Fly ash soil conditioner and preparation method thereof

Abstract

The invention belongs to the technical field of agriculture, and provides a fly ash soil conditioner and a preparation method thereof, the fly ash soil conditioner is prepared from the following raw materials by mass: 50-70 parts of modified fly ash, 15-25 parts of humic acid, 30-40 parts of an organic matrix, 3-5 parts of diatomite, 6-10 parts of zeolite powder, 1.5-3.0 parts of a microbial agent, and 0.5-1.5 parts of calcium carboxymethyl cellulose. The fly ash is used as a main raw material, resource utilization of industrial wastes is realized, and the soil improvement cost is reduced. The modified fly ash is combined with the organic matrix and the microbial agent, so that the water-retaining property, the air permeability and the nutrient slow-release effect of the soil are remarkably improved. The nitrogen-fixing bacteria, the phosphate solubilizing bacteria and the trichoderma are compounded, so that the nitrogen and phosphorus conversion of soil is promoted, and the reproduction of pathogenic bacteria is inhibited. The modification time of the fly ash is greatly shortened through the microwave activation technology, the product stability is improved through the extrusion granulation technology, and the method is suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a fly ash soil conditioner and a preparation method thereof. Background Art

[0002] Traditional soil conditioners mostly rely on chemical synthetic materials or single organic matter, which have problems such as high cost, easy to cause soil compaction, and short-lived fertilizer effect. Although fly ash, as an industrial waste, has the physical structural characteristics of potential soil improvement, its direct application is prone to heavy metal pollution, and its alkalinity may destroy the balance of soil microorganisms. In the prior art, the modification process of fly ash is complicated, and its synergistic effect with microbial agents and organic matrices has not been fully developed. Therefore, there is an urgent need for an efficient, environmentally friendly, and multifunctional fly ash-based soil conditioner that can not only utilize industrial waste as a resource, but also improve soil fertility and microbial activity. Summary of the invention

[0003] The object of the present invention is to provide a fly ash soil conditioner and a preparation method thereof, so as to overcome the defects in the prior art.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a fly ash soil conditioner, which is prepared by including the following raw materials in parts by weight:

[0006] 50-70 parts of modified fly ash, 15-25 parts of humic acid, 30-40 parts of organic matrix, 3-5 parts of diatomaceous earth, 6-10 parts of zeolite powder, 1.5-3.0 parts of microbial agent, and 0.5-1.5 parts of carboxymethyl cellulose calcium.

[0007] Preferably, the particle size of the diatomaceous earth is 0.1 to 0.5 mm;

[0008] The particle size of the zeolite powder is 0.1-0.5 mm.

[0009] Preferably, the microbial agent comprises nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, and the mass ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:1.

[0010] The present invention also provides a method for preparing a fly ash soil conditioner, comprising the following steps:

[0011] (1) mixing a citric acid solution and fly ash, and then performing microwave activation to obtain modified fly ash;

[0012] (2) mixing the sludge and corn stalks and inoculating the composite bacterial agent, and then fermenting and turning the compost in sequence to obtain an organic matrix;

[0013] (3) mixing the modified fly ash, humic acid, organic matrix, diatomaceous earth, zeolite powder, microbial agent and carboxymethyl cellulose calcium and performing extrusion granulation to obtain composite particles;

[0014] (4) The composite particles are allowed to stand for aging to obtain the fly ash soil conditioner.

[0015] Preferably, the mass fraction of the citric acid solution in step (1) is 10-15%, the liquid-to-solid ratio of the citric acid solution to fly ash in step (1) is 2-4:0.5-1.5, and the mixing time is 1-3 hours.

[0016] Preferably, the temperature of microwave activation in step (1) is 200° C., the time of microwave activation is 10 to 20 minutes, and the power of microwave activation is 600 to 800W.

[0017] Preferably, in step (2), the dry weight ratio of sludge to corn stalks is 2-4:0.8-1.5;

[0018] In the step (2), the composite bacteria include cellulose decomposing bacteria and thermophilic actinomycetes, and the mass ratio of the composite bacteria to corn stalks is 1:100-120.

[0019] Preferably, the fermentation temperature in step (2) is 55-60° C., and the fermentation time is 5-8 days;

[0020] The frequency of turning the compost is 18 to 24 hours per time.

[0021] Preferably, the rotation speed of the extrusion granulation in step (3) is 40 to 60 r / min.

[0022] Preferably, the aging time in step (4) is 30 to 50 hours.

[0023] Beneficial effects:

[0024] (1) The present invention uses fly ash as the main raw material, realizes resource utilization of industrial waste, and reduces the cost of soil improvement.

[0025] (2) The present invention combines modified fly ash with organic matrix and microbial agent to significantly improve soil water retention, air permeability and nutrient release effect.

[0026] (3) The present invention combines nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma to promote soil nitrogen and phosphorus conversion and inhibit the reproduction of pathogenic bacteria.

[0027] (4) The present invention significantly shortens the modification time of fly ash through microwave activation technology, and the extrusion granulation process improves product stability, which is suitable for large-scale production.

[0028] (5) The present invention reduces the alkalinity of fly ash through citric acid modification, avoids the dissolution of heavy metals, and ensures the safety of long-term application. DETAILED DESCRIPTION

[0029] The present invention provides a fly ash soil conditioner, which is prepared by including the following raw materials in parts by weight:

[0030] 50-70 parts of modified fly ash, 15-25 parts of humic acid, 30-40 parts of organic matrix, 3-5 parts of diatomaceous earth, 6-10 parts of zeolite powder, 1.5-3.0 parts of microbial agent, and 0.5-1.5 parts of carboxymethyl cellulose calcium.

[0031] In the present invention, the mass fraction of the modified fly ash is preferably 52 to 68 parts, more preferably 54 to 66 parts, and even more preferably 56 to 64 parts.

[0032] In the present invention, the mass fraction of the humic acid is preferably 16 to 24 parts, more preferably 17 to 23 parts, and even more preferably 18 to 22 parts.

[0033] In the present invention, the mass fraction of the organic matrix is ​​preferably 31 to 39 parts, more preferably 32 to 38 parts, and even more preferably 33 to 37 parts.

[0034] In the present invention, the mass fraction of the diatomaceous earth is preferably 3.2 to 4.8 parts, more preferably 3.4 to 4.6 parts, and even more preferably 3.6 to 4.4 parts.

[0035] In the present invention, the mass fraction of the zeolite powder is preferably 6.5 to 9.5 parts, more preferably 7 to 9 parts, and even more preferably 7.5 to 8.5 parts.

[0036] In the present invention, the mass fraction of the microbial agent is preferably 1.6 to 2.9 parts, more preferably 1.7 to 2.8 parts, and even more preferably 1.8 to 2.7 parts.

[0037] In the present invention, the mass fraction of the carboxymethylcellulose calcium is preferably 0.5 to 1.4 parts, more preferably 0.7 to 1.3 parts, and even more preferably 0.8 to 1.2 parts.

[0038] In the present invention, the particle size of the diatomaceous earth is preferably 0.1 to 0.5 mm, more preferably 0.2 to 0.4 mm, and even more preferably 0.3 mm.

[0039] In the present invention, the particle size of the zeolite powder is preferably 0.1 to 0.5 mm, more preferably 0.2 to 0.4 mm, and even more preferably 0.3 mm.

[0040] In the present invention, the microbial agent preferably includes nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, and the mass ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is preferably 1:1:1.

[0041] The present invention also provides a method for preparing a fly ash soil conditioner, comprising the following steps:

[0042] (1) mixing a citric acid solution and fly ash, and then performing microwave activation to obtain modified fly ash;

[0043] (2) mixing the sludge and corn stalks and inoculating the composite bacterial agent, and then fermenting and turning the compost in sequence to obtain an organic matrix;

[0044] (3) mixing the modified fly ash, humic acid, organic matrix, diatomaceous earth, zeolite powder, microbial agent and carboxymethyl cellulose calcium and performing extrusion granulation to obtain composite particles;

[0045] (4) The composite particles are allowed to stand for aging to obtain the fly ash soil conditioner.

[0046] In the present invention, the mass fraction of the citric acid solution in step (1) is 10-15%, more preferably 11-14%, and more preferably 12-13%.

[0047] In the present invention, the liquid-to-solid ratio of the citric acid solution to the fly ash in the step (1) is preferably 2-4:0.5-1.5, more preferably 2.2-3.8:0.6-1.4, and more preferably 2.4-3.6:0.7-1.3.

[0048] In the present invention, the mixing time is preferably 1 to 3 hours, more preferably 1.5 to 2.5 hours, and more preferably 2 hours.

[0049] In the present invention, the temperature of microwave activation in step (1) is preferably 200-300°C, more preferably 220-280°C, and even more preferably 240-260°C.

[0050] In the present invention, the microwave activation time is preferably 10 to 20 min, more preferably 12 to 18 min, and even more preferably 14 to 16 min.

[0051] In the present invention, the power of the microwave activation is preferably 600-800W, more preferably 620-780W, and even more preferably 650-750W.

[0052] In the present invention, the dry weight ratio of sludge to corn straw in step (2) is preferably 2-4:0.8-1.5, more preferably 2.2-3.8:0.9-1.4, and more preferably 2.4-3.6:1.0-1.3.

[0053] In the present invention, the moisture content of the sludge in step (2) is preferably 50-80%, more preferably 55-75%, and even more preferably 60-70%.

[0054] In the present invention, the composite bacteria in step (2) preferably include cellulose decomposing bacteria and thermophilic actinomycetes, and the mass ratio of the composite bacteria to corn straw is preferably 1:100-120, more preferably 1:102-118, and even more preferably 1:105-115.

[0055] In the present invention, the fermentation temperature in step (2) is preferably 55-60°C, more preferably 56-59°C, and even more preferably 57-58°C.

[0056] In the present invention, the fermentation time is preferably 5 to 8 days, more preferably 6 to 7 days.

[0057] In the present invention, the frequency of turning the compost is preferably 18 to 24 hours / time, more preferably 19 to 23 hours / time, and even more preferably 20 to 22 hours / time.

[0058] In the present invention, the rotation speed of the extrusion granulation in step (3) is preferably 40 to 60 r / min, more preferably 42 to 58 r / min, and even more preferably 45 to 55 r / min.

[0059] In the present invention, the aging time in step (4) is preferably 30 to 50 hours, more preferably 32 to 48 hours, and even more preferably 35 to 45 hours.

[0060] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0061] Example 1

[0062] A 10% mass fraction of citric acid solution and fly ash were mixed evenly in a liquid-solid ratio of 3:1, and left for 2 hours, and then microwave activated at 250°C and 700W for 15 minutes to increase the surface porosity and obtain modified fly ash; sludge with a moisture content of 60% and corn straw were mixed in a dry weight ratio of 3:1 and inoculated with a composite bacterial agent obtained by mixing cellulose decomposing bacteria and thermophilic actinomycetes, and then fermented at 55°C for 7 days, and turned the pile every 24 hours in the middle, to obtain an organic matrix;

[0063] 60 parts of modified fly ash, 20 parts of humic acid, 35 parts of organic matrix, 4 parts of diatomaceous earth, 8 parts of zeolite powder, 2 parts of microbial agent (mixed by nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, wherein the mass ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:1) and 1 part of calcium carboxymethyl cellulose are mixed, and extrusion granulation is performed at a speed of 50 r / min to obtain composite particles; the composite particles are allowed to stand and age for 48 hours to obtain the fly ash soil conditioner.

[0064] Example 2

[0065] The citric acid solution with a mass fraction of 12% and the fly ash were mixed evenly at a liquid-solid ratio of 2:0.5, and left for 2 hours, and then microwave activated at 200°C and a power of 600W for 10 minutes to increase the surface porosity and obtain modified fly ash; sludge with a moisture content of 50% and corn straw were mixed at a dry weight ratio of 2:0.8 and inoculated with a composite bacterial agent obtained by mixing cellulose decomposing bacteria and thermophilic actinomycetes, and then fermented at 55°C for 7 days, and turned the pile every 24 hours in the middle, to obtain an organic matrix;

[0066] Take 50 parts of modified fly ash, 15 parts of humic acid, 30 parts of organic matrix, 3 parts of diatomaceous earth, 6 parts of zeolite powder, 1.5 parts of microbial agent (mixed by nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, wherein the mass ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:1) and 0.5 parts of calcium carboxymethyl cellulose, mix them, extrude granulate at a speed of 40r / min to obtain composite particles; let the composite particles stand for aging for 48h to obtain the fly ash soil conditioner.

[0067] Example 3

[0068] A 10% mass fraction of citric acid solution and fly ash were mixed evenly in a liquid-solid ratio of 3:1, and left for 2 hours, and then microwave activated at 250°C and 700W for 15 minutes to increase the surface porosity and obtain modified fly ash; sludge with a moisture content of 60% and corn straw were mixed in a dry weight ratio of 3:1 and inoculated with a composite bacterial agent obtained by mixing cellulose decomposing bacteria and thermophilic actinomycetes, and then fermented at 55°C for 7 days, and turned the pile every 24 hours in the middle, to obtain an organic matrix;

[0069] 70 parts of modified fly ash, 25 parts of humic acid, 40 parts of organic matrix, 5 parts of diatomaceous earth, 10 parts of zeolite powder, 3 parts of microbial agent (mixed by nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, wherein the mass ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:1) and 1.5 parts of calcium carboxymethyl cellulose are mixed, extruded and granulated at a speed of 55r / min to obtain composite particles; the composite particles are allowed to stand and age for 35h to obtain the fly ash soil conditioner. .

[0070] Example 4

[0071] A citric acid solution with a mass fraction of 15% and fly ash were mixed evenly at a liquid-solid ratio of 4:1.5, and left for 3 hours, and then microwave activated at 300°C and 800W for 15 minutes to increase the surface porosity and obtain modified fly ash; sludge with a moisture content of 80% and corn straw were mixed at a dry weight ratio of 3:1 and inoculated with a composite bacterial agent obtained by mixing cellulose decomposing bacteria and thermophilic actinomycetes, and then fermented at 60°C for 7 days, and turned the pile every 24 hours in the middle to obtain an organic matrix;

[0072] 60 parts of modified fly ash, 20 parts of humic acid, 35 parts of organic matrix, 4 parts of diatomaceous earth, 8 parts of zeolite powder, 2 parts of microbial agent (mixed by nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, wherein the mass ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:1) and 1 part of calcium carboxymethyl cellulose are mixed, and extrusion granulation is performed at a speed of 50 r / min to obtain composite particles; the composite particles are allowed to stand and age for 48 hours to obtain the fly ash soil conditioner.

[0073] Example 5

[0074] The citric acid solution with a mass fraction of 11% and fly ash were mixed evenly in a liquid-solid ratio of 3:1, and left for 2 hours, and then microwave activated at 250°C and 700W for 15 minutes to increase the surface porosity and obtain modified fly ash; sludge with a moisture content of 60% and corn straw were mixed in a dry weight ratio of 3:1 and inoculated with a composite bacterial agent obtained by mixing cellulose decomposing bacteria and thermophilic actinomycetes, and then fermented at 55°C for 7 days, and turned the pile every 24 hours in the middle to obtain an organic matrix;

[0075] 56 parts of modified fly ash, 16 parts of humic acid, 33 parts of organic matrix, 3.6 parts of diatomaceous earth, 7 parts of zeolite powder, 1.8 parts of microbial agent (mixed by nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, wherein the mass ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:1) and 1.2 parts of calcium carboxymethyl cellulose are mixed, extruded and granulated at a speed of 50 r / min to obtain composite particles; the composite particles are allowed to stand and age for 48 hours to obtain the fly ash soil conditioner.

[0076] As can be seen from the above embodiments, the present invention provides a fly ash soil conditioner and a preparation method thereof, which is prepared by the following raw materials in mass fractions: 50-70 parts of modified fly ash, 15-25 parts of humic acid, 30-40 parts of organic matrix, 3-5 parts of diatomaceous earth, 6-10 parts of zeolite powder, 1.5-3.0 parts of microbial agent, and 0.5-1.5 parts of carboxymethyl cellulose calcium. The present invention uses fly ash as the main raw material to realize the resource utilization of industrial waste and reduce the cost of soil improvement. The present invention combines modified fly ash with organic matrix and microbial agent to significantly improve the water retention, air permeability and nutrient release effect of soil. The present invention combines nitrogen-fixing bacteria, phosphate-dissolving bacteria and Trichoderma to promote soil nitrogen and phosphorus conversion and inhibit the reproduction of pathogens. The present invention greatly shortens the modification time of fly ash through microwave activation technology, and the extrusion granulation process improves product stability, which is suitable for large-scale production. The present invention reduces the alkalinity of fly ash through citric acid modification, avoids the dissolution of heavy metals, and ensures the safety of long-term application.

[0077] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fly ash soil conditioner, characterized in that: The preparation is obtained by including the following raw materials in parts by weight: 50-70 parts of modified fly ash, 15-25 parts of humic acid, 30-40 parts of organic matrix, 3-5 parts of diatomaceous earth, 6-10 parts of zeolite powder, 1.5-3.0 parts of microbial agent, and 0.5-1.5 parts of carboxymethyl cellulose calcium.

2. A fly ash soil conditioner according to claim 1, characterized in that: The particle size of the diatomaceous earth is 0.1 to 0.5 mm; The particle size of the zeolite powder is 0.1-0.5 mm.

3. The fly ash soil conditioner according to claim 1, characterized in that: The microbial agent comprises nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma, and the mass ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and Trichoderma is 1:1:

1.

4. The method for preparing a fly ash soil conditioner according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) mixing a citric acid solution and fly ash, and then performing microwave activation to obtain modified fly ash; (2) mixing the sludge and corn stalks and inoculating the composite bacterial agent, and then fermenting and turning the compost in sequence to obtain an organic matrix; (3) mixing the modified fly ash, humic acid, organic matrix, diatomaceous earth, zeolite powder, microbial agent and carboxymethyl cellulose calcium and performing extrusion granulation to obtain composite particles; (4) The composite particles are allowed to stand for aging to obtain the fly ash soil conditioner.

5. The preparation method according to claim 4, characterized in that: The mass fraction of the citric acid solution in step (1) is 10-15%, and the liquid-to-solid ratio of the citric acid solution to fly ash in step (1) is 2-4: 0.5~1.5, and the mixing time is 1~3h.

6. The preparation method according to claim 1, characterized in that: The temperature of microwave activation in the step (1) is 200-300° C., the time of microwave activation is 10-20 min, and the power of microwave activation is 600-800 W.

7. The preparation method according to claim 4, characterized in that: In step (2), the dry weight ratio of sludge to corn stalks is 2-4:0.8-1.5; In the step (2), the composite bacteria include cellulose decomposing bacteria and thermophilic actinomycetes, and the mass ratio of the composite bacteria to corn stalks is 1:100-120.

8. The preparation method according to claim 4, characterized in that: The fermentation temperature in step (2) is 55-60° C. and the fermentation time is 5-8 days; The frequency of turning the compost is 18 to 24 hours per time.

9. The preparation method according to claim 4, characterized in that: The rotation speed of the extrusion granulation in the step (3) is 40 to 60 r / min.

10. The preparation method according to claim 4, characterized in that: The aging time in step (4) is 30 to 50 hours.