Dopamine-type improved conditioning fertilizer specially used for saline-alkali land and preparation method thereof

Abstract

The present invention belongs to the technical field of fertilizer development, and specifically, relates to a dopamine-type improved conditioning fertilizer for saline-alkali land and a preparation method thereof. The present invention is based on fertilizer, and dopamine prepared from papermaking black liquor and an organic amine template are added to the fertilizer, and then a cross-linking agent and an initiator are added, and then pressurized granulation is performed to obtain the dopamine-type improved conditioning fertilizer. The dopamine-type improved conditioning fertilizer can realize self-polymerization into polydopamine in the alkaline soil environment of saline-alkali land, and the template agent tetrapropylammonium hydroxide can perform corresponding pore formation by utilizing the potential difference signal generated by glutathione in the plant body, thereby realizing the controllable polymerization of dopamine, realizing the adjustment of pore size and polymerization degree, and polydopamine locks sodium in saline-alkali land, thereby returning the pH value to the normal land range, effectively improving the saline-alkali land environment and being beneficial to plant growth.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizer development, and in particular relates to a dopamine-type improved conditioning fertilizer specially used for saline-alkali land and a preparation method thereof. Background Art

[0002] With the rapid development of social economy and the continuous advancement of urbanization, the reduction of cultivated land area and soil desertification are becoming increasingly serious. Secondary salinization of soil occurs frequently, especially in water-scarce and arid areas. In the case of insufficient reserve cultivated land, an important way to develop ecological industries and expand development space is to effectively control saline-alkali land. Developing and sustainably utilizing saline-alkali land, preventing soil salinization and saline-alkali land salt return, can greatly alleviate the pressure on my country's grain and non-staple food, expand the space for survival and development, and is of great significance to ensuring national food security and the sustainable development of agriculture, forestry, animal husbandry, sideline production, fishery and ecological recycling industries.

[0003] At present, the main methods for the treatment of saline-alkali land include desulfurized gypsum, flooding with water to wash salt, concealed pipes to drain salt, spraying of salt-tolerant microorganisms, and large-scale use of organic fertilizers. Although the above methods have certain effects in improving the salinity of soil, they still cannot effectively solve the problem of salt return caused by large water consumption, water pollution, and soil moisture evaporation, which is not conducive to the later growth of plants.

[0004] Therefore, how to provide a new type of treatment technology that is pollution-free, low-cost and effective is a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0005] In view of the above problems existing in the prior art, the object of the present invention is to provide a dopamine-type improved conditioning fertilizer specially used for saline-alkali land and a preparation method thereof.

[0006] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A dopamine-type improved conditioning fertilizer specially used for saline-alkali land comprises the following components in parts by weight: 10-40 parts of fertilizer, 5-10 parts of dopamine, 0.5-2 parts of organic amine template, 0.3-0.7 parts of initiator and 0.1-0.2 parts of cross-linking agent.

[0008] Optionally, the mass ratio of the dopamine to the organic amine template is (6-10):1.

[0009] Optionally, the organic amine template is tetrapropylammonium hydroxide.

[0010] Optionally, the fertilizer includes two or more of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer.

[0011] Optionally, the initiator is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, potassium persulfate and sodium persulfate.

[0012] Optionally, the cross-linking agent is one or more of polyethyleneimine, 1,4-butanediol diglycidyl ether and N,N-methylenebisacrylamide.

[0013] The preparation method of the above-mentioned dopamine-type improved conditioning fertilizer for saline-alkali land includes the following steps: adding dopamine and an organic amine template into the fertilizer and stirring and mixing; then adding a crosslinking agent and an initiator, mixing, pressurizing and granulating to obtain the dopamine-type improved conditioning fertilizer for saline-alkali land.

[0014] Optionally, the pressure of the pressurized granulation is 0.4-0.8 MPa, the time is 20-30 min, and the particle size range is: 2-4 mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The dopamine-based improved conditioning fertilizer of the present invention can realize self-polymerization into polydopamine in the alkaline soil environment of saline-alkali land. Polydopamine locks sodium in the saline-alkali land, thereby returning the pH value to the normal range of the land; and by utilizing the potential difference signal generated by glutathione in the plant body, the template agent tetrapropylammonium hydroxide can perform corresponding pore formation, thereby realizing the controllable polymerization of dopamine and realizing the adjustment of pore size and polymerization degree. Under the appropriate dopamine to template agent dosage ratio of the present invention, the formed polydopamine has an appropriate pore size and polymerization degree, and the Na + The free flow of water not only improves the saline-alkali land environment, but also maintains the Na content of plants in the soil. + demand.

[0017] (2) The raw materials used in the present invention are cheap and readily available, which can effectively reduce the manufacturing cost. The selected raw materials are relatively mild and easy to operate, and can improve soil fertility without causing harm to the soil, thereby reducing the salinity of saline-alkali land, lowering the pH value, and increasing crop yields;

[0018] (3) The present invention is environmentally friendly, has good restoration effect, is not prone to salinization, is simple and easy to operate, has a wide range of applications, and is highly sustainable. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with specific embodiments.

[0020] Urea: Chemical formula: CH4N2O, CAS: 57-13-6; 37955-36-5.

[0021] The remaining raw materials are conventional commercially available products.

[0022] Preparation of dopamine: dopamine was prepared according to the method in patent CN115215752A, and the specific steps are as follows:

[0023] Take 100g of papermaking black liquor (rice and wheat black liquor), add hydrochloric acid to adjust the pH to 4.5, react at 45°C and normal pressure for 5h, filter the reaction liquid, and dry the precipitate to obtain 44.3g of product A.

[0024] To product A, 12 g of formic acid and 0.05 g of Ru / C reduction catalyst were added, and the mixture was reacted for 6 h at 150° C. with nitrogen (as protective gas) at an initial pressure of 1 MPa. The reaction liquid was filtered and evaporated to extract 4.03 g of product B.

[0025] Add 6 g of methanol and 0.1 g of ZrO2 hydrolysis catalyst to product B, react for 1 h at 400 ° C and fill with nitrogen (as protective gas) at an initial pressure of 5 MPa, filter the reaction liquid, and evaporate to extract 4.00 g of product C;

[0026] The product C was dissolved in p-xylene solvent, 0.1 g of Ru / hydroxyapatite grafted catalyst and ammonia gas with an initial pressure of 0.2 MPa (as a nucleophilic reagent) were added, and nitrogen gas with an initial pressure of 0.8 MPa was introduced to adjust the pressure (to reduce product gasification and increase the yield). The reaction was carried out at 200°C for 8 h, and the reaction liquid was filtered and evaporated to obtain 2.56 g of dopamine. The purity of dopamine was measured to be 99.9%.

[0027] Example 1

[0028] By mass, 15 parts of urea and 15 parts of superphosphate were added to 10 parts of dopamine, and then 8 parts of 20wt% tetrapropylammonium hydroxide (TPAOH) solution were added and stirred evenly. Then 0.4 parts of azobisisobutyronitrile and 0.1 parts of polyethyleneimine were added and mixed. The solid was collected by filtration and dried. The solid was pressurized to 0.04 MPa and maintained for 20 minutes before entering a granulator for granulation to obtain a dopamine-type improved conditioning fertilizer for saline-alkali soil treatment.

[0029] Example 2

[0030] By mass, 26 parts of urea and 10 parts of calcium phosphate were added to 8 parts of dopamine, and then 5 parts of 20wt% TPAOH solution were added and stirred evenly. Then 0.3 parts of azobisisoheptanenitrile and 0.1 parts of polyethyleneimine were added and mixed. The solid was collected by filtration and dried. The solid was pressurized to 0.04 MPa and maintained for 20 minutes before entering a granulator for granulation to obtain a dopamine-type improved conditioning fertilizer for saline-alkali soil treatment.

[0031] Example 3

[0032] By mass, 15 parts of urea and 15 parts of calcium phosphate were added to 10 parts of dopamine, and then 8 parts of 20wt% TPAOH solution were added and stirred evenly. Then 0.6 parts of potassium persulfate and 0.2 parts of N,N-methylenebisacrylamide were added, mixed, the solid was collected by filtration and dried, pressurized to 0.04 MPa and maintained for 20 minutes, and then entered into a granulator for granulation to obtain a dopamine-type improved conditioning fertilizer for saline-alkali soil treatment.

[0033] Comparative Example 1

[0034] By mass, 15 parts of urea and 15 parts of superphosphate were added to 10 parts of dopamine, and then 0.4 parts of azobisisobutyronitrile and 0.1 parts of polyethyleneimine were added and mixed. The solid was collected by filtration and then dried. The solid was pressurized to 0.04 MPa and maintained for 20 minutes before entering a granulator for granulation to obtain a dopamine-type improved conditioning fertilizer for saline-alkali soil treatment.

[0035] Comparative Example 2

[0036] By mass, 10 parts of dopamine were dissolved in a solution of TRIs-HCl (pH=8.5), and 0.4 parts of azobisisobutyronitrile and 0.1 parts of polyethyleneimine were added. After reacting for 24 hours, the mixture was centrifuged, washed with water and dried. 15 parts of urea and 15 parts of superphosphate and 8 parts of 20wt% TPAOH solution were added and stirred evenly. The solid was collected by filtration and dried. The mixture was pressurized to 0.04 MPa and maintained for 20 minutes before entering a granulator for granulation to obtain a dopamine-type improved conditioning fertilizer for saline-alkali soil treatment.

[0037] The effect of the dopamine-based improved conditioning fertilizer prepared in the above embodiment was evaluated, and the conditioning fertilizer was used for soil treatment in saline-alkali land. The treatment method is as follows:

[0038] Spread dopamine-type improved conditioning fertilizer evenly on the surface of saline-alkali land at a rate of 30kg / mu, then till the land, irrigate, drain and dry.

[0039] The performance of the saline-alkali soil before and after treatment was tested and the degree of polymerization of polydopamine was tested. The results are shown in Table 1.

[0040] Table 1 Test results of saline-alkali soil properties and polymerization degree in different examples

[0041]

[0042] The saline-alkali land treated with improved conditioning fertilizer was used for sunflower cultivation, and a blank control group (untreated saline-alkali soil) was set up to statistically analyze the growth of sunflowers. The results are shown in Table 2.

[0043] Table 2 Growth of sunflower

[0044]

[0045] It can be seen from Table 1 and Table 2 that the saline-alkali land dopamine-type improved conditioning fertilizer prepared by the present invention can well improve the saline-alkali land environment. The pH value after treatment returns to normal, and the organic matter content increases significantly from 0.2% to more than 12%. The soil environment is more conducive to plant growth, and the per-acre yield of sunflower is higher.

Claims

1. A method for preparing a dopamine-based improved conditioning fertilizer for saline-alkali land, characterized in that: The following steps are involved: Dopamine and an organic amine template are added to the fertilizer and stirred and mixed; then a cross-linking agent and an initiator are added and mixed, and granulated under pressure to obtain a dopamine-type improved conditioning fertilizer for saline-alkali land; The raw materials include the following components in parts by weight: 10-40 parts of fertilizer, 5-10 parts of dopamine, 0.5-2 parts of organic amine template, 0.3-0.7 parts of initiator, and 0.1-0.2 parts of cross-linking agent; The fertilizers include nitrogen fertilizers and phosphorus fertilizers; The organic amine template is tetrapropylammonium hydroxide; The initiator is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, potassium persulfate and sodium persulfate; The cross-linking agent is one or more of polyethyleneimine, 1,4-butanediol diglycidyl ether and N,N-methylenebisacrylamide.

2. The method for preparing a dopamine-based improved conditioning fertilizer for saline-alkali land according to claim 1, characterized in that: The mass ratio of the dopamine to the organic amine template is (6-10):

1.

3. The method for preparing a dopamine-based improved conditioning fertilizer for saline-alkali land according to claim 1, characterized in that The pressure of the pressurized granulation is 0.4-0.8 MPa, the time is 20-30 min, and the particle size range is: 2~4 mm.

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