Remediation agent suitable for acidified soil improvement and application thereof

Abstract

The invention discloses a repairing agent suitable for acidified soil improvement, which is prepared by mixing modified zeolite, composite charcoal, polyacrylamide, dolomite powder, cellulose, modified bentonite and livestock manure according to a mixing mass ratio of (10-15): (20-25): (5-8): (10-12): (8-12): (20-25): (10-12), and the modified zeolite is prepared by modifying zeolite particles with the particle size of 1-3mm through acid and alkali treatment. The composite biochar is prepared by mixing biochar and a complex microbial inoculant; the acidified soil can be neutralized through the charcoal and the dolomite powder, the pH value of the acidified soil can be effectively increased, the acidified hard soil can be fundamentally changed and the soil structure can be improved through the cooperation of the modified zeolite and the bentonite, multiple microbial strains can promote the restoration of soil biodiversity and ecological functions, meanwhile, soil re-acidification is avoided, and the soil quality is improved. The soil fertility is improved, the crop growth is promoted, and the sustainable utilization of the soil is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and in particular to a remediation agent suitable for improving acidified soil and applications thereof. Background Art

[0002] Acidification is an important aspect of the soil weathering process, which leads to a decrease in pH value and the formation of acidic soil, affecting the activity of organisms in the soil, changing the form of nutrients in the soil, reducing the effectiveness of nutrients, and causing free manganese and aluminum ions to dissolve into the soil solution, which has a toxic effect on crops. Soil acidification is a serious problem facing global agricultural production. It will lead to a decline in soil fertility, reduced crop yields and a deterioration of the ecological environment.

[0003] Traditional soil acidification improvement methods mainly include the application of alkaline substances such as lime and gypsum, but these methods have problems such as short-term effects and easy soil compaction. Therefore, the present invention proposes a repair agent suitable for acidified soil improvement and its application to solve the problems existing in the prior art. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to propose a remediation agent suitable for acidified soil improvement and its application. The remediation agent suitable for acidified soil improvement can neutralize acidified soil through biochar and dolomite powder, effectively increasing the pH value of acidified soil. The modified zeolite combined with bentonite can fundamentally change the acidified hard soil and improve the soil structure. A variety of microbial species can promote the recovery of soil biodiversity and ecological functions while avoiding soil re-acidification, improving soil fertility, promoting crop growth, and realizing sustainable soil utilization. It has important application value and broad market prospects.

[0005] To achieve the purpose of the present invention, the present invention is implemented through the following technical scheme: a repair agent suitable for improving acidified soil, including modified zeolite, composite biochar, polyacrylamide, dolomite powder, cellulose, modified bentonite and livestock manure mixed in a mixing mass ratio of 10-15:20-25:5-8:10-12:8-12:20-25:10-12, the modified zeolite is prepared by modifying zeolite particles with a particle size of 1 to 3 mm through acid and alkali treatment, and the composite biochar is prepared by mixing biochar and a composite bacterial agent.

[0006] A further improvement is that the mass ratio of the biochar to the composite bacterial agent is 70-75:25-30, the composite bacterial agent comprises a mixture of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, jelly-like Bacillus and yeast, and the biochar is made by pyrolysis and carbonization of rice husks and corn straw.

[0007] A further improvement is that the modified bentonite is prepared by mixing and drying the bentonite treated with nano-grinding and an aqueous solution of potassium salt and phosphate salt.

[0008] A further improvement is that the preparation method of the repair agent specifically includes:

[0009] Step 1: Pretreatment of the raw materials: first, zeolite particles are modified by acid and alkali treatment to obtain modified zeolite; then, rice husks and corn stalks are pyrolyzed and carbonized to produce biochar, which is then mixed with a composite bacterial agent to produce composite biochar; finally, potassium salt and phosphate salt are used to prepare a mixed aqueous solution and mixed with nano-bentonite to produce modified bentonite;

[0010] Step 2: Pre-mixing the base material: first, dissolve polyacrylamide in water at a mass ratio of 1:1 to prepare an aqueous solution, then add the modified zeolite, stir and absorb, and then dry to obtain a zeolite base material;

[0011] Step 3: Mixing the outer covering material: Add the composite biochar, modified bentonite and livestock manure into a blender and dry mix them. Then, prepare the cellulose into a glue solution and add 2 / 3 of the total amount into the blender and mix them to obtain the base outer covering material.

[0012] Step 4: outsourcing granulation processing, adding the zeolite base material to the base outsourcing material, fully mixing and granulating to obtain a semi-finished improver;

[0013] Step 5: Forming and drying treatment: Mix the dolomite powder with the remaining 1 / 3 of the cellulose glue, then add the semi-finished improver into the mixture, stir, filter out, and dry to obtain the soil remediation agent.

[0014] A further improvement is that the acid-base treatment of the zeolite particles in step 1 is specifically performed by first using a 0.01 mol / L oxalic acid aqueous solution for acid treatment, then using a 0.9 mol / L sodium hydroxide aqueous solution for alkali treatment, and finally using 0.11 mol / L disodium ethylenediaminetetraacetic acid for pickling. After the acid treatment, alkali treatment and pickling, the particles are rinsed with deionized water and dried. The drying conditions are drying at a temperature of 240 to 260° C. for 40 to 50 minutes.

[0015] A further improvement is that in the step 1, the pyrolysis carbonization treatment of rice husks and corn straw is specifically to first crush the corn straw and dry it, then mix it with the rice husk and dry mix it, and then place it in a pyrolysis furnace at 350-400°C for pyrolysis reaction to generate solid biochar.

[0016] A further improvement is that in the step 1, the biochar and the composite bacterial agent are mixed and cultivated, specifically, the biochar and the bacterial culture medium are first mixed in a mass ratio of 80:20 to prepare a composite culture medium, and then the composite bacterial agent is sprinkled on the composite culture medium for bacterial cultivation. After the culture medium is exhausted, it is dried in a dry environment at 40-55°C, and finally the composite culture medium and the cultivated bacterial strain are crushed and ground into powder to obtain composite biochar.

[0017] The further improvement is that: in the step 1, the molar ratio of potassium and phosphorus in the mixed aqueous solution is 2:1, the mass ratio of the mixed aqueous solution to the nano-bentonite is 15:85, after being fully mixed, the mixture is dried at 280-320° C. for 30-40 minutes, and finally crushed and ground to obtain the modified bentonite.

[0018] Further improvements are as follows: in step 2, the drying condition is 280-360° C. for 1-2 hours; in step 3, the specific method for preparing the cellulose glue is to mix cellulose and water in a mass ratio of 1:2 and then add the mixture into a homogenizer for high-pressure homogenization to obtain the cellulose glue; and in step 5, the drying condition is 40-55° C. for 8-12 hours.

[0019] The invention discloses an application of a repair agent suitable for improving acidified soil in acidified soil repair.

[0020] The beneficial effects of the present invention are as follows: the present invention can neutralize acidified soil through biochar and dolomite powder, effectively increase the pH value of acidified soil, fundamentally change acidified hard soil and improve soil structure through modified zeolite combined with bentonite, and multiple microbial strains can promote the recovery of soil biodiversity and ecological functions while avoiding soil re-acidification, improving soil fertility, promoting crop growth, and realizing sustainable soil utilization. It has important application value and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a flow chart of the preparation method of the present invention. DETAILED DESCRIPTION

[0022] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0023] The microorganisms in the composite bacterial agent were all purchased directly, among which the round brown nitrogen-fixing bacteria were purchased from Gaide Chemical Network, brand Shanghai Bangjing; the phosphate-solubilizing bacteria were purchased from Shandong Qilu Chemical Technology Co., Ltd.; the jelly-like Bacillus was purchased from Alibaba website; and the yeast was purchased from Alibaba website.

[0024] In the following examples, the bacterial culture medium used was NA solid culture medium.

[0025] Example 1

[0026] according to Figure 1 As shown, this embodiment provides a repair agent suitable for improving acidified soil, including modified zeolite, composite biochar, polyacrylamide, dolomite powder, cellulose, modified bentonite and livestock manure in a mixing ratio of 15:20:8:12:10:25:10 by mass, and the composite bacterial agent contains nitrogen-fixing bacteria, phosphate-solubilizing bacteria, jelly-like Bacillus and yeast.

[0027] The preparation method of the repair agent suitable for improving acidified soil specifically includes:

[0028] Step 1: Pretreatment of the raw materials: first, zeolite particles are modified by acid and alkali treatment to obtain modified zeolite; then, rice husks and corn stalks are pyrolyzed and carbonized to produce biochar, which is then mixed with a composite bacterial agent at a mass ratio of 75:25 to produce composite biochar; finally, potassium chloride and potassium dihydrogen phosphate are used to prepare a mixed aqueous solution and mixed with nano-bentonite to produce modified bentonite;

[0029] The rice husk and corn straw pyrolysis carbonization process is to first crush the corn straw and dry it, then mix it with the rice husk and dry mix it, and then place it in a pyrolysis furnace at 400℃ to generate solid biochar.

[0030] The acid-base treatment of the zeolite particles specifically includes first using a 0.01 mol / L oxalic acid aqueous solution to acid-treat the zeolite particles with a particle size of 1 to 3 mm, then using a 0.9 mol / L sodium hydroxide aqueous solution to alkaline-treat the acid-washed zeolite particles, and finally using 0.11 mol / L disodium ethylenediaminetetraacetic acid to acid-wash the particles. After the acid treatment, alkaline treatment, and acid washing, the particles are rinsed with deionized water and dried at 260°C for 40 minutes.

[0031] The biochar and composite microbial agent mixed cultivation specifically comprises the following steps: firstly, the biochar and the culture medium are mixed to prepare a composite culture medium (the mixing ratio is 1:5); then, the composite microbial agent is inoculated on the composite culture medium to cultivate the culture medium; after the culture medium is completely consumed, the culture medium is dried in a dry environment at 40°C; finally, the composite culture medium and the cultivated culture medium are crushed and ground into powder to obtain composite biochar;

[0032] The molar ratio of potassium and phosphorus in the mixed aqueous solution is 2:1, and the mass ratio of the mixed aqueous solution to nano-bentonite is 15:85. After being fully mixed, the solution is dried at 280° C. for 40 minutes, and finally crushed and ground to obtain modified bentonite.

[0033] Step 2: Pre-mixing of the base material: first dissolve polyacrylamide in water at a mass ratio of 1:1 to prepare an aqueous solution, then add modified zeolite for stirring and absorption, and then dry to obtain a zeolite base material, wherein the drying condition is 360°C for 1 hour.

[0034] Step 3: Mixing the outer covering material: Add the composite biochar, modified bentonite and livestock manure into a blender and dry mix them. Then, prepare the cellulose into a glue solution and add 2 / 3 of the total amount into the blender and mix them to obtain the base outer covering material.

[0035] The specific method for preparing cellulose glue is to mix cellulose and water in a mass ratio of 1:2, add the mixture into a homogenizer and perform high-pressure homogenization to obtain cellulose glue.

[0036] Step 4: Outsourcing granulation processing: adding the zeolite base material to the base outsourcing material, fully mixing and then granulating to obtain a semi-finished improver product.

[0037] Step 5: Forming and drying treatment: Mix the dolomite powder with the remaining 1 / 3 of the cellulose glue, then add the semi-finished improver into it, stir it, filter it out, and dry it to obtain the soil remediation agent, wherein the drying condition is 45°C for 10 hours.

[0038] Application Example 1

[0039] This embodiment provides an application of a remediation agent suitable for improving acidified soil in acidified soil remediation: the soil remediation agent prepared in Example 1 was applied in an acidified soil field (pH 5.4) at a rate of 80 kg / mu. After application, the field was plowed, and finally corn crops were planted and irrigated. At the same time, as a control, a traditional commercially available Lupusen acidic soil remediation bacterial agent was applied in acidified soil with the same acidification degree in the same area at a rate of 20 kg / mu, and chemical fertilizer was applied simultaneously at a rate of 55 kg / mu. The same variety of corn crops was planted, and the corn was harvested after one season of maturity. The soil of the two fields where different remediation agents were applied was sampled and the nutrient content and pH value were determined using a soil fertilizer nutrient rapid tester, as shown in Table 1.

[0040] Table 1

[0041] This application soil remediation agent Traditional soil remediation agents Moisture content (%) 66 56 Salt content (%) 0.02 0.05 pH 7 6 Total nitrogen content (g / kg) 3.6 1.8 Organic matter content (%) 8 4 Ammonium nitrogen content (mg / kg) 26 18 Nitrate nitrogen content (mg / kg) 21 15 Available phosphorus content (mg / kg) 18 12 Available potassium content (mg / kg) 123 82 Yield per mu (jin) 1355 1080

[0042] As can be seen from the above table, the remediation agent of the present application is more effective than traditional remediation agents in remediating acidified soil, and has a certain improvement on the yield of cultivated crops. This is because the zeolite particles and modified bentonite in the remediation agent of the present application can fundamentally change the properties of the soil, and can achieve the effect of efficient adsorption and slow release when combined with biochar. It has a good effect of maintaining and slow-releasing nutrients and water in the soil, allowing the soil to provide nutrients for plant growth for a long time. The various added bacterial species and microorganisms can form a symbiotic relationship between the soil and the crop roots, converting nutrients that are difficult for plants to absorb in the soil into nutrients that are easy to absorb, thereby promoting soil nutrient circulation.

[0043] At the same time, biochar itself contains a variety of alkaline substances, which, when combined with dolomite powder, can effectively neutralize the acidic substances in acidic soil, thereby repairing the acidic soil. The yeast in the composite bacterial agent can keep the repaired soil neutral for a long time, effectively avoiding soil re-acidification.

[0044] Example 2

[0045] The same as Example 1, except that the raw materials of the repair agent suitable for acidified soil improvement include modified zeolite, composite biochar, polyacrylamide, dolomite powder, cellulose, modified bentonite and livestock manure, which are mixed in a mixing mass ratio of 10:22:7:10:12:20:12, and the composite bacterial agent includes nitrogen-fixing bacteria, phosphate-solubilizing bacteria, jelly-like Bacillus and yeast.

[0046] Example 3

[0047] The same as Example 1, except that the raw materials of the repair agent suitable for acidified soil improvement include modified zeolite, composite biochar, polyacrylamide, dolomite powder, cellulose, modified bentonite and livestock manure, which are mixed in a mixing mass ratio of 12:25:5:12:8:22:11, and the composite bacterial agent includes nitrogen-fixing bacteria, phosphate-solubilizing bacteria, jelly-like Bacillus and yeast.

[0048] Application Example 2

[0049] The same as Application Example 1, except that the remediation agent in Example 1 was replaced by Examples 2 and 3. The final corn yields were 1209 kg and 1225 kg, respectively. Although slightly lower than that of the application example, they were significantly higher than the yield of traditional soil remediation bacterial agent planting.

[0050] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A remediation agent suitable for improving acidified soil, characterized by: The invention comprises modified zeolite, composite biochar, polyacrylamide, dolomite powder, cellulose, modified bentonite and livestock manure, which are mixed in a mass ratio of 10-15:20-25:5-8:10-12:8-12:20-25:10-12. The modified zeolite is prepared by modifying zeolite particles with a particle size of 1 to 3 mm through acid and alkali treatment. The composite biochar is prepared by mixing biochar and a composite bacterial agent.

2. A repair agent suitable for improving acidified soil according to claim 1, characterized in that: The mass ratio of the biochar to the composite bacterial agent is 70-75:25-30. The composite bacterial agent comprises nitrogen-fixing bacteria, phosphate-solubilizing bacteria, jelly-like Bacillus and yeast. The biochar is prepared by pyrolysis and carbonization of rice husks and corn straw.

3. The repair agent suitable for improving acidified soil according to claim 1, characterized in that: The modified bentonite is prepared by mixing bentonite treated with nano-grinding and an aqueous solution of potassium salt and phosphate salt, and then drying and grinding the mixture.

4. The repair agent suitable for improving acidified soil according to claim 1, characterized in that: The preparation method of the repair agent specifically includes: Step 1: Pretreatment of raw materials: First, zeolite particles are modified by acid and alkali treatment to obtain modified zeolite; then, rice husks and corn stalks are pyrolyzed and carbonized to produce biochar, which is then mixed with a composite bacterial agent for cultivation to produce composite biochar; finally, potassium salt and phosphate salt are used to prepare a mixed aqueous solution, which is then mixed with nano-bentonite to produce modified bentonite; Step 2: Pre-mixing of the base material: first, polyacrylamide is dissolved in water at a mass ratio of 1:1 to prepare an aqueous solution, and then the modified zeolite is added for stirring and absorption, and then dried to prepare a zeolite base material; Step 3: Mixing of outer covering materials: Add composite biochar, modified bentonite and livestock manure into a blender and dry mix them. Then, prepare cellulose into a glue solution and add 2 / 3 of the total amount into the blender and mix to obtain the base outer covering material. Step 4: Outsourcing granulation processing: adding the zeolite base material to the base outsourcing material, mixing thoroughly and then granulating to obtain the semi-finished improver; Step 5: Forming and drying: Mix the dolomite powder with the remaining 1 / 3 of the cellulose glue, then add the semi-finished improver into the mixture, stir, filter out, and dry to obtain the soil remediation agent.

5. The repair agent suitable for improving acidified soil according to claim 4, characterized in that: The acid-base treatment of the zeolite particles in step 1 is specifically as follows: first, acid treatment is performed using a 0.01 mol / L aqueous solution of oxalic acid, then alkali treatment is performed using a 0.9 mol / L aqueous solution of sodium hydroxide, and finally, pickling is performed using 0.11 mol / L disodium ethylenediaminetetraacetic acid. After the acid treatment, alkali treatment, and pickling, the particles are rinsed with deionized water and dried. The drying conditions are drying at a temperature of 240 to 260° C. for 40 to 50 minutes.

6. The repair agent suitable for improving acidified soil according to claim 4, characterized in that: In the step 1, the pyrolysis carbonization treatment of rice husks and corn straws is specifically to first crush the corn straws and dry them, then mix them with the rice husks, and then place them in a pyrolysis furnace at 350-400° C. to generate solid biochar.

7. The repair agent suitable for improving acidified soil according to claim 4, characterized in that: In the step 1, the biochar and the composite bacterial agent are mixed and cultivated, specifically, the biochar and the bacterial culture medium are first mixed in a mass ratio of 80:20 to prepare a composite culture medium, and then the composite bacterial agent is sprinkled on the composite culture medium for bacterial cultivation. After the culture medium is completely consumed, it is dried in a dry environment at 40-55° C., and finally the composite culture medium and the cultivated bacterial strain are crushed and ground into powder to obtain the composite biochar.

8. The repair agent suitable for improving acidified soil according to claim 4, characterized in that: In the step 1, the molar ratio of potassium and phosphorus in the mixed aqueous solution is 2:1, and the mass ratio of the mixed aqueous solution to the nano-bentonite is 15:

85. After being fully mixed, the mixture is dried at 280-320° C. for 30-40 minutes, and finally crushed and ground to obtain the modified bentonite.

9. The repair agent suitable for improving acidified soil according to claim 4, characterized in that: The drying condition in step 2 is 280-360° C. for 1-2 hours. The specific method for preparing the cellulose glue in step 3 is to mix cellulose and water in a mass ratio of 1:2 and then add the mixture into a homogenizer for high-pressure homogenization to obtain the cellulose glue. The drying condition in step 5 is 40-55° C. for 8-12 hours.

10. Use of the repair agent suitable for improving acidified soil according to claim 1 in acidified soil repair.

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