A trace element complex regulator and a preparation method thereof

Abstract

The present application relates to a kind of trace element composite regulator and its preparation method, belong to the technical field of soil regulator.The preparation method of composite regulator includes the following steps: 1) humic acid is added to alkaline solution and stirred, after adding activator and heating reaction, temperature is reduced to room temperature, and modified humic acid is obtained;2) attapulgite and hydrochloric acid are stirred and mixed, washed, dried, after adding sodium chloride and stirring, solid is taken and washed again, after adding modifier and microwave treatment, modified humic acid is added and ground, freeze-dried, and mixture is obtained;3) the mixture and rice husk ash are stirred and mixed, and composite regulator is obtained.The present application is modified humic acid with modified attapulgite, modified attapulgite improves its hydrophobicity, and modified attapulgite forms adsorption to modified humic acid, so that the mixture is more stable, and trace element is less likely to be lost in the process of composite regulator regulating soil.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil conditioners, and relates to a medium and trace element composite conditioner and a preparation method thereof. BACKGROUND

[0002] Soil is the foundation of agricultural development, and its quality has an important influence on the sustainable development of agriculture. Soil provides essential nutrient elements, especially medium and trace elements, to plants, which not only depends on the total amount of these elements, but also relates to their bioavailability. The bioavailability mainly depends on the chemical form of these elements in the soil. For example, elements in the dissolved and exchangeable states are most easily absorbed and utilized by plants. However, in recent years, a large amount of nitrogen, phosphorus and potassium fertilizers have been invested, but the investment in medium and trace elements has been ignored, resulting in a decline in soil quality, and the effective content of medium and trace elements in many places is lower than the critical value for crop absorption and utilization.

[0003] Lime soil has a high pH value and is rich in calcium carbonate, resulting in low availability of many trace elements. In the acid soil widely distributed in the south, calcium, magnesium and other medium and trace elements are lost more and have a low content.

[0004] Humic acid is a natural organic macromolecular compound containing various functional groups such as carboxyl, carbonyl, hydroxyl and quinone groups, and has high reactivity. When humic acid enters the soil, it will adsorb and complex with medium and trace elements, thereby affecting the bioavailability of medium and trace nutrients. On the market, humic acid is generally oxidized and modified to increase the content of carboxyl groups, but carboxyl groups are easily dissociated at a high pH and are not suitable for use in acid soil. SUMMARY

[0005] The purpose of the present application is to provide a medium and trace element composite conditioner and a preparation method thereof. The present application modifies humic acid, so that the presence of a large number of sulfonic acid groups makes it more soluble, and it is easier to combine with medium elements such as calcium and magnesium and trace elements such as copper, zinc, iron and manganese in low-pH soil. Modified humic acid is combined with modified attapulgite, which improves the hydrophobicity of the modified attapulgite, and the modified attapulgite forms an adsorption with the modified humic acid, so that the mixture is more stable, and the medium and trace elements are less likely to be lost during the conditioning of the soil by the composite conditioner.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] A medium and trace element composite conditioner, and a preparation method thereof, includes the following steps:

[0008] 1) humic acid is added to an alkaline solution and stirred and mixed, an activating agent is added, and after heating and reaction, the temperature is lowered to room temperature to obtain modified humic acid; the modified humic acid has the advantages of a small molecular weight and a large number of sulfonic acid groups, and thus has stronger solubility and is more easily combined with medium elements such as calcium and magnesium and trace elements such as copper, zinc, iron and manganese in low-pH soil;

[0009] 2) attapulgite and hydrochloric acid are stirred and mixed, washed and dried, sodium chloride is added, heated and stirred, and then the solid is washed twice, a modifier is added and subjected to microwave treatment, and then modified humic acid is added and ground, and freeze-drying is performed to obtain a mixture; after the modification of attapulgite by the modifier, part of the organic groups of the modifier replace the inorganic cations of attapulgite, the hydrophobicity of attapulgite is improved, the adsorption capacity of modified attapulgite for modified humic acid is enhanced, the mixture is more stable, and the trace elements are less likely to be lost during the regulation of the soil by the composite regulator;

[0010] 3) the mixture and rice husk ash are stirred and mixed to obtain a composite regulator.

[0011] As a preferred technical solution of the present application, in step 1), the heating reaction is performed at a temperature of 65-75℃ for 4-5h.

[0012] As a preferred technical solution of the present application, in step 1), the mass ratio of the humic acid, the alkaline solution and the activating agent is 1:10:0.20-0.25.

[0013] As a preferred technical solution of the present application, in step 1), the alkaline solution is a 0.25-0.03mol / L sodium hydroxide aqueous solution; and the activating agent is a 20-23% mass concentration sodium sulfite aqueous solution.

[0014] As a preferred technical solution of the present application, in step 2), the stirring and mixing are performed at 25℃ for 3.0-3.5h; the washing is performed until neutral; the heating and stirring are performed at a temperature of 90-95℃ and a rotation speed of 400-500r / min for 2.0-2.5h; the secondary washing is performed by washing with deionized water for 5 times; and the grinding is performed through a 200-mesh sieve.

[0015] As a preferred technical solution of the present application, in step 2), the dosages of the attapulgite, the hydrochloric acid, the sodium chloride, the modifier and the modified humic acid are 44-46g:95-100mL:100-110mL:0.30-0.35g:60-70g.

[0016] As a preferred technical scheme of the present application, in step 2), the microwave treatment is performed at a frequency of 100-120 Hz for 5-10 min.

[0017] As a preferred technical scheme of the present application, in step 2), the sodium chloride is a 0.5 mol / L aqueous sodium chloride solution; the concentration of the hydrochloric acid is 3 mol / L; and the modifier is one or both of octadecyl trimethyl ammonium chloride and hexadecyl trimethyl ammonium chloride.

[0018] As a preferred technical scheme of the present application, in step 3), the rice husk ash has a mesh number of 100-120; and the mass ratio of the mixture to the rice husk ash is 4.0-5.5:0.8-1.3.

[0019] As a preferred technical scheme of the present application, the rice husk ash in all the examples and comparative examples of the present application is uniform, and specifically, the rice husk ash has a silicon content of 40% and a carbon content of 20%.

[0020] The present application has the following beneficial effects:

[0021] The present application is modified by humic acid, and the presence of a large amount of sulfonic acid groups makes it more soluble, and it is easier to combine with medium elements such as calcium and magnesium and trace elements such as copper, zinc, iron and manganese in low-pH soil. The modified humic acid is combined with modified attapulgite, the modified attapulgite improves its hydrophobicity, and the modified attapulgite forms adsorption with the modified humic acid, so that the mixture is more stable, and the trace elements are less likely to be lost during the soil adjustment process of the composite regulator. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purposes, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with examples.

[0023] Example 1

[0024] A preparation method of a medium and trace element composite regulator comprises the following steps:

[0025] 1) Humic acid is added to an alkaline solution and stirred to mix, an activator is added, and after heating reaction, the temperature is lowered to room temperature to obtain modified humic acid; wherein the heating reaction is performed at a temperature of 65℃ for 4h; the mass ratio of the humic acid, the alkaline solution and the activator is 1:10:0.20; the alkaline solution is a 0.25 mol / L aqueous sodium hydroxide solution; and the activator is a 20% mass concentration aqueous sodium sulfite solution;

[0026] 2) stirring and mixing attapulgite and hydrochloric acid, washing and drying, then adding sodium chloride, heating and stirring, taking the solid to wash for the second time, adding modifier, microwave treatment, adding modified humic acid, grinding, freeze-drying to obtain a mixture; wherein the stirring and mixing conditions are stirring for 3.0 h at 25℃; the washing conditions are washing to neutral; the heating and stirring conditions are stirring for 2.0 h at 90℃ and 400 r / min; the second washing conditions are washing 5 times with deionized water; the microwave treatment conditions are 100 Hz frequency for 5 min; the grinding conditions are passing through a 200-mesh screen; the mass ratio of attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 44 g:95 mL:100 mL:0.30 g:60 g; the sodium chloride is a 0.5 mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3 mol / L; the modifier is octadecyl trimethyl ammonium chloride.

[0027] 3) stirring and mixing the mixture and rice husk ash to obtain a composite regulator; wherein the mesh number of the rice husk ash is 100 mesh; the mass ratio of the mixture and rice husk ash is 4.0:0.8.

[0028] Example 2

[0029] A preparation method of a microelement composite regulator comprises the following steps:

[0030] 1) stirring and mixing humic acid into an alkaline solution, adding an activator for heating reaction, then cooling to room temperature to obtain modified humic acid; wherein the heating reaction conditions are 67℃ for 4.2 h; the mass ratio of humic acid, alkaline solution and activator is 1:10:0.21; the alkaline solution is a 0.21 mol / L sodium hydroxide aqueous solution; the activator is a 20.6% mass concentration sodium sulfite aqueous solution;

[0031] 2) stirring and mixing attapulgite and hydrochloric acid, washing and drying, then adding sodium chloride, heating and stirring, taking the solid to wash for the second time, adding modifier, microwave treatment, adding modified humic acid, grinding, freeze-drying to obtain a mixture; wherein the stirring and mixing conditions are stirring for 3.1 h at 25℃; the washing conditions are washing to neutral; the heating and stirring conditions are stirring for 2.1 h at 91℃ and 420 r / min; the second washing conditions are washing 5 times with deionized water; the microwave treatment conditions are 104 Hz for 6 min; the grinding conditions are passing through a 200-mesh screen; the mass ratio of attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 44.4 g:96 mL:102 mL:0.31 g:62 g; the sodium chloride is a 0.5 mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3 mol / L; the modifier is octadecyl trimethyl ammonium chloride.

[0032] 3) stirring and mixing the mixture and rice husk ash to obtain a composite regulator; wherein the mesh number of the rice husk ash is 100 mesh; the mass ratio of the mixture and rice husk ash is 4.3:0.9.

[0033] Example 3

[0034] A preparation method of a microelement composite regulator comprises the following steps:

[0035] 1) stirring and mixing humic acid into an alkaline solution, adding an activator for heating reaction, then cooling to room temperature to obtain modified humic acid; wherein the heating reaction conditions are 69℃ for 4.4 h; the mass ratio of humic acid, alkaline solution and activator is 1:10:0.22; the alkaline solution is a 0.16 mol / L sodium hydroxide aqueous solution; the activator is a 21.2% mass concentration sodium sulfite aqueous solution;

[0036] 2) stirring and mixing attapulgite and hydrochloric acid, washing and drying, then adding sodium chloride, heating and stirring, taking the solid to wash for the second time, adding modifier, microwave treatment, adding modified humic acid, grinding, freeze-drying to obtain a mixture; wherein the stirring and mixing conditions are stirring for 3.2 h at 25℃; the washing conditions are washing to neutral; the heating and stirring conditions are stirring for 2.2 h at 92℃ and 440 r / min; the second washing conditions are washing 5 times with deionized water; the microwave treatment conditions are 108 Hz frequency for 7 min; the grinding conditions are passing through a 200-mesh screen; the mass ratio of attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 44.8 g:97 mL:104 mL:0.32 g:64 g; the sodium chloride is a 0.5 mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3 mol / L; the modifier is octadecyl trimethyl ammonium chloride.

[0037] 3) stirring and mixing the mixture and rice husk ash to obtain a composite regulator; wherein the mesh number of the rice husk ash is 110; the mass ratio of the mixture and rice husk ash is 4.6:1.

[0038] Example 4

[0039] A preparation method of a microelement composite regulator comprises the following steps:

[0040] 1) stirring and mixing humic acid into an alkaline solution, adding an activator for heating reaction, then cooling to room temperature to obtain modified humic acid; wherein the heating reaction conditions are 71℃ for 4.6 h; the mass ratio of humic acid, alkaline solution and activator is 1:10:0.23; the alkaline solution is a 0.12 mol / L sodium hydroxide aqueous solution; the activator is a 21.8% mass concentration sodium sulfite aqueous solution;

[0041] 2) stirring and mixing attapulgite and hydrochloric acid, washing and drying, then adding sodium chloride, heating and stirring, taking the solid to wash for the second time, adding modifier, microwave treatment, adding modified humic acid, grinding, freeze-drying to obtain a mixture; wherein the stirring and mixing conditions are stirring for 3.3 h at 25℃; the washing conditions are washing to neutral; the heating and stirring conditions are stirring for 2.3 h at 93℃ and 460 r / min; the second washing conditions are washing 5 times with deionized water; the microwave treatment conditions are 112 Hz frequency for 8 min; the grinding conditions are passing through a 200-mesh screen; the mass ratio of attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 45.2 g:98 mL:106 mL:0.33 g:66 g; the sodium chloride is a 0.5 mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3 mol / L; the modifier is octadecyl trimethyl ammonium chloride.

[0042] 3) stirring and mixing the mixture and rice husk ash to obtain a composite regulator; wherein the mesh number of the rice husk ash is 110; the mass ratio of the mixture and rice husk ash is 4.9:1.1.

[0043] Example 5

[0044] A preparation method of a microelement composite regulator comprises the following steps:

[0045] 1) stirring and mixing humic acid into an alkaline solution, adding an activator for heating reaction, then cooling to room temperature to obtain modified humic acid; wherein the heating reaction conditions are 73℃ for 4.8 h; the mass ratio of humic acid, alkaline solution and activator is 1:10:0.24; the alkaline solution is a 0.07 mol / L sodium hydroxide aqueous solution; the activator is a 22.4% mass concentration sodium sulfite aqueous solution;

[0046] 2) stirring and mixing attapulgite and hydrochloric acid, washing and drying, then adding sodium chloride, heating and stirring, taking the solid to wash for the second time, adding modifier, microwave treatment, adding modified humic acid, grinding, freeze-drying to obtain a mixture; wherein the stirring and mixing conditions are stirring for 3.4 h at 25℃; the washing conditions are washing to neutral; the heating and stirring conditions are stirring for 2.4 h at 94℃ and 480 r / min; the second washing conditions are washing 5 times with deionized water; the microwave treatment conditions are 116 Hz frequency for 9 min; the grinding conditions are passing through a 200-mesh screen; the mass ratio of attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 45.6 g:99 mL:108 mL:0.34 g:68 g; the sodium chloride is a 0.5 mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3 mol / L; the modifier is octadecyl trimethyl ammonium chloride.

[0047] 3) stirring and mixing the mixture and rice husk ash to obtain a composite regulator; wherein the mesh number of the rice husk ash is 120 meshes; the mass ratio of the mixture and rice husk ash is 5.2:1.2.

[0048] Example 6

[0049] A preparation method of a microelement composite regulator comprises the following steps:

[0050] 1) adding humic acid to an alkaline solution and stirring and mixing, adding an activator and heating to react, then cooling to room temperature to obtain modified humic acid; wherein the heating reaction conditions are 75℃ for 5 h; the mass ratio of humic acid, alkaline solution and activator is 1:10:0.25; the alkaline solution is a 0.03 mol / L sodium hydroxide aqueous solution; the activator is a 23% mass concentration sodium sulfite aqueous solution;

[0051] 2) the attapulgite and hydrochloric acid are stirred and mixed, washed and dried, then sodium chloride is added and stirred and heated, the solid is washed twice, a modifier is added and treated by microwave, then modified humic acid is added and ground, and the mixture is freeze-dried to obtain a composite modifier; the stirring and mixing is performed at 25°C for 3.5h; the washing is performed until neutral; the stirring and heating is performed at 95°C and a rotation speed of 500r / min for 2.5h; the washing is performed 5 times with deionized water; the microwave treatment is performed at a frequency of 120Hz for 10min; the grinding is performed through a 200-mesh sieve; the attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid are used in a ratio of 46g:100mL:110mL:0.35g:70g; the sodium chloride is a 0.5mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3mol / L; and the modifier is octadecyl trimethyl ammonium chloride.

[0052] 3) the mixture and rice husk ash are stirred and mixed to obtain a composite modifier; the rice husk ash has a mesh number of 120; and the mass ratio of the mixture to the rice husk ash is 5.5:1.3.

[0053] Comparative Example 1

[0054] Comparative Example 1 is different from Example 5 in that no activator is added, and the other components, preparation steps and parameters are the same.

[0055] Comparative Example 2

[0056] Comparative Example 2 is different from Example 5 in that no modifier is added, and the other components, preparation steps and parameters are the same.

[0057] Comparative Example 3

[0058] Comparative Example 3 is different from Example 5 in that no modified humic acid is added, and the other components, preparation steps and parameters are the same.

[0059] Comparative Example 4

[0060] Comparative Example 4 is different from Example 5 in that modified humic acid and rice husk ash are stirred and mixed to obtain a composite modifier; the rice husk ash has a mesh number of 120; the mass ratio of the modified humic acid to the rice husk ash is 5.2:1.2, and the other components, preparation steps and parameters are the same.

[0061] Comparative Example 5

[0062] Comparative Example 5 is different from Example 5 in that step 2) is different.

[0063] Step 2) After the attapulgite and hydrochloric acid are stirred and mixed, washed and dried, sodium chloride is added and stirred and heated, the solid is washed again, a modifier is stirred and treated, modified humic acid is ground, and the mixture is freeze-dried to obtain a mixture; wherein the stirring and mixing conditions are 3.5 h of stirring at 25°C; the washing conditions are washing to neutral; the heating and stirring conditions are 2.5 h of stirring at a temperature of 95°C and a rotation speed of 500 r / min; the second washing conditions are washing 5 times with deionized water; the stirring and treating conditions are 10 min of stirring at 3000 r / min; the grinding conditions are passing through a 200-mesh sieve; the amount ratio of the attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 46 g:100 mL:110 mL:0.35 g:70 g; the sodium chloride is a 0.5 mol / L sodium chloride aqueous solution; the concentration of the hydrochloric acid is 3 mol / L; and the modifier is octadecyl trimethyl ammonium chloride.

[0064] The remaining components, preparation steps and parameters are consistent.

[0065] Test:

[0066] Red soil is collected from Guangfu Town, Nanchang County, Nanchang City, Jiangxi Province, and is a field plot with uniform fertility and medium fertility. The 0-20 cm plough layer soil is naturally air-dried, passed through a 1 mm sieve, and mixed uniformly for use. The basic physicochemical properties are as follows: pH 4.63, organic matter content 16.34 g / kg, total nitrogen 1.22 g / kg, available phosphorus 14.85 mg / kg, available potassium 180.22 mg / kg, available calcium 363.08 mg / kg, available copper 1.67 mg / kg, available zinc 2.88 mg / kg, available iron 9.99 mg / kg, available manganese 25.00 mg / kg, and available magnesium 96.81 mg / kg.

[0067] The red soil is set up into 12 treatment groups, and no composite regulator is applied as a blank group, and the remaining 11 groups are applied with the composite regulators prepared in Examples 1-6 and Comparative Examples 1-5; the composite regulator is mixed with 500 g of red soil at a dosage of 100 mg / kg, loaded into a culture bottle, the water content is adjusted to 60% of the field water holding capacity, placed in an artificial climate chamber, and incubated at 25°C, and the soil humidity is kept constant. Each treatment is repeated 3 times.

[0068] Sampling is performed at 10, 30 and 45 days of incubation, respectively, the soil samples are naturally air-dried, ground through a 1 mm sieve, and tested. The test method: the water-soluble calcium and magnesium in the soil are extracted with water (soil to water ratio 1:5), and the content of the corresponding elements in the extract is determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the test results are shown in Table 1.

[0069] Table 1

[0070]

[0071] From the test results in Table 1, it can be seen that the composite regulator prepared in Examples 1-6 has a significantly better regulating ability for calcium and magnesium elements than Comparative Examples 1-5.

[0072] The above description is only the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to make equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the present application, and which is based on the technical essence of the present application, still belongs to the scope of the technical solution of the present application.

Claims

1. A method for preparing a complex regulator of trace elements, characterized in that, The preparation method includes the following steps: 1) Add humic acid to an alkaline solution and stir to mix. Add an activator and heat at 65-75℃ for 4-5 hours. Then cool to room temperature to obtain modified humic acid. 2) Mix attapulgite and hydrochloric acid, wash and dry, add sodium chloride, heat and stir, take the solid for a second wash, add modifier and microwave treatment, add modified humic acid and grind, freeze dry to obtain a mixture; 3) After mixing the mixture with rice husk ash, a composite regulator is obtained; In step 1), the alkaline solution is a 0.25-0.03 mol / L sodium hydroxide aqueous solution; the activator is a 20-23% (w / w) sodium sulfite aqueous solution; and the mass ratio of the humic acid, alkaline solution, and activator is 1:10:0.20-0.

25. In step 2), the modifier is one or both of octadecyltrimethylammonium chloride and hexadecyltrimethylammonium chloride; the sodium chloride is a 0.5 mol / L aqueous solution of sodium chloride; the hydrochloric acid has a concentration of 3 mol / L; and the ratio of attapulgite, hydrochloric acid, sodium chloride, modifier and modified humic acid is 44-46 g: 95-100 mL: 100-110 mL: 0.30-0.35 g: 60-70 g. In step 2), the mixing conditions are: stirring at 25°C for 3.0-3.5 hours; the washing conditions are: washing until neutral; the heating and stirring conditions are: stirring at 90-95°C and 400-500 r / min for 2.0-2.5 hours; the secondary washing conditions are: washing 5 times with deionized water; and the grinding conditions are: passing through a 200-mesh sieve. In step 2), the microwave treatment conditions are 100-120Hz frequency and 5-10min.

2. The preparation method of a micronutrient composite regulator according to claim 1, characterized in that: In step 3), the rice husk ash has a mesh size of 100-120; the mass ratio of the mixture to the rice husk ash is 4.0-5.5:0.8-1.

3.

3. A micronutrient composite regulator prepared by the preparation method according to any one of claims 1-2.

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