A method for promoting the generation of humic acid and increasing the amount of carbon sequestration in lignocellulose organic waste compost

Abstract

The present application belongs to the technical field of solid waste treatment and resource utilization, and particularly relates to a method for promoting generation of humic acid in lignocellulose organic waste compost and increasing carbon sequestration amount. The present application promotes degradation of lignocellulose in lignocellulose organic waste compost by inoculating functional bacteria agent lignocellulose efficient hydrolysis bacteria, promotes directional conversion of small-molecule organic components into humic acid by jointly adding organic solid waste rich in humic acid precursors and catalytic materials, increases the action time of the functional bacteria agent, improves the synergistic conversion of humic acid, reduces mineralization, and improves the quality of the compost product.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of solid waste treatment and resource utilization, and particularly relates to a method for promoting the generation of humic acid in the composting of lignocellulose organic waste and increasing the amount of carbon sequestration. BACKGROUND

[0002] Agricultural waste refers to organic substances discarded in the entire agricultural production process. Among them, lignocellulose organic solid waste is the main component of agricultural waste. At present, the treatment method of lignocellulose organic solid waste is still discarded and incinerated, but this treatment method will destroy soil fertility and cause air pollution, and its leachate and odor will further threaten the environment and human health.

[0003] Composting is the main means of resource treatment of lignocellulose organic solid waste, and humic acid substances beneficial to agricultural production can be generated in the composting process. However, the mineralization of indigenous microorganisms produces CO2 and other greenhouse gases, resulting in carbon loss of compost products and reducing the content of humic acid. Inoculation of functional bacteria in composting can quickly promote the degradation of lignocellulose into small molecular organic components, but this small molecular organic component accelerates the growth and reproduction of indigenous microorganisms, enhances the mineralization in composting, increases carbon loss, and at the same time inhibits the growth of functional bacteria. Therefore, a method for degrading lignocellulose organic waste that can increase carbon sequestration and simultaneously drive small molecular organic components to synthesize humic acid is urgently needed. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a method for promoting the generation of humic acid in the composting of lignocellulose organic waste and increasing the amount of carbon sequestration. The method of the present application can increase the amount of carbon sequestration and simultaneously drive small molecular organic components to synthesize humic acid.

[0005] The present application provides a method for promoting the generation of humic acid in the composting of lignocellulose organic waste and increasing the amount of carbon sequestration, comprising the following steps:

[0006] Inoculating lignocellulose efficient hydrolysis bacteria in the composting material to be composted, and carrying out composting; the composting material to be composted comprises lignocellulose organic waste;

[0007] After adding organic waste rich in humic acid precursors and catalytic materials in the later stage of composting, continue to carry out composting;

[0008] The organic waste rich in humic acid precursors comprises chicken manure;

[0009] The catalytic material comprises manganese dioxide.

[0010] Preferably, the particle size of the lignocellulose organic waste is ≤3cm.

[0011] Preferably, the high-efficiency lignocellulose hydrolysis bacteria comprise Bacillus subtilis.

[0012] Preferably, the inoculation dose of the high-efficiency lignocellulose hydrolysis bacteria is 1% to 3% of the dry weight of the material to be composted; and the effective viable count of the Bacillus subtilis is preferably (1-9)×10 9 CFU / mL.

[0013] Preferably, the carbon-nitrogen ratio of the material to be composted is 25 to 30; and the moisture content of the material to be composted is 60% to 70%.

[0014] Preferably, the material to be composted further comprises chicken manure.

[0015] Preferably, the mass ratio of the lignocellulose organic waste to the chicken manure in the material to be composted is (4.8-5.2):(0.8-1.2).

[0016] Preferably, the time of the later stage of composting comprises a composting cooling period and a composting maturation period.

[0017] Preferably, the organic waste rich in humic acid precursors and the catalytic material are added once respectively during the composting cooling period and the composting maturation period.

[0018] Preferably, the mass ratio of the catalytic material to the material to be composted is 100:5; and the mass ratio of the material to be composted to the organic waste rich in humic acid precursors is (4.8-5.2):(0.8-1.2).

[0019] The present application provides a method for promoting the formation of humic acid and increasing the amount of carbon sequestration in lignocellulosic organic waste compost, comprising the following steps: inoculating lignocellulosic high-efficiency hydrolysis bacteria in the composting material, and carrying out composting; the composting material comprises lignocellulosic organic waste; after adding organic waste rich in humic acid precursors and catalytic materials in the later stage of composting, the composting is continued. The present application promotes the degradation of lignocellulose in lignocellulosic organic waste compost by inoculating functional bacteria of lignocellulosic high-efficiency hydrolysis bacteria, promotes the directional conversion of small molecular organic components into humic acid by adding organic solid waste rich in humic acid precursors and catalytic materials, increases the action time of functional bacteria, improves the synergistic conversion of humic acid, reduces mineralization, and improves the quality of compost products. In the early stage of lignocellulosic organic waste composting, the present application inoculates lignocellulosic high-efficiency hydrolysis bacteria, destroys the crystal connection structure of lignocellulose, and forms a large amount of small molecular organic components easily utilized by microorganisms in the middle stage of composting. Then, a large amount of microorganism-easily-utilized organic components are generated in the later stage of composting. At this time, the addition of organic solid waste rich in humic acid precursors and catalytic materials promotes the rapid polymerization of small molecular organic components to form humic acid, reduces the consumption of small molecular organic components by indigenous bacteria, inhibits the growth of indigenous bacteria, and reduces the competitive pressure of functional bacteria, so as to realize the sustained action of functional bacteria, reduce mineralization, increase the amount of carbon sequestration, and promote the formation of humic acid. The present application realizes the directional humification of organic components to the greatest extent, and realizes the efficient resource utilization of organic solid waste. The method of the present application can increase the action time of functional bacteria, promote the degradation of lignocellulose and the formation of humic acid, reduce the mineralization caused by the further utilization of small molecular organic components, realize the directional humification of organic components to the greatest extent, and realize the efficient resource utilization of organic solid waste. The test results show that, by using the method of the present application, after 45 days of composting experiment, the experimental group is increased by 24% compared with the control group, and the organic carbon content is not reduced compared with the control group, but increased by 5%. It is proved that the combined addition of functional bacteria and precursors increases the synergistic conversion of humic acid, effectively reduces the mineralization in composting, and increases the carbon sequestration of products. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Theoretical concept diagram of Example 1 of the present application;

[0021] Figure 2 Organic carbon change curve in the composting process of Example 1;

[0022] Figure 3 Humus change curve in the composting process of Example 1;

[0023] Figure 4 Organic carbon change curve in the composting process of Comparative Example 1;

[0024] Figure 5Humus change curve in the composting process of the example 2. DETAILED DESCRIPTION

[0025] The present application provides a method for promoting the generation of humic acid and increasing the amount of carbon sequestration in lignocellulosic organic waste composting, comprising the following steps:

[0026] Inoculating lignocellulosic high-efficiency hydrolysis bacteria in the material to be composted, and then composting; the material to be composted comprises lignocellulosic organic waste.

[0027] After adding organic waste rich in humic acid precursors and catalytic materials in the later stage of composting, the composting is continued.

[0028] The organic waste rich in humic acid precursors comprises chicken manure.

[0029] The catalytic material comprises manganese dioxide.

[0030] The present application inoculates lignocellulosic high-efficiency hydrolysis bacteria in the material to be composted, and then composts; the material to be composted comprises lignocellulosic organic waste.

[0031] In the present application, the lignocellulosic organic waste preferably comprises rice straw; the particle size of the lignocellulosic organic waste is preferably ≤3 cm, and more preferably 2-3 cm. In the present application, the lignocellulosic high-efficiency hydrolysis bacteria preferably comprise Bacillus subtilis, which can secrete lignocellulose-degrading enzymes; the Bacillus subtilis is preferably purchased from the China General Microbiological Culture Collection Center, and the preservation number is CGMCC1.821. In the present application, the inoculation dose of the lignocellulosic high-efficiency hydrolysis bacteria is preferably 1%-3% of the dry weight of the material to be composted, and more preferably 2%; the effective viable bacterial count of the lignocellulosic high-efficiency hydrolysis bacteria is preferably (1-9)×10 9 CFU / mL. In the present application, the carbon-nitrogen ratio of the material to be composted is preferably 25-30, which is preferably adjusted by adding chicken manure to the lignocellulosic organic waste; the water content of the material to be composted is preferably 60%-70%, and more preferably 65%; the water content of the material to be composted is preferably adjusted by adding distilled water. In the present application, the material to be composted preferably further comprises chicken manure; the mass ratio of lignocellulosic organic waste to chicken manure in the material to be composted is (4.8-5.2):(0.8-1.2), and more preferably 5:1.

[0032] The present application continues the composting after adding organic waste rich in humic acid precursors and catalytic materials in the later stage of composting.

[0033] In the present application, the time of the post-composting period preferably comprises a composting cooling period and a composting maturation period. In the present application, the composting cooling period is a period after the composting high-temperature period when the temperature of the composting core drops to below 50°C; the composting maturation period is a period after the cooling period when the temperature of the composting is relatively stable; and the temperature of the composting in the composting maturation period is preferably 20-30°C, more preferably 25°C.

[0034] In the present application, the organic waste rich in humic acid precursors and the catalytic material are preferably added once respectively in the composting cooling period and the composting maturation period.

[0035] In the present application, the mass ratio of the amount of the catalytic material added each time to the mass of the material to be composted is preferably 100:5; and the mass ratio of the amount of the material to be composted to the amount of the organic waste rich in humic acid precursors added each time is preferably (4.8-5.2):(0.8-1.2), more preferably 5:1.

[0036] The technical solutions in the present application will be described clearly and completely below in combination with the embodiments in the present application.

[0037] Embodiment 1

[0038] The theoretical conceptual diagram of Embodiment 1 of the present application is shown in Figure 1 .

[0039] The residues from the previous year's crop harvesting; the chicken manure is obtained from a fresh sample from a chicken farm, and the efficient lignocellulose-degrading bacterial agent is Bacillus subtilis CGMCC 1.821 (purchased from the China General Microbiological Culture Collection Center), with an effective viable bacterial count of 10 9 CFU / mL;

[0040] The method of the present application is a method for increasing carbon sequestration and promoting the synergistic conversion of humic acid by jointly adding functional bacterial agents and precursors in rice straw compost, and the method comprises the following steps:

[0041] (1) Before starting the composting, the obtained straw is crushed to a length of 2-3 cm, then the carbon-nitrogen ratio is adjusted to 25-30 using chicken manure, the water content of the material is adjusted to 60%-65% using distilled water, and a lignocellulose-degrading bacterial agent is inoculated into the material, with an inoculation amount of 2% of the dry weight of the material.

[0042] (2) After the pre-treatment is completed, the composting is performed. When the composting enters the cooling period (7 days) and the maturation period (23 days), chicken manure and manganese dioxide are added to the composting core, respectively, with a final mixing ratio of rice straw to chicken manure of 1:5, and the amount of manganese dioxide added each time is 5.03%.

[0043] The material treated by the above two steps is the experimental group, and the material without any treatment is the control group, and a composting experiment is carried out for 45 days. The experimental results are shown in Figure 2 andFigure 3 .Depend on Figure 2 and Figure 3 As can be seen, after 45 days of composting experiment, the humus content in the experimental group increased by 24.01% compared to the control group, while the organic carbon content did not decrease but instead increased by 5%. This indicates that the experimental group effectively reduced mineralization in the compost, increased carbon sequestration in the product, and improved product quality. The humus content increased from 44.12 g / kg to 54.78 g / kg.

[0044] Comparative Example 1

[0045] The rice straw comes from the residue after the previous year's crop harvest, and the efficient lignocellulose hydrolysing bacteria is Bacillus subtilis CGMCC1.821 (China General Microbiological Culture Collection Center).

[0046] Before composting begins, the obtained straw is shredded to a length of 2-3 cm. Then, chicken manure is used to adjust the carbon-to-nitrogen ratio to 25-30, and distilled water is used to adjust the moisture content of the material to 60%-65%. Finally, a high-efficiency lignocellulose hydrolysing agent (with an effective viable count of 10) is inoculated into the material. 9 The inoculum volume is 2% of the dry weight of the material (CFU / mL).

[0047] The materials processed using the above steps were used as the experimental group, while the untreated materials served as the control group. A 45-day composting experiment was conducted, and the results are detailed below. Figure 4 ,Depend on Figure 4 It can be seen that after 45 days of composting, the organic carbon content in the experimental group was lower than that in the control group at different stages of composting. At the end of composting, the content was 14.91% lower than that in the control group. This indicates that inoculation with functional microbial agents accelerated the mineralization of organic carbon.

[0048] Comparative Example 2

[0049] Rice straw comes from the residue after the previous year's crop harvest; chicken manure comes from fresh samples from chicken farms.

[0050] After composting begins, wait until the composting enters the cooling period (7 days) and the maturation period (23 days) before adding chicken manure and manganese dioxide to the compost pile. The final mass ratio of rice straw to chicken manure is 1:5. Manganese dioxide is added in two batches, with each addition accounting for 5% of the mass of rice straw. The manganese dioxide is added on the 7th and 23rd days of composting.

[0051] The materials processed using the above steps were used as the experimental group, while the untreated materials served as the control group. A 45-day composting experiment was conducted, and the results are detailed below. Figure 5 ,Depend on Figure 5 It can be seen that after 45 days of composting experiment, the humic content in the experimental group increased by 14.62% compared with the control group. This indicates that adding humic acid synthesis precursors helps promote the formation of humic matter in compost.

[0052] Although the above embodiments have been described in detail, they are only some embodiments of the present application but not all the embodiments. Other embodiments can be obtained according to the above embodiments without creativity, and these embodiments also belong to the protection scope of the present application.

Claims

1. A method for promoting humic acid generation and increasing carbon sequestration in lignocellulosic organic waste composting, comprising the following steps: The material to be composted is inoculated with highly efficient lignocellulose hydrolysing bacteria for composting; the material to be composted includes lignocellulose organic waste and chicken manure; the mass ratio of lignocellulose organic waste to chicken manure in the material to be composted is (4.8-5.2):(0.8-1.2); the carbon-nitrogen ratio of the material to be composted is 25-30. After adding organic waste rich in humic acid precursors and catalytic materials in the later stage of composting, composting continues; the later stage of composting includes the cooling period and the maturation period; organic waste rich in humic acid precursors and catalytic materials are added once each in the cooling period and the maturation period. The ratio of the amount of the catalytic material added to the mass of the material to be composted is 5:100 each time. The organic waste rich in humic acid precursors includes chicken manure; The catalytic material includes manganese dioxide; The highly efficient lignocellulose hydrolysing bacteria is Bacillus subtilis CGMCC1.821; The inoculation dose of the highly efficient lignocellulose hydrolysing bacteria is 1% to 3% of the dry weight of the material to be composted.

2. The method according to claim 1, characterized in that, The particle size of the wood fiber organic waste is ≤3cm.

3. The method according to claim 1, characterized in that, The effective viable count of the Bacillus subtilis is (1–9) × 10⁻⁶. 9 CFU / mL.

4. The method according to claim 1, characterized in that, The moisture content of the material to be composted is 60% to 70%.

5. The method according to claim 1, characterized in that, The mass ratio of the compostable material to the organic waste rich in humic acid precursors added each time is (4.8-5.2):(0.8-1.2).

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