Highly humified carbon material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of microbial carrier preparation, and particularly relates to a highly humified carbon material as well as a preparation method and application thereof. The invention provides a preparation method of a highly humified carbon material, which comprises the following steps: mixing straws with a back-mixed solution, carrying out hydrothermal reaction to obtain the highly humified carbon material, and specifically limiting the mass ratio of the straws to the back-mixed solution and the hydrothermal reaction conditions. Straw is selected as a carrier to prepare a raw material, a back-mixed solution is adopted to assist a hydrothermal carbonization technology, the hydrothermal humification degree of the straw is enhanced, sterilization is synchronously achieved, and the high-humification carbon-based material is obtained. The obtained highly humified carbon-based material has the characteristics of good pore structure, high specific surface area, good water holding capacity, high humic acid content, environmental friendliness and the like, and has wide application prospects in the fields of agricultural production and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial carrier preparation, and specifically relates to a high-humification carbon material and a preparation method and application thereof. Background Art

[0002] Microbial fertilizer is based on a carrier and is prepared by using the specific functions of microorganisms. Microbial fertilizer can improve fertilizer utilization, improve the quality of agricultural products, increase yields, and improve the physical and chemical properties of soil, and has gradually become a research hotspot. However, in actual applications, microbial fertilizers have problems such as poor stability, low survival rate, difficulty in preservation, and great environmental impact, which are closely related to the microbial carrier used.

[0003] The ideal carrier should have a large number of orderly arranged micropores, with characteristics such as large specific surface area and strong adsorption capacity. At the same time, the carrier must be conducive to the survival and function of the bacteria, can be produced repeatedly and stably, and be non-toxic and harmless to crops and soil. However, the existing technology for preparing microbial carriers is mostly used for sewage treatment, and the technology has high energy consumption, which increases the cost of the product. At present, how to improve the microbial loading capacity of the carrier and improve the field planting effect is an urgent problem to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a high-humification carbon material and a preparation method and application thereof. The high-humification carbon material prepared by the method of the present invention has a large specific surface area, a stable structure, a strong water holding capacity and a high humic acid content.

[0005] The present invention provides a method for preparing a high-humification carbon material, comprising the following steps: mixing straw with a back-mixing solution, and performing a hydrothermal reaction to obtain a high-humification carbon material;

[0006] The mass ratio of the straw to the back-mixed solution is 1:2-5;

[0007] The temperature of the hydrothermal reaction is 180-240° C.; the time of the hydrothermal reaction is 1-3 hours;

[0008] The back-mixed solution includes a humic precursor auxiliary agent and deionized water; the mass ratio of the humic precursor auxiliary agent to the deionized water is 3:7 to 6:4;

[0009] The humification precursor auxiliary agent includes fermentation liquid of poultry and livestock manure.

[0010] As a preferred embodiment, the straw includes at least one of wheat straw, corn straw, rice straw and soybean straw.

[0011] As a preferred solution, before mixing the straw with the back-mixing solution, the method further comprises: pulverizing the straw to obtain pulverized straw; the particle size of the pulverized straw is 1 to 3 mm.

[0012] As a preferred embodiment, after the hydrothermal reaction is completed, the method further comprises: performing solid-liquid separation on the reaction product of the hydrothermal reaction to collect solid matter; and washing and drying the solid matter.

[0013] As a preferred solution, the EC value of the washed solid material is less than 4 mS / cm.

[0014] As a preferred embodiment, the pH of the washed solid matter is 6.8-7.2.

[0015] As a preferred solution, the water content of the dried solid material is less than 1.0%.

[0016] The present invention also provides a highly humified carbon material prepared by the preparation method described in the above scheme, wherein the specific surface area of ​​the highly humified carbon material is 1.606 to 7.406 m 2 / g, the average pore size is 15.763~25.054nm, and the humic acid content is 32.07%~42.22%.

[0017] The present invention also provides the highly humified carbon material prepared by the preparation method described in the above scheme or the use of the highly humified carbon material described in the above scheme as a microbial carrier.

[0018] The present invention also provides a microbial fertilizer, comprising the high-humification carbon material described in the above scheme and a microbial agent loaded on the high-humification carbon material.

[0019] Beneficial effects:

[0020] The present invention provides a method for preparing a highly humified carbon material, comprising the following steps: mixing straw with a back-mixed solution, performing a hydrothermal reaction, and obtaining a highly humified carbon material; the mass ratio of the straw to the back-mixed solution is 1:2-5; the temperature of the hydrothermal reaction is 180-240°C; the time of the hydrothermal reaction is 1-3h; the back-mixed solution comprises a humification precursor auxiliary agent and deionized water; the mass ratio of the humification precursor auxiliary agent to the deionized water is 3:7-6:4; the humification precursor auxiliary agent comprises a fermentation liquid of poultry and livestock manure. The present invention selects straw as a carrier to prepare raw materials, adopts a back-mixed solution-assisted hydrothermal carbonization technology, enhances the hydrothermal humification degree of the straw, and simultaneously achieves sterilization to obtain a highly humified carbon-based material. The highly humified carbon-based material prepared by the method of the present invention has a specific surface area of ​​1.606-7.406m 2 / g, and the average pore volume is between 0.980 and 0.983 cm 3 / g, the average pore size is between 15.763 and 25.054nm, the moisture content is less than 1.0%, the salt content is less than 4mS / cm, the humic acid content is between 32.07% and 42.22%. It has the characteristics of good pore structure, high specific surface area, good water holding capacity, high humic acid content and environmental friendliness, and has broad application prospects in agricultural production and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0022] Figure 1 The humic acid content of the highly humified carbon materials of Examples 1 to 16 is shown in Figure 1, where different lowercase letters represent data with significant differences, p < 0.05;

[0023] Figure 2 The SEM electron microscope images of the highly humified carbon materials of Examples 1 to 4;

[0024] Figure 3 The SEM electron microscope images of the highly humified carbon materials of Examples 5 to 8;

[0025] Figure 4 The SEM electron microscope images of the highly humified carbon materials of Examples 9 to 12;

[0026] Figure 5 The SEM electron microscope images of the highly humified carbon materials of Examples 13 to 16;

[0027] Figure 6 This is a functional group type analysis diagram of highly humified carbon materials of Examples 1 to 16;

[0028] Figure 7 The SEM electron microscope images of the highly humified carbon materials of Examples 17 to 20;

[0029] Figure 8 The experimental diagram of aseptic soil cultivation of different high humified carbon materials in Application Example 3, wherein A is the blank treatment group CKS; B is the wheat straw humified treatment group WHS; C is the corn straw humified treatment group MHS; D is the rice straw humified treatment group RHS;

[0030] Fig. 9 Schematic diagram of microbial fertilizer. DETAILED DESCRIPTION

[0031] The present invention provides a method for preparing a high-humification carbon material, comprising the following steps: mixing straw with a back-mixing solution, and performing a hydrothermal reaction to obtain a high-humification carbon material;

[0032] The mass ratio of the straw to the back-mixed solution is 1:2-5;

[0033] The temperature of the hydrothermal reaction is 180-240° C.; the time of the hydrothermal reaction is 1-3 hours;

[0034] The back-mixed solution includes a humic precursor auxiliary agent and deionized water; the mass ratio of the humic precursor auxiliary agent to the deionized water is 3:7 to 6:4;

[0035] The humification precursor auxiliary agent includes fermentation liquid of poultry and livestock manure.

[0036] The present invention pulverizes the straw to obtain pulverized straw; as an embodiment, the straw includes at least one of wheat straw, corn straw, rice straw and soybean straw. In a specific embodiment of the present invention, when the straw includes wheat straw, corn straw and rice straw, the mass ratio of the wheat straw, corn straw and rice straw is 1:1 to 2:1, for example, 1:1:1 or 1:2:1. As an embodiment, the particle size of the pulverized straw is 1 to 3 mm. In a specific embodiment of the present invention, the particle size of the pulverized straw can be 1 mm, 2 mm or 3 mm.

[0037] As an embodiment, the present invention mixes a humification precursor aid and deionized water to obtain a back-mixed solution. As an embodiment, the mass ratio of the humification precursor aid and the deionized water is 3:7 to 6:4. In a specific embodiment of the present invention, the mass ratio of the humification precursor aid and the deionized water can be 3:7, 4:6, 5:5 or 5:4. As an embodiment, the humification precursor aid includes a fermentation liquid of livestock manure. As an embodiment, the livestock manure includes at least one of chicken manure, cow manure and pig manure; as an embodiment, the preparation of the humification precursor aid includes: fermenting the livestock manure under aerobic or anaerobic conditions for 30 to 45 days, filtering to obtain an extract as a humification precursor aid; the water content is maintained at 60% to 90% during the fermentation.

[0038] The crushed straw is obtained, and the present invention mixes the crushed straw with a back-mixing solution to obtain a mixture. As an embodiment, the mass ratio of the straw to the back-mixing solution of the present invention is 1:2-5. In a specific embodiment of the present invention, the mass ratio of the straw to the back-mixing solution can be 1:2, 1:3, 1:4 or 1:5. The back-mixing solution of the present invention provides nutrients that are easier to decompose for the hydrothermal reaction, and combines with polymers such as cellulose and lignin obtained by decomposing the straw during the reaction process, promotes the formation of valence bonds, enhances the humification degree of the straw during the hydrothermal humification process, promotes the formation of a porous structure, and is beneficial to the reconstruction of the functional groups on the surface of the carrier, thereby increasing the nutrient content of the carrier.

[0039] After obtaining the mixture, the mixture is subjected to a hydrothermal reaction to obtain a reaction product of the hydrothermal reaction. As an embodiment, the temperature of the hydrothermal reaction is 180 to 240°C; the time of the hydrothermal reaction is 1 to 3 hours. As an embodiment, the pressure of the hydrothermal reaction of the present invention is 2 to 6 Pa. In a specific embodiment of the present invention, the temperature of the hydrothermal reaction can be 180°C, 200°C, 220°C or 240°C; the time of the hydrothermal reaction can be 1h, 1.5h, 2h or 3h. The present invention limits the conditions of the hydrothermal reaction. Under this reaction condition, the surface layer and internal wood and fiber structure of the straw are decomposed to a certain extent, so that the porous structure inside the straw is exposed, which promotes the accelerated decomposition of the straw, and forms a rich porous structure and more nutrients that are easily absorbed.

[0040] After obtaining the reaction product of the hydrothermal reaction, the method further includes: performing solid-liquid separation on the reaction product of the hydrothermal reaction to collect solid matter; washing the solid matter to obtain washed solid matter. As an embodiment, the washing of the present invention includes: washing the solid matter with deionized water; as an embodiment, the EC value of the washed solid matter is less than 4mS / cm; as an embodiment, the pH of the washed solid matter is 6.8 to 7.2. The present invention limits the EC value and pH value of the washed solid matter to meet the requirements for the subsequent preparation of microbial fertilizers.

[0041] The washed solid matter is obtained, and the present invention dries the washed solid matter to obtain a highly humified carbon material. As an embodiment, the drying temperature of the present invention is 60 to 70° C. In a specific embodiment of the present invention, the drying temperature can be any temperature value between 60 and 70° C. As an embodiment, the water content of the highly humified carbon material, i.e. the dried solid matter, is less than 1.0%.

[0042] The present invention provides a highly humified carbon material prepared by the preparation method described in the above scheme, wherein the specific surface area of ​​the highly humified carbon material is 1.606 to 7.406 m 2 / g, an average pore size of 15.763-25.054 nm, and a humic acid content of 32.07%-42.22%. As an embodiment, the average pore volume of the highly humified carbon material is 0.980-0.983 cm 3 / g, moisture content <1.0%, salt content <4mS / cm, pH 6.8-7.2. The high humification carbon material of the present invention has good pore structure, high specific surface area, good water holding capacity, high humic acid content and environmentally friendly characteristics, which is comparable to the specific surface area of ​​1.300m of peat, an ideal carrier for microorganisms. 2 / g and an average pore size of 7.64nm, which is more conducive to microbial colonization and nutrient adsorption.

[0043] The present invention also provides a highly humified carbon material prepared by the preparation method described in the above scheme or the use of the highly humified carbon material described in the above scheme as a microbial carrier. The highly humified carbon material described in the present invention has good pore bonding, high specific surface area and humic acid content, and can be used as a microbial carrier.

[0044] The present invention also provides a microbial fertilizer, including the high-humification carbon material described in the above scheme and the microbial agent loaded on the high-humification carbon material. As an embodiment, the preparation of the microbial fertilizer of the present invention includes: mixing the high-humification carbon material and the microbial agent. The present invention does not limit the type of the microbial agent, and does not limit the mixing method. In a specific embodiment of the present invention, the microbial fertilizer (such as Fig. 9 shown).

[0045] In order to further illustrate the present invention, a highly humified carbon material provided by the present invention and its preparation method and application are described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0046] The corn straw, wheat straw, rice straw and livestock manure used in the embodiments and comparative examples of the present invention are all derived from the same batch of raw materials.

[0047] Example 1

[0048] (1) Preparation of humus precursor aid: Keep the water content of livestock and poultry manure (cow manure and pig manure) at 60% to 70%, aerobically ferment for 30 to 45 days, and use the extract from the pile as the humus precursor aid.

[0049] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 3:7 to obtain a back-mixed solution.

[0050] (3) Straw crushing: Dry wheat straw is taken as raw material and crushed to a particle size of 1 mm to obtain crushed wheat straw.

[0051] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:2 and mixed. The reaction conditions were 180° C. for 1 h, during which the pressure was controlled at 2 to 6 Pa.

[0052] (5) Washing: The solid matter after the hydrothermal reaction in step (4) is washed with deionized water until the salt content of the leaching solution after washing is less than 4 mS / cm.

[0053] (6) Drying: Drying the solid matter washed in step (5) at 60-70° C. until the water content is less than 1.0%, thereby obtaining a highly humified carbon material.

[0054] Example 2

[0055] A method for preparing a highly humified carbon material similar to that of Example 1 is as follows:

[0056] (1) Prepare a humic precursor adjuvant according to step (1) of Example 1.

[0057] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water are mixed in a mass ratio of 4:6 to obtain a back-mixed solution.

[0058] (3) Prepare crushed straw according to step (3) of Example 1.

[0059] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:3 and mixed. The reaction conditions were 200° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0060] (5) Proceed according to step (5) of Example 1.

[0061] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0062] Example 3

[0063] A method for preparing a highly humified carbon material similar to that of Example 1 is as follows:

[0064] (1) Prepare a humic precursor adjuvant according to step (1) of Example 1.

[0065] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water are mixed in a mass ratio of 1:1 to obtain a back-mixed solution.

[0066] (3) Prepare crushed straw according to step (3) of Example 1.

[0067] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:4 and mixed. The reaction conditions were 220° C. for 2 h, during which the pressure was controlled at 2 to 6 Pa.

[0068] (5) Proceed according to step (5) of Example 1.

[0069] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0070] Example 4

[0071] A method for preparing a highly humified carbon material similar to that of Example 1 is as follows:

[0072] (1) Prepare a humic precursor adjuvant according to step (1) of Example 1.

[0073] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water were mixed in a mass ratio of 6:4 to obtain a back-mixed solution.

[0074] (3) Prepare crushed straw according to step (3) of Example 1.

[0075] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:5 and mixed. The reaction conditions were 240° C. for 3 h, during which the pressure was controlled at 2 to 6 Pa.

[0076] (5) Proceed according to step (5) of Example 1.

[0077] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0078] Example 5

[0079] A method for preparing a highly humified carbon material similar to that of Example 1 is as follows:

[0080] (1) Prepare a humic precursor adjuvant according to step (1) of Example 1.

[0081] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water were mixed in a mass ratio of 6:4 to obtain a back-mixed solution.

[0082] (3) Corn stalk crushing: Dry corn stalks were taken as raw materials and crushed to a particle size of 1 mm to obtain crushed corn stalks.

[0083] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:4 and mixed. The reaction conditions were 180° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0084] (5) Proceed according to step (5) of Example 1.

[0085] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0086] Example 6

[0087] A method for preparing a highly humified carbon material similar to that of Example 5 is as follows:

[0088] (1) Prepare a humic precursor adjuvant according to step (1) of Example 5.

[0089] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water are mixed in a mass ratio of 1:1 to obtain a back-mixed solution.

[0090] (3) Prepare pulverized straw according to step (3) of Example 5.

[0091] (4) The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) are placed in a reaction kettle at a mass ratio of 1:5 and mixed. The reaction conditions are 200° C. for 1 hour, during which the pressure is controlled to be 2 to 6 Pa.

[0092] (5) Proceed according to step (5) of Example 5.

[0093] (6) Carry out the operation according to step (6) of Example 5 to obtain a highly humified carbon material.

[0094] Example 7

[0095] A method for preparing a highly humified carbon material similar to that of Example 5 is as follows:

[0096] (1) Prepare a humic precursor adjuvant according to step (1) of Example 5.

[0097] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water are mixed in a mass ratio of 4:6 to obtain a back-mixed solution.

[0098] (3) Prepare pulverized straw according to step (3) of Example 5.

[0099] (4) The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:2 and mixed. The reaction conditions were 220° C. for 3 h, during which the pressure was controlled at 2 to 6 Pa.

[0100] (5) Proceed according to step (5) of Example 5.

[0101] (6) Carry out the operation according to step (6) of Example 5 to obtain a highly humified carbon material.

[0102] Example 8

[0103] A method for preparing a highly humified carbon material similar to that of Example 5 is as follows:

[0104] (1) Prepare a humic precursor adjuvant according to step (1) of Example 5.

[0105] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water are mixed in a mass ratio of 3:7 to obtain a back-mixed solution.

[0106] (3) Prepare pulverized straw according to step (3) of Example 5.

[0107] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:3 and mixed. The reaction conditions were 240° C. for 2 h, during which the pressure was controlled at 2 to 6 Pa.

[0108] (5) Proceed according to step (5) of Example 5.

[0109] (6) Carry out the operation according to step (6) of Example 5 to obtain a highly humified carbon material.

[0110] Example 9

[0111] A method for preparing a highly humified carbon material similar to that of Example 1 is as follows:

[0112] (1) Prepare a humic precursor adjuvant according to step (1) of Example 1.

[0113] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 4:6 to obtain a back-mixed solution.

[0114] (3) Rice straw crushing: Dry rice straw is taken as raw material and crushed to a particle size of 1 mm to obtain crushed rice straw.

[0115] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:5 and mixed. The reaction conditions were 180° C. for 2 h, during which the pressure was controlled at 2 to 6 Pa.

[0116] (5) Proceed according to step (5) of Example 1.

[0117] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0118] Example 10

[0119] A method for preparing a highly humified carbon material similar to that of Example 9 is as follows:

[0120] (1) Prepare a humic precursor adjuvant according to step (1) of Example 9.

[0121] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 3:7 to obtain a back-mixed solution.

[0122] (3) Prepare pulverized straw according to step (3) of Example 9.

[0123] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:4 and mixed. The reaction conditions were 200° C. for 3 h, during which the pressure was controlled at 2 to 6 Pa.

[0124] (5) Proceed according to step (5) of Example 9.

[0125] (6) Follow step (6) of Example 9 to obtain a highly humified carbon material.

[0126] Embodiment 11

[0127] A method for preparing a highly humified carbon material similar to that of Example 9 is as follows:

[0128] (1) Prepare a humic precursor adjuvant according to step (1) of Example 9.

[0129] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 6:4 to obtain a back-mixed solution.

[0130] (3) Prepare pulverized straw according to step (3) of Example 9.

[0131] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:3 and mixed. The reaction conditions were 220° C. for 1 h, during which the pressure was controlled at 2 to 6 Pa.

[0132] (5) Proceed according to step (5) of Example 9.

[0133] (6) Follow step (6) of Example 9 to obtain a highly humified carbon material.

[0134] Example 12

[0135] A method for preparing a highly humified carbon material similar to that of Example 9 is as follows:

[0136] (1) Prepare a humic precursor adjuvant according to step (1) of Example 9.

[0137] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 1:1 to obtain a back-mixed solution.

[0138] (3) Prepare pulverized straw according to step (3) of Example 9.

[0139] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:2 and mixed. The reaction conditions were 240° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0140] (5) Proceed according to step (5) of Example 9.

[0141] (6) Follow step (6) of Example 9 to obtain a highly humified carbon material.

[0142] Embodiment 13

[0143] A method for preparing a highly humified carbon material similar to that of Example 1 is as follows:

[0144] (1) Prepare a humic precursor adjuvant according to step (1) of Example 1.

[0145] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 1:1 to obtain a back-mixed solution.

[0146] (3) Straw crushing: dry wheat, corn and rice straw are taken as raw materials, and crushed to a particle size of 1 mm to obtain wheat crushed straw, corn crushed straw and rice crushed straw, and the wheat crushed straw, corn crushed straw and rice crushed straw are mixed in a mass ratio of 1:1:1 to obtain a mixed straw raw material.

[0147] (4) Hydrothermal reaction: The mixed straw raw material prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:3 and mixed. The reaction conditions were 180° C. for 3 h, during which the pressure was controlled at 2 to 6 Pa.

[0148] (5) Proceed according to step (5) of Example 1.

[0149] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0150] Embodiment 14

[0151] A method for preparing a highly humified carbon material similar to that of Example 13 is as follows:

[0152] (1) Prepare a humic precursor adjuvant according to step (1) of Example 13.

[0153] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 6:4 to obtain a back-mixed solution.

[0154] (3) Prepare crushed straw according to step (3) of Example 13.

[0155] (4) Hydrothermal reaction: the mixed straw raw material prepared in step (3) and the back-mixed solution prepared in step (2) are placed in a reaction kettle at a mass ratio of 1:2 and mixed. The reaction conditions are 200° C. for 2 h, during which the pressure is controlled at 2 to 6 Pa.

[0156] (5) Proceed according to step (5) of Example 13.

[0157] (6) Follow the steps (6) of Example 13 to obtain a highly humified carbon material.

[0158] Embodiment 15

[0159] A method for preparing a highly humified carbon material similar to that of Example 13 is as follows:

[0160] (1) Prepare a humic precursor adjuvant according to step (1) of Example 13.

[0161] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 3:7 to obtain a back-mixed solution.

[0162] (3) Prepare crushed straw according to step (3) of Example 13.

[0163] (4) Hydrothermal reaction: The mixed straw raw material prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:5 and mixed. The reaction conditions were 220° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0164] (5) Proceed according to step (5) of Example 13.

[0165] (6) Follow the steps (6) of Example 13 to obtain a highly humified carbon material.

[0166] Example 16

[0167] A method for preparing a highly humified carbon material similar to that of Example 13 is as follows:

[0168] (1) Prepare a humic precursor adjuvant according to step (1) of Example 13.

[0169] (2) Preparation of back-mixed solution: The humic precursor additive prepared in step (1) is mixed with deionized water in a mass ratio of 4:6 to obtain a back-mixed solution.

[0170] (3) Prepare crushed straw according to step (3) of Example 13.

[0171] (4) Hydrothermal reaction: The mixed straw raw material prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:4 and mixed. The reaction conditions were 240° C. for 1 h, during which the pressure was controlled at 2 to 6 Pa.

[0172] (5) Proceed according to step (5) of Example 13.

[0173] (6) Follow the steps (6) of Example 13 to obtain a highly humified carbon material.

[0174] Comparative Example 1

[0175] (1) Corn stalk crushing: Dry corn stalks were taken as raw materials and crushed to a particle size of 1 mm to obtain crushed corn stalks.

[0176] (2) Hydrothermal reaction: The pulverized straw prepared in step (1) and deionized water were placed in a reaction kettle at a mass ratio of 1:4 and mixed. The reaction conditions were 180° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0177] (3) Washing: The solid matter after the hydrothermal reaction in step (2) is washed with deionized water until the salt content of the leaching solution after washing is less than 4 mS / cm.

[0178] (4) Drying: Drying the solid matter washed in step (3) at 60-70° C. until the water content is less than 30%, thereby obtaining a highly humified carbon material.

[0179] Comparative Example 2

[0180] A method for preparing a highly humified carbon material similar to that of Example 5 is as follows:

[0181] (1) Prepare a humic precursor adjuvant according to step (1) of Example 5.

[0182] (2) Prepare the back-mixing solution according to step (2) of Example 5.

[0183] (3) Prepare pulverized straw according to step (3) of Example 5.

[0184] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:1 and mixed. The reaction conditions were 180° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0185] (5) Proceed according to step (5) of Example 5.

[0186] (6) Carry out the operation according to step (6) of Example 5 to obtain a highly humified carbon material.

[0187] Comparative Example 3

[0188] A method for preparing a highly humified carbon material similar to that of Example 5 is as follows:

[0189] (1) Prepare a humic precursor adjuvant according to step (1) of Example 5.

[0190] (2) Prepare the back-mixing solution according to step (2) of Example 5.

[0191] (3) Prepare pulverized straw according to step (3) of Example 5.

[0192] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:8 and mixed. The reaction conditions were 180° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0193] (5) Proceed according to step (5) of Example 5.

[0194] (6) Carry out the operation according to step (6) of Example 5 to obtain a highly humified carbon material.

[0195] Application Example 1

[0196] The raw material type, reaction temperature, reaction time, mass ratio of straw to back-mixed solution (liquid-to-solid ratio) and back-mixed solution concentration (back-mixed solution ratio, mass percentage of humic precursor adjuvant in back-mixed solution) of Examples 1 to 16 were used as factors (see Table 1), and range and variance analysis was performed on the humic acid content. The analysis results are shown in Tables 2 and 3.

[0197] Table 1 Preparation factors and levels of highly humified carbon materials

[0198]

[0199] Table 2 Range analysis of humic acid content of different highly humified carbon materials

[0200]

[0201] Table 3 Variance analysis of humic acid content of different highly humified carbon materials

[0202]

[0203]

[0204] According to the results in Table 2, the influence of the five influencing factors is as follows: reaction temperature > back-mixing solution ratio > straw type > residence time > liquid-solid ratio. Optimum level: 180°C, back-mixing solution 60%, corn straw, 1.5h, solid-liquid ratio 3. In addition, the results in Table 3 show that, except for the solid-liquid ratio, there are significant differences between the different levels of other factors. Therefore, among Examples 1 to 16, the humic acid content of the high-humification carbon material prepared in Example 5 is the highest.

[0205] Application Example 2

[0206] (1) Determination of EC value of highly humified carbon materials

[0207] The EC values ​​of the highly humified carbon materials prepared in Examples 1 to 16 were tested respectively. The method for testing the EC value was carried out with reference to HJ 802-2016 and the literature [“Physical and chemical properties and microstructural changes of tomato straw hydrothermal biochar under different reaction conditions, Huang Jiaqing et al., Henan Agricultural Sciences, 2023”]. During the test process described in this application example, the solid-liquid ratio was set to 1:50, and the test results are shown in Table 4.

[0208] Table 4 EC values ​​of highly humified carbon materials of Examples 1 to 16

[0209] Example EC(μS / cm) Standard Deviation 1 1200.40 23.97 2 1310.83 52.69 3 1032.73 13.62 4 901.43 4.47 5 1081.80 5.16 6 992.87 57.31 7 921.43 35.56 8 802.80 1.28 9 383.10 9.88 10 980.07 3.83 11 1011.90 13.44 12 934.83 45.64 13 1072.80 18.10 14 1147.10 25.53 15 771.07 21.41 16 654.97 2.33

[0210] From the results in Table 4, it can be seen that the EC values ​​of Examples 1 to 16 are all less than 4 mS / cm, which meets the fertilizer requirements.

[0211] (2) Determination of humic acid content in highly humified carbon materials

[0212] The humic acid content of the highly humified carbon materials prepared in Examples 1 to 16 and Comparative Examples 1 to 3 and peat (purchased from Shandong Guangsu Agricultural Technology Co., Ltd.) was tested respectively. The determination method was based on GB / T 11957-2001. The test results Figure 1 As shown in Tables 5 and 6.

[0213] Table 5 Humic acid content of highly humified carbon materials in Examples 1 to 16 and Comparative Examples 1 to 3

[0214] Group Humic acid content (%) Example 1 37.67 Example 2 34.94 Example 3 33.53 Example 4 36.49 Example 5 41.55 Example 6 38.27 Example 7 34.02 Example 8 35.08 Example 9 32.41 Example 10 34.29 Embodiment 11 35.24 Example 12 36.18 Embodiment 13 40.05 Embodiment 14 37.36 Embodiment 15 33.31 Example 16 34.31 peat 47.23

[0215] Table 6 Humic acid content of highly humified carbon materials in Example 5 and Comparative Examples 1 to 3

[0216] Group Humic acid content (%) Example 5 41.55a Comparative Example 1 29.8c Comparative Example 2 36.2b Comparative Example 3 38.5b

[0217] Note: Different lowercase letters indicate significant differences in the data, p < 0.05.

[0218] according to Figure 1As shown in Table 5, the humic acid content of the high humified carbon materials obtained under different preparation conditions is different, and the humic acid content in different embodiments is as follows: 5>13>6>1>14>4>12>11>8>2>16>10>7>3>15>9. Among them, the humic acid content of Example 5 is the highest, 41.55%, which belongs to corn stalks, and the humic acid content of the corn stalk group (Examples 5-9) is the highest, which is 37.23%. Based on the humic acid content of the high humified carbon material prepared in Example 5, the humic acid content of the high humified carbon material prepared in Comparative Examples 1-3 was analyzed for significance. The results showed that when deionized water was used to replace the humic precursor auxiliary agent and the solid-liquid ratio was changed, the humic acid content was significantly (p < 0.05) decreased (Table 6).

[0219] (3) Observation of highly humified carbon materials using scanning electron microscopy (SEM)

[0220] The highly humified carbon materials prepared in Examples 1 to 16 were observed using a scanning electron microscope. Figures 2 to 5 As shown, the number in the upper right corner represents an embodiment, the box represents that microbial spores are attached to the carrier, and the red circle represents that microbial spores exist inside the pores.

[0221] according to Figure 2 to Figure 5 It can be seen that the wax layer on the surface of the straw cracks to form flaky debris, and the easily decomposed substances on the surface and inside fall off the cellulose skeleton, resulting in pores of different sizes. Some SEMs can clearly observe the exposure of the internal vascular bundle pores; however, in different embodiments, the degree of damage to the wax layer on the surface of the straw and the internal tube wall is different, and the size, depth and distribution range of the pores exposed on the surface of the straw are different, and the space available for microbial colonization is different. In addition, in the SEM results, it was observed that spherical or lumpy microorganisms were attached to the highly humified carbon material, indicating that the highly humified carbon material has the potential to be a microbial carrier.

[0222] (4) Determination of the specific surface area and mesopore size of highly humified carbon materials

[0223] The high humification carbon materials prepared in Examples 1 to 16 were respectively measured for specific surface area and mesopore size distribution characteristics using a specific surface area meter (BET). Before the test, the high humification carbon materials were dried at 65°C for more than 3 hours, and the empty test tube and the test tube after the sample were weighed. 2 After adsorption, degassing at 120℃ for 7h and cooling, the sample was put into a heat preservation bag and tested on the machine. The test results are shown in Table 7.

[0224] Table 7 BET determination of different highly humified carbon materials

[0225] Example <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Average pore volume (cm 3 / g)]]> Average pore size (nm) 1 1.816 0.981 19.686 2 3.99 0.981 16.289 3 5.561 0.980 21.021 4 4.571 0.981 18.885 5 1.606 0.980 22.336 6 4.317 0.982 19.220 7 6.289 0.982 19.311 8 6.332 0.982 22.575 9 3.627 0.981 15.763 10 3.934 0.981 21.818 11 4.953 0.980 17.882 12 6.019 0.983 25.054 13 4.013 0.982 16.277 14 3.832 0.981 23.726 15 6.819 0.981 19.259 16 7.406 0.982 21.566

[0226] According to the results in Table 7, among Examples 1 to 16, Example 16 has the highest specific surface area, which is 7.406 m 2 / g; the average pore volume of Example 12 is up to 0.983cm 3 / g; the average pore size of Example 8 is the highest, which is 22.575nm. The average specific surface area, average pore volume and average pore size of the wheat straw treatment group are 3.985m 2 / g, 0.981cm 3 / g, 18.970nm, and the average specific surface area, average pore volume and average pore diameter of the corn straw treatment group were 4.636m 2 / g, 0.982cm 3 / g, 20.861nm, and the average specific surface area, average pore volume and average pore diameter of the rice straw treatment group were 4.633m 2 / g, 0.981cm 3 / g, 20.129nm, and the average specific surface area, average pore volume and average pore diameter of the mixed straw treatment group were 5.518m 2 / g, 0.981cm 3 / g, 20.207nm. The average values ​​of pore volume and pore diameter of corn straw (Examples 5-9) are slightly higher than those of other straws, but the specific surface area is lower than that of mixed straw (Examples 13-16).

[0227] (5) Analysis of surface functional group types of highly humified carbon materials

[0228] The highly humified carbon materials prepared in Examples 1 to 16 and peat (purchased from Shandong Guangsu Agricultural Technology Co., Ltd.) were analyzed for surface functional group types using Fourier transform infrared spectrometer (FTIR) in infrared spectroscopy. The test results are as follows: Figure 6 shown.

[0229] Peat is an ideal carrier for microorganisms and has various types of functional groups, providing a good living environment for microorganisms. The present invention compares the functional group types of high humification carbon materials prepared in different embodiments with peat. Figure 6 It can be seen that 3400cm -1 The left and right are the stretching vibration areas of hydroxyl (OH). Affected by temperature and other conditions, the hydroxyl absorption peaks of different materials are slightly offset. -1 The absorption peak at is caused by the unsaturated hydrocarbon -CH 2 -The antisymmetric stretching vibration is mainly caused by the incomplete decomposition of cellulose, hemicellulose and lignin in the straw. 1850~1450cm -1 The main vibration areas in the region are benzene ring, C=C double bond and C=O double bond. The results show that the range of 1650-1450cm -1There are C=C, carbonyl-C=O and other aromatic groups in the region, 799cm -1 The benzene ring substitution absorption peak at 1300~1000cm -1 The region is mainly the stretching vibration region of CO. The FTIR results show that this region contains CO, COC and CN groups. In 16 examples, 1630 cm -1 The absorption peak at is caused by -NH 2 In-plane vibration deformation occurs, but only in Examples 1, 5 and 9; 799 cm -1 The absorption peak is caused by -NH 2 The out-of-plane vibration deformation and the outer bending vibration of CH are generated in all 16 examples. These two places are related to the functional groups introduced by the auxiliary reagents in the preparation. The results show that the highly humified carbon material prepared by the method of the present invention has a variety of functional groups, and there are more nitrogen-containing groups, which can provide more nitrogen sources. In actual fertilization, it can be supplied to plants and microorganisms for assimilation, promote crop growth and the construction of rhizosphere community composition, provide a good living environment for microorganisms, and increase the number of microorganisms that survive and the stability of the effect in application.

[0230] Embodiment 17

[0231] A method for preparing a highly humified carbon material is as follows:

[0232] (1) Preparation of humus precursor aid: Livestock and poultry manure (cow manure and pig manure) is fermented under aerobic or anaerobic conditions, maintaining a moisture content of 60% to 90%. After being left for 30 to 45 days, the extract is filtered to obtain a humus precursor aid.

[0233] (2) Preparation of back-mixed solution: The humic precursor additive and deionized water were mixed in a mass ratio of 6:4 to obtain a back-mixed solution.

[0234] (3) Corn stalk crushing: Dry corn stalks were taken as raw materials and crushed to a particle size of 1 mm to obtain crushed corn stalks.

[0235] (4) Hydrothermal reaction: The pulverized straw prepared in step (3) and the back-mixed solution prepared in step (2) were placed in a reaction kettle at a mass ratio of 1:3 and mixed. The reaction conditions were 180° C. for 1.5 h, during which the pressure was controlled at 2 to 6 Pa.

[0236] (5) Proceed according to step (5) of Example 1.

[0237] (6) Carry out the operation according to step (6) of Example 1 to obtain a highly humified carbon material.

[0238] Embodiment 18

[0239] A method for preparing a highly humified carbon material similar to Example 17 is as follows:

[0240] (1) Prepare a humic precursor adjuvant according to step (1) of Example 17.

[0241] (2) Prepare the back-mix solution according to step (2) of Example 17.

[0242] (3) Straw crushing: Dry wheat straw is taken as raw material and crushed to a particle size of 1 mm to obtain crushed wheat straw.

[0243] (4) Carry out hydrothermal reaction according to step (4) of Example 17.

[0244] (5) Proceed according to step (5) of Example 17.

[0245] (6) Follow the steps (6) of Example 17 to obtain a highly humified carbon material.

[0246] Embodiment 19

[0247] A method for preparing a highly humified carbon material similar to Example 17 is as follows:

[0248] (1) Prepare a humic precursor adjuvant according to step (1) of Example 17.

[0249] (2) Prepare the back-mix solution according to step (2) of Example 17.

[0250] (3) Rice straw crushing: Dry rice straw is taken as raw material and crushed to a particle size of 1 mm to obtain crushed rice straw.

[0251] (4) Carry out hydrothermal reaction according to step (4) of Example 17.

[0252] (5) Proceed according to step (5) of Example 17.

[0253] (6) Follow the steps (6) of Example 17 to obtain a highly humified carbon material.

[0254] Embodiment 20

[0255] A method for preparing a highly humified carbon material similar to Example 17 is as follows:

[0256] (1) Prepare a humic precursor adjuvant according to step (1) of Example 17.

[0257] (2) Prepare the back-mix solution according to step (2) of Example 17.

[0258] (3) Straw crushing: dry wheat, corn and rice straw are taken as raw materials, and crushed to a particle size of 1 mm to obtain wheat crushed straw, corn crushed straw and rice crushed straw, and the wheat crushed straw, corn crushed straw and rice crushed straw are mixed in a mass ratio of 1:2:1 to obtain a mixed straw raw material.

[0259] (4) Carry out hydrothermal reaction according to step (4) of Example 17.

[0260] (5) Proceed according to step (5) of Example 17.

[0261] (6) Follow the steps (6) of Example 17 to obtain a highly humified carbon material.

[0262] Application Example 3

[0263] (1) Humic acid content of high humified carbon materials

[0264] The humic acid content of the highly humified carbon materials prepared in Examples 17 to 20 was measured respectively. The measuring method was the same as step (2) in Application Example 2. The test results are shown in Table 8.

[0265] Table 8 Humic acid content of highly humified carbon materials of Examples 17 to 20

[0266] Group Humic acid content (%) Embodiment 17 42.22 Embodiment 18 38.73 Embodiment 19 39.37 Embodiment 20 41.32

[0267] According to Table 8, the humic acid content of the highly humified carbon materials prepared in Examples 17 to 20 is 38.73% to 42.22%, wherein the humic acid content of the highly humified carbon material in Example 17 is the highest at 42.22%.

[0268] (2) Observation of highly humified carbon materials using scanning electron microscopy (SEM)

[0269] The highly humified carbon materials prepared in Examples 17 to 20 were observed using a scanning electron microscope. Figure 7 As shown, the numbers in the upper right corner represent embodiments, and the boxes represent microbial spores attached to the carrier.

[0270] according to Figure 7 It can be seen that the wax layer on the surface of the straw can be obviously observed to crack into flaky debris, the easily decomposable substances on the surface and inside fall off the cellulose skeleton, and the pores of the vascular bundles inside the straw are exposed to form macropores, which can be used for microbial colonization; it can also be observed that spherical or lumpy microorganisms are attached to the highly humified carbon material, indicating that the carrier materials prepared in Examples 17 to 20 also have the potential to be used as microbial carriers.

[0271] (3) Sterile soil culture experiment

[0272] (1) Sterile soil preparation: 100 g sterilized dry soil was added to the culture box, and the sterilization conditions were 121°C, 1.5 h, 2 times. The culture boxes were randomly divided into 4 groups, each with 3 replicates, and were recorded as blank treatment (CKS), wheat straw humification treatment (WHS), corn straw humification treatment (MHS), and rice straw humification treatment (RHS).

[0273] (2) Carrier treatment: The surfaces of the highly humified carbon materials prepared in Examples 17, 18 and 19 were irradiated with ultraviolet light for more than 12 h and were recorded as corn straw humified carbon material (MHS), wheat straw humified carbon material (WHS) and rice straw humified carbon material (RHS), respectively.

[0274] (3) Sample addition: 2 g of wheat straw humified carbon material, corn straw humified carbon material and rice straw humified carbon material treated in step (2) were added to the WHS group, MHS group and RHS group, respectively; no other substances were added to the CKS group.

[0275] (4) Cultivation: After the sample addition treatment, sterile water was applied to each group, and the soil moisture was maintained at 60% of the field water holding capacity. The culture was carried out for 30 days, and sterile operations were performed throughout the process. During the culture process, the soil surface was observed to see if there was mycelium formation. The results were as follows: Figure 8 As shown, A is the blank treatment group CKS; B is the wheat straw humification treatment group WHS; C is the corn straw humification treatment group MHS; D is the rice straw humification treatment group RHS.

[0276] according to Figure 8 It can be seen that after 3 days of sample culture, no hyphae were observed on the surface of the CKS soil, while the soil surfaces of the WHS group, MHS group and RHS group were covered with a layer of hyphae, indicating that there was microbial colonization inside the carrier.

[0277] In summary, the highly humified carbon material prepared by the method of the present invention has a more stable structure, a higher specific surface area and nutrient content compared with similar biomass carriers, and is sterilized simultaneously during the preparation process, which can meet the space and nutrients for the growth and reproduction of microorganisms, while also having the effects of promoting plant growth and improving soil. The highly humified carbon material of the present invention can be used as a good carrier and plant-based fertilizer for microbial agents, can make use of agricultural waste as fertilizer, and can improve the soil environment by regulating the structure of soil microbial communities while providing nutrients. It is a green, environmentally friendly and pollution-free carrier material, and has broad application prospects in agricultural production and other fields.

[0278] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a highly humified carbon material, characterized in that: The following steps are involved: The straw is mixed with the back-mixing solution and subjected to a hydrothermal reaction to obtain a highly humified carbon material; The mass ratio of the straw to the back-mixed solution is 1:2-5; The temperature of the hydrothermal reaction is 180-240° C.; the time of the hydrothermal reaction is 1-3 hours; The back-mixed solution includes a humic precursor auxiliary agent and deionized water; the mass ratio of the humic precursor auxiliary agent to the deionized water is 3:7 to 6:4; The humification precursor auxiliary agent includes fermentation liquid of poultry and livestock manure.

2. The preparation method according to claim 1, characterized in that: The straw includes at least one of wheat straw, corn straw, rice straw and soybean straw.

3. The preparation method according to claim 1, characterized in that: Before mixing the straw with the back-mixing solution, the method further comprises: crushing the straw to obtain crushed straw; the particle size of the crushed straw is 1 to 3 mm.

4. The preparation method according to claim 1, characterized in that: After the hydrothermal reaction is completed, the method further includes: performing solid-liquid separation on the reaction product of the hydrothermal reaction to collect solid matter; and washing and drying the solid matter.

5. The preparation method according to claim 4, characterized in that: The EC value of the washed solid material is less than 4 mS / cm.

6. The preparation method according to claim 4 or 5, characterized in that: The pH of the washed solid matter is 6.8-7.

2.

7. The preparation method according to claim 4, characterized in that: The water content of the dried solid matter is less than 1.0%.

8. The highly humified carbon material prepared by the preparation method according to any one of claims 1 to 7, characterized in that: The specific surface area of ​​the highly humified carbon material is 1.606 to 7.406 m 2 / g, the average pore size is 15.763~25.054nm, and the humic acid content is 32.07%~42.22%.

9. Use of the highly humified carbon material prepared by the preparation method according to any one of claims 1 to 7 or the highly humified carbon material according to claim 8 as a microbial carrier.

10. A microbial fertilizer, characterized in that: It comprises the highly humified carbon material as claimed in claim 8 and a microbial agent loaded on the highly humified carbon material.

Images