Black land improver based on biomass power plant ash and preparation method

Abstract

The invention discloses a black land conditioner based on biomass power plant ash and a preparation method, and relates to the technical field of soil conditioners, the preparation method comprises the following steps: S1, raw material preparation and crushing treatment; s2, nutrition proportioning; s3, proportioning and mixing; and S4, performing granulation. The black land improver prepared by the invention takes the biomass ash of the power plant as a main raw material, can effectively reduce the application of chemical fertilizers, has trace elements which are necessary for plant growth and are lacked in soil, and can be slowly released in the soil, improve the nutrient distribution in the soil, promote the nutrient absorption of crops and increase the yield. Heavy metals in soil are passivated, and the bioavailability of the heavy metals in the soil is reduced. Meanwhile, the prepared black land improver can effectively improve the physical and chemical properties of soil, maintain the pore structure of the soil and enhance the water and fertilizer retention capacity of the soil. Moreover, biomass ash generated by a biomass power plant can be fully and effectively utilized, the treatment cost is reduced, and the benefits of enterprises are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvers, and in particular to a black soil improver based on biomass power plant ash and slag and a preparation method thereof. Background Art

[0002] Biomass ash and slag have a loose and porous structure, good air permeability and water permeability, a large specific surface area, high surface energy, large porosity, strong water absorption and air absorption capacity. The main components are elements such as silicon, calcium, magnesium, phosphorus, potassium, manganese, iron, copper, and zinc. These nutrient elements are essential for plant growth and lacking in the soil, and can be slowly released in the soil for plants to absorb and utilize. Therefore, one of the purposes of the present invention is to make biomass ash and slag into a black soil improver. Summary of the Invention

[0003] The present invention discloses a black soil improver based on biomass power plant ash and slag and a preparation method thereof, aiming to solve the technical problems in the background art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A preparation method of a black soil improver based on biomass power plant ash and slag includes the following steps:

[0006] S1. Raw material preparation and crushing treatment: Take the biomass ash and slag from the power plant, crush and sieve them with a crusher, and dry them by blowing air for later use to obtain pretreated biomass ash and biomass slag.

[0007] S2. Nutrient ratio: Select ammonium chloride, potassium dihydrogen phosphate, and potassium chloride as nutrient additives, and sieve the additives for later use.

[0008] S3. Batching and mixing: According to the compound fertilizer design formula, weigh the biomass ash and biomass slag respectively, mix them with magnesium chloride, ammonium chloride, potassium dihydrogen phosphate, and starch, add deionized water and mix until semi-moist, then let it stand, grind, and dry to obtain activated biomass ash and activated biomass slag.

[0009] S4. Granulation: Add the activated biomass ash and activated biomass slag obtained in S3 to humic acid and bentonite, mix them evenly, add water and mix, then send them into the internal of an extrusion granulator for granulation respectively, and use a far-infrared dryer for drying treatment during the granulation process, and screen to obtain soil improver A and soil improver B.

[0010] In a preferred embodiment, the original biomass ash and slag obtained in step S1 are from the waste generated after the combustion of a biomass power plant, with a pH of 8.9 - 12.54 and a conductivity of 865.3 - 2956 μS / cm.

[0011] In a preferred embodiment, the fineness of the pretreated biomass ash obtained in step S1 is 80 - 100 mesh, and the fineness of the pretreated biomass residue is 100 - 120 mesh.

[0012] In a preferred embodiment, the additive obtained in step S2 passes through a <1 mm sieve.

[0013] In a preferred embodiment, the nutrient formula in step S2 is set as follows: the mass fraction of total nutrients (N + P 2 O 5 + K 2 O) > 15%; the addition amount of biomass ash residue > 15%; the addition amount of humic acid is 10%; the addition amount of organic fertilizer is 25%.

[0014] In a preferred embodiment, in step S3, 16.8% of the pretreated biomass ash and 15.8% of the pretreated biomass residue are respectively mixed with 6.3% of magnesium chloride, 14.6% of ammonium chloride, and 12.5% of potassium dihydrogen phosphate.

[0015] In a preferred embodiment, the mixture obtained in step S3 is added with water and stirred, deionized water is added to make the resulting mixture in a semi - wet state and left standing for 12 h, and then it is placed in a forced - air drying oven and dried at 45 °C to constant weight.

[0016] In a preferred embodiment, in step S4, the activated biomass ash, the activated biomass residue, humic acid, and bentonite are fully and evenly mixed. The specific ratio is 80 - 94% of activated biomass ash / activated biomass residue, and 5 - 10% of humic acid and bentonite.

[0017] In a preferred embodiment, deionized water with a mass 0.15 - 0.30 times that of the mixture is added to the mixture obtained in step S4, and after mixing and stirring, when granulating the mixture is completed, the temperature during drying by a far - infrared dryer is 70 - 150 °C, and the mixture is dried to a water mass ratio of 8 - 10%.

[0018] A black - soil conditioner based on biomass - power - plant ash residue is prepared by the preparation method of the above - mentioned black - soil conditioner based on biomass - power - plant ash residue.

[0019] As can be seen from the above, the black - soil conditioner and its preparation method provided by the present invention break through the limitation of the single function of traditional soil conditioners. The prepared black - soil conditioner has trace elements necessary for plant growth and lacking in the soil, which can be slowly released in the soil for plants to absorb and utilize. It can effectively inhibit the decline of soil pH and conductivity, improve the soil structure, significantly passivate heavy metal ions, reduce the absorption and utilization of plants, and at the same time enhance soil fertility and promote crop growth. It is of great significance for restoring soil health, improving agricultural production capacity, and ensuring ecological environment safety.

[0020] The present invention provides a black soil conditioner based on biomass power plant ash and its preparation method. Using the biomass ash of the power plant as the raw material, the preparation method is simple and the cost is controllable. It can fully and effectively utilize the biomass ash generated by the biomass power plant, reduce the application of chemical fertilizers, reduce the treatment cost of the biomass ash of the power plant, and improve the efficiency of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow chart of a black soil conditioner based on biomass power plant ash and its preparation method proposed by the present invention.

[0022] Figure 2 It is a detailed process flow chart of a black soil conditioner based on biomass power plant ash and its preparation method proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0024] Embodiment 1

[0025] Refer to Figure 1-2 , a preparation method of a black soil conditioner based on biomass power plant ash, including the following steps:

[0026] S1. Raw material preparation and crushing treatment. Take the biomass ash of the power plant, crush it through a sieve with a pulverizer, and dry it by blowing air for later use to obtain pretreated biomass ash and biomass slag;

[0027] The original biomass ash and slag obtained in step S1 are derived from the waste generated after the combustion of the biomass power plant. The fineness of the pretreated biomass ash is 80-100 mesh, the fineness of the pretreated biomass slag is 100-120 mesh, and the fineness of the starch is 100 mesh.

[0028] S2. Nutrient ratio. Select ammonium chloride, potassium dihydrogen phosphate, and potassium chloride as nutrient additives, and all the additives are sieved for later use;

[0029] All the additives obtained in step S2 are sieved through a <1mm sieve. Nutrient formula setting: the mass fraction of the total nutrients (N+P2O5+K2O) > 15%; the addition amount of biomass ash and slag > 15%; the addition amount of humic acid is 10%; the addition amount of organic fertilizer is 25%.

[0030] S3. Batching and mixing: According to the compound fertilizer design formula, weigh the biomass ash and biomass residue respectively, and mix them with magnesium chloride, ammonium chloride, potassium dihydrogen phosphate, and starch. Add deionized water and mix until it reaches a semi-wet state, then let it stand, grind, and dry to obtain activated biomass ash and activated biomass residue.

[0031] In step S3, 16.8% of the pretreated biomass ash and 15.8% of the pretreated biomass residue are respectively mixed with 6.3% of magnesium chloride, 14.6% of ammonium chloride, 12.5% of potassium dihydrogen phosphate, and 8.5% of starch. The mixture is stirred with water to make the resulting mixture in a semi-wet state and left to stand for 12 h. Then it is placed in a forced-air drying oven and dried at 45 °C until a constant weight is reached.

[0032] S4. Granulation: Add the activated biomass ash and activated biomass residue in S3 to humic acid and bentonite, mix them evenly, and send them into the internal part of an extrusion granulator for granulation. During the granulation process, use a far-infrared dryer for drying treatment to obtain soil conditioner A and soil conditioner B.

[0033] In step S4, the activated biomass ash, activated biomass residue, humic acid, and bentonite are mixed evenly. The specific ratio is 80 - 94% of activated biomass ash / activated biomass residue, and 5 - 10% of humic acid and bentonite. Add deionized water with a mass 0.15 - 0.30 times that of the mixture to the mixture and stir. After granulating the mixture, when drying through a far-infrared dryer, the temperature is 70 - 150 °C, and the mixture is dried until the water content by mass is 8 - 10%.

[0034] Example 2

[0035] In this experiment, the soil conditioners in Example 1 were used for the heavy metal element content analysis experiment, aiming to explore the environmental risk analysis of the heavy metal element content in this soil conditioner.

[0036] The experiment used microwave digestion method to digest the conditioner. Weigh 0.5 g of each of the two soil conditioners into digestion tubes, add a mixed solution of HF:HNO3:H2O2 = 3:4:1, and dissolve it fully. Place the digestion tank on a fuming plate and heat it at 150 °C for half an hour, then cool it. Put it into a microwave digestion instrument for digestion. After digestion, place the digestion tank on the fuming plate and heat it until the liquid in the tank remains about 1 ml, then add deionized water to make the volume up to 50 ml. Use an inductively coupled plasma mass spectrometer to measure the heavy metal content of the constant-volume liquid.

[0037] The experimental results are shown in Table 1. By comparing the heavy metal element content in the two soil conditioners and the requirements for the risk values of Pb, Cr, Cd, Hg, As, Ni, Cu, etc. in GB 15618 - 2018 as the reference standard, it is found that the heavy metal content in the two soil conditioners is within the national standard requirements.

[0038] Table 1 Heavy metal content in soil conditioner (mg / kg)

[0039] Component Pb Cr Cd Zn As Ni Cu Soil conditioner A 24.10 131.60 0.44 38.64 9.33 1.01 26.72 Soil conditioner B 20.82 87.20 0.08 39.65 9.69 5.74 29.61 GB15618-2018 ≤140 ≤300 ≤0.60 ≤250 ≤25 ≤100 ≤200

[0040] In summary, this example shows that the application of this soil conditioner to the soil will not cause pollution of heavy metal elements to the soil environment.

[0041] Example Three

[0042] In this experiment, the soil conditioner in Example One was used for soil cultivation experiment to explore the effects of this soil conditioner on soil physical and chemical properties, available Cd content, and nutrient content.

[0043] A total of two control groups were set up in the experiment, namely the control group (CK, without adding soil conditioner) and the treatment groups (TA, the addition amount of soil conditioner A is 100 g / kg; TB, the addition amount of soil conditioner B is 100 g / kg). Before the experiment started, the collected soil samples were air-dried, ground, and passed through a 2 mm sieve. 400 g of soil was evenly mixed with the corresponding proportion of soil conditioner, placed in a washed plastic beaker, and placed in a constant temperature and humidity box. The soil water content was adjusted to about 62% by the weighing method. Each group was treated with 4 parallels. After 30 days of cultivation, the soil samples were collected. After the experiment ended, the collected soil samples were air-dried, ground, and passed through a 2 mm sieve. Weigh 10 g of soil sample into a 100 ml centrifuge tube, add 50 ml of deionized water at a soil-water ratio of 1:5, stir with a magnetic stirrer for 20 min and then let it stand for 30 min, and then use a pH meter to measure the pH value of the supernatant and an electrical conductivity meter to measure the electrical conductivity of the supernatant. The available Cd content in the soil was measured by the national standard method GB / T 23739-2009; the available potassium content in the soil was measured by the national standard DB63 / T 1820-2020; the available phosphorus content in the soil was measured by the national standard DB63 / T 1822-2020; the total nitrogen content in the soil was measured by the national standard HJ 717-2014.

[0044] It can be seen from the analysis of Table 2 that compared with the CK group, the TA treatment (applying soil conditioner A) increased the soil pH by 1.3 units, and the TB treatment (applying soil conditioner B) increased the soil pH by 1.11 units. The EC increased by 0.9 and 0.8 times respectively, alleviating the soil acidification problem; the available Cd content decreased by 20% and 15% respectively, reducing the bioavailability of Cd in the soil; the available potassium content in the soil increased by 1.5 and 1.4 times respectively, the available phosphorus content increased by 2.7 and 3.1 times respectively, and the total nitrogen content increased by 2.4 and 2.1 times respectively, improving the soil fertility.

[0045] Table 2 Effects of soil amendments on soil physical and chemical properties, available Cd content, and nutrient content

[0046]

[0047] In summary, applying this soil amendment can alleviate soil acidification, improve soil fertility, reduce the available Cd content in the soil, and decrease its bioavailability.

[0048] Example 4

[0049] In this experiment, the soil amendment from Example 1 was used for a pot experiment to explore the multiple effects of this soil amendment in alleviating soil acidification, promoting plant growth, and reducing heavy metal uptake.

[0050] A total of two control groups were set up in the experiment, namely the control group (CK, without adding soil amendment) and the treatment groups (TA, with a soil amendment A addition amount of 100 g / kg; TB, with a soil amendment B addition amount of 100 g / kg). Before the experiment started, the collected soil samples were air-dried, ground, and passed through a 2 mm sieve. The soil was evenly mixed with the soil amendment and filled into plastic planting pots with a diameter of 17 cm and a height of 12 cm, with 2 kg of soil in each pot. The corn seeds were disinfected with 10% hydrogen peroxide for 15 min and then rinsed clean with deionized water. The seeds were placed on a moist filter paper and then placed in an incubator at 32 °C for 48 h. After the corn seeds germinated, the seeds were sown into the flower pots, with 4 seeds sown in each pot. When the corn seedlings grew to 2 - 3 cm, they were thinned, and 2 corn seedlings were left for subsequent experiments. Each treatment had 4 replicates. The temperature was controlled at 25 - 28 °C and the humidity at 50% - 60%. After 21 days of cultivation, plant samples and soil samples were collected. After the experiment ended, the collected soil samples were air-dried, ground, and passed through a 2 mm sieve. Weighed 10 g of soil samples into a 100 ml centrifuge tube, added 50 ml of deionized water at a soil-water ratio of 1:5, stirred with a magnetic stirrer for 20 min, then left to stand for 30 min, and used a pH meter to measure the pH value of the supernatant and a conductivity meter to measure the conductivity of the supernatant. Used a metal tape measure to measure the plant height. Using the oven-drying and weighing method, the whole sampled plant was rinsed until there was no soil attachment, blanched at 105 °C for 30 min, dried at 70 °C to a constant weight, and then weighed to obtain the plant biomass data. The Cd content in the plant samples was determined using the national standard method DB61 / T902.1 - 2013.

[0051] Analysis of Table 3 shows that compared with the CK group, the TA treatment (application of soil conditioner A) increased the soil pH by 0.98 units, and the TB treatment (application of soil conditioner A) increased the soil pH by 0.96 units. The EC increased by 1.6 and 1.2 times respectively, alleviating the problem of soil acidification; the plant height of the above-ground part of the corn increased by 14.1 and 11.2 cm respectively, promoting plant growth; the biomass of the corn increased by 35% and 26% respectively, increasing the biomass of the crop and promoting crop growth; the Cd content in the plant decreased by 49% and 60% respectively, reducing the migration of Cd to the crop.

[0052] Table 3 Effects of soil conditioners on soil physical and chemical properties, plant growth and Cd uptake

[0053]

[0054] In summary, during the cultivation process, due to the absorption of plant growth, the acidity of the soil increased, the pH decreased, and the conductivity decreased. By applying this soil conditioner, the decrease of soil pH and conductivity can be effectively inhibited, the nutrients absorbed by the crop can be provided, the plant height and biomass of the plant can be promoted, which helps to increase the crop yield. At the same time, the heavy metals are passivated, and the absorption of heavy metal element Cd by the crop is reduced. Finally, the safety production goals of improving the soil, treating heavy metal pollution and improving the growth status of the crop are achieved.

[0055] In conclusion: The black soil conditioner based on biomass power plant ash and its preparation method provided by the present invention break through the limitation of the single function of traditional soil conditioners. The prepared black soil conditioner has trace elements necessary for plant growth and lacking in the soil, which can be slowly released in the soil and supply plants for absorption and utilization. It can effectively alleviate soil acidity, improve soil structure, passivate heavy metals, reduce plant absorption, and at the same time enhance soil fertility and promote crop growth. Using the biomass ash of the power plant as the base material, the preparation method is simple and the cost is controllable. It can realize the full and effective utilization of the biomass ash generated by the biomass power plant. While reducing the application of chemical fertilizers, it reduces the treatment cost of the biomass ash of the power plant and improves the benefits of the enterprise.

[0056] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a black soil conditioner based on biomass power plant ash, comprising the following steps: S1, raw material preparation and crushing treatment, take the biomass ash and slag from the power plant, crush and screen it with a crusher, and then use it for later use after air drying to obtain pre-treated biomass ash and biomass slag; S2, nutritional ratio, select ammonium chloride, potassium dihydrogen phosphate and potassium chloride as nutritional additives, and the additives are sieved for use; S3, batching and mixing, according to the formula of compound fertilizer design, weigh biomass ash and biomass residue, mix them with magnesium chloride, ammonium chloride and potassium dihydrogen phosphate respectively, add deionized water to mix until semi-wet state, stand and grind to dry, to obtain activated biomass ash and activated biomass residue; S4, granulation, adding humic acid and bentonite to the activated biomass ash and activated biomass residue in S3, mixing thoroughly, adding water and mixing, and sending the mixture into the interior of an extrusion granulator for granulation, using a far-infrared dryer for drying, and obtaining soil conditioner A and soil conditioner B after screening.

2. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: The raw biomass ash obtained in step S1 comes from waste generated after combustion in a biomass power plant.

3. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: The fineness of the pretreated biomass ash obtained in step S1 is 80-100 mesh, and the fineness of the pretreated biomass slag is 100-120 mesh.

4. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: The additives obtained in step S2 are all sieved through a <1 mm sieve.

5. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: Nutritional formula setting: the mass fraction of total nutrients (N+P2O5+K2O) is >15%; the addition amount of biomass ash is >15%; the addition amount of humic acid is 10%; and the addition amount of organic fertilizer is 25%.

6. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: In step S3, the 16.8% pretreated biomass ash and 15.8% pretreated biomass residue are mixed with 6.3% magnesium chloride, 14.6% ammonium chloride, and 12.5% ​​potassium dihydrogen phosphate, respectively.

7. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: The mixed material in step S3 is stirred with water to make the obtained mixture in a semi-wet state and allowed to stand for 12 hours, and then placed in a forced air drying oven at 45° C. to dry to constant weight.

8. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: In step S4, the activated biomass ash and activated biomass residue are fully and evenly mixed with humic acid and bentonite, and the specific ratio is 80-94% of activated biomass ash / activated biomass residue, and 5-10% of humic acid and bentonite.

9. The method for preparing a black soil conditioner based on biomass power plant ash according to claim 1, characterized in that: Deionized water in an amount of 0.15-0.30 times the mass of the mixture is added to the mixture obtained in step S4 and mixed and stirred. After the mixture is granulated, it is dried in a far-infrared dryer at a temperature of 70-150° C. until the water content is 8-10%.

10. A black soil conditioner based on biomass power plant ash, characterized in that: The black soil conditioner is prepared by the preparation method of a biomass power plant ash-based black soil conditioner as described in any one of claims 1 to 9.

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