Ultrahigh-temperature aerobic fermentation auxiliary material and preparation method and application thereof

Abstract

The application provides a kind of superhigh temperature aerobic fermentation auxiliary material and its preparation method and application.Superhigh temperature aerobic fermentation auxiliary material includes leaves, modified phosphogypsum, phosphorus-solubilizing bacteria and binder, and the mass ratio of leaves, modified phosphogypsum, phosphorus-solubilizing bacteria and binder is (40-50):(10-20):(0.5-2):(3-6).The superhigh temperature aerobic fermentation auxiliary material can realize aerobic fermentation of municipal sludge at superhigh temperature (>=80 DEG C), so as to make municipal sludge resource utilization, and the raw material of the superhigh temperature aerobic fermentation auxiliary material is easy to obtain, the preparation method is simple, and can be widely used.

Description

Technical Field

[0001] This invention relates to the field of organic solid waste resource utilization technology, and in particular to an ultra-high temperature aerobic fermentation auxiliary material, its preparation method and application. Background Technology

[0002] With urbanization, the annual output of municipal sewage sludge has exceeded 70 million tons. Municipal sewage sludge is rich in organic matter and nutrients, making its resource utilization necessary. Aerobic fermentation is one of the lowest-cost and least carbon-emission methods for resource utilization of municipal sewage sludge. However, municipal sewage sludge typically has a high water content and insufficient biodegradable organic matter, making it unable to initiate aerobic fermentation on its own. Therefore, a large amount of auxiliary materials need to be added during aerobic fermentation to shorten fermentation time, improve fermentation efficiency, and enhance the quality of fermentation products.

[0003] Existing auxiliary materials (such as rice husks, straw, and garden waste) are mostly crushed and directly mixed with municipal sludge for aerobic fermentation. However, when these auxiliary materials are used for aerobic fermentation, the fermentation temperature is relatively low (50-70℃), which not only limits the degree to which easily decomposed organic matter can be decomposed, but also makes it difficult to kill harmful substances such as insect eggs and pathogens in municipal sludge.

[0004] To address this issue, existing technologies typically involve adding ultra-high temperature microbial agents to increase the temperature of aerobic fermentation (80°C and above). However, the storage conditions for ultra-high temperature microbial agents are quite demanding, which is not conducive to large-scale industrial applications. Summary of the Invention

[0005] This invention provides an ultra-high temperature aerobic fermentation adjuvant that can achieve aerobic fermentation of urban sewage sludge at ultra-high temperature (≥80℃), thereby enabling the resource utilization of urban sewage sludge. Furthermore, the raw materials for this ultra-high temperature aerobic fermentation adjuvant are readily available, the preparation method is simple, and it can be widely promoted and used.

[0006] This invention provides a method for preparing ultra-high temperature aerobic fermentation excipients, which can produce the above-mentioned ultra-high temperature aerobic fermentation excipients. The preparation method is simple to operate, has low production cost, and can be widely promoted and applied.

[0007] This invention provides a method for treating municipal sludge. Using the aforementioned aerobic fermentation adjuvant for aerobic fermentation treatment can not only promote the decomposition of easily decomposable organic matter, but also effectively kill harmful substances such as insect eggs and pathogens in municipal sludge.

[0008] This invention provides an ultra-high temperature aerobic fermentation adjuvant, comprising leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and a binder, wherein the mass ratio of leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and binder is (40-50):(10-20):(0.5-2):(3-6).

[0009] The ultra-high temperature aerobic fermentation adjuvant as described above, wherein the phosphate-solubilizing bacteria include Bacillus subtilis, Bacillus licheniformis, and actinomycetes;

[0010] Furthermore, the mass ratio of Bacillus subtilis, Bacillus licheniformis, and actinomycetes in the phosphate-solubilizing bacteria is (2-3):(2-3):(1:2).

[0011] The ultra-high temperature aerobic fermentation adjuvant as described above, wherein the binder is selected from bentonite and / or anhydrous calcium chloride.

[0012] This invention provides a method for preparing the ultra-high temperature aerobic fermentation adjuvant as described above, comprising the following steps:

[0013] The leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and binder are mixed sequentially, granulated, and dried to obtain the ultra-high temperature aerobic fermentation adjuvant.

[0014] The preparation method described above further includes activating the leaves, the activation treatment comprising:

[0015] 1) Crush the leaves to 1-3cm, then pile them up to a thickness of 1-1.5 meters, and add water to make the moisture content of the pile reach more than 50%;

[0016] 2) Allow the mixture to stand still for aerobic fermentation until the internal temperature of the pile reaches above 60°C, then maintain this temperature for 2-3 days.

[0017] The present invention also provides a method for treating municipal sludge, comprising: mixing the municipal sludge with the ultra-high temperature aerobic fermentation auxiliary material as described above to obtain a material to be fermented, and performing aerobic fermentation treatment on the material to be fermented to obtain a fermentation product.

[0018] The processing method described above further includes pretreatment of the ultra-high temperature aerobic fermentation adjuvant, wherein the pretreatment includes:

[0019] Sprinkle water on the surface of the ultra-high temperature aerobic fermentation auxiliary material to moisten it, and then pile it up for 12-24 hours to make its internal temperature >50℃.

[0020] For each ton of the ultra-high temperature aerobic fermentation auxiliary material, 50-150 kg of water is sprinkled.

[0021] In the treatment method described above, the volume ratio of the municipal sludge to the ultra-high temperature aerobic fermentation auxiliary material is (1-3):1; and / or,

[0022] The aerobic fermentation treatment includes:

[0023] The material to be fermented is piled up to a thickness of 1-1.5m and left to stand. After the temperature inside the pile reaches ≥80℃, the first turning and turning process is carried out for 5-7 days. Then, the pile is left to stand for another 5-7 days for the second turning and turning process. The pile is left to stand until the moisture content is ≤50%.

[0024] The processing method described above further includes a regeneration process for the ultra-high temperature aerobic fermentation adjuvant, wherein the regeneration process includes:

[0025] The fermentation products are screened to obtain ultra-high temperature aerobic fermentation adjuvants to be regenerated;

[0026] The regenerated ultra-high temperature aerobic fermentation auxiliary material is stacked to bring the temperature inside the stack to 30-50℃, thus obtaining the regenerated ultra-high temperature aerobic fermentation auxiliary material.

[0027] The processing method described above further includes mixing the regenerated ultra-high temperature aerobic fermentation auxiliary material with the ultra-high temperature aerobic fermentation auxiliary material at a mass ratio of 1:(2-3) before performing aerobic fermentation treatment.

[0028] This invention provides an ultra-high temperature aerobic fermentation adjuvant, comprising a specific composition of leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and a binder. During aerobic fermentation, the temperature of this ultra-high temperature aerobic fermentation adjuvant can reach over 80°C, which can more fully decompose the easily decomposable organic matter in municipal sludge and effectively kill harmful substances such as insect eggs and pathogens in municipal sludge.

[0029] This invention provides a method for preparing ultra-high temperature aerobic fermentation adjuvants, which is used to prepare the above-mentioned ultra-high temperature aerobic fermentation adjuvants. The preparation method is simple to operate, has low production cost, and is suitable for widespread application.

[0030] This invention provides a method for treating municipal sludge. By using the above-mentioned ultra-high temperature aerobic fermentation auxiliary material for aerobic fermentation treatment, the efficient treatment of municipal sludge can be achieved at a lower cost. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The first aspect of the present invention provides an ultra-high temperature aerobic fermentation adjuvant, comprising leaves, modified phosphogypsum, phosphate-solubilizing bacteria and a binder, wherein the mass ratio of leaves, modified phosphogypsum, phosphate-solubilizing bacteria and binder is (40-50):(10-20):(0.5-2):(3-6).

[0033] The leaves can be common fallen leaves commonly used in the field, and in some embodiments, the leaves are fresh fallen leaves.

[0034] Modified phosphogypsum is phosphogypsum modified from limestone. In some embodiments, the modified phosphogypsum has a particle size of less than 200 mesh, a pH of 5-7, a moisture content of ≤30%, and a P2O5 mass percentage content of ≥0.5%. Modified phosphogypsum can accelerate the reproduction rate of aerobic and ultra-high temperature bacteria, increase the available phosphorus content of fermentation products to over 30%, and improve the quality of aerobic fermentation products.

[0035] The present invention does not impose any particular limitation on the binder, and it can be any binder commonly used in the art. In some embodiments, the binder can be bentonite or anhydrous calcium chloride, and the particle size of the binder is less than 200 mesh.

[0036] Phosphate-releasing agents can accelerate aerobic fermentation, rapidly increasing the early temperature of the fermentation system. They also have a phosphorus-releasing effect, converting insoluble phosphates (such as calcium phosphate) into soluble phosphates. This increases the available phosphorus content and reacts with some harmful heavy metals in municipal sludge to form phosphates that fix the heavy metals, removing over 50% of the available form of heavy metals such as Pb and Cd.

[0037] The ultra-high temperature aerobic fermentation adjuvant of this invention includes specific amounts of tree leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and a binder. When applied to the aerobic fermentation treatment of municipal sludge, it can raise the temperature of the aerobic fermentation treatment to above 80°C and maintain it for more than 5 days, which helps to more fully decompose the easily decomposable organic matter in the municipal sludge and effectively kill harmful substances such as insect eggs and pathogens in the municipal sludge. At the same time, it can shorten the fermentation time by 5-15 days. Furthermore, this ultra-high temperature aerobic fermentation adjuvant can also remove heavy metals such as Pb and Cd from the municipal sludge. The raw materials used in this ultra-high temperature aerobic fermentation adjuvant are all solid wastes, which are not only simple, readily available, and low in cost, but also reduce the cost of aerobic fermentation of municipal sludge while eliminating solid waste. This ultra-high temperature aerobic fermentation adjuvant is simple to operate when applied to aerobic fermentation treatment and can be widely promoted and used.

[0038] It is worth mentioning that the ultra-high temperature aerobic fermentation adjuvant of the present invention can be reused. In some embodiments, it can be reused 3-5 times, which has excellent economic value.

[0039] This invention does not specifically limit the phosphate-solubilizing bacteria, and can use any microbial agent with phosphate-solubilizing activity commonly used in the art. In some embodiments of this invention, the phosphate-solubilizing bacteria include Bacillus subtilis, Bacillus licheniformis, and actinomycetes;

[0040] Furthermore, among the phosphate-solubilizing bacteria, the mass ratio of Bacillus subtilis, Bacillus licheniformis, and actinomycetes is (2-3):(2-3):(1:2).

[0041] When phosphate-solubilizing bacteria include the above-mentioned components, when applied to the preparation of ultra-high temperature aerobic fermentation adjuvants, they can further accelerate the aerobic fermentation process, increase the early temperature of the fermentation system, and have a better phosphate-solubilizing effect, thereby improving the treatment effect of municipal sludge.

[0042] This invention does not impose any particular limitation on the binder; it can be any binder commonly used in the art. For example, the binder is selected from bentonite and / or anhydrous calcium chloride. In some embodiments, the particle size of the binder is less than 200 mesh.

[0043] A second aspect of the present invention provides a method for preparing an ultra-high temperature aerobic fermentation adjuvant according to the first aspect, comprising the following steps:

[0044] Leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and binder are mixed sequentially, granulated, and dried to obtain an ultra-high temperature aerobic fermentation adjuvant.

[0045] Specifically, leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and binders are mixed to ensure uniform mixing. The uniformly mixed raw materials are then granulated to form ultra-high temperature aerobic fermentation auxiliary material precursors with particles of a specific size. Finally, the precursors are dried to remove moisture, thus obtaining the ultra-high temperature aerobic fermentation auxiliary material.

[0046] In some embodiments, high-density granulation can be performed in a granulator to obtain a precursor of ultra-high temperature aerobic fermentation feedstock with a particle size of 1-2 cm and a density of >1.3 g / cm3. The drying treatment can be low-temperature thermal drying or sun drying to obtain an ultra-high temperature aerobic fermentation feedstock with a moisture content of less than 10%.

[0047] The preparation method of the present invention can prepare the ultra-high temperature aerobic fermentation adjuvant of the first aspect. The prepared ultra-high temperature aerobic fermentation adjuvant can be stored for more than 90 days (the storage temperature can be room temperature or above 30°C). The preparation method is simple to operate and is suitable for widespread application.

[0048] In some embodiments of the present invention, the method further includes activating the leaves, wherein the activation treatment includes:

[0049] 1) Crush the leaves to 1-3cm, then pile them up to a thickness of 1-1.5 meters, and add water to make the moisture content of the pile reach more than 50%;

[0050] 2) Allow the mixture to stand still for aerobic fermentation until the internal temperature of the pile reaches above 60°C, then maintain this temperature for 2-3 days.

[0051] Specifically, the leaves are crushed to 1-3cm and then piled up to obtain a 1-1.5m thick pile. Water is added to the pile to make the moisture content of the pile reach more than 50%. The pile is then left to undergo aerobic fermentation until the internal temperature reaches more than 60℃. This process is maintained for 2-3 days to allow the thermophilic bacteria to accumulate initially, thereby activating the leaves.

[0052] The leaves obtained by this method have a high degree of enrichment of thermophilic bacteria, which can further increase the aerobic fermentation temperature of ultra-high temperature aerobic fermentation auxiliary materials.

[0053] In some embodiments, after activation treatment, the leaves can be pulverized to a size of less than 2 mm, allowing for better synergy with other components and improving the overall performance of the ultra-high temperature aerobic fermentation adjuvant. Further, the leaf size can be ≤1 mm.

[0054] A third aspect of the present invention provides a method for treating municipal sludge, comprising: mixing municipal sludge with an ultra-high temperature aerobic fermentation auxiliary material of the first aspect of the present invention to obtain a material to be fermented, and performing aerobic fermentation treatment on the material to be fermented to obtain a fermentation product.

[0055] This invention does not specifically limit the type of municipal sludge; it can be any type of municipal sludge commonly used in the art. Exemplarily, municipal sludge may include raw sludge or biogas residue formed after anaerobic digestion. In some embodiments, the municipal sludge has the following characteristics: organic matter content ≥30%, moisture content ≤80%, total phosphorus content <0.5%, available phosphorus content <80 mg / kg, ascarid egg mortality rate <80%, and total bacterial count >10. 8 MPN / kg dry sludge.

[0056] The municipal sludge treatment method of the present invention specifically includes: mixing municipal sludge with ultra-high temperature aerobic fermentation auxiliary material of the first aspect to make the municipal sludge and ultra-high temperature aerobic fermentation auxiliary material evenly mixed to obtain a material to be fermented; then performing aerobic fermentation treatment on the material to be fermented to decompose the organic matter in the municipal sludge, kill insect eggs and pathogens in the municipal sludge, remove heavy metals in the municipal sludge, and obtain fermentation products.

[0057] The municipal sludge treatment method of the present invention uses the above-mentioned aerobic fermentation auxiliary material for aerobic decomposition and removal of impurities in municipal sludge, thereby realizing the resource utilization of municipal sludge.

[0058] In some embodiments of the present invention, the pretreatment of the ultra-high temperature aerobic fermentation adjuvant is further included, the pretreatment comprising:

[0059] Sprinkle water on the surface of the ultra-high temperature aerobic fermentation auxiliary material to moisten it, and then pile it up for 12-24 hours to make its internal temperature >50℃.

[0060] For each ton of ultra-high temperature aerobic fermentation auxiliary material, 50-150 kg of water is sprinkled.

[0061] The pretreatment of ultra-high temperature aerobic fermentation auxiliary materials specifically includes: sprinkling water on the surface of the auxiliary materials to moisten them, then piling the moistened auxiliary materials for 12-24 hours to activate the fermentation activity of the materials until the internal temperature of the auxiliary materials exceeds 50℃, thus achieving pretreatment. Sprinkling 50-150 kg of water per ton of auxiliary materials is sufficient to fully activate their fermentation activity.

[0062] Pretreatment of the ultra-high temperature aerobic fermentation auxiliary material using the above methods can improve its activity, thereby increasing the efficiency of aerobic fermentation treatment and improving the treatment effect of municipal sludge.

[0063] In some embodiments of the present invention, when the volume ratio of municipal sludge to ultra-high temperature aerobic fermentation auxiliary material is (1-3):1, the treatment effect of municipal sludge can be further improved on the basis of saving ultra-high temperature aerobic fermentation auxiliary material.

[0064] Furthermore, the aerobic fermentation treatment includes:

[0065] The material to be fermented is piled up to a thickness of 1-1.5cm and left to stand. After the temperature inside the pile reaches ≥80℃, the first turning and turning treatment is carried out for 5-7 days. Then, it is left to stand for another 5-7 days for the second turning and turning treatment. The pile is left to stand until the moisture content is ≤50%.

[0066] Specifically, the aerobic fermentation treatment includes: piling the material to be fermented to a thickness of 1-1.5 cm to form a pile, letting it stand until the temperature inside the pile is ≥80℃, and then performing a first turning and turning treatment for 5-7 days to improve the uniformity of the aerobic fermentation treatment. After standing for another 5-7 days, a second turning and turning treatment is performed to further improve the uniformity of the aerobic fermentation treatment. The pile is then left to stand until it becomes soft, has no obvious odor, and has a moisture content ≤50%, thus completing the aerobic fermentation treatment.

[0067] In some implementations, the temperature inside the pile can be measured daily, and the moisture content of the pile can be measured weekly.

[0068] The present invention can achieve full and efficient treatment of municipal sludge through the above-mentioned aerobic fermentation treatment, fully killing harmful substances such as insect eggs and pathogens in municipal sludge, and fully decomposing easily decomposable organic matter.

[0069] In some embodiments of the present invention, a regeneration process for the ultra-high temperature aerobic fermentation adjuvant is further included, the regeneration process comprising:

[0070] The fermentation products were screened to obtain the ultra-high temperature aerobic fermentation adjuvant to be regenerated;

[0071] The ultra-high temperature aerobic fermentation auxiliary material to be regenerated is stacked to make the temperature inside the stack 30-50℃, thus obtaining the regenerated ultra-high temperature aerobic fermentation auxiliary material.

[0072] Specifically, the regeneration process of ultra-high temperature aerobic fermentation auxiliary materials includes: screening the fermentation products to separate the unused ultra-high temperature aerobic fermentation auxiliary materials, obtaining ultra-high temperature aerobic fermentation auxiliary materials to be regenerated; then stacking the ultra-high temperature aerobic fermentation auxiliary materials to form a pile, adjusting the height of the pile and external conditions (e.g., storing it in sunlight) to maintain the temperature inside the pile at 30-50°C to preserve the activity of high-temperature bacteria, thereby obtaining regenerated ultra-high temperature aerobic fermentation auxiliary materials.

[0073] This invention enables the recycling of ultra-high temperature aerobic fermentation admixtures through regeneration, thereby saving production costs. In some embodiments, the time interval between two aerobic fermentation treatments can be less than one week (the time interval between aerobic fermentation treatment using ultra-high temperature aerobic fermentation admixtures and aerobic fermentation treatment using regenerated ultra-high temperature aerobic fermentation admixtures), and the ultra-high temperature aerobic fermentation admixtures can be reused 3-5 times.

[0074] Furthermore, the ultra-high temperature aerobic fermentation auxiliary material can be mixed with the regenerated ultra-high temperature aerobic fermentation auxiliary material at a mass ratio of 1:(2-3) before aerobic fermentation treatment, thereby improving the utilization rate of the ultra-high temperature aerobic fermentation auxiliary material. In some embodiments, the particle size of the regenerated ultra-high temperature aerobic fermentation auxiliary material can be ≤0.5cm before being mixed with the ultra-high temperature aerobic fermentation auxiliary material.

[0075] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0076] Example 1

[0077] The municipal sludge treatment method of this embodiment includes the following steps:

[0078] 1) Preparation of ultra-high temperature aerobic fermentation adjuvants

[0079] Crush fresh leaves to a diameter of 1-3 cm, pile them up to a thickness of 1.5 meters, add water and stir to make the moisture content of the pile reach 65%, let it stand and ferment aerobically. After 7 days, the internal temperature reaches about 65℃ and is maintained for 3 days. Then, crush the leaves further to less than 1 mm.

[0080] Modified phosphogypsum was obtained by mixing phosphogypsum with a mesh size of less than 200 mesh and quicklime at a mass ratio of 40:1. The modified phosphogypsum had a pH value of 6.5, a water content of 14.2%, and a P2O5 mass percentage of 1.56%.

[0081] Bacillus subtilis, Bacillus licheniformis and actinomycetes were mixed in a mass ratio of 2:2:1 to prepare phosphate-solubilizing bacteria;

[0082] By weight, 40 parts of leaves, 10 parts of modified phosphogypsum, 0.5 parts of phosphorus solubilizing agent and 4 parts of binder are mixed evenly and then placed into a granulator for granulation. The particle size is mostly between 1.5-2cm (average about 1.8cm). After that, it is dried in a sunroom until the moisture content is 8.9%, forming an ultra-high temperature aerobic fermentation auxiliary material.

[0083] 2) Treatment of municipal sludge

[0084] a) After sprinkling water on the surface of the ultra-high temperature aerobic fermentation auxiliary material from step 1) until it is moist, pile it up for 12 hours until the internal temperature reaches 54.2℃; wherein, approximately 100 kg of water is sprinkled per ton of ultra-high temperature aerobic fermentation auxiliary material;

[0085] The dried municipal sludge anaerobic digestion residue was mixed evenly with the above-treated ultra-high temperature aerobic fermentation auxiliary material at a volume ratio of 1:1, piled up to a thickness of 1.4m, and left to stand. The temperature of the pile was measured daily. After about 3 days, the pile temperature reached 80℃ and was maintained for 7 days (the highest temperature during this period reached 89.2℃). At this time, the first turning treatment was carried out, and the turning was necessary to ensure that the inner and outer parts were fully mixed. After 2 days, the pile temperature reached above 80℃ again (the highest temperature reached 81.8℃). After another 4 days, the temperature dropped to 68.7℃, and the second turning treatment was carried out and left to stand. The turning was necessary to ensure that the inner and outer parts were fully mixed. One day after the second turning treatment, the pile temperature reached the highest value of 70.5℃ after the second turning treatment. After about 5 days, the pile became soft and had no obvious odor, and the sludge moisture content dropped to 46.8%, completing the fermentation and obtaining the fermentation product. The entire sludge fermentation process took 22 days.

[0086] The municipal sludge was from Lu'an City. The anaerobic digestion residue of this municipal sludge contained a moisture content of 76.7%, an organic matter content of 35.2%, soluble Pb and Cd contents of 22.8 mg / kg and 1.15 mg / kg respectively, a total phosphorus content of 0.42%, an available phosphorus content of 92 mg / kg, a roundworm egg mortality rate of 69.3%, and a total bacterial count of 1.35 × 10⁻⁶. 9 MPN / kg dry sludge;

[0087] The fermentation products contained soluble Pb and Cd at 8.33 mg / kg and 0.41 mg / kg, respectively (reductions of 63.5% and 56.8%), available phosphorus at 224 mg / kg (an increase of 143.5%), a 98.6% mortality rate for Ascaris eggs, and a total bacterial count of 0.73 × 10⁻⁶. 7 MPN / kg dry sludge;

[0088] b. The fermentation products are screened to separate the unused ultra-high temperature aerobic fermentation auxiliary materials, which are then dried until the surface is dry to obtain regenerated ultra-high temperature aerobic fermentation auxiliary materials with an average particle size of 1.6 cm.

[0089] Example 2

[0090] The municipal sludge treatment method of this embodiment includes the following steps:

[0091] 1) Preparation of ultra-high temperature aerobic fermentation adjuvants

[0092] Crush fresh leaves to a diameter of 1-3 cm, pile them up to a thickness of 1.3 meters, add water and stir to make the moisture content of the pile reach 60%, let it stand and ferment aerobically. After 8 days, the internal temperature reaches about 65℃ and is maintained for 3 days. Then, crush the leaves further to less than 1 mm.

[0093] Modified phosphogypsum was obtained by mixing phosphogypsum with a mesh size of less than 200 mesh and quicklime at a mass ratio of 40:1. The modified phosphogypsum had a pH value of 6.5, a water content of 14.2%, and a P2O5 mass percentage of 1.56%.

[0094] Bacillus subtilis, Bacillus licheniformis and actinomycetes were mixed in a mass ratio of 3:3:1 to prepare phosphate-solubilizing bacteria;

[0095] By weight, 50 parts of leaves, 10 parts of modified phosphogypsum, 1.5 parts of phosphorus solubilizing agent and 5 parts of binder are mixed evenly and then placed into a granulator for granulation. The particle size is mostly between 1.5-2cm (average about 1.8cm). After that, it is dried in a sunroom until the moisture content is 9%, forming an ultra-high temperature aerobic fermentation auxiliary material.

[0096] 2) Treatment of municipal sludge

[0097] a) After sprinkling water on the surface of the ultra-high temperature aerobic fermentation auxiliary material from step 1) until it is moist, pile it up for 12 hours until the internal temperature reaches 54.2℃; wherein, 120kg of water is sprinkled on each ton of ultra-high temperature aerobic fermentation auxiliary material;

[0098] The dried municipal sludge anaerobic digestion residue was mixed evenly with the above-treated ultra-high temperature aerobic fermentation auxiliary material at a volume ratio of 2:1, piled up to a thickness of 1.3m, and left to stand. The temperature of the pile was measured daily. After about 3 days, the pile temperature reached 80℃ and was maintained for 6 days (the highest temperature during this period reached 87.1℃). At this time, the first turning treatment was carried out, and the turning was necessary to ensure that the inner and outer parts were fully mixed. After 2 days, the pile temperature reached above 80℃ again (the highest temperature reached 82.3℃). After another 4 days, the temperature dropped to 68.7℃, and the second turning treatment was carried out and left to stand. The turning was necessary to ensure that the inner and outer parts were fully mixed. One day after the second turning treatment, the pile temperature reached the highest value of 69.1℃ after the second turning treatment. After about 8 days, the pile became soft and had no obvious odor, and the sludge moisture content dropped to 46.8%, completing the fermentation and obtaining the fermentation product. The entire sludge fermentation process took 24 days.

[0099] The municipal sludge was from Lu'an City. The anaerobic digestion residue of this municipal sludge contained a moisture content of 76.7%, an organic matter content of 35.2%, soluble Pb and Cd contents of 22.8 mg / kg and 1.15 mg / kg respectively, a total phosphorus content of 0.42%, an available phosphorus content of 92 mg / kg, a roundworm egg mortality rate of 69.3%, and a total bacterial count of 1.35 × 10⁻⁶. 9 MPN / kg dry sludge;

[0100] The fermentation products contained soluble Pb and Cd at 11.42 mg / kg and 0.57 mg / kg, respectively, with an available phosphorus content of 189 mg / kg. The mortality rate of Ascaris eggs was 95.6%, and the total bacterial count was 4.75 × 10⁻⁶. 7 MPN / kg dry sludge;

[0101] b. The fermentation products are screened to separate the unused ultra-high temperature aerobic fermentation auxiliary materials, which are then dried until the surface is dry to obtain regenerated ultra-high temperature aerobic fermentation auxiliary materials with an average particle size of 1.6 cm.

[0102] Example 3

[0103] The municipal sludge treatment method in this embodiment is basically the same as that in Embodiment 1, except that:

[0104] 1) Preparation of ultra-high temperature aerobic fermentation adjuvants

[0105] Excluding the activation treatment of fresh leaves, fresh leaves are used directly to prepare ultra-high temperature aerobic fermentation feedstock.

[0106] 2) Treatment of municipal sludge

[0107] The temperature of the sludge pile was measured daily. After about 4 days, the temperature reached 80.4℃. After 7 days, the temperature dropped to 69.5℃. At this time, the first turning and turning process was carried out. The turning and turning process was necessary to ensure that the inner and outer parts were fully mixed. After 2 days, the highest temperature of the pile was 79.2℃. After another 5 days, the temperature dropped to 61.3℃. The second turning and turning process was carried out, followed by settling. Three days after the second turning and turning process, the temperature of the pile reached the highest value of 62.4℃ after the second turning and turning process. After about 9 days, the pile reached a soft state with no obvious odor, and the sludge moisture content dropped to 49.1%. The fermentation was completed, and the fermentation products were obtained. The entire sludge fermentation process took 27 days.

[0108] The fermentation products contained soluble Pb and Cd at 14.73 mg / kg and 0.62 mg / kg, respectively, with an available phosphorus content of 171 mg / kg. The mortality rate of Ascaris eggs was 96.5%, and the total bacterial count was 5.79 × 10⁻⁶. 7 MPN / kg dry sludge.

[0109] Comparative Example 1

[0110] The municipal sludge treatment method in this comparative example is basically the same as that in Example 1, except that...

[0111] Use dried rice husks to replace the auxiliary material for ultra-high temperature aerobic fermentation.

[0112] The highest temperature of the pile was only 65.4℃, and fermentation took about 39 days to complete.

[0113] The diameter of the dried rice husks was 1-2 cm. The fermentation products contained soluble phosphorus (Pb) and soluble cadmium (Cd) of 19.56 mg / kg and 0.91 mg / kg, respectively, with an available phosphorus content of 155 mg / kg. The mortality rate of Ascaris eggs was 87.3%, and the total bacterial count was 1.91 × 10⁻⁶. 8 MPN / kg dry sludge.

[0114] Comparative Example 2

[0115] The treatment method for municipal sludge in this comparative example is basically the same as that in Example 1, except that phosphate-solubilizing bacteria are not added.

[0116] The highest temperature of the pile was 71.2°C, and fermentation took about 30 days to complete.

[0117] The fermentation products contained soluble Pb and Cd at 14.96 mg / kg and 0.74 mg / kg, respectively, with an available phosphorus content of 168 mg / kg. The mortality rate of Ascaris eggs was 95.6%, and the total bacterial count was 9.2 × 10⁻⁶. 7 MPN / kg dry sludge.

[0118] As can be seen from the examples and comparative examples, the ultra-high temperature aerobic fermentation adjuvant of the present invention can achieve aerobic fermentation of urban sludge at ≥80℃, which can save fermentation time. Moreover, the fermented sludge has low soluble Pb and Cd content, low available phosphorus content, high ascarid egg mortality rate, and low total bacterial count.

[0119] 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 high-temperature aerobic fermentation adjuvant, characterized in that, The mixture comprises leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and a binder, wherein the mass ratio of leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and binder is (40-50):(10-20):(0.5-2):(3-6); the phosphate-solubilizing bacteria include Bacillus subtilis, Bacillus licheniformis, and actinomycetes; the modified phosphogypsum is limestone-modified phosphogypsum, wherein the particle size of the modified phosphogypsum is less than 200 mesh, the pH is 5-7, the moisture content is ≤30%, and the mass percentage of P2O5 in the modified phosphogypsum is ≥0.5%.

2. The ultra-high temperature aerobic fermentation adjuvant according to claim 1, characterized in that, The mass ratio of Bacillus subtilis, Bacillus licheniformis, and actinomycetes in the phosphate-solubilizing bacteria is (2-3):(2-3):(1-2).

3. The ultra-high temperature aerobic fermentation adjuvant according to any one of claims 1-2, characterized in that, The binder is selected from bentonite and / or anhydrous calcium chloride.

4. A method for preparing an ultra-high temperature aerobic fermentation adjuvant according to any one of claims 1-3, characterized in that, Includes the following steps: The leaves, modified phosphogypsum, phosphate-solubilizing bacteria, and binder are mixed sequentially, granulated, and dried to obtain the ultra-high temperature aerobic fermentation adjuvant.

5. The preparation method according to claim 4, characterized in that, It also includes activating the leaves, the activation process comprising: 1) Crush the leaves to 1-3cm, then pile them up to a thickness of 1-1.5 meters, and add water to make the moisture content of the pile reach more than 50%; 2) Allow the mixture to stand still and undergo aerobic fermentation until the internal temperature of the pile reaches above 60°C, then maintain this temperature for 2-3 days.

6. A method for treating municipal sewage sludge, characterized in that, include: The municipal sludge is mixed with the ultra-high temperature aerobic fermentation auxiliary material according to any one of claims 1-3 to obtain a material to be fermented, and the material to be fermented is subjected to aerobic fermentation treatment to obtain fermentation products.

7. The processing method according to claim 6, characterized in that, It also includes pretreatment of the ultra-high temperature aerobic fermentation adjuvant, the pretreatment including: Sprinkle water on the surface of the ultra-high temperature aerobic fermentation auxiliary material to moisten it, and then pile it up for 12-24 hours to make its internal temperature >50℃. For each ton of the ultra-high temperature aerobic fermentation auxiliary material, 50-150 kg of water is sprinkled.

8. The processing method according to claim 6 or 7, characterized in that, The volume ratio of the municipal sludge to the ultra-high temperature aerobic fermentation additive is (1-3):1; and / or, The aerobic fermentation treatment includes: The material to be fermented is piled up to a thickness of 1-1.5m and left to stand. After the temperature inside the pile reaches ≥80℃, the first turning and turning treatment is carried out for 5-7 days. Then, it is left to stand for another 5-7 days for the second turning and turning treatment. The pile is left to stand until the moisture content is ≤50%.

9. The processing method according to any one of claims 6-7, characterized in that, It also includes the regeneration treatment of ultra-high temperature aerobic fermentation adjuvants, wherein the regeneration treatment includes: The fermentation products are screened to obtain ultra-high temperature aerobic fermentation adjuvants to be regenerated; The regenerated ultra-high temperature aerobic fermentation auxiliary material is stacked to bring the temperature inside the stack to 30-50℃, thus obtaining the regenerated ultra-high temperature aerobic fermentation auxiliary material.

10. The processing method according to claim 9, characterized in that, It also includes mixing the regenerated ultra-high temperature aerobic fermentation auxiliary material with the ultra-high temperature aerobic fermentation auxiliary material at a mass ratio of 1:(2-3) before performing aerobic fermentation treatment.