Modified soil conditioner containing garden waste

Abstract

The invention discloses a modified soil conditioner containing garden waste, and belongs to the technical field of soil conditioners. Comprising the following raw materials in parts by weight: 40-60 parts of garden waste, 10-20 parts of chlorinated polypropylene and 15-30 parts of modified polyacrylamide. According to the prepared soil conditioner, garden waste is used as a biomass charcoal raw material, the surface of the soil conditioner is acidified through chlorinated polypropylene, the performance of the conditioner is improved, and the cost is saved; compared with common polyacrylamide, the prepared modified polyacrylamide is better in water retention capacity and better in soil improvement effect; therefore, the soil conditioner prepared by the invention is good in soil improvement effect and low in cost, also realizes recycling of waste resources, and has important application value in the technical field of soil conditioners.

Description

Technical Field

[0001] The invention belongs to the technical field of soil conditioners, and in particular relates to a modified soil conditioner containing garden waste. Background Art

[0002] Green waste refers to the green plant prunings, dead branches and leaves, grass clippings, and flower rot produced during greening maintenance in urban areas or large botanical gardens. As an organic waste, green waste contains rich beneficial nutrients, a large amount of lignin, cellulose, and hemicellulose.

[0004] With the continuous development and utilization of land, there are many obstacles to land due to human factors and soil-forming factors, such as poor soil structure, salinization, acidification, weak water retention, etc., which make land productivity low. People's production practice and research have found that adding soil conditioners to soil with obstacles can improve soil properties and increase land productivity. They are not the main materials for providing plant nutrients, but can significantly increase crop yields and improve product quality. Gardening waste is rich in beneficial nutrients. Using it as a soil conditioner can not only improve the quality of the land to a certain extent, but also realize the reuse of gardening waste. However, the improvement effect of a single gardening waste on the soil is limited, so it is necessary to enhance its improvement effect to meet the higher demands in the field of soil conditioner technology. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a modified soil conditioner containing garden waste.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A modified soil conditioner containing garden waste is prepared by the following steps:

[0008] A1. Add garden waste into a pulverizer for pulverization, mix with chlorinated polypropylene, place in a drying oven at 100° C. to dry until the water is removed, and then place in a tubular furnace for carbonization. After carbonization is completed, biochar is obtained;

[0009] A2. The biochar, distilled water and modified polyacrylamide prepared in step A1 are stirred and mixed evenly, and the mixture is placed in an oven for dehydration to obtain a modified soil conditioner containing garden waste.

[0010] Furthermore, the raw materials are calculated in parts by weight as follows: 40-60 parts of garden waste, 10-20 parts of chlorinated polypropylene, and 15-30 parts of modified polyacrylamide.

[0011] Furthermore, the dehydration condition in the oven is to bake in an oven at 60° C. for 3-5 hours until the moisture content reaches 20-30%.

[0012] Furthermore, the carbonization conditions are 500-600° C. and carbonization time is 4-6 hours.

[0013] Using garden waste as raw material for biochar not only reduces costs, but also realizes the recycling of waste resources. Moreover, the obtained biochar can be used as one of the raw materials for improver, which can improve soil fertility, improve soil structure and ensure the healthy growth of crops. In addition, chlorinated polypropylene can generate hydrogen chloride gas during the carbonization process, which is absorbed by biochar and acidifies the surface of biochar, so it can be applied to alkaline soil contaminated by heavy metals. Finally, biochar is modified by modified polyacrylamide to increase the hydrophilic groups in biochar, improve the water retention capacity and adhesion of biochar, and reduce the cost of water retention and water saving.

[0014] Furthermore, the modified polyacrylamide is prepared by the following steps:

[0015] Add allyl polyoxyethylene ether, acrylamide, deionized water and isopropanol to a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, stir and mix evenly, then add (NH4)2S2O8 (initiator) to start the reaction. After the reaction is completed, stop stirring and wait for the device to cool to room temperature to obtain modified polyacrylamide.

[0016] Furthermore, the usage ratio of allyl polyoxyethylene ether, acrylamide, deionized water, isopropanol, and (NH4)2S2O8 is 10g:15g:100mL:2g:0.3g.

[0017] Furthermore, the reaction was a stirring reaction, the temperature was controlled at 80° C., and the reaction lasted for 4 hours.

[0018] Under the action of the initiator, allyl polyoxyethylene ether and acrylamide undergo polymerization reaction to obtain modified polyacrylamide;

[0019] Polyacrylamide is an artificial conditioner that can reduce soil bulk density, increase the content of large aggregates, improve soil structure, enhance soil water retention and water holding capacity, adsorb and fix soil nutrients, have good fertilizer retention capacity, and reduce soil nutrient loss. In addition, polyacrylamide can also promote crop growth and increase crop yields. In addition, polyacrylamide is not easily decomposed by soil microorganisms, has a long-lasting effect, and is harmless to soil microorganisms and soil animals.

[0020] It should be added that by modifying polyacrylamide and grafting allyl polyoxyethylene ether, polyoxyethylene ether contains a large number of hydroxyl groups and ether bonds and has extremely strong hydrophilicity, which can further enhance the water retention properties of polyacrylamide and improve the soil improvement effect.

[0021] Beneficial effects of the present invention:

[0022] 1. The soil conditioner prepared by the present invention uses garden waste as biochar raw material and uses chlorinated polypropylene to acidify its surface, which not only improves the performance of the conditioner but also saves costs;

[0023] 2. The modified polyacrylamide has better water retention performance and better soil improvement effect than ordinary polyacrylamide;

[0024] Therefore, the soil conditioner prepared by the present invention has good soil improvement effect, low cost, and realizes the recycling of waste resources, and has important application value in the field of soil conditioner technology. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1

[0027] Preparation of modified polyacrylamide:

[0028] To a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, add 10 g of allyl polyoxyethylene ether, 15 g of acrylamide, 100 mL of deionized water and 2 g of isopropanol. After stirring and mixing evenly, add 0.3 g of (NH4)2S2O8. Control the reaction temperature to 80°C and stir the reaction for 4 hours. After the reaction is completed, stop stirring and wait for the device to cool to room temperature to obtain modified polyacrylamide.

[0029] Embodiment 2

[0030] Preparation of modified polyacrylamide:

[0031] To a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, add 20 g of allyl polyoxyethylene ether, 30 g of acrylamide, 200 mL of deionized water and 4 g of isopropanol. After stirring and mixing evenly, add 0.6 g of (NH4)2S2O8. Control the reaction temperature to 80°C and stir the reaction for 4 hours. After the reaction is completed, stop stirring and wait for the device to cool to room temperature to obtain modified polyacrylamide.

[0032] Embodiment 3

[0033] A1. 40 g of garden waste was added to a grinder for grinding, mixed with 10 g of chlorinated polypropylene, placed in a drying oven at 100 ° C until the water was removed, and then placed in a tubular furnace at 500 ° C for carbonization for 4 h to obtain biochar;

[0034] A2. The biochar obtained in step A1, 200 mL of distilled water and 15 g of modified polyacrylamide obtained in Example 1 were stirred and mixed evenly, placed in an oven at 60° C. and dried for 3 h, and taken out when the moisture content was 20%, to obtain a modified soil conditioner containing garden waste.

[0035] Embodiment 4

[0036] A1. 50 g of garden waste was added to a grinder for grinding, mixed with 15 g of chlorinated polypropylene, placed in a drying oven at 100 ° C until the water was removed, and then placed in a tubular furnace at 550 ° C for carbonization for 5 h to obtain biochar;

[0037] A2. The biochar obtained in step A1, 200 mL of distilled water and 22.5 g of modified polyacrylamide obtained in Example 2 were stirred and mixed evenly, placed in an oven at 60° C. and dried for 4 h. When the moisture content was 25%, the mixture was taken out to obtain a modified soil conditioner containing garden waste.

[0038] Embodiment 5

[0039] A1. Add 60g of garden waste into a grinder for grinding, mix with 20g of chlorinated polypropylene, place in a drying oven at 100°C to dry until the water is removed, and then place in a tubular furnace at 600°C for carbonization for 6h to obtain biochar;

[0040] A2. The biochar prepared in step A1, 200 mL of distilled water and 30 g of modified polyacrylamide prepared in Example 2 were stirred and mixed evenly, placed in an oven at 60° C. and dried for 5 h. When the moisture content was 30%, the mixture was taken out to obtain a modified soil conditioner containing garden waste.

[0041] Comparative Example 1

[0042] Use a commercially available soil conditioner.

[0043] Comparative Example 2

[0044] Ordinary polyacrylamide of the same mass was used to replace the modified polyacrylamide in Example 5, and the remaining steps were the same as those in Example 5 to prepare a soil conditioner.

[0045] The examples 3, 4 and 5, and the comparative examples 1 and 2 were mixed with deionized water in a centrifuge tube at a ratio of solid:liquid = 1:10 (w / v), and the centrifuge tube was placed in a horizontal oscillator and oscillated at a constant temperature of 25° C. and 180 rpm for 1 hour, and the pH value of the supernatant was measured with a pH meter;

[0046] In a PVC tube with a bulk density of 1.5 g / cm, a diameter of 10 cm and a height of 12 cm, Examples 3, 4 and 5, and Comparative Examples 1 and 2 were added respectively, and the bottom end of the tube was sealed with gauze, the soil filling height was 10 cm, and the soil column was moistened to saturation by self-absorption. After 24 hours, it was placed in an artificial climate box (temperature 35°C, relative humidity 70%) for cultivation, and the lower limit of the moisture content of the soil column was controlled to be 80% of the field water holding capacity (field water holding capacity treated with CK). If it was lower than this moisture content, the soil column was saturated and then continued to be placed in the climate box for cultivation for 60 days.

[0047] The soil was taken with a circular knife and the soil water content at different water suctions was determined using a centrifuge;

[0048] The soil bulk density was calculated by drying, the soil specific gravity was determined by the pycnometer method, and the total soil porosity was obtained by the formula: total soil porosity = (1-bulk density / specific gravity) × 100%;

[0049] Soil organic matter content was determined using potassium dichromate volumetry;

[0050] The measured results are shown in the following table:

[0051] Test items Embodiment 3 Embodiment 4 Embodiment 5 Comparative Example 1 Comparative Example 2 Effective water content / % 23.1 24.5 25.9 16.4 19.1 Total soil porosity / % 52.3 52.7 53.0 37.4 51.8 Organic matter content / % 64.4 64.5 64.5 57.1 64.2

[0052] It can be seen from the above table that the soil conditioner prepared in the embodiment of the present invention has a good effect on improving the soil, and the effective water content, total soil porosity and organic matter content are higher than those of the control example. It also realizes the recycling of waste resources and has important application value in the field of soil conditioner technology.

[0053] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A modified soil conditioner containing garden waste, characterized in that: Prepared by the following steps: A1. Add garden waste into a pulverizer for pulverization, mix with chlorinated polypropylene, place in a drying oven at 100° C. to dry until the water is removed, and then place in a tubular furnace for carbonization. After carbonization is completed, biochar is obtained; A2. The biochar, distilled water and modified polyacrylamide prepared in step A1 are stirred and mixed evenly, placed in an oven at 60° C. and dried for 3-5 hours, and taken out when the moisture content is 20-30%, to obtain a modified soil conditioner containing garden waste.

2. The modified soil conditioner containing garden waste according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 40-60 parts of garden waste, 10-20 parts of chlorinated polypropylene, and 15-30 parts of modified polyacrylamide.

3. The modified soil conditioner containing garden waste according to claim 1, characterized in that: The dehydration condition in the oven is to bake in an oven at 60° C. for 3-5 hours until the moisture content is 20-30%.

4. The modified soil conditioner containing garden waste according to claim 1, characterized in that: The carbonization conditions are 500-600° C. and carbonization time of 4-6 hours.

5. The modified soil conditioner containing garden waste according to claim 1, characterized in that: The modified polyacrylamide is prepared by the following steps: After allyl polyoxyethylene ether, acrylamide, deionized water and isopropanol are stirred and mixed evenly, (NH4)2S2O8 is added, the reaction temperature is controlled to 80°C, and the reaction is stirred for 4 hours. After the reaction is completed, the stirring is stopped and the device is cooled to room temperature to obtain modified polyacrylamide.

6. The modified soil conditioner containing garden waste according to claim 4, characterized in that: The usage ratio of allyl polyoxyethylene ether, acrylamide, deionized water, isopropanol and (NH4)2S2O8 is 10g:15g:100mL:2g:0.3g.

7. The modified soil conditioner containing garden waste according to claim 4, characterized in that: The reaction was stirred at 80° C. for 4 h.