hours until the logarithmic growth phase is reached and then freeze-dried for later use.

[0047] (3) Cultivate Shewanella oneidensis MR-1

[0048] The inoculum size, culture medium composition, and culture conditions are the same as for Clostridium butyricum.

[0049] (4) Mix the above three strains in proportion to obtain a strain mixture.

[0050] (5) Grind the pyrite tailings to obtain mineral powder, and pass it through a 100-120 mesh sieve.

[0051] (6) The bacterial mixture prepared in step 4 is mixed with the mineral powder carrier in step 5 in a mass ratio of 10wt% to 90wt% using a bio-adhesive to prepare a mineral powder composite electroactive microbial agent with a particle size of 1-3mm.

[0052] The microbial agent prepared in this embodiment is used in the treatment of agricultural organic waste:

[0053] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from the agricultural farm. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 35.26 L / kg, the gas production efficiency increased by 48.52%, and the fermentation cycle was shortened from 58 days to 40 days.

[0054] Example 2

[0055] The mineral powder composite electroactive microbial agent in this embodiment is basically the same as in Example 1, except for the ratio of raw materials:

[0056] It contains a mixture of microorganisms consisting of metal-reducing Gastrobacterium, Clostridium butyricum, and Shewanella, as well as mineral powder.

[0057] The ratio of metal-reducing *Geobacterium metallurgum*, *Clostridium butyricum*, and *Shewanella* by weight is 6:4:5. The bacterial mixture comprises 20 wt% of the inoculum and 80 wt% of the mineral powder.

[0058] The preparation method is as follows:

[0059] (1) Culture of Geobacter metallireducens

[0060] Microbial strain and culture medium composition: Metal-reducing Geobacterium strain (0.5–1 wt%, optimal 1 wt%), distilled or deionized water (60–70 wt%, optimal 65 wt%), ferric citrate (10–20 wt%, optimal 15 wt%), tryptone (10–15 wt%, optimal 10 wt%), yeast extract (1–5 wt%, optimal 5 wt%), and sodium chloride (2–5 wt%, optimal 4 wt%).

[0061] In this embodiment, the above-mentioned bacterial strains and culture medium are mixed according to a total weight ratio of 100wt% (the optimal value), and then anaerobically cultured at 25-35℃ for about 10-12 hours until the logarithmic growth phase before being freeze-dried for later use.

[0062] (2) Cultivation of Clostridium butyricum

[0063] Inoculum and culture medium composition: Clostridium butyricum strain (0.5–1 wt%, preferably 1 wt%), distilled or deionized water (40–60 wt%, preferably 50 wt%), tryptone (10–20 wt%, preferably 15 wt%), agar powder (10–30 wt%, preferably 20 wt%), yeast extract (1–10 wt%, preferably 6 wt%), soybean peptone (1–5 wt%, preferably 5 wt%), and sodium chloride (1–3 wt%, preferably 3 wt%).

[0064] In this embodiment, the above-mentioned bacterial strains and culture medium are mixed according to a total weight ratio of 100wt% (the optimal value), and then kept at 30-35℃ for 18-24 hours until the logarithmic growth phase is reached and then freeze-dried for later use.

[0065] (3) Cultivate Shewanella oneidensis MR-1

[0066] The inoculum size, culture medium composition, and culture conditions are the same as for Clostridium butyricum.

[0067] (4) Mix the above three strains in proportion to obtain a strain mixture.

[0068] (5) Grind the pyrite tailings to obtain mineral powder, and pass it through a 100-120 mesh sieve.

[0069] (6) The bacterial mixture prepared in step 4 is mixed with the mineral powder carrier in step 5 in a mass ratio of 20wt% to 80wt% using a bio-adhesive to prepare a mineral powder composite electroactive microbial agent with a particle size of 1-3mm.

[0070] The microbial agent prepared in this embodiment is used in the treatment of agricultural organic waste:

[0071] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from the agricultural farm. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 39.87 L / kg, the gas production efficiency increased by 54.47%, and the fermentation cycle was shortened from 58 days to 35 days.

[0072] Example 3

[0073] The mineral powder composite electroactive microbial agent in this embodiment is basically the same as in Example 1, except for the ratio of raw materials:

[0074] It contains a mixture of microorganisms consisting of metal-reducing Gastrobacterium, Clostridium butyricum, and Shewanella, as well as mineral powder.

[0075] The ratio of metal-reducing *Geobacterium*, *Clostridium butyricum*, and *Shewanella* by weight is 4.5:2:4. The bacterial mixture comprises 15 wt% of the inoculum and 85 wt% of the mineral powder.

[0076] The preparation method is as follows:

[0077] (1) Culture of Geobacter metallireducens

[0078] Microbial strain and culture medium composition: Metal-reducing Geobacterium strain (0.5–1 wt%, optimal 1 wt%), distilled or deionized water (60–70 wt%, optimal 65 wt%), ferric citrate (10–20 wt%, optimal 15 wt%), tryptone (10–15 wt%, optimal 10 wt%), yeast extract (1–5 wt%, optimal 5 wt%), and sodium chloride (2–5 wt%, optimal 4 wt%).

[0079] In this embodiment, the above-mentioned bacterial strains and culture medium are mixed according to a total weight ratio of 100wt% (the optimal value), and then anaerobically cultured at 25-35℃ for about 10-12 hours until the logarithmic growth phase before being freeze-dried for later use.

[0080] (2) Cultivation of Clostridium butyricum

[0081] Inoculum and culture medium composition: Clostridium butyricum strain (0.5–1 wt%, preferably 1 wt%), distilled or deionized water (40–60 wt%, preferably 50 wt%), tryptone (10–20 wt%, preferably 15 wt%), agar powder (10–30 wt%, preferably 20 wt%), yeast extract (1–10 wt%, preferably 6 wt%), soybean peptone (1–5 wt%, preferably 5 wt%), and sodium chloride (1–3 wt%, preferably 3 wt%).

[0082] In this embodiment, the above-mentioned bacterial strains and culture medium are mixed according to a total weight ratio of 100wt% (the optimal value), and then kept at 30-35℃ for 18-24 hours until the logarithmic growth phase is reached and then freeze-dried for later use.

[0083] (3) Cultivate Shewanella oneidensis MR-1

[0084] The inoculum size, culture medium composition, and culture conditions are the same as for Clostridium butyricum.

[0085] (4) Mix the above three strains in proportion to obtain a strain mixture.

[0086] (5) Grind the pyrite tailings to obtain mineral powder, and pass it through a 100-120 mesh sieve.

[0087] (6) The bacterial mixture prepared in step 4 is mixed with the mineral powder carrier in step 5 in a mass ratio of 15wt% to 85wt% using a bio-adhesive to prepare a mineral powder composite electroactive microbial agent with a particle size of 1-3mm.

[0088] The microbial agent prepared in this embodiment is used in the treatment of agricultural organic waste:

[0089] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from the agricultural farm. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 43.12 L / kg, the gas production efficiency increased by 57.9%, and the fermentation cycle was shortened from 58 days to 27 days.

[0090] Example 4

[0091] The mineral powder composite electroactive microbial agent in this embodiment is basically the same as in embodiment 3, except for the type of mineral. In this embodiment, the mineral is magnetite.

[0092] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 37.42 L / kg, the gas production efficiency increased by 51.49%, and the fermentation cycle was shortened from 58 days to 44 days.

[0093] Comparative Example 1

[0094] The microbial agent in this comparative example is basically the same as in Example 3, except that the microbial agent does not contain minerals.

[0095] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 32.44 L / kg, the gas production efficiency increased by 44.05%, and the fermentation cycle was shortened from 58 days to 49 days.

[0096] Comparative Example 2

[0097] The bacterial agent in this comparative example is basically the same as in Example 3, except for the ratio of the bacterial species in the bacterial mixture. In this example, the ratio of metallo-reducing bacillus, clostridium butyricum, and Shewanella is 2:5:6.

[0098] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 32.25 L / kg, the gas production efficiency increased by 43.72%, and the fermentation cycle was shortened from 58 days to 47 days.

[0099] Comparative Example 3

[0100] The bacterial agent in this comparative example is basically the same as in Example 3, except that the types of bacteria in the bacterial mixture are different. This example does not contain metal-reducing Geobacterium.

[0101] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 28.09 L / kg, the gas production efficiency increased by 35.38%, and the fermentation cycle was shortened from 58 days to 50 days.

[0102] Comparative Example 4

[0103] The bacterial agent in this comparative example is basically the same as in Example 3, except that the types of bacteria in the bacterial mixture are different. This example does not contain Clostridium butyricum.

[0104] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 30.12 L / kg, the gas production efficiency increased by 39.74%, and the fermentation cycle was shortened from 58 days to 47 days.

[0105] Comparative Example 5

[0106] The bacterial agent in this comparative example is basically the same as in Example 3, except that the types of bacteria in the bacterial mixture are different. This example does not contain Shewanella.

[0107] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from the agricultural farm. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 27.69 L / kg, the gas production efficiency increased by 34.45%, and the fermentation cycle was shortened from 58 days to 51 days.

[0108] Comparative Example 6

[0109] The microbial agent in this comparative example is basically the same as in Example 3, except that the microbial mixture accounts for 40 wt% and the mineral powder accounts for 60 wt%.

[0110] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from the agricultural farm. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 25.69 L / kg, the gas production efficiency increased by 29.34%, and the fermentation cycle was shortened from 58 days to 49 days.

[0111] Comparative Example 7

[0112] The bacterial agent in this comparative example is basically the same as in Example 3, except that Geobacter metallireducens is replaced with Geobacter sulfurreducens.

[0113] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 28.47 L / kg, the gas production efficiency increased by 36.24%, and the fermentation cycle was shortened from 58 days to 46 days.

[0114] Example 8

[0115] The bacterial agent in this comparative example is basically the same as in Example 3, except that the mineral powder is zeolite, which is almost non-conductive.

[0116] The prepared microbial agent was added to the anaerobic fermenter at a ratio of 1 / 1000 to the mass of duck manure waste from agricultural farms. The total raw material was 1 ton of duck manure, 1 kg of the prepared treatment agent was added, the reaction temperature was 35℃, and 200 kg of sludge was inoculated. Compared with the system without the treatment agent, the gas production rate increased from 18.15 L / kg to 32.87 L / kg, the gas production efficiency increased by 44.78%, and the fermentation cycle was shortened from 58 days to 48 days.

Claims

1. A mineral powder composite electroactive microbial agent, characterized in that: Based on a total mass of 100 wt%, the bacterial agent comprises 15 wt% of a bacterial strain mixture and 85 wt% of conductive mineral powder; the bacterial strain mixture contains metal-reducing *Geobacterium* (…). Geobacter metallireducens Clostridium butyricum ( Clostridium butyricum ) and Shewanella ( Shewanella oneidensis ), calculated by mass parts, the metal-reducing Geobacterium ( Geobacter metallireducens Clostridium butyricum ( Clostridium butyricum ) and Shewanella ( Shewanella oneidensis The ratio of the conductive mineral powder to the conductive mineral powder is 4.5:2:4; the conductive mineral powder is pyrite, and the particle size of the conductive mineral powder is 100-120 mesh; the particle size of the bacterial agent is 1-3 mm.

2. The application of a mineral powder composite electroactive microbial agent, characterized in that: The microbial agent according to claim 1 is applied to the treatment of agricultural organic waste.

3. The application of the mineral powder composite electroactive microbial agent according to claim 2, characterized in that: The amount of the microbial agent used is 1 to 3 wt‰ of the amount of agricultural organic waste.

4. The application of the mineral powder composite electroactive microbial agent according to claim 3, characterized in that: Sludge is also added to the agricultural organic waste.

5. The application of the mineral powder composite electroactive microbial agent according to claim 4, characterized in that: The amount of sludge added is 20-30 wt% of the agricultural organic waste.

6. The application of a mineral powder composite electroactive microbial agent according to any one of claims 2-5, characterized in that: The agricultural organic waste refers to livestock and poultry manure, agricultural straw, or fruit peels and residues.