Preparation method of camellia oleifera shell biomass charcoal improved water-retaining agent and greenhouse gas emission reduction application of camellia oleifera shell biomass charcoal improved water-retaining agent

Abstract

The invention discloses a preparation method of a camellia oleifera shell biomass charcoal improved water-retaining agent and greenhouse gas emission reduction application of the camellia oleifera shell biomass charcoal improved water-retaining agent, and belongs to the technical field of soil improvement. Comprising the following steps: calcining and crushing camellia oleifera shells to obtain camellia oleifera shell biomass charcoal powder; and mixing the camellia oleifera shell biomass charcoal powder with polyacrylamide according to a mass ratio of 10: 1, adding water, fully mixing to obtain a mixed glue solution, drying, crushing and sieving to obtain the camellia oleifera shell biomass charcoal improved water-retaining agent. The camellia oleifera shell biomass charcoal is adopted to improve polyacrylamide to form a novel improved water-retaining agent, the water-retaining agent can improve the soil structure and increase the soil moisture, the air permeability and the moisture condition of the soil can be adjusted, a nitrogen source for denitrification of microorganisms is reduced by reducing DON and NO3-N in the soil, the nitrogen source is reduced, and the nitrogen source is reduced. Therefore, the generation of NO is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of soil improvement, and in particular relates to a preparation method of a camellia oleifera shell biochar improved water retaining agent and its application in greenhouse gas emission reduction. Background Art

[0002] Camellia oleifera Abel. is a woody oil crop unique to China, mainly planted in the acidic red soil area south of the Yangtze River. Camellia oleifera Abel. is rich in nutrients, rich in oleic acid, linoleic acid, etc., and has a mellow taste. It is a high-quality edible oil; Camellia oleifera is also an excellent industrial raw material and can be used in soap, cosmetics, rubber and other industries. In addition, the oil extracted from the seeds of Camellia oleifera and the residues left after oil extraction can be used as medicine, with the effects of clearing heat and detoxifying, cooling blood and stopping bleeding. Camellia oleifera has important applications in many fields and is an economic crop with a very broad market prospect. However, during the cultivation of Camellia oleifera, the large-scale application of nitrogen fertilizers aggravates the degree of soil acidification, leading to an increase in nitrogen oxide gas emissions. On the one hand, maintaining soil moisture plays an important role in achieving high and stable yields of Camellia oleifera. On the other hand, soil moisture affects the nitrification and denitrification processes by regulating soil ventilation, redox state and microbial dynamics, thereby affecting NO emissions.

[0003] Polyacrylamide (PAM) is a widely used water-retaining agent that can enhance soil aggregation, stabilize soil structure, and prevent soil erosion, thereby increasing soil moisture content. However, the water-retaining effect of polyacrylamide may be limited by factors such as soil properties, such as clay content, electrolyte levels, and organic matter. Summary of the invention

[0004] In view of the above technical problems, the present invention proposes a preparation method of a camellia oleifera shell biochar improved water retaining agent and its application in greenhouse gas emission reduction.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a camellia oleifera shell biochar improved water-retaining agent comprises the following steps: calcining and crushing camellia oleifera shells to obtain camellia oleifera shell biochar powder; mixing the camellia oleifera shell biochar powder with polyacrylamide in a mass ratio of 10:1, adding water and fully mixing to obtain a mixed glue solution, drying, crushing and sieving to obtain a camellia oleifera shell biochar improved water-retaining agent.

[0007] Furthermore, the conditions of calcination and crushing are: calcination at 450° C. for 1 hour, cooling for 1 hour, and crushing to pass through a 0.25 mm sieve.

[0008] Furthermore, the polyacrylamide is anionic polyacrylamide with an average molecular weight of ≥10 million.

[0009] Furthermore, the crushing and screening refers to crushing to a particle size of 0.053-0.25 mm.

[0010] The present invention also provides a camellia oleifera shell biomass charcoal improved water retaining agent prepared by the preparation method.

[0011] The present invention also provides an application of a camellia oleifera shell biochar improved water retaining agent in soil improvement.

[0012] Furthermore, the oil-tea camellia shell biochar improved water-retaining agent improves soil by fixing nitrogen in the soil and reducing greenhouse gas emissions.

[0013] Furthermore, the amount of the camellia oleifera shell biochar improved water retaining agent added to the soil is 4wt%.

[0014] Compared with the prior art, the present invention has the following advantages and technical effects:

[0015] The present invention uses tea shell biomass charcoal to improve polyacrylamide to form a new improved water retaining agent. The water retaining agent can improve soil structure and increase soil moisture, help regulate soil air permeability and moisture conditions, and reduce DON and NO3 in the soil. - -N is used to reduce the nitrogen source for microbial denitrification, thereby reducing the production of NO. The use of tea shell biochar as an amendment realizes the recycling of agricultural by-products and reduces the environmental burden of waste.

[0016] The method of the invention is environmentally friendly and helps to achieve sustainable development of agriculture by reducing the use of chemical fertilizers and lowering greenhouse gas emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on the NO emission rate in soil;

[0019] Figure 2 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on the interannual dynamics of NO emission rates in soil;

[0020] Figure 3 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on soil pH;

[0021] Figure 4 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on soil moisture. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0024] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0025] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0026] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0027] Studies have shown that the combined use of biochar and polyacrylamide helps reduce greenhouse gas emissions. However, the effect of camellia shell biochar-modified polyamide on NO emissions from camellia forest soil is still unclear. The present invention uses camellia shell biochar to improve polyacrylamide to form a new improved water-retaining agent. By comparing the effects of adding only polyacrylamide and modified polyacrylamide water-retaining agent to the camellia forest soil on soil NO emission rate, physical and chemical properties, etc., the preparation method of camellia shell biochar-modified water-retaining agent and the mechanism of reducing soil NO emissions from camellia forest soil are explored. After research, it was found that the application of polyacrylamide improved with camellia shell biochar has better nitrification inhibition in the soil, which can effectively reduce nitric oxide emissions caused by denitrification. The specific technical scheme is as follows:

[0028] A method for preparing a camellia oleifera shell biochar improved water-retaining agent comprises the following steps: placing the camellia oleifera shell in a muffle furnace at 450°C for 1 hour, cooling for 1 hour, and crushing and passing through a 0.25mm sieve after cooling to obtain camellia oleifera shell biochar powder for later use; mixing the camellia oleifera shell biochar and polyacrylamide in a mass ratio of 10:1, adding an appropriate amount of water, mixing and stirring to obtain a mixed glue solution, placing the mixed glue solution in a 60°C oven for drying, crushing and sieving to leave particles between 0.053 and 0.25mm, and obtaining the camellia oleifera shell biochar improved water-retaining agent.

[0029] In the following preferred embodiments of the present invention, the polyacrylamide is purchased from Sinopharm Chemical Reagent Co., Ltd. and is an anionic polyacrylamide with an average molecular weight of not less than 10 million.

[0030] The camellia oleifera shell biochar improved water-retaining agent can be prepared by the preparation method.

[0031] The oil-tea camellia shell biochar improved water-retaining agent can be applied to soil improvement.

[0032] Biochar is a carbon-rich soil conditioner formed by high-temperature pyrolysis under low oxygen or oxygen-limited conditions, with a high specific surface area, porous structure and hydrophilic groups. The biochar produced by pyrolysis of camellia oleifera shell waste has natural hydrophilic groups and adsorption strength. After adding polyacrylamide, this biochar becomes an enhanced water-retaining agent, increasing its hydrophilicity and adhesion. Improving the water-retaining agent with camellia oleifera shell biochar not only makes up for the inherent limitations of polyacrylamide, but also reduces the waste of camellia oleifera shell resources. Most importantly, the water-retaining agent prepared by the method of the present invention can effectively reduce the nitric oxide greenhouse gas emissions caused by denitrification, indicating that the water-retaining agent improved with camellia oleifera shell biochar has certain greenhouse gas emission reduction and soil nitrogen fixation potential, and is expected to provide scientific support for greenhouse gas emission reduction in camellia oleifera forests.

[0033] The soil and gas samples used in the following embodiments and comparative examples of the present invention were collected from an intensively managed oil-tea plantation in Jinxian County, Nanchang City, Jiangxi Province, China (26°42′N, 115°4′E). The average age of the oil-tea plantation is 14 years, the average tree height is 2.3 meters, and the spacing between rows is 3×3.5 meters. The soil type is typical red soil. The climate here is a subtropical humid monsoon climate, with an average annual precipitation of about 1600 mm and an average annual temperature of 17.5°C. The physical and chemical properties of the soil samples are shown in Table 1.

[0034] Table 1 Basic physical and chemical properties of soil and camellia oleifera shell biochar samples

[0035]

[0036] All raw materials used in the following examples and comparative examples of the present invention are commercially available products.

[0037] The technical solution of the present invention is further illustrated by the following embodiments.

[0038] Example 1

[0039] Preparation of a Camellia oleifera shell biochar improved water-retaining agent:

[0040] The camellia oleifera shell was fired in a muffle furnace at 450°C for 1 hour, cooled for 1 hour, and then crushed and sieved through a 0.25 mm sieve to obtain the camellia oleifera shell biomass charcoal powder for later use; the camellia oleifera shell biomass charcoal and polyacrylamide were mixed in a mass ratio of 10:1, and water was added until all the raw materials were dissolved to obtain a mixed glue solution, which was placed in an oven at 60°C for drying, crushed and sieved to leave particles between 0.053 and 0.25 mm to obtain the camellia oleifera shell biomass charcoal improved water-retaining agent.

[0041] Application Example 1

[0042] A 1 square meter area was established under each tea tree in the fertilization area, and 170 g of the water retainer prepared in Example 1 was applied to each area, wherein the water retainer was mixed with the soil before use, and the proportion of the water retainer in the soil was 10 wt%, recorded as 10% MP group.

[0043] Comparative application example 1

[0044] A 1 square meter area was established under each tea tree in the fertilization area, and 68 g of the water retainer prepared in Example 1 was applied to each area, wherein the water retainer was mixed with the soil before use, and the proportion of the water retainer in the soil was 4 wt%, recorded as 4% MP group.

[0045] Comparative Application Example 2

[0046] A 1 square meter area was established under each tea oil tree in the fertilization area, and 8 g of polyacrylamide was applied in each area, wherein the polyacrylamide was mixed with water before use, and the proportion of polyacrylamide in water was 0.4‰, recorded as 0.4‰ P group.

[0047] Comparative Application Example 3

[0048] A 1 square meter area was established under each tea oil tree in the fertilization area, and 20 g of polyacrylamide was applied in each area, wherein the polyacrylamide was mixed with water before use, and the proportion of polyacrylamide in the water was 1‰, recorded as 1‰P group.

[0049] Comparative Application Example 4

[0050] A 1-square-meter area was established under each tea oil tree in the fertilization area without adding any water retaining agent, which was recorded as the Con group.

[0051] Effect verification

[0052] Detection of soil modification effect:

[0053] 1. Test method:

[0054] Five treatments were included in the study: 10% MP group, 4% MP group, 0.4‰ P group, 1‰ P group and Con group, and each treatment had four replicates.

[0055] Data collected during the experiment included NO emission rate, soil pH, nitrate nitrogen (NO3 - -N) content, soluble nitrogen (DON) content. NO emission rate is calculated using NO-NO2-NO x The soil pH was measured by a pH meter (LE438pH, METTER TOLEDO, Shanghai), and the soil moisture was measured by a soil three-parameter instrument (TDR350). The experimental results were analyzed by variance analysis (ANOVA) to analyze the effects of different treatments, and multiple comparisons (Duncan's LSD) were used for significance tests. JMP9.0 software was used for data analysis.

[0056] 2. The relevant data of Application Example 1 and Comparative Examples 1-4 are as follows:

[0057] Figure 1 , Figure 2 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on the soil NO emission rate and interannual dynamics.

[0058] Depend on Figure 1 It can be seen that the samples in Application Example 1 significantly reduced the soil NO emission rate, which was 30.33% lower than that in Comparative Application Example 4, 14.49% lower than that in Comparative Application Example 3, 17.11% lower than that in Comparative Application Example 2, and 17.06% lower than that in Comparative Application Example 1, indicating that the 10% MP used in Example 1 has the best effect on NO emission reduction in oil tea forest soil.

[0059] Figure 2 The interannual dynamic changes in soil NO emission rates between different treatments were shown. The application of polyacrylamide and tea oil shell biochar modified polyacrylamide significantly reduced the soil NO emission rate. As a water-retaining agent, polyacrylamide can improve soil structure and increase soil moisture, which may affect the activity and metabolic process of microorganisms in the soil. Biochar has a porous structure and high specific surface area, which can adsorb nitrogen compounds in the soil. Polyacrylamide modified by biochar has a better soil NO emission reduction effect.

[0060] Figure 3 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on soil pH.

[0061] Depend on Figure 3 It can be seen that the addition of PAM and biochar-modified PAM both increased soil pH, and the application of 10% MP significantly increased soil pH, which increased by 2.7% compared with Comparative Application Example 4, 0.65% compared with Comparative Application Example 3, and 2.22% compared with Comparative Application Example 1, indicating that the 10% MP used in Example 1 has the best effect on improving the acidification of oil tea forest soil. The increase in soil pH usually leads to changes in microbial activity. Most microorganisms are sensitive to pH, and higher pH values ​​may inhibit the nitrification and denitrification processes that produce NO.

[0062] Figure 4 The effects of the samples of Application Example 1 and Comparative Application Examples 1-4 on soil moisture.

[0063] Depend on Figure 4 It can be seen that compared with comparative application example 4, embodiment 1 applying 10% MP increased soil moisture by 4.5%, compared with comparative application example 3, it increased by 10.46%, compared with comparative application example 2, it increased by 11.60%, and compared with comparative application example 1, it increased by 10.25%, indicating that the 10% MP used in embodiment 1 has the best effect on NO emission reduction in oil palm forest soil and the best effect on soil water retention.

[0064] Polyacrylamide and Camellia oleifera shell biochar-modified polyacrylamide jointly affected the production of NO in soil by improving soil structure, regulating soil moisture, adsorbing nitrogen compounds, and changing the availability of pH.

[0065] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a water-retaining agent improved by biochar from oil-tea camellia shells, characterized in that: The following steps are involved: Camellia oleifera shells are calcined and crushed to obtain camellia oleifera shell biomass charcoal powder; the camellia oleifera shell biomass charcoal powder is mixed with polyacrylamide at a mass ratio of 10:1, water is added to fully mix to obtain a mixed glue solution, and the mixture is dried, crushed and sieved to obtain a camellia oleifera shell biomass charcoal improved water retaining agent.

2. The method for preparing the camellia oleifera shell biochar improved water retaining agent according to claim 1, characterized in that: The calcination and crushing conditions are as follows: calcination at 450° C. for 1 hour, cooling for 1 hour, and crushing to pass through a 0.25 mm sieve.

3. The method for preparing the camellia oleifera shell biochar improved water retaining agent according to claim 1, characterized in that: The polyacrylamide is anionic polyacrylamide with an average molecular weight of ≥10 million.

4. The method for preparing the camellia oleifera shell biochar improved water retaining agent according to claim 1, characterized in that: The crushing and screening refers to crushing to a particle size of 0.053-0.25 mm.

5. A camellia oleifera shell biochar improved water-retaining agent prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the camellia oleifera shell biochar improved water retaining agent as claimed in claim 5 in soil improvement.

7. The use according to claim 6, characterized in that: The oil-tea camellia shell biochar improved water-retaining agent improves soil through soil nitrogen fixation and reduction of greenhouse gas emissions.

8. The use according to claim 6, characterized in that: The amount of the camellia oleifera shell biochar improved water retaining agent added to the soil is 4 wt %.

Images