Soil cation heavy metal repairing agent and preparation method thereof

Abstract

The invention provides a soil cation heavy metal repairing agent and a preparation method thereof. The soil cation heavy metal repairing agent is prepared from the following raw materials in parts by mass: 30 to 40 parts of inorganic fertilizer B, 40 to 60 parts of organic fertilizer C and 10 to 20 parts of starch glue, wherein the inorganic fertilizer B is prepared from the following raw materials in parts by mass: 40-60 parts of a carrier A, 24-36 parts of monoammonium phosphate and 16-24 parts of potassium sulfate; the carrier A is prepared by mixing pyrolytic charcoal, attapulgite and kaolin; the organic fertilizer C is prepared by mixing dry cow dung, potassium hydroxide and K2SO3; the starch glue is prepared by mixing corn starch, CaO2 and deionized water. According to the soil cation heavy metal repairing agent and the preparation method thereof, cation heavy metal can be converted from an effective state to a low-activity state by adding the soil repairing agent, so that the mobility and bioavailability of the cation heavy metal in soil are reduced, and the soil cation heavy metal repairing agent is low in cost and easy to popularize and apply on a large scale.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a soil cationic heavy metal repair agent and a preparation method thereof. Background Art

[0002] Soil is an important part of the ecosystem, where a large number of microorganisms, plants and animals live. With the acceleration of industrialization and agricultural modernization, soil pollution, especially heavy metal pollution, has become a global environmental problem. These heavy metal pollutants accumulate in the soil, reducing soil fertility and affecting human health through the food chain. At the same time, excessive use of pesticides and fertilizers has also aggravated heavy metal pollution. Therefore, controlling soil heavy metal pollution and restoring soil ecological balance have become urgent issues that need to be addressed. Scientific and effective measures need to be taken to ensure food security and human health and promote sustainable development. Summary of the invention

[0003] The purpose of the present invention is to provide a soil cationic heavy metal repair agent and a preparation method thereof, which can convert cationic heavy metals from an effective state into a low-activity state, thereby reducing their mobility and bioavailability in the soil.

[0004] The purpose of the present invention can be achieved by the following technical measures: a soil cationic heavy metal repair agent, which is composed of the following raw materials in parts by weight:

[0005] Inorganic fertilizer B 30-40 parts, organic fertilizer C 40-60 parts, starch glue 10-20 parts;

[0006] The inorganic fertilizer B is composed of the following raw materials in parts by mass: 40-60 parts of carrier A, 24-36 parts of monoammonium phosphate, and 16-24 parts of potassium sulfate;

[0007] The carrier A is made of a mixture of pyrolyzed biochar, attapulgite and kaolin;

[0008] The organic fertilizer C is made by mixing dry cow dung, potassium hydroxide and K2SO3;

[0009] The starch glue is prepared by mixing corn starch, CaO2 and deionized water.

[0010] The purpose of the present invention can also be achieved by the following technical measures:

[0011] The carrier A is obtained by mixing pyrolysis biochar, attapulgite and kaolin in a mass ratio of 35-45:20-40:25-35.

[0012] The organic fertilizer C is prepared from dry cow dung, potassium hydroxide and K2SO3 in a mass ratio of 86.2:7.8:6.

[0013] The starch glue is prepared from corn starch, CaO2 and deionized water in a mass ratio of 10-20:5-10:70-85.

[0014] The object of the present invention can also be achieved by the following technical measures: a method for preparing a soil cationic heavy metal repair agent, the preparation method of the soil cationic heavy metal repair agent comprising:

[0015] Step 1, preparing pyrolytic biochar, mixing pyrolytic biochar, attapulgite and kaolin to obtain carrier material A;

[0016] Step 2, uniformly mix 40-60 parts of carrier A, 24-36 parts of monoammonium phosphate, and 16-24 parts of potassium sulfate to obtain inorganic fertilizer B;

[0017] Step 3, washing the dry cow dung with deionized water, mechanically kneading it, drying it, adding potassium hydroxide and deionized water to cook it, and then adding K2SO3 and deionized water to stir it to obtain an organic fertilizer C rich in fulvic acid;

[0018] Step 4, granulating the inorganic fertilizer B, organic fertilizer C, and starch glue in a mass ratio of 30-40:40-60:10-20 using a granulator to obtain a soil cationic heavy metal repair agent.

[0019] The purpose of the present invention can also be achieved by the following technical measures:

[0020] In step 1, 5-10 g of rice husk and rice straw are crushed into 30-50 meshes with a pulverizer, and the mixture is heated to 400-600° C. at a rate of 5° C. / min in a tubular furnace for pyrolysis for 2 hours under a nitrogen atmosphere to obtain 100-200 mesh pyrolysis biochar; the pyrolysis biochar, attapulgite, and kaolin are uniformly mixed in a mass ratio of 35-45:20-40:25-35 to obtain a carrier A.

[0021] In step 3, 5-10 g of dry cow dung with a moisture content of 30% is taken, washed with deionized water, mechanically kneaded, dried, 0.45-0.9 g of potassium hydroxide and 100-200 mL of deionized water are added, and the mixture is steamed at 60-80° C. for 2-4 hours, followed by adding 0.35-0.7 g of K2SO3 and 50-80 mL of deionized water and stirring for 1-3 hours to obtain an organic fertilizer C rich in fulvic acid.

[0022] In step 3, the mass ratio of dry cow dung, potassium hydroxide and K2SO3 in the obtained fulvic acid-rich organic fertilizer C is 86.2:7.8:6.

[0023] In step 4, starch glue is prepared by oxidizing 10-20 parts of corn starch, 25-10 parts of CaO, and 70-85 parts of deionized water for 40-60 minutes.

[0024] In step 4, the particle size of the prepared soil cationic heavy metal remediation agent is 2-4 mm.

[0025] The soil cationic heavy metal repair agent and preparation method thereof in the present invention, wherein the repair agent combines biochar, nanoclay (attapulgite, kaolin, etc.), fulvic acid type organic fertilizer, calcium dihydrogen phosphate, etc., to passivate divalent cadmium (Cd(II)) and divalent lead (Pb(II)) in the soil, and can also provide nutrients for plants, realizing the integration of soil pollution control and nutrient conditioning. The present invention can convert cationic heavy metals from an effective state to a low-activity state by adding a soil repair agent, thereby reducing their mobility and bioavailability in the soil, and the cost is low, and it is easy to promote and apply on a large scale. Biochar and nanoclay (attapulgite, kaolin, etc.) have a high heavy metal adsorption capacity, and the independently developed fulvic acid type quick-rot fertilizer is rich in a variety of groups (carboxyl, hydroxyl, amino, etc.) that can chelate with heavy metal ions, and can repair soil contaminated by cationic heavy metals while providing fertilizer effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of a specific embodiment of the method for preparing the soil cationic heavy metal repair agent of the present invention;

[0027] Figure 2 Schematic diagram of the content of soluble Cd(II) and Pb(II) in soil in a specific embodiment 2 of the present invention;

[0028] Figure 3 Schematic diagram of plant height (A and D), thousand-grain weight (B and E), and per-acre yield (C and F) of rapeseed and wheat before and after soil remediation in a specific embodiment 2 of the present invention. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0031] The soil cationic heavy metal repair agent of the present invention is granulated with inorganic fertilizer B prepared from carrier material A, organic fertilizer C and starch glue in a mass ratio of 30-40:40-60:10-20.

[0032] The carrier material A is obtained by mixing pyrolysis biochar, attapulgite, and kaolin in a mass ratio of 35-45:20-40:25-35;

[0033] Inorganic fertilizer B is obtained by mixing carrier A, monoammonium phosphate and potassium sulfate in a mass ratio of 40-60:24-36:16-24;

[0034] Organic fertilizer C was prepared from dry cow dung, potassium hydroxide, and K2SO3 in a mass ratio of 86.2:7.8:6;

[0035] The starch glue is prepared from corn starch, CaO2 and deionized water in a mass ratio of 10-20:5-10:70-85.

[0036] like Figure 1 As shown, Figure 1 The flowchart of the preparation method of the soil cationic heavy metal repair agent of the present invention is as follows. The preparation method of the soil cationic heavy metal repair agent comprises:

[0037] (1) 5-10 g of rice husk and rice straw were crushed into 30-50 meshes by a pulverizer, and pyrolyzed in a tube furnace at a rate of 5°C / min to 400-600°C for 2 hours under a nitrogen atmosphere to obtain biochar (100-200 meshes). The pyrolyzed biochar (35-45 wt%), attapulgite (100-200 meshes, 20-40 wt%), and kaolin (100-200 meshes, 25-35 wt%) were mixed uniformly to obtain carrier material A;

[0038] (2) uniformly mixing the carrier A (40-60 wt%), monoammonium phosphate (24-36 wt%), and potassium sulfate (16-24 wt%) obtained in (1) to obtain an inorganic fertilizer B;

[0039] (3) 5-10 g of dry cow dung with a moisture content of 30% was taken, washed with deionized water, mechanically rubbed, dried, added with 0.45-0.9 g of potassium hydroxide and 100-200 mL of deionized water, and boiled at 60-80° C. for 2-4 hours, and then added with 0.35-0.7 g of K2SO3 and 50-80 mL of deionized water and stirred for 1-3 hours to obtain an organic fertilizer C rich in fulvic acid (the mass ratio of dry cow dung, potassium hydroxide, and K2SO3 was 86.2:7.8:6).

[0040] (4) the inorganic fertilizer B, the organic fertilizer C, and the starch glue (10-20wt% corn starch + 5-10wt% CaO2 + 70-85wt% deionized water oxidized for 40-60 minutes) are granulated with a granulator at a mass ratio of 30-40:40-60:10-20 to obtain an organic-inorganic composite granular fertilizer D (particle size 2-4mm), which is the soil cationic heavy metal repair agent of the present invention;

[0041] Organic-inorganic compound granular fertilizer D was applied to land contaminated by heavy metals at a rate of 40-60 kg / mu. After 15 days, the contents of soluble Cd(II) and Pb(II) in the soil reached 0.1-0.2 mg / kg and 50-70 mg / kg. Rapeseed and wheat were planted on the land. After 200 days, the plant height, 1000-grain weight and per-mu yield of rapeseed and wheat reached 110-130 cm and 65-75 cm, 2.75-3.25 g and 40-50 g, and 250-300 kg and 520-620 kg, respectively.

[0042] The following are several specific embodiments of the present invention.

[0043] Example 1

[0044] In a specific embodiment 1 of the present invention, the preparation method of the soil cationic heavy metal repair agent includes the following steps:

[0045] (1) 5 g of rice husk and rice straw were crushed into 30 meshes by a pulverizer, and pyrolyzed in a tube furnace at a rate of 5°C / min to 400°C for 2 hours under a nitrogen atmosphere to obtain biochar (100 mesh). The pyrolyzed biochar (35 wt%), attapulgite (100 mesh, 40 wt%), and kaolin (100 mesh, 25 wt%) were mixed evenly to obtain carrier material A;

[0046] (2) The carrier A (60 wt%) obtained in (1), monoammonium phosphate (24 wt%), and potassium sulfate (16 wt%) were uniformly mixed to obtain an inorganic fertilizer B;

[0047] (3) Take 5g of dry cow dung with a moisture content of 30%, wash with deionized water and then mechanically rub, dry, add 0.45g of potassium hydroxide and 100mL of deionized water and cook at 60°C for 2 hours, then add 0.35g of K2SO3 and 50mL of deionized water and stir for 1 hour to obtain an organic fertilizer C (the mass ratio of dry cow dung, potassium hydroxide and K2SO3 is 86.2:7.8:6) rich in xanthohumic acid;

[0048] (4) the inorganic fertilizer B, the organic fertilizer C, and the starch glue (10 wt% corn starch + 5 wt% CaO2 + 85 wt% deionized water oxidized for 40 minutes) are granulated with a granulator at a mass ratio of 30:60:10 to obtain an organic-inorganic composite granular fertilizer D (particle size 2 mm), which is the soil cationic heavy metal repair agent of the present invention;

[0049] In this embodiment, organic-inorganic compound granular fertilizer D is applied to land contaminated by heavy metals at 40 kg / mu. After 15 days, the contents of soluble Cd(II) and Pb(II) in the soil reach 0.1 mg / kg and 50 mg / kg, respectively. Rapeseed and wheat are planted on the land. After 200 days, the plant height, 1000-grain weight and per-mu yield of rapeseed and wheat reach 110 cm and 65 cm, 2.75 g and 40 g, and 250 kg and 520 kg, respectively.

[0050] Example 2

[0051] In a specific embodiment 1 of the present invention, the preparation method of the soil cationic heavy metal repair agent includes the following steps:

[0052] (1) 7 g of rice husk and rice straw were crushed into 40 meshes using a pulverizer, and pyrolyzed in a tube furnace at a rate of 5°C / min to 500°C for 2 hours under a nitrogen atmosphere to obtain biochar (150 mesh). The pyrolyzed biochar (40 wt%), attapulgite (150 mesh, 30 wt%), and kaolin (150 mesh, 30 wt%) were mixed evenly to obtain carrier material A;

[0053] (2) The carrier A (50 wt%), monoammonium phosphate (30 wt%) and potassium sulfate (20 wt%) obtained in (1) are uniformly mixed to obtain an inorganic fertilizer B;

[0054] (3) 7.5 g of dry cow dung with a moisture content of 30% was taken, mechanically rubbed after washing with deionized water, dried, added with 0.675 g of potassium hydroxide and 150 mL of deionized water and boiled at 70 ° C for 3 hours, then added with 0.525 g of K2SO3 and 65 mL of deionized water and stirred for 2 hours to obtain an organic fertilizer C rich in fulvic acid (the mass ratio of dry cow dung, potassium hydroxide, and K2SO3 was 86.2:7.8:6);

[0055] (4) the inorganic fertilizer B, the organic fertilizer C, and the starch glue (15wt% corn starch + 7wt% CaO2 + 78wt% deionized water oxidized for 50 minutes) are granulated with a granulator at a mass ratio of 35:50:15 to obtain an organic-inorganic composite granular fertilizer D (particle size 3 mm), which is the soil cationic heavy metal repair agent of the present invention;

[0056] In this example, organic-inorganic compound granular fertilizer D was applied to the land contaminated by heavy metals at a rate of 50 kg / mu. After 15 days, the content of soluble Cd(II) and Pb(II) in the soil reached 0.15 mg / kg and 60 mg / kg (as shown in Table 1). Figure 2 As shown), rapeseed and wheat were planted on the land. After 200 days, the plant height, 1000-grain weight and per-acre yield of rapeseed and wheat reached 120 cm and 70 cm, 3 g and 45 g, 275 kg and 570 kg (as shown). Figure 3 shown).

[0057] Example 3

[0058] In a specific embodiment 1 of the present invention, the preparation method of the soil cationic heavy metal repair agent includes the following steps:

[0059] (1) 10 g of rice husk and rice straw were crushed into 50 meshes using a pulverizer, and pyrolyzed in a tube furnace at a rate of 5°C / min to 600°C for 2 hours under a nitrogen atmosphere to obtain biochar (200 mesh). The pyrolyzed biochar (45 wt%), attapulgite (200 mesh, 20 wt%), and kaolin (200 mesh, 35 wt%) were mixed evenly to obtain carrier material A;

[0060] (2) The carrier A (40 wt%), monoammonium phosphate (36 wt%) and potassium sulfate (24 wt%) obtained in (1) were mixed uniformly to obtain an inorganic fertilizer B;

[0061] (3) Take 10g of dry cow dung with a moisture content of 30%, wash with deionized water and then mechanically rub, dry, add 0.9g of potassium hydroxide and 200mL of deionized water and cook at 80°C for 4 hours, then add 0.7g of K2SO3 and 80mL of deionized water and stir for 3 hours to obtain an organic fertilizer C (the mass ratio of dry cow dung, potassium hydroxide and K2SO3 is 86.2:7.8:6) rich in xanthohumic acid;

[0062] (4) the inorganic fertilizer B, the organic fertilizer C, and the starch glue (20wt% corn starch + 10wt% CaO2 + 70wt% deionized water oxidized for 60 minutes) are granulated with a granulator at a mass ratio of 40:40:20 to obtain an organic-inorganic composite granular fertilizer D (particle size 4 mm), which is the soil cationic heavy metal repair agent of the present invention;

[0063] In this implementation, organic-inorganic compound granular fertilizer D was applied to land contaminated by heavy metals at a rate of 60 kg / mu. After 15 days, the contents of soluble Cd(II) and Pb(II) in the soil reached 0.2 mg / kg and 70 mg / kg, respectively. Rapeseed and wheat were planted on the land. After 200 days, the plant height, 1000-grain weight, and per-mu yield of rapeseed and wheat reached 130 cm and 75 cm, 3.25 g and 50 g, and 300 kg and 620 kg, respectively.

[0064] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0065] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

Claims

1. Soil cationic heavy metal remediation agent, characterized in that: The soil cationic heavy metal repair agent is composed of the following raw materials in parts by weight: Inorganic fertilizer B 30-40 parts, organic fertilizer C 40-60 parts, starch glue 10-20 parts; The inorganic fertilizer B is composed of the following raw materials in parts by weight: 40-60 parts of carrier A, 24-36 parts of monoammonium phosphate, and 16-24 parts of potassium sulfate; The carrier A is made of a mixture of pyrolyzed biochar, attapulgite and kaolin; The organic fertilizer C is made by mixing dry cow dung, potassium hydroxide and K2SO3; The starch glue is prepared by mixing corn starch, CaO2 and deionized water.

2. The soil cationic heavy metal repair agent according to claim 1, characterized in that: The carrier A is obtained by mixing pyrolysis biochar, attapulgite and kaolin in a mass ratio of 35-45:20-40:25-35.

3. The soil cationic heavy metal repair agent according to claim 1, characterized in that: The organic fertilizer C is prepared from dry cow dung, potassium hydroxide and K2SO3 in a mass ratio of 86.2:7.8:

6.

4. The soil cationic heavy metal repair agent according to claim 1, characterized in that: The starch glue is prepared from corn starch, CaO2 and deionized water in a mass ratio of 10-20:5-10:70-85.

5. A method for preparing a soil cationic heavy metal repair agent, characterized in that: The preparation method of the soil cationic heavy metal repair agent comprises: Step 1, preparing pyrolytic biochar, mixing pyrolytic biochar, attapulgite and kaolin to obtain carrier material A; Step 2, uniformly mix 40-60 parts of carrier A, 24-36 parts of monoammonium phosphate, and 16-24 parts of potassium sulfate to obtain inorganic fertilizer B; Step 3, washing the dry cow dung with deionized water, mechanically kneading it, drying it, adding potassium hydroxide and deionized water to cook it, and then adding K2SO3 and deionized water to stir it to obtain an organic fertilizer C rich in fulvic acid; Step 4, granulating the inorganic fertilizer B, organic fertilizer C, and starch glue in a mass ratio of 30-40:40-60:10-20 using a granulator to obtain a soil cationic heavy metal repair agent.

6. The method for preparing the soil cationic heavy metal repair agent according to claim 5, characterized in that: In step 1, 5-10 g of rice husk and rice straw are crushed into 30-50 meshes with a pulverizer, and the mixture is heated to 400-600° C. at a rate of 5° C. / min in a tubular furnace for pyrolysis for 2 hours under a nitrogen atmosphere to obtain 100-200 mesh pyrolysis biochar; the pyrolysis biochar, attapulgite, and kaolin are uniformly mixed in a mass ratio of 35-45:20-40:25-35 to obtain a carrier A.

7. The method for preparing the soil cationic heavy metal repair agent according to claim 5, characterized in that: In step 3, 5-10 g of dry cow dung with a moisture content of 30% is taken, washed with deionized water, mechanically kneaded, dried, 0.45-0.9 g of potassium hydroxide and 100-200 mL of deionized water are added, and the mixture is steamed at 60-80° C. for 2-4 hours, followed by adding 0.35-0.7 g of K2SO3 and 50-80 mL of deionized water and stirring for 1-3 hours to obtain an organic fertilizer C rich in fulvic acid.

8. The method for preparing the soil cationic heavy metal repair agent according to claim 7, characterized in that: In step 3, the mass ratio of dry cow dung, potassium hydroxide and K2SO3 in the obtained fulvic acid-rich organic fertilizer C is 86.2:7.8:

6.

9. The method for preparing the soil cationic heavy metal repair agent according to claim 5, characterized in that: In step 4, starch glue is prepared by oxidizing 10-20 parts of corn starch, 25-10 parts of CaO, and 70-85 parts of deionized water for 40-60 minutes.

10. The method for preparing the soil cationic heavy metal repair agent according to claim 5, characterized in that: In step 4, the particle size of the prepared soil cationic heavy metal remediation agent is 2-4 mm.

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