Water retention material as well as preparation method and application thereof

Abstract

The invention provides a water-retaining material as well as a preparation method and application thereof, and finds that corn glume has extremely high water absorption rate and can be used as an excellent water-retaining material. The glume is obtained by crushing corncobs and then carrying out winnowing and gradient sieving, and the particle size is 2-3mm. In order to effectively utilize the material, the obtained corn glume, a binder, an expanding agent and water are mixed and granulated to prepare water-retaining agent particles, and the water-retaining agent particles are easy and convenient to apply, high in water-retaining capacity and capable of effectively improving the water-retaining capacity of soil and improving the temperature, humidity, conductivity and bulk density of the soil; therefore, the method has important commercial value for soil and land improvement.

Description

Technical Field

[0001] This invention relates to the field of water-retaining materials technology, and in particular to a water-retaining material, its preparation method, and its application. Background Technology

[0002] Water-retaining materials are an important research topic in agriculture and environmental protection. Northwest and North my country are arid regions with scarce water resources. The rational use of water-retaining materials can inhibit water evaporation, prevent soil erosion, improve soil structure, and increase land utilization, which is of great significance to agricultural development in inland areas.

[0003] Currently, water-retaining materials include chemical water-retaining materials and bio-based water-retaining materials made by modifying biomass materials and adding acrylic acid, acrylamide, and chemical cross-linking agents. The latter has relatively better water retention and water-saving measures. However, some of these materials still contain chemical materials that pose potential hazards to the environment and human health, resulting in a certain degree of pollution. Long-term use can harm the environment and human health, failing to achieve true environmental protection. Furthermore, the materials themselves have a certain cost, hindering large-scale promotion. Summary of the Invention

[0004] This invention provides a water-retaining material, its preparation method, and its application. The invention discovers that the husk of corn has a very strong water absorption capacity and can be used as a water-retaining material. However, corn husks have a very low density and are thin and light, making them easy to be blown away by the wind. They are difficult to retain in the soil in dry areas and are inconvenient to apply. Therefore, this material is prepared into granules with a binder, a swelling agent, and water. These granules are easy to transport and use, have a strong water retention capacity, and can be used to enhance the soil's water retention capacity and improve soil structure.

[0005] In a first aspect, the present invention provides a water-retaining agent containing corn husks.

[0006] my country has a huge corn production, with a planting area of ​​over 600 million mu and an annual output of over 50 million tons of corn cobs. The corn husks produced from corn cobs have a wide range of sources and are low in cost.

[0007] This invention reveals that when corn cobs are crushed and then sieved through a gradient sieve, the resulting corn husks exhibit a strong water absorption capacity, reaching up to 1452.5% of their original weight, far exceeding the absorption capacity of other parts, making them highly suitable as a water-retaining material. The remaining crushed corn cob fragments can be used as chemical raw materials, industrial wastewater adsorbents, and edible fungi culture media, further reducing the cost of corn husks.

[0008] Preferably, the corn husk in the above-mentioned water-retaining agent is prepared by crushing corn cobs and obtaining corn husks by air separation, wherein the particle size of the corn husk is 2-3 mm.

[0009] Preferably, the water-retaining agent comprises corn husks, binder, swelling agent and water, and the raw materials added by weight include: 10-30 parts corn husks, 5-15 parts binder, 5-25 parts swelling agent and 40-70 parts water.

[0010] More preferably, the above-mentioned water-retaining agent raw materials, by weight, include: 16-22 parts corn husks, 8.3-11.1 parts binder, 8.3-22.2 parts expansion agent, and 44-66 parts water.

[0011] The above ratio can achieve a final granulation rate of over 95%, and the granule weight is also at its optimal level, with each granule weighing approximately 0.022g-0.155g and having a particle size of approximately 4.01mm-11.02mm. Water-retaining agent granules at this weight have a better effect and are more in line with application requirements.

[0012] More preferably, the binder in the above-mentioned water-retaining agent is any one of polyvinyl alcohol, ..., preferably polyvinyl alcohol.

[0013] The expanding agent is either sodium bentonite or corn starch, preferably sodium bentonite.

[0014] Binders can improve the granulation rate of water-retaining agents and facilitate application, while expanding agents can further enhance water retention capacity and improve soil structure after application, making the soil more loose. After testing various binders and expanding agents, this invention found that polyvinyl alcohol and sodium bentonite can achieve the above effects well, and also have the advantages of being environmentally friendly and low-cost, making them suitable for large-scale applications.

[0015] Preferably, the preparation method of the above-mentioned water-retaining agent is as follows: (1) Weigh each raw material according to the mass ratio; (2) First add corn husks, then add binder and expansion agent, and stir well; (3) Add all the water at once and stir well; (4) Pour the well-stirred raw materials into the pellet mill to granulate.

[0016] The above-mentioned pellet mill can be any machine with pelletizing function, preferably a disc pellet mill (manufacturer: Zhengzhou Huachuang Machinery Co., Ltd., item number HCYP-500) (speed button adjusted to 2.5, disc tilt angle 45°). This formula and program produce pellets with high yield and moderate hardness, which are easy to transport and store.

[0017] The applicant tried using ground corn husk powder for granulation, which resulted in water-retaining agent granules with higher hardness, easier transportation and application, and a longer shelf life, but the water retention performance deteriorated, making it a losing proposition.

[0018] In a second aspect, the present invention provides the application of the above-mentioned water-retaining agent in any of the following: (1) Improve soil water retention capacity.

[0019] (2) Reduce the diurnal temperature range of the soil.

[0020] (3) Improve soil electrical conductivity.

[0021] (4) Reduce soil bulk density.

[0022] Applying the water-retaining agent of this invention can significantly reduce the maximum temperature difference between 12:00 and 14:00 in the soil during summer, reduce water evaporation, and make it more conducive to water retention; it can improve soil electrical conductivity, thereby increasing the soil cation exchange capacity; it can reduce soil bulk density, making the soil looser, improving aeration and water permeability, and enhancing soil fertility.

[0023] Thirdly, the present invention provides a method for improving soil, comprising incorporating the aforementioned water-retaining agent into the soil.

[0024] Preferably, the water-retaining agent is incorporated into the soil in the above methods in the form of strip application, hole application, broadcast application, layered application, or application mixed with fertilizer.

[0025] Preferably, the application rate of the water-retaining agent in the above method is 60-80 kg / mu, and more preferably 70 kg / mu.

[0026] The beneficial effects of this invention are as follows: (1) This invention utilizes agricultural waste corn cobs, processes and screens them to obtain corn husks with high water absorption ratio, and produces a new type of biomass water-retaining agent by optimizing the granulation process with sodium-based bentonite and other materials. The optimized water-retaining agent has a high granulation rate, moderate hardness, and is easy to transport and store.

[0027] (2) The above-mentioned water-retaining agent particles are environmentally friendly and pollution-free. They have a good effect on soil improvement in arid areas. In practical applications, the soil with the water-retaining agent of this invention added has a maximum increase of 14.12% in water content, a maximum increase of 21.0% in electrical conductivity, a maximum decrease of 9.5% in diurnal temperature range, and a maximum decrease of 6.6% in bulk density compared to the soil without the addition. This is of great significance for land improvement in arid areas. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 The image shows the appearance of the water-retaining agent prepared according to the proportions of each group in Example 2.

[0030] Figure 2 The image shows the appearance of the water-retaining agent prepared according to the proportions of each group in Example 3.

[0031] Figure 3 The image shows the appearance of the water-retaining agent prepared according to the proportions of each group in Example 4. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] Example 1: Screening of Water-Retaining Components This embodiment provides the screening and testing of water-retaining components in corn cobs. Take whole corn cobs, crush them, and then pass them through air separation and sieves at a gradient of 30 mesh, 40 mesh, 50 mesh, 60 mesh, 80 mesh, 100 mesh, and 120 mesh to obtain corn cob fragments, bran, and light husks (mainly 2-3 mm in diameter) of different particle sizes.

[0034] [1] The mixed particles that were not sieved, the corn cob fragments, bran, husks and husk powder that were screened out by gradient screening were subjected to water absorption tests according to the method described in "Tang Qiaolin. Preparation and performance study of corn straw cellulose-based water-absorbing composite materials [D]. Xihua University, 2021".

[0035] The results are shown in Table 1. It can be seen that among the products after corn cob crushing, corn husk has the highest water absorption rate, reaching 1452.5%, which is far higher than other parts. Therefore, it was selected as the raw material for water retention agent.

[0036] Example 2 This embodiment provides a method for preparing a water-retaining agent.

[0037] The steps for preparing a water-retaining agent are as follows: The pellet mill can feed a total of 1000g of material at a time.

[0038] (1) Weigh out the raw materials according to the mass ratio of corn husk: polyvinyl alcohol: sodium bentonite: water 2:1:3:4, with a total weight of 1000g.

[0039] (2) First add the glumes, then add polyvinyl alcohol and sodium bentonite, and stir evenly.

[0040] (3) Add water all at once and stir well.

[0041] (4) After the raw materials are evenly mixed, pour them into a disc pellet mill (manufacturer: Zhengzhou Huachuang Machinery Co., Ltd., item number HCYP-500) (adjust the speed button to 2.5 and the disc tilt angle to 45°) for rotary pelleting.

[0042] The prepared water-retaining agent has the following appearance: Figure 1 As shown, its granulation rate is about 80%.

[0043] Example 3

[0044] The only difference between this embodiment and Example 2 is that the weight ratio of the components of the water-retaining agent is husk: polyvinyl alcohol: sodium bentonite: water = 2:1:1:8. The water-retaining agent prepared according to this ratio has the following appearance. Figure 2 As shown, its granulation rate is 80%–90%. Example 4 The only difference between this embodiment and Example 2 is that the weight ratio of the components of the water-retaining agent is husk: polyvinyl alcohol: sodium bentonite: water = 2:1:2:4. The water-retaining agent prepared according to this ratio has the following appearance. Figure 3 As shown, its granulation rate is 96%–99%.

[0045] Example 5 The only difference between this embodiment and Embodiment 4 is that polyvinyl alcohol is replaced with sodium bentonite.

[0046] Example 6 The only difference between this embodiment and Embodiment 4 is that sodium-based bentonite is replaced with calcium-based bentonite.

[0047] Comparative Example 1 The only difference between this comparative example and Example 4 is that the glumes are replaced with ground glumes powder.

[0048] Comparative Example 2 The only difference between this comparative example and Example 4 is that polyvinyl alcohol is replaced with konjac powder.

[0049] Comparative Example 3 The only difference between this comparative example and Example 4 is that sodium-based bentonite is replaced with industrial starch.

[0050] Experimental Example 1 The water-retaining agents obtained in Examples 2-6 and Comparative Examples 1-3 were tested for their water absorption capacity, particle size, and hardness according to the method in Example 1. The results are shown in Table 2.

[0051] After studying the granulation performance of the water-retaining agent prepared from corn husks, this invention tried various formulations and finally found that the formulation of husk:polyvinyl alcohol:sodium bentonite:water = 2:1:2:4 in Example 4 had the best water absorption performance.

[0052] Experiment Example 2: Soil Water Retention Capacity Test This experiment was conducted at the oat planting base of Jian'ai Father's Love Ranch Chengde Co., Ltd. The control group did not use a water-retaining agent, while the experimental group received the water-retaining agent prepared in Example 4 at a rate of 70 kg per mu (approximately 0.067 hectares). The agent was applied once using a fertilizer spreader before oat sowing, followed by tilling to a depth of 20 cm using a rotary tiller to ensure thorough mixing of the water-retaining agent with the soil. Oat sowing took place on June 23, 2024. Samples were taken on July 12 (oat seedling stage) and August 17 (oat tillering and jointing stage), with 15 replicates each time, to test the soil moisture content. In this experiment, 60 kg of water-retaining agent was applied once before oat sowing.

[0053] Table 3. Effects of water-retaining agents on soil moisture content

[0054] The test results are shown in Table 3. The average soil moisture content increased by 14.12% when the water-retaining agent of the present invention was used, indicating that the water-retaining agent can effectively lock in moisture and improve the water retention of the soil even when plants are growing.

[0055] Experiment Example 3: Soil Comprehensive Improvement Capacity Test This embodiment was tested at the oat planting base of Hebei Saibei State Farms Agricultural Development Group Co., Ltd. The control group did not use water-retaining agent, while the experimental group used 70 kg of water-retaining agent per mu. The water-retaining agent prepared in this invention and the commercially available environmentally friendly water-retaining agent Shikerun (Chengdu Xinfu Technology Co., Ltd., fertilizer registration number: NY886-2010) were used respectively. Oat sowing was carried out on May 30, 2024. Sampling was conducted once on July 12 during the jointing and booting stages, with 15 replicates, and the soil temperature, moisture content and electrical conductivity were tested (measured between 12:00 and 14:00) (Table 4). Sampling was conducted once on August 17 between the milk stage and the waxy stage of oat, with 15 replicates, and the soil temperature and moisture content were tested (Table 5).

[0056] Test method: Soil temperature and electrical conductivity were measured using a COMBI 5000 soil eight-parameter analyzer (model or technical specifications: German STEPS / COMBI 5000). Brand: German STEPS.

[0057] Table 4. Effects of water-retaining agents on soil temperature, humidity, and electrical conductivity.

[0058] Table 5. Effects of water-retaining agents on soil temperature and humidity.

[0059] As shown in Tables 4 and 5, the water-retaining agent of this invention can significantly improve soil moisture content and electrical conductivity, and reduce the diurnal temperature range of the soil. Its effects almost comprehensively surpass those of commercially available environmentally friendly water-retaining agents. In the soil temperature difference test, the water-retaining agent of this invention was on par with the commercially available water-retaining agent in July (Table 4), but significantly lower in August (Table 5), indicating that the water-retaining agent of this invention has better long-term stability. In the soil moisture content test, it was significantly higher than the commercially available water-retaining agent in both months; the electrical conductivity test showed a substantial improvement over the commercially available water-retaining agent. This demonstrates that the water-retaining agent prepared by this invention has excellent soil water retention and soil quality improvement capabilities, and its effects are long-lasting.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-retaining agent, characterized in that, The water-retaining agent contains corn husks.

2. The water-retaining agent according to claim 1, characterized in that, The method for preparing corn husks is as follows: corn cobs are crushed and air-separated at a speed of 50-100 m / s to obtain corn husks. The corn husks are collected in a closed factory building with a height of 15 meters. The particle size of the corn husks is 2-3 mm.

3. The water-retaining agent according to any one of claims 1 or 2, characterized in that, It contains corn husks, binder, expanding agent and water. The raw materials added by weight are: 10-30 parts corn husks, 5-15 parts binder, 5-25 parts expanding agent and 40-70 parts water.

4. The water-retaining agent according to any one of claims 1-3, characterized in that, The raw materials added, by weight, include: 16-22 parts corn husks, 8.3-11.1 parts binder, 8.3-22.2 parts expansion agent, and 44-66 parts water.

5. The water-retaining agent according to any one of claims 3 or 4, characterized in that, The binder is any one of polyvinyl alcohol, industrial starch, and konjac flour, preferably polyvinyl alcohol; The expanding agent is either sodium bentonite or industrial starch, preferably sodium bentonite.

6. The water-retaining agent according to any one of claims 1-5, characterized in that, The water-retaining agent is prepared by: (1) Weigh each raw material according to the mass ratio; (2) First add corn husks, then add binder and expansion agent, and stir well; (3) Add all the water at once and stir well; (4) Pour the well-stirred raw materials into the pellet mill to granulate.

7. The use of the water-retaining agent according to any one of claims 1-6 in any of the following: (1) Improve soil water retention capacity; (2) Reduce the diurnal temperature range of the soil; (3) Improve soil electrical conductivity; (4) Reduce soil bulk density.

8. A method for improving soil, characterized in that, The water-retaining agent according to any one of claims 1-6 is incorporated into the soil.

9. The method according to claim 8, characterized in that, Water-retaining agents can be incorporated into the soil in various ways, including strip application, hole application, broadcast application, layer application, and mixing with fertilizer.

10. The method according to any one of claims 8 or 9, characterized in that, The application rate of water-retaining agent is 60-80 kg / mu, preferably 70 kg / mu.

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