A soilless culture substrate composition and use

Abstract

This invention provides a soilless cultivation substrate composition and its application. The soilless cultivation substrate composition includes a first component and a second component. The first component includes modified phosphogypsum, a first municipal sludge fermentation product, an alkaline buffer, perlite, phosphate-solubilizing bacteria, and zeolite. The second component includes modified phosphogypsum, a second municipal sludge fermentation product, and rooting powder. The first municipal sludge fermentation product has a D50 not higher than 1 mm and a D60 not higher than 2 mm; the second municipal sludge fermentation product has a D50 not lower than 3 mm and a D60 not lower than 4 mm. The modified phosphogypsum has a median particle size of 200-300 mesh, a pH of 6.0-8.0, a fluoride ion mass percentage not higher than 0.1%, and a Cd ion content not higher than 0.5 mg / kg. This soilless cultivation substrate composition can achieve efficient utilization of phosphogypsum and municipal sludge, achieve good greening effects, and improve plant survival rates.

Description

Technical Field

[0001] This invention relates to the field of soilless cultivation technology, to a soilless cultivation substrate composition, and more particularly to a soilless cultivation substrate composition and its application. Background Technology

[0002] Phosphate mines are a crucial raw material for phosphate fertilizer production in my country. However, the mining process generates large amounts of exposed phosphate mine bodies and waste such as phosphogypsum. Under long-term rainwater runoff, these deposits leach large quantities of acidic substances, sulfur, phosphorus, phosphorus, heavy metals, and other pollutants, causing severe pollution that is difficult and costly to treat. Meanwhile, with my country's urbanization, the annual production of municipal sewage sludge has exceeded 56 million tons. Therefore, the resource utilization of phosphogypsum and municipal sewage sludge has become an urgent issue.

[0003] The utilization of phosphogypsum is mostly limited to direct mulching with topsoil followed by revegetation for ecological restoration of phosphate mines or phosphogypsum storage facilities, but this requires large amounts of topsoil. Alternatively, phosphogypsum can be used in building materials, but this application is limited and the quantities used are small. Municipal sewage sludge, rich in organic matter and nutrients, can be applied to the land after anaerobic digestion or aerobic fermentation. However, aerobic fermentation sludge is too loose and permeable, which, when used on a large scale, severely reduces soil bulk density and water retention, leading to low plant survival rates and limited effectiveness compared to ordinary fertilizers. Furthermore, phosphogypsum or municipal sewage sludge can be applied to hydroponics to achieve resource utilization of solid waste, but in practical applications, poor greening effects and low plant survival rates remain problems.

[0004] Therefore, there is an urgent need to develop a soilless cultivation substrate to achieve efficient utilization of phosphogypsum and municipal sludge, as well as to achieve better greening effects and improve plant survival rates. Summary of the Invention

[0005] This invention provides a soilless cultivation substrate composition that enables the efficient utilization of phosphogypsum and municipal sludge, achieves better greening effects, and improves plant survival rates.

[0006] This invention provides a method for using a cultivation substrate composition. By using the above-mentioned soilless cultivation substrate composition, phosphogypsum and municipal sludge can be fully utilized to realize the resource utilization of solid waste resources, and it has a good greening effect and a high plant survival rate.

[0007] This invention provides a soilless cultivation substrate composition, comprising a first component and a second component;

[0008] The first component comprises 40-80 parts by weight of modified phosphogypsum, 20-50 parts by weight of fermentation products of municipal sludge, 3-5 parts by weight of alkaline buffer, 2-4 parts by weight of perlite, 0.5-1 parts by weight of phosphate-solubilizing bacteria, and 1-2 parts by weight of zeolite.

[0009] The second component comprises 40-60 parts by weight of modified phosphogypsum, 20-30 parts by weight of fermentation product of second municipal sludge, and 0.5-2 parts by weight of rooting powder;

[0010] The D50 of the first municipal sludge fermentation product is not higher than 1 mm, and the D60 is not higher than 2 mm.

[0011] The D50 of the second municipal sludge fermentation product is not less than 3mm, and the D60 is not less than 4mm.

[0012] The modified phosphogypsum has a median particle size of 200-300 mesh, a pH of 6.0-8.0, a fluoride ion content of no more than 0.1% by mass, and a Cd ion content of no more than 0.5 mg / kg.

[0013] Furthermore, the mass ratio of the modified phosphogypsum to the fermentation product of the first municipal sludge in the first component is (4-5):(2-4).

[0014] Furthermore, the bulk density of the modified phosphogypsum is >0.8 g / cm³. 3 And / or, the modified phosphogypsum contains >65% calcium sulfate dihydrate by mass, and / or, the modified phosphogypsum has a moisture content <25%, and / or, the modified phosphogypsum contains >0.5% available phosphorus by mass.

[0015] Furthermore, the pH value of the first municipal sludge fermentation product is 7 to 9.5, and / or the mass percentage of organic matter in the first municipal sludge fermentation product is >15%, and / or the moisture content of the first municipal sludge fermentation product is <50%.

[0016] Furthermore, the pH value of the second municipal sludge fermentation product is 7 to 9.5, and / or the mass percentage of organic matter in the second municipal sludge fermentation product is >30%, and / or the moisture content of the second municipal sludge fermentation product is <40%.

[0017] Furthermore, the bulk density of the first municipal sludge fermentation product is <0.7 g / cm³. 3 And / or, the bulk density of the second municipal sludge fermentation product is <0.4 g / cm³. 3 .

[0018] Furthermore, the alkaline buffer has a particle size of <200 mesh, and / or the perlite has a particle size of <50 mesh, and / or the zeolite has a particle size of <50 mesh.

[0019] Furthermore, the organic matter content of the first component is 5-20% by mass, and / or the moisture content of the first component is <30%, and / or the pH of the first component is 6-8, and / or the seed germination index of the first component is >70%.

[0020] The present invention also provides a method for using a soil-based cultivation substrate composition, comprising the following steps:

[0021] (1) Lay the second component on the plot that needs to be revegetated, and carry out the first watering and the first compaction;

[0022] (2) Then, continue to lay the first component on the compacted second component surface, and carry out the second watering and second compaction;

[0023] The ratio of the laying volume of the second component to the laying volume of the first component is (7-11):(5-8).

[0024] Furthermore, in step (1), the second component is laid to a thickness of 35–55 cm, and / or the amount of water sprayed is 1–2 L / m. 2 And / or, the thickness of the second component after the first compaction is 25-45 cm;

[0025] And / or, in step (2), the thickness of the first component is 25-40 cm, and / or, the amount of water sprayed is 1-2 L / m. 2 And / or, the thickness of the first component after the second compaction is 20-35 cm.

[0026] The soilless cultivation substrate composition of the present invention includes a first component and a second component. By using the first component and the second component comprising the above-mentioned composition, and by controlling the mass fraction of each substance in the first component and the second component, the D50 and D60 of the first municipal sludge fermentation product and the second municipal sludge fermentation product, and the mass percentage content of the particle size, pH, fluoride ions and Cd ions of the modified phosphogypsum, the components can synergistically influence each other, thereby achieving a better greening effect and improving the plant survival rate. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] The first aspect of the present invention provides a soilless cultivation substrate composition, comprising a first component and a second component;

[0029] The first component includes 40-80 parts by weight of modified phosphogypsum, 20-50 parts by weight of fermentation products of municipal sludge, 3-5 parts by weight of alkaline buffer, 2-4 parts by weight of perlite, 0.5-1 parts by weight of phosphate-solubilizing bacteria, and 1-2 parts by weight of zeolite.

[0030] The second component includes 40-60 parts by weight of modified phosphogypsum, 20-30 parts by weight of fermentation product of municipal sludge, and 0.5-2 parts by weight of rooting powder.

[0031] The D50 of the fermentation products of municipal sludge is not higher than 1 mm, and the D60 is not higher than 2 mm.

[0032] The D50 of the fermentation products of the second municipal sludge is not less than 3mm, and the D60 is not less than 4mm.

[0033] The median particle size of the modified phosphogypsum is 200-300 mesh, the pH of the modified phosphogypsum is 6.0-8.0, the mass percentage of fluoride ions in the modified phosphogypsum is not higher than 0.1%, and the content of Cd ions in the modified phosphogypsum is not higher than 0.5 mg / kg.

[0034] In this invention, D50 refers to the particle size corresponding to a cumulative particle size distribution of 50%, and D60 refers to the particle size corresponding to a cumulative particle size distribution of 60%. For example, D60 of 3mm means that the proportion of particles with a diameter <3mm is 60%.

[0035] The preparation method of modified phosphogypsum in this invention is not particularly limited. It is sufficient that the median particle size of the final modified phosphogypsum is 200–300 mesh, the pH is 6.0–8.0, the mass percentage of fluoride ions is not higher than 0.1%, and the content of Cd ions is not higher than 0.5 mg / kg. In one embodiment, it can be prepared by including the following steps:

[0036] The phosphogypsum was ball-milled and sieved to obtain phosphogypsum with a particle size of 50-800 mesh. Then, it was ultrasonically washed with sludge fermentation broth to remove fluoride and Cd ions, so that the mass percentage of fluoride ions was not higher than 0.1% and the Cd ion content was not higher than 0.5 mg / kg. Finally, it was modified with quicklime. Specifically, 10-15 parts by mass of the washed phosphogypsum, 2-6 parts by mass of quicklime, and 1-2 parts by mass of water were thoroughly mixed and left to stand for 5-7 days to obtain modified phosphogypsum with a pH of 6.0-8.0.

[0037] Furthermore, the powder of the above-mentioned phosphogypsum after ball milling and sieving has a particle size of 50-800 mesh and a bulk density >0.8 g / cm³. 3It has a pH value of 2-5, a calcium sulfate dihydrate content of >55% by mass, a water content of <25%, and an available phosphorus content of >0.5% by mass.

[0038] Furthermore, the aforementioned sludge fermentation broth is a solution formed after anaerobic digestion of municipal sludge. This sludge fermentation broth is rich in small-molecule organic acids, with a pH value of 5.5–6.5. These small-molecule organic acids can not only effectively dissolve fluoride ions and Cd ions, reducing the content of harmful substances, but also increase the content of microorganisms and nutrients in phosphogypsum.

[0039] Furthermore, based on the total weight of small molecule organic acids, the acetic acid content in the sludge fermentation liquid is not less than 55 wt%, and the concentration of small molecule organic acids in the sludge fermentation liquid, calculated as acetic acid, is 400–800 mg / L.

[0040] Furthermore, the ultrasonic power density is 0.3–0.6 W / mL, with a 10–20 s pause every 40–50 s of operation, for a total operating time of 300–500 s. Since fluoride and Cd ions mostly exist in sparingly soluble forms, ultrasonication, with ultrasonic parameters controlled within the aforementioned range, can accelerate the dissolution of these pollutants, further reducing the content of fluoride and Cd ions in phosphogypsum.

[0041] This invention does not specifically limit the preparation methods of the first and second municipal sludge fermentation products. In one embodiment, the first and second municipal sludge fermentation products can be obtained by aerobic fermentation of municipal sludge and auxiliary materials, followed by sieving of the fermentation products. The auxiliary materials include at least one of rice husks, straw, peanut shells, and leaves. This invention does not specifically limit the temperature, fermentation time, stacking height, moisture content, oxygen supply, pH value, carbon-nitrogen ratio, and carbon-phosphorus ratio during the fermentation process; it is only necessary that the D50 and D60 of the sieved first and second municipal sludge fermentation products fall within the aforementioned ranges.

[0042] Furthermore, the fermentation products of municipal sludge before screening have a particle size of <6cm, are soft and odorless, have a pH of 7.0–9.5, an organic matter content of >25%, a moisture content of <45%, and a bulk density of <0.6g / cm³. 3 .

[0043] The present invention does not specifically limit the types of alkaline buffers and rooting powders. For example, alkaline buffers include at least one of calcium carbonate and magnesium carbonate; rooting powders include at least one of humic acid, indoleacetic acid, and sodium naphthaleneacetate.

[0044] This invention does not specifically limit the source of alkaline buffer, perlite, phosphate-solubilizing bacteria, zeolite, and rooting powder; products prepared by commercially available products or conventional preparation methods known to those skilled in the art can be used.

[0045] The soilless cultivation substrate composition of the present invention includes a first component and a second component, wherein both the first and second components include modified phosphogypsum and municipal sludge fermentation products, enabling efficient utilization of solid waste. Simultaneously, the first and second components respectively include the aforementioned components, and the mass fractions of each component, the D50 and D60 of the first and second municipal sludge fermentation products, the median particle size of the modified phosphogypsum, the pH, and the contents of fluoride and Cd ions are limited to within the aforementioned ranges. This allows the components and the components to synergistically cooperate, thereby enabling seeds to quickly take root and germinate in the substrate, achieving a high plant survival rate.

[0046] Furthermore, the soilless cultivation substrate composition of this invention has a simple formula and is easy to manufacture. Plants can be planted without the addition of imported soil, and the growth rate and biomass of herbaceous plants are significantly improved compared to ordinary imported soil, which can reduce restoration costs and save imported soil resources. At the same time, since the plant survival rate of the soilless cultivation substrate composition of this invention is high, no additional water-retaining agents or fertilizer-retaining agents are needed, the required maintenance time is short, and the greening effect is long-lasting. Moreover, the modified phosphogypsum has a low content of harmful substances such as fluoride ions and Cd ions, ensuring safety in use.

[0047] In one specific embodiment, the mass ratio of modified phosphogypsum to the fermentation product of the first municipal sludge in the first component is (4-5):(2-4). Within this range, the plant biomass and long-term survival rate can be further improved.

[0048] In one specific embodiment, the bulk density of the modified phosphogypsum is >0.8 g / cm³. 3 Within this range, water loss can be effectively prevented, plant survival rates can be improved, and better greening results can be achieved.

[0049] In one specific embodiment, the modified phosphogypsum contains >65% calcium sulfate dihydrate by mass. Within this range, it can effectively improve soil quality and promote plant growth.

[0050] In one specific embodiment, the modified phosphogypsum has a moisture content of <25%. Within this range, phosphogypsum clumping can be effectively avoided, thereby further improving the greening effect and increasing the plant survival rate.

[0051] In one specific embodiment, the modified phosphogypsum contains >0.5% by mass of available phosphorus. Within this range, the soilless cultivation substrate composition can have a higher available phosphorus content, enabling seeds to germinate and root more quickly, and further improving the early growth rate of seedlings.

[0052] In one specific embodiment, the pH value of the fermentation product of the first municipal sludge is 7–9.5. Within this range, the fermentation product of the first municipal sludge has a strong acid buffering capacity, thereby further preventing phosphogypsum from acidifying and improving the long-term survival rate of plants.

[0053] In one specific embodiment, the organic matter content of the fermentation products of the first municipal sludge is >15% by mass. Within this range, sufficient organic matter can be provided for plant growth, thereby improving plant survival rate.

[0054] In one specific embodiment, the moisture content of the first municipal sludge fermentation product is <50%. Within this range, a better greening effect can be achieved, resulting in a higher seed germination rate.

[0055] In one specific embodiment, the pH value of the fermentation products of the second municipal sludge is 7–9.5. Within this range, the acid buffering capacity of the fermentation products of the second municipal sludge can be improved.

[0056] In one specific embodiment, the organic matter content of the fermentation products of the second municipal sludge is >30% by mass. Within this range, sufficient organic matter can be provided for plant roots.

[0057] In one specific embodiment, the moisture content of the fermentation product of the second municipal sludge is <40%. Within this range, the fermentation product is relatively fully decomposed and can reach a soft and odorless state.

[0058] In one specific embodiment, the bulk density of the fermentation product of the first municipal sludge is <0.7 g / cm³. 3 Within this range, moisture loss can be effectively prevented.

[0059] In one specific embodiment, the bulk density of the fermentation product of the second municipal sludge is <0.4 g / cm³. 3 Within this range, better water retention can be achieved, preventing water loss and improving plant survival rates.

[0060] In one specific embodiment, the alkaline buffer has a particle size of <200 mesh. Within this range, the alkaline buffer can be mixed evenly with the fermentation products, ensuring a complete reaction.

[0061] In one specific embodiment, the perlite has a particle size of <50 mesh. Within this range, the fertilizer and water retention of the soilless cultivation substrate can be improved, and its air permeability is also good, which is beneficial to plant survival.

[0062] In one specific embodiment, the zeolite particle size is <50 mesh. Within this range, zeolite has a strong adsorption capacity and can effectively adsorb fluoride ions and Cd ions in the soilless cultivation substrate, thereby further improving the plant survival rate.

[0063] It should be noted that the larger the mesh number, the smaller the particle size. Therefore, the particle size of the alkaline buffer in this invention is <200 mesh, which means that the particle size of the alkaline buffer is finer than 200 mesh. For example, the particle size of the alkaline buffer is 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh or 500 mesh.

[0064] Similarly, perlite with a particle size <50 mesh means that the perlite particle size is finer than 50 mesh. For example, perlite with a particle size of 60 mesh, 70 mesh, 80 mesh, 90 mesh, or 100 mesh; zeolite with a particle size <50 mesh means that zeolite with a particle size of 60 mesh, 70 mesh, 80 mesh, 90 mesh, or 100 mesh.

[0065] In one specific embodiment, the organic matter content of the first component is 5% to 20% by mass. Within this range, sufficient organic matter can be provided for plant growth.

[0066] In one specific embodiment, the moisture content of the first component is <30%, and / or the pH of the first component is 6-8. Within this range, plant growth is promoted, further enhancing the greening effect.

[0067] In one specific implementation, the seed germination index of the first component is >70%. Specifically, this can be achieved by subjecting the municipal sludge to sufficient aerobic fermentation, resulting in a seed germination index of >70% for the first component.

[0068] Specifically, the seed germination index in this invention can be obtained by measuring the seed germination experiment, and the specific steps include:

[0069] Take 20g of the first component fresh sample, add 200mL of distilled water, shake for 20min, and extract at 30℃ for 24 hours. Filter the supernatant using slow-speed filter paper and set the filtrate aside. Place filter paper of appropriate size in two 9cm petri dishes, and add 20 plump, similarly sized small Chinese cabbage seeds to each dish. Use a pipette to transfer 5.0mL of the aforementioned filtrate to one petri dish as the experimental group; use a pipette to transfer 5.0mL of distilled water to the other petri dish as the control group. Place the petri dishes of the experimental and control groups in an incubator at (25±1)℃ and 80% humidity for 24h. Measure the seed germination rate and root length. Repeat the experiment 3 times for each group and take the average value. Then, the seed germination index (%) = (seed germination rate of the experimental group × seed root length) / (seed germination rate of the control group × seed root length) × 100.

[0070] A second aspect of the present invention provides a method of using a soilless culture substrate composition, comprising the following steps:

[0071] (1) Lay the second component on the plot that needs to be revegetated, and carry out the first watering and the first compaction;

[0072] (2) Then, continue to lay the first component on the compacted second component surface, and carry out the second watering and second compaction;

[0073] The ratio of the laying volume of the second component to the laying volume of the first component is (7-11):(5-8).

[0074] Specifically, in step (1), a second component of a soilless cultivation substrate is laid on the surface of the plot that needs to be revegetated, and the first watering and first compaction are carried out.

[0075] The present invention does not specifically limit the amount of water sprayed in the first watering and the thickness of the second component after the first compaction.

[0076] In step (2), a layer of the first component is laid on the surface of the second component after the first compaction, and the second watering and second compaction are carried out.

[0077] The present invention does not specifically limit the amount of water sprayed in the second watering and the thickness of the first component after the second compaction.

[0078] The ratio of the laying volume of the second component to the laying volume of the first component is (7-11):(5-8).

[0079] In this invention, the laying volume refers to the product of the laying area and the laying thickness, assuming the same laying area.

[0080] The method of using the soilless cultivation substrate composition of the present invention involves laying the second component and the first component sequentially on the surface of the plot to be revegetated, with the ratio of the volume of the second component to the volume of the first component being within the aforementioned range. This not only maintains the looseness and oxygen content of the lower substrate, allowing plant roots to grow rapidly downwards and absorb more nutrients, but also prevents the evaporation and loss of water from the upper substrate, thus achieving the effect of water and fertilizer retention. This promotes rapid seed germination and root development, thereby improving the revegetation effect and increasing the plant survival rate.

[0081] In one specific embodiment, the second component is laid to a thickness of 35–55 cm, and / or the amount of water sprayed in the first application is 1–2 L / m. 2 And / or, the thickness of the second component after the first compaction is 25–45 cm. When the thickness of the second component is 35–55 cm, it can provide sufficient nutrients for the roots; when the amount of water sprayed in the first spray is 1–2 L / m² 2 When the second component is compacted, it can keep the second component moist without flooding the roots. When the thickness of the second component after the first compaction is 25-45cm, it can ensure sufficient growth space for the roots while avoiding the formation of large gaps, allowing the roots to fully contact the substrate.

[0082] In one specific embodiment, the first component is laid to a thickness of 25–40 cm, and / or the amount of water sprayed is 1–2 L / m. 2 And / or, the thickness of the second component after the second compaction is 20–35 cm. When the thickness of the first component is 25–40 cm, it can provide sufficient nutrients and growth substrate for plant growth; when the amount of water sprayed is 1–2 L / m²... 2 When the first component is compacted, it keeps the seeds moist without damaging them. When the thickness of the first component after the second compaction is 20-35cm, it allows the seeds some room to grow while preventing rapid water loss, thus achieving the effect of water and fertilizer retention.

[0083] The soilless cultivation substrate composition of the present invention will be described in detail below through specific embodiments.

[0084] Example 1

[0085] (1) After ball milling and sieving, the medium-coarse particles with a particle size between 100 and 600 mesh were taken, and the bulk density was measured to be 1.15 g / cm³. 3 The pH value is 4.1, the mass percentage of calcium sulfate dihydrate is 70.3%, the water content is 14.1%, the mass percentage of available phosphorus is 1.2%, the measured F ion content is 0.46%, and the Cd content is 1.77 mg / kg;

[0086] (2) The phosphogypsum after screening was ultrasonically washed with sludge fermentation liquid, which is a solution formed after anaerobic digestion of sludge, with a pH value of 5.7; based on the total weight of small molecule organic acids, the acetic acid content was 63.2 wt%, and the concentration of small molecule organic acids was 656 mg / L; the ultrasonic power density was 0.5 W / mL, with a 10-second pause every 50 seconds, and a total running time of 500 seconds;

[0087] (3) The leached phosphogypsum was modified by mixing 15 parts by weight of the leached phosphogypsum, 3 parts by weight of quicklime, and 2 parts by weight of water thoroughly and allowing it to stand for 5-7 days to obtain modified phosphogypsum. The modified phosphogypsum had a median particle size of approximately 300 mesh, a pH of 6.1, an F ion content reduced to 0.07%, a Cd content reduced to 0.16 mg / kg, and a bulk density of 0.92 g / cm³. 3 The mass percentage of calcium sulfate dihydrate is 67.2%, the water content is 18.9%, and the mass percentage of available phosphorus is 0.72%.

[0088] (4) The fermented municipal sludge fermentation product (particle size < 6cm, soft and odorless, pH = 7.8, organic matter content 31.5%, moisture content 32.6%, loose bulk density 0.51g / cm³) 3The samples were sieved to obtain the first municipal sludge fermentation product and the second municipal sludge fermentation product. The bulk density of the first municipal sludge fermentation product was 0.62 g / cm³. 3 The D50 was 0.8 mm, the D60 was 1.5 mm, the pH was 7.7, the organic matter content was 18.9% by mass, and the moisture content was 37.7%; the bulk density of the fermentation product of the second municipal sludge was 0.36 g / cm³. 3 The D50 is 3.6 mm, the D60 is 4.7 mm, the pH is 7.9, the organic matter content is 39.7% by mass, and the water content is 28.2%.

[0089] (5) Take 50 parts by weight of modified phosphogypsum, 30 parts by weight of the first municipal sludge fermentation product, 5 parts by weight of calcium carbonate powder (particle size 300-500 mesh), 2 parts by weight of perlite powder (particle size 50-100 mesh), 1 part by weight of phosphate-solubilizing bacteria and 2 parts by weight of zeolite (particle size 50-100 mesh) and mix them thoroughly to obtain the first component; the organic matter content of the first component is 9.2%, the water content is 24.3%, the pH value is 6.9, and the seed germination index is 82%; take 50 parts by weight of modified phosphogypsum, 30 parts by weight of the second municipal sludge fermentation product and 1 part by weight of rooting powder and mix them thoroughly to obtain the second component;

[0090] (6) Lay a 45cm thick second component on the surface of the plot that needs to be revegetated. Sprinkle 1.5L of water per square meter and compact it to a certain extent. The thickness after compaction is 37.0cm. Then lay a 35cm thick first component on the surface of the compacted second component. Sprinkle 1.5L of water per square meter and compact it to a certain extent. The thickness after compaction is 26.9cm. Let it stand for 3 days.

[0091] (7) Sow ryegrass seeds at a rate of 20g per square meter. The plants will begin to germinate gradually after 2 days. During this period, water the field to maintain the water level. After 15 days, the average plant height of the ryegrass will reach 26.2cm, with the highest plant height reaching 39.7cm. The biomass will be 0.79kg / m². 2 The green coverage rate reached 100%, and no further watering or maintenance was required. There was no obvious wilting within 3 months.

[0092] Example 2

[0093] (1) After ball milling and sieving, the medium-coarse particles with a particle size between 100 and 400 mesh were taken, and the bulk density was measured to be 1.27 g / cm³. 3 The pH value is 4.2, the mass percentage of calcium sulfate dihydrate is 71.5%, the water content is 15.4%, the mass percentage of available phosphorus is 1.4%, the measured F ion content is 0.42%, and the Cd content is 1.92 mg / kg;

[0094] (2) The phosphogypsum after screening was ultrasonically washed with sludge fermentation liquid, which is a solution formed after anaerobic digestion of sludge, with a pH value of 5.7; based on the total weight of small molecule organic acids, the acetic acid content was 63.2 wt%, and the concentration of small molecule organic acids was 656 mg / L; the ultrasonic power density was 0.5 W / mL, with a 10-second pause every 50 seconds, and a total running time of 500 seconds;

[0095] (3) The leached phosphogypsum was modified by mixing 15 parts by weight of the leached phosphogypsum, 3.5 parts by weight of quicklime, and 2 parts by weight of water thoroughly and allowing it to stand for 5-7 days to obtain modified phosphogypsum. The modified phosphogypsum had a median particle size of approximately 200 mesh, a pH of 6.7, an F ion content reduced to 0.05%, a Cd content reduced to 0.15 mg / kg, and a bulk density of 1.01 g / cm³. 3 The mass percentage of calcium sulfate dihydrate is 68.3%, the water content is 19.2%, and the mass percentage of available phosphorus is 0.62%.

[0096] (4) The fermented municipal sludge fermentation product (particle size < 4.5 cm, soft and odorless, pH = 7.9, organic matter content 35.7%, moisture content 35.3%, loose bulk density 0.51 g / cm³) 3 The product was screened to obtain the first municipal sludge fermentation product and the second municipal sludge fermentation product. The bulk density of the first municipal sludge fermentation product was 0.69 g / cm³. 3 The D50 was 0.7 mm, the D60 was 1.3 mm, the pH was 8.2, the organic matter content was 20.3% by mass, and the moisture content was 39.5%. The bulk density of the fermentation product of the second municipal sludge was 0.39 g / cm³. 3 The D50 is 3.2 mm, the D60 is 4.3 mm, the pH is 7.4, the organic matter content is 43.7% by mass, and the water content is 26.2%.

[0097] (5) Take 60 parts by weight of modified phosphogypsum, 25 parts by weight of the first municipal sludge fermentation product, 3 parts by weight of calcium carbonate powder (particle size 200-300 mesh), 3 parts by weight of perlite powder (particle size 100-200 mesh), 0.6 parts by weight of phosphate-solubilizing bacteria and 1 part by weight of zeolite (particle size 100-200 mesh) and mix them thoroughly to obtain the first component; the organic matter content of the first component is 6.3%, the water content is 26.3%, the pH value is 6.4, and the seed germination index is 89%; take 40 parts by weight of modified phosphogypsum, 20 parts by weight of the second municipal sludge fermentation product and 1 part by weight of rooting powder and mix them thoroughly to obtain the second component;

[0098] (6) Lay a 55cm thick second component on the surface of the plot that needs to be revegetated, sprinkle 2L of water per square meter and compact it to a certain extent. The thickness after compaction is 39.2cm. Then lay a 40cm thick first component on the compacted second component, sprinkle 2L of water per square meter and compact it to a certain extent. The thickness after compaction is 31.4cm. Let it stand for 3 days.

[0099] (7) Sow ryegrass seeds at a rate of 20g per square meter. The plants will begin to germinate gradually after 2 days. During this period, water the field to maintain the water level. After 15 days, the average height of the ryegrass plants will reach 25.5cm, with the highest plant height reaching 39.2cm. The biomass will be 0.77kg / m². 2 The green coverage rate reached 100%, and no further watering or maintenance was required. There was no obvious wilting within 3 months.

[0100] Example 3

[0101] The preparation method of the soilless cultivation substrate composition in this embodiment is basically the same as that in Example 1. The difference is that in step (5), the composition of the first component is changed. Specifically, 40 parts by mass of modified phosphogypsum, 50 parts by mass of the first municipal sludge fermentation product, 5 parts by mass of calcium carbonate powder (particle size 300-500 mesh), 2 parts by mass of perlite powder (particle size 50-100 mesh), 1 part by mass of phosphate-solubilizing bacteria and 2 parts by mass of zeolite (particle size 50-100 mesh) are thoroughly mixed to obtain the first component. The organic matter content of the first component is 17.2%, the water content is 26.9%, the pH value is 7.4, and the seed germination index is 71%.

[0102] In step (7), 20g of ryegrass seeds were sown per square meter. The plants began to germinate gradually after 2 days. During this period, watering was carried out to maintain the water level in the field. After 15 days, the average height of the ryegrass plants reached 19.2cm, with the highest plant height reaching 31.7cm, and the biomass was 0.53kg / m². 2 The green coverage rate reached 92%, but after that, no more watering and maintenance were carried out. Within 3 months, the plants withered, with a withering rate of about 20%.

[0103] Example 4

[0104] The preparation method of the soilless cultivation substrate composition in this embodiment is basically the same as that in Example 1. The difference is that in step (1), after ball milling and sieving the phosphogypsum, the medium-coarse particles with a particle size between 100 and 600 mesh are taken, and the loose bulk density is measured to be 1.19 g / cm³. 3 The pH value is 4.1, the mass percentage of calcium sulfate dihydrate is 79.3%, the water content is 15.2%, the mass percentage of available phosphorus is 0.47%, the measured F ion content is 0.49%, and the Cd content is 1.90 mg / kg;

[0105] In step (3), the modified phosphogypsum has a median particle size of approximately 300 mesh, a pH of 6.1, an F ion content reduced to 0.09%, a Cd content reduced to 0.22 mg / kg, and a bulk density of 0.94 g / cm³. 3 The mass percentage of calcium sulfate dihydrate is 69.2%, the water content is 18.3%, and the mass percentage of available phosphorus is 0.12%.

[0106] In step (5), the organic matter content of the first component is 9.2%, the water content is 23.5%, the pH value is 6.8, and the seed germination index is 74%.

[0107] In step (7), 20g of ryegrass seeds were sown per square meter. The plants began to germinate gradually after 4 days. During this period, watering was carried out to maintain the water level in the field. After 15 days, the average height of the ryegrass plants reached 20.7cm, with the highest plant height reaching 24.7cm. The biomass was 0.59kg / m². 2 The green coverage rate reached 85%, but no watering and maintenance were carried out afterwards. Within 3 months, the plants withered, with a withering rate of about 15%.

[0108] Example 5

[0109] The preparation method of the soilless cultivation substrate composition in this embodiment is basically the same as that in Example 1. The difference is that in step (4), the fermented municipal sludge fermentation product (particle size < 6cm, soft and odorless, pH = 7.1, organic matter content 21.5%, moisture content 42.6%, loose bulk density 0.57g / cm³) is used. 3 The fermentation products were screened to obtain the first municipal sludge fermentation product and the second municipal sludge fermentation product. The bulk density of the first municipal sludge fermentation product was 0.61 g / cm³. 3 The D50 was 0.9 mm, the D60 was 1.6 mm, the pH was 7.6, the organic matter content was 12.9% by mass, and the moisture content was 47.3%. The bulk density of the fermentation product of the second municipal sludge was 0.35 g / cm³. 3 The D50 is 3.1 mm, the D60 is 4.2 mm, the pH is 7.3, the organic matter content is 30.2% by mass, and the water content is 32.7%.

[0110] In step (5), the organic matter content of the first component is 4.4%, the water content is 27.2%, the pH value is 6.4, and the seed germination index is 69%.

[0111] In step (7), 20g of ryegrass seeds were sown per square meter. The plants began to germinate gradually after 3 days. During this period, watering was carried out to maintain the water level in the field. After 15 days, the average height of the ryegrass plants reached 17.2cm, with the highest plant height reaching 22.7cm, and the biomass was 0.51kg / m². 2The green coverage rate reached 82%, but no watering and maintenance were carried out afterwards. Within 3 months, obvious wilting appeared, with a wilting rate of about 25%.

[0112] Example 6

[0113] The preparation method of the soilless cultivation substrate composition in this embodiment is basically the same as that in Example 1. The difference is that in step (6), a second component with a thickness of 32cm is laid on the surface of the plot that needs to be revegetated. After sprinkling 1.5L of water per square meter, it is compacted to a certain extent, and the thickness after compaction is 21.3cm. Then, a first component with a thickness of 35cm is laid on the surface of the compacted second component. After sprinkling 1.5L of water per square meter, it is compacted to a certain extent, and the thickness after compaction is 26.9cm. Let it stand for 3 days.

[0114] In step (7), 20g of ryegrass seeds were sown per square meter. The plants began to germinate gradually after 2 days. During this period, watering was carried out to maintain the water level in the field. After 15 days, the average height of the ryegrass plants reached 24.2cm, with the highest plant height reaching 33.7cm, and the biomass was 0.73kg / m². 2 The green coverage rate reached 90%, and no further watering or maintenance was required. There was no wilting within 3 months.

[0115] Example 7

[0116] The preparation method of the soilless cultivation substrate composition in this embodiment is basically the same as that in Example 1. The difference is that in step (6), a second component with a thickness of 45cm is laid on the surface of the plot that needs to be revegetated. After sprinkling 1.5L of water per square meter, it is compacted to a certain extent, and the thickness after compaction is 37.0cm. Then, a first component with a thickness of 24cm is laid on the surface of the compacted second component. After sprinkling 1.5L of water per square meter, it is compacted to a certain extent, and the thickness after compaction is 15.9cm. Let it stand for 3 days.

[0117] In step (7), 20g of ryegrass seeds were sown per square meter. The plants began to germinate gradually after 2 days. During this period, watering was carried out to maintain the water level in the field. After 15 days, the average height of the ryegrass plants reached 17.2cm, with the highest plant height reaching 20.4cm, and the biomass was 0.52kg / m². 2 The green coverage rate reached 100%, and no further watering or maintenance was required. There was no wilting within 3 months.

[0118] Comparative Example 1

[0119] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1. The difference is that the first component is completely replaced with unscreened fermented sludge in this comparative example, while the other steps are kept the same as in Example 1, and no seed germination occurs.

[0120] Comparative Example 2

[0121] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1, except that in step (5), the first component is completely replaced with the modified phosphogypsum in step (3) of Example 1.

[0122] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Only a very small number of seeds germinated after 5 days. During this period, watering was maintained to keep the field moist. After 15 days, the average height of the ryegrass plants was generally less than 12cm, with the tallest reaching 15.7cm. The biomass was approximately 0.03kg / m². 2 The green coverage rate is less than 5%, and no watering or maintenance is carried out afterward. After 1.5 months, the plants wither and turn yellow, with a withering rate of about 50%.

[0123] Comparative Example 3

[0124] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1. The difference is that in step (5), the first municipal sludge fermentation product in the first component and the second municipal sludge fermentation product in the second component are completely replaced with ordinary imported soil. The other steps are the same as in Example 1.

[0125] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 4 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 18cm, with the tallest reaching approximately 19.7cm, and the biomass was 0.31kg / m². 2 The green coverage rate was about 85%. After that, no watering and maintenance were carried out. After 1.5 months, the plants turned yellow and withered, with a withering rate of about 35%.

[0126] Comparative Example 4

[0127] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1. The difference is that in step (5), the first component consists of 90 parts by mass of phosphogypsum, 15 parts by mass of the first municipal sludge fermentation product, 2 parts by mass of alkaline buffer, 1 part by mass of perlite, 0.3 parts by mass of phosphate-solubilizing bacteria, and 3 parts by mass of zeolite. The other steps are consistent with those in Example 1.

[0128] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 4 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 15.3cm, with the tallest reaching approximately 16.7cm, and the biomass was 0.28kg / m². 2 The green coverage rate was about 70%. After that, no watering and maintenance were carried out. After 1.5 months, the plants turned yellow and withered, with a withering rate of about 30%.

[0129] Comparative Example 5

[0130] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1, except that in step (5), the second component is entirely modified phosphogypsum.

[0131] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 3 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 19.3cm, with the tallest reaching 24.9cm, and the biomass was 0.34kg / m². 2 The green coverage rate was about 80%, but after that, no watering and maintenance were carried out, and after 3 months, all of them turned yellow and withered.

[0132] Comparative Example 6

[0133] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1, except that in step (5), the second municipal sludge fermentation product in the second component is replaced with the first municipal sludge fermentation product.

[0134] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 5 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 22.3cm, with the tallest reaching 27.5cm, and the biomass was 0.42kg / m². 2 The green coverage rate was about 70%, but after that, no watering and maintenance were carried out, and after 3 months, all of them turned yellow and withered.

[0135] Comparative Example 7

[0136] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1, except that in step (5), the first municipal sludge fermentation product in the first component is replaced with the second municipal sludge fermentation product.

[0137] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 3 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 24.1cm, with the tallest reaching 29.9cm, and the biomass was 0.27kg / m². 2 The green coverage rate was about 40%, but after that, no watering and maintenance were carried out, and after 2 months, all of them turned yellow and withered.

[0138] Comparative Example 8

[0139] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1. The difference is that in step (5), the first municipal sludge fermentation product in the first component is replaced with the second municipal sludge fermentation product, and the second municipal sludge fermentation product in the second component is replaced with the first municipal sludge fermentation product.

[0140] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 3 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 21.1cm, with the tallest reaching 25.4cm, and the biomass was 0.21kg / m². 2 The green coverage rate was about 35%, but after that, no watering and maintenance were carried out, and after 2 months, all of them turned yellow and withered.

[0141] Comparative Example 9

[0142] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1, except that in step (3), phosphogypsum from a different source is used, with a loose bulk density of 1.15 g / cm³. 3 The modified phosphogypsum had a pH of 5.9, a calcium sulfate dihydrate content of 74.5% by mass, a water content of 16.4%, an available phosphorus content of 0.7% by mass, an F ion content of 1.44%, and a Cd content of 6.92 mg / kg. After the same modification treatment, a modified phosphogypsum with a pH of 10.6, an F ion content of 0.6%, a Cd content of 3.66 mg / kg, an available phosphorus content of 0.3% by mass, and a median particle size of 500 mesh was obtained.

[0143] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began after 3 days. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 13.5cm, with the tallest reaching 18.2cm, and the biomass was 0.12kg / m². 2 The green coverage rate was about 40%, and no watering or maintenance was carried out afterwards. After 3 months, about 70% of the plants turned yellow and withered.

[0144] Comparative Example 10

[0145] The soilless cultivation substrate composition in this comparative example is basically the same as that in Example 1, except that the second component is laid with a thickness of 60cm and compacted to a thickness of 49cm; the first component is laid with a thickness of 20cm and compacted to a thickness of 16cm.

[0146] In this comparative study, ryegrass seeds were sown at a rate of 20g per square meter. Germination began approximately 3 days later. During this period, watering was maintained to keep the field moist. After 15 days, the average plant height was 22.3cm, with the tallest reaching 26.5cm, and the biomass was 0.46kg / m². 2 The green coverage rate is about 85%. After that, no watering and maintenance were carried out. After 2 months, the proportion of yellowing and withering was about 25%.

[0147] See Table 1 for specific data.

[0148] Table 1

[0149]

[0150]

[0151] As shown in Table 1:

[0152] The soilless cultivation substrates used in Examples 1-7 achieved better greening effects and had a higher plant survival rate compared to Comparative Examples 1-10. In Example 1, plants began to germinate gradually after 2 days, and after 15 days, the average plant height of ryegrass reached 26.2 cm, with the highest plant height reaching 39.7 cm, and the biomass was 0.79 kg / m³. 2 The green coverage rate reached 100%, and no further watering or maintenance was required. No significant wilting was observed within three months. This demonstrates that the soilless cultivation substrate of this invention can achieve efficient utilization of phosphogypsum and municipal sludge, resulting in good greening effects and improved plant survival rates.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soilless cultivation substrate composition, characterized in that, This includes the second component and the first component, laid sequentially from bottom to top; The first component comprises 40-80 parts by weight of modified phosphogypsum, 20-50 parts by weight of fermentation products of municipal sludge, 3-5 parts by weight of alkaline buffer, 2-4 parts by weight of perlite, 0.5-1 parts by weight of phosphate-solubilizing bacteria, and 1-2 parts by weight of zeolite. The second component comprises 40-60 parts by weight of modified phosphogypsum, 20-30 parts by weight of fermentation product of second municipal sludge, and 0.5-2 parts by weight of rooting powder; The D50 of the first municipal sludge fermentation product is not higher than 1 mm, and the D60 is not higher than 2 mm. The D50 of the second municipal sludge fermentation product is not less than 3mm, and the D60 is not less than 4mm. The modified phosphogypsum has a median particle size of 200-300 mesh, a pH of 6.0-8.0, a fluoride ion content of no more than 0.1% by mass, and a Cd ion content of no more than 0.5 mg / kg. The pH value of the first municipal sludge fermentation product is 7-9.5, the mass percentage of organic matter in the first municipal sludge fermentation product is >15%, and the water content of the first municipal sludge fermentation product is <50%. The pH value of the second municipal sludge fermentation product is 7-9.5, the mass percentage of organic matter in the second municipal sludge fermentation product is >30%, and the water content of the second municipal sludge fermentation product is <40%.

2. The soilless cultivation substrate composition according to claim 1, characterized in that, The mass ratio of the modified phosphogypsum and the fermentation product of the first municipal sludge in the first component is (4-5):(2-4).

3. The soilless cultivation substrate composition according to claim 1 or 2, characterized in that, The bulk density of the modified phosphogypsum is >0.8 g / cm³. 3 The modified phosphogypsum contains >65% calcium sulfate dihydrate by mass, <25% water content, and >0.5% available phosphorus by mass.

4. The soilless cultivation substrate composition according to claim 1 or 2, characterized in that, The bulk density of the first municipal sludge fermentation product is <0.7 g / cm³. 3 The bulk density of the second municipal sludge fermentation product is <0.4 g / cm³. 3 .

5. The soilless cultivation substrate composition according to claim 1 or 2, characterized in that, The alkaline buffer has a particle size of <200 mesh, the perlite has a particle size of <50 mesh, and the zeolite has a particle size of <50 mesh.

6. The soilless cultivation substrate composition according to claim 1 or 2, characterized in that, The first component has an organic matter content of 5-20% by mass, a water content of <30%, a pH of 6-8, and a seed germination index of >70%.

7. A method of using the soilless culture substrate composition according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Lay the second component on the plot that needs to be revegetated, and carry out the first watering and first compaction; (2) Then, the first component is laid on the compacted second component surface, and the second watering and second compaction are carried out; The ratio of the laying volume of the second component to the laying volume of the first component is (7-11): (5-8).

8. The method of using the soilless cultivation substrate composition according to claim 7, characterized in that, In step (1), the second component is laid to a thickness of 35-55 cm, and the amount of water sprayed is 1-2 L / m. 2 After the first compaction, the thickness of the second component is 25-45 cm; In step (2), the thickness of the first component is 25-40 cm, and the amount of water sprayed is 1-2 L / m. 2 After the second compaction, the thickness of the first component is 20-35 cm.

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