Sludge solidification method and solidification material

Abstract

The invention provides a sludge curing method and a curing material, and relates to the field of sludge treatment.The curing method comprises the steps that bacillus pasteurii bacterial sludge is prepared; calculating the addition amount of nutrient substances; calculating the addition amount of a mineralizer; the method comprises the following steps: adding bacterial sludge and nutrient substances required by the bacterial sludge into sludge to be treated, stirring, then adding bentonite, stirring, then adding slag, desulfurized gypsum, cement, urea and calcium chloride, and uniformly stirring to obtain a sludge mixture; 70-80 parts by mass of slag, 10-15 parts by mass of desulfurized gypsum, 15-20 parts by mass of cement and 20-25 parts by mass of bentonite are needed for curing 100 parts by mass of sludge, and 1g-4g of bacterial sludge is added into per kilogram of sludge mixture. According to the invention, solid waste resources can be utilized while the sludge is treated, and the problems of large cement consumption and low economical efficiency in the sludge treatment process are solved.

Description

Technical Field

[0001] The invention relates to the field of sludge treatment, and in particular to a sludge solidification method and solidification material. Background Art

[0002] In the field of urban sewage treatment, the phenomenon of "heavy water and light sludge" has existed for a long time. Although sewage treatment technology has developed rapidly, sludge treatment technology has not developed synchronously. At present, the effective disposal rate of sludge is less than 20%, and a large amount of sludge has not been effectively disposed of, and the situation is very serious. Converting sludge into fill, roadbed fill or other large-volume building materials through solidification / stabilization treatment of sludge is one of the more effective ways to utilize resources. Traditional sludge solidification materials are still mainly cement: cement solidification is to add cement to sludge, and use various products formed by cement hydration reaction to convert sludge into a tightly structured solidified body. At the same time, pollutants are enclosed in the solidified body through encapsulation, precipitation, adsorption and other effects, so as to achieve the purpose of improving the physical and mechanical properties of sludge and reducing the release of pollutants. The sludge has a very high water content. If it is blended according to the optimal water-cement ratio, a large amount of cement (about twice the mass of sludge) will be required, which will undoubtedly significantly increase the treatment cost. Patent CN117602859 discloses a sludge building material processing system and method. The sludge building material processing system provided by the technology effectively shortens the processing time of sludge building material through the organic combination of sludge drying unit, sludge building material unit and self-made curing agent. However, the processing system uses a large amount of cement as a curing agent, which is not economical. The large amount of disodium ethylenediaminetetraacetic acid used will also cause harm to the human body, and a large amount of waste gas is generated during the production process.

[0003] Therefore, it is urgent to propose a practical sludge disposal method based on the current research status of sludge solidification / stabilization and considering environmental and economic factors in combination with the basic characteristics of sludge. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art or related technology, and provides a sludge solidification method and solidification material, which overcomes the difficult problems of low early strength and high heavy metal ion concentration of the solidified body obtained by the traditional solidification method, greatly utilizes solid waste resources while treating the sludge, and solves the problems of large cement consumption and low economy in sludge treatment.

[0005] The first aspect of the present invention discloses a sludge solidification method, comprising: preparing bacterial sludge: placing a liquid culture medium in which Bacillus pasteurianus is cultured in a centrifuge for treatment, discarding the supernatant, and obtaining Bacillus pasteurian bacterial sludge; calculating the amount of nutrient addition: taking a certain mass of Bacillus pasteurian bacterial sludge and diluting it, comparing it by a method of counting bacteria with super depth of field, obtaining the ratio of the number of bacteria per unit volume between the bacterial sludge dilution and the liquid culture medium, and calculating the mass of nutrients required for a certain mass of Bacillus pasteurian bacterial sludge according to the bacterial number ratio when the nutrient content of the liquid culture medium is known; calculating the amount of mineralizer addition: mixing the bacterial sludge and the corresponding amount of nutrients and Add sufficient amounts of calcium chloride and urea for sufficient reaction, use hydrochloric acid pickling method to obtain the amount of calcium carbonate generated, and calculate the amount of mineralizer added based on the principle of calcium ion conservation; add sludge solidification materials: add bacterial sludge and nutrients required for bacterial sludge to the sludge to be treated and stir, then add bentonite and stir, then add slag, desulfurized gypsum, cement, urea and calcium chloride and stir evenly to obtain a sludge mixture. In terms of mass parts, for every 100 parts of sludge solidified, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement, and 20-25 parts of bentonite are required, and each kilogram of sludge mixture contains 1g~4g of bacterial sludge.

[0006] In this technical solution, the sludge has a very high moisture content and is difficult to dehydrate. The use of bacterial liquid not only increases the moisture content but also has a high probability of failing to solidify the sludge. Therefore, the present invention uses bacterial sludge and solid waste materials to solidify the sludge. Bacillus pasteurianus has good urease activity and heavy metal tolerance. After cracks are generated in the solidified sludge mixture, the pasteurian spores wake up and continue to mineralize with unreacted urea and CaCl2 to generate CaCO3 precipitation and repair the cracks. In addition, bentonite has strong adsorption, can stabilize heavy metal ions in sludge, and can provide a skeleton for solidified sludge.

[0007] According to the sludge solidification method provided by the present invention, preferably, the process of culturing Bacillus pasteurianus includes: preparing a liquid culture medium, wherein each 1L of the liquid culture medium contains 5g of peptone, 3g of beef extract and a sufficient amount of deionized water, and sterilizing it in a 120°C environment for 60 minutes; after cooling to room temperature in a sterile environment, inoculating a 4% volume fraction of Bacillus pasteurianus seed solution; and shaking and culturing at 36°C and 140 r / min for 24 hours to obtain a liquid culture medium cultured with Bacillus pasteurianus.

[0008] The sludge solidification method provided by the present invention preferably further comprises: sludge sterilization: sterilizing the sludge to be treated by irradiating the sludge to be treated with an ultraviolet lamp before adding the bacterial sludge to the sludge to be treated for 1 hour, during which the sludge is stirred every 20 minutes.

[0009] The sludge solidification method provided by the present invention preferably further comprises: curing the sludge mixture: loading the sludge mixture into a mold, wrapping it with a plastic wrap after demoulding, and placing it in a constant temperature and humidity box for curing.

[0010] According to the sludge solidification method provided by the present invention, preferably, the steps of adding bacterial sludge and nutrients required for the bacterial sludge to the sludge to be treated and stirring, and then adding bentonite for stirring, specifically include: adding bacterial sludge, beef extract and trypsin to the sludge to be treated and stirring thoroughly, stirring once every 1 hour, and adding bentonite and stirring for 3 minutes after stirring 8 times.

[0011] According to the sludge solidification method provided by the present invention, preferably, slag, desulfurized gypsum, cement, urea and calcium chloride are added and stirred evenly, and the stirring time is controlled within 2 minutes.

[0012] According to the sludge solidification method provided by the present invention, preferably, the mass ratio of sludge, slag, desulfurized gypsum, cement and bentonite is 1:0.75:0.1:0.15:0.2.

[0013] The second aspect of the present invention also discloses a solidification material, comprising: solid waste-based materials, microbial sludge and mineralizers; wherein the solid waste-based materials include sludge, slag, desulfurized gypsum, cement and bentonite. In terms of mass fractions, for every 100 parts of sludge solidified, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement and 20-25 parts of bentonite are required. The microbial sludge is obtained by discarding the supernatant of a liquid culture medium of Bacillus pasteurianus after centrifugation. The mineralizers include calcium chloride and urea.

[0014] According to the solidification material provided by the present invention, preferably, the liquid culture medium of Bacillus pasteurianus contains 5g of peptone, 3g of beef extract and sufficient deionized water per 1L, and the nutrients required by the bacterial sludge in the process of solidifying the sludge are calculated by the following steps: 1-4g of bacterial sludge is contained in every 1000g of sludge mixture; the mass of nutrients required by the bacterial sludge is calculated by comparing the number of bacteria per unit volume of the liquid culture medium after dilution of 1-4g of bacterial sludge.

[0015] According to the solidification material provided by the present invention, preferably, the addition amount of calcium chloride and urea is calculated by the following steps: the bacterial mud and the corresponding addition amount of nutrients are mixed and sufficient amounts of calcium chloride and urea are added for sufficient reaction, the amount of calcium carbonate generated is obtained by hydrochloric acid pickling method, and the addition amount of mineralizer is calculated according to the principle of calcium ion conservation.

[0016] The beneficial effects achieved by the present invention include at least:

[0017] The present invention solidifies the sludge by adding Bacillus basilicum to the sludge mixture, which solves the problem that the use of bacterial liquid not only increases the water content but also has a high probability of failing to solidify the sludge. The sludge is solidified without increasing its water content, which greatly increases the time required for solidifying the sludge.

[0018] The present invention is based on the principle of microbial mineralization. It can not only produce a certain solidification effect in a relatively short period of time, greatly improving the strength of the early solid waste-based solidified sludge body, and solving the problem of low early strength of the solid waste-based solidified sludge body, but also effectively reduces the concentration of heavy metals, and has a good stabilizing effect on heavy metal pollutants. The final solidified body can also be used as an engineering material and applied to highway subgrades, so that cracks generated by long-term use or external forces have a certain self-repairing effect.

[0019] The solid waste-based materials of the present invention include desulfurized gypsum and slag, and 0.75 tons of slag and 0.1 tons of desulfurized gypsum can be used for each ton of sludge processed. This not only reduces the human and material resources required for cement production and the generation of various harmful gases and dust in the production process, but also reasonably utilizes solid waste resources, solving the problems of low environmental, resource and economic efficiency of ordinary silicate cement solidified sludge.

[0020] The present invention adopts bentonite as an auxiliary solidification material, which has the characteristics of high water absorption rate, high adsorption capacity, etc. Under a reasonable dosage, it can significantly improve the strength of the solidified body, enhance its integrity, reduce permeability, and effectively reduce the dissolution of pollutants, which not only effectively reduces the processing cost, but also plays a positive role in enhancing the solidification / stabilization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic flow chart of a sludge solidification method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0022] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Embodiment 1:

[0024] like Figure 1 As shown, according to one embodiment of the present invention, a sludge solidification method is disclosed, comprising:

[0025] S1. Cultivation of microorganisms: Each liter of liquid culture medium contains 5 g of peptone, 3 g of beef extract and sufficient deionized water. The liquid culture medium is sterilized at 120 °C for 60 min, cooled to room temperature in a sterile environment, and then inoculated with 4% volume fraction of Bacillus pasteurianus seed solution. Finally, it is cultured at 36 °C and 140 r / min with shaking for 24 h.

[0026] S2, preparing bacterial sludge: centrifuge the liquid culture medium cultured with Bacillus pasteurianus at 4000 rpm for 10 min, discard the supernatant to obtain bacterial sludge. The amount of bacterial sludge used depends on the total mass of the sludge mixture. In this embodiment, 1 g of bacterial sludge is added per kilogram of the sludge mixture.

[0027] S3, calculate the amount of nutrients to be added: dilute 1g of bacterial sludge and compare it with the normal cultured bacterial solution through super depth of field to count bacteria. The ratio of the number of bacteria per unit volume of bacterial sludge to that of bacterial solution is about 80:1. Then, according to the ratio, calculate that 0.24g of beef extract and 0.40g of trypsin should be added to the culture medium of the corresponding volume of bacterial sludge.

[0028] S4, calculate the amount of mineralizer added: add 0.24 g beef extract and 0.40 g tryptone and sufficient amount of CaCl2 and urea to the bacterial sludge dilution and put it in a shaker to make it fully react. After 3 days, discard the supernatant and dry it. Use hydrochloric acid pickling method to obtain the amount of CaCO3 generated, and then calculate the amount of CaCO3 generated according to CaCl2. 2+ Conservation, use formula (1) and formula (2) to calculate the amount of CaCl2 and urea:

[0029] (1)

[0030] (2)

[0031] in, is the mass of calcium carbonate (g), is the mass of calcium chloride (g), is the mass of calcium carbonate (g), is the mass of urea (g), is the relative molecular mass of calcium carbonate (44.00), is the relative molecular mass of calcium chloride (110.99), is the relative molecular mass of calcium carbonate (100), is the relative molecular mass of urea (60.06).

[0032] S5, sludge sterilization: Place the UV lamp into the sludge for sterilization for 1 hour, stirring every 20 minutes.

[0033] S6, add sludge solidification materials: add bacterial sludge, beef extract and trypsin to the sludge and stir thoroughly, stir once every 1 hour, stir 8 times and then add bentonite and stir for 3 minutes. The 8 stirrings are to make the pasteurella produce a certain amount of urease first. After the solidified body (sludge mixture) is formed, the urease stored in the body and the environment can immediately decompose urea to produce CO3 2- , and then with Ca 2+It reacts with other heavy metal ions in the sludge to form carbonate precipitation to improve the strength of the solidified body and stabilize heavy metals. After cracks are generated in the later stage, the pasteurella spores wake up and continue to react with unreacted urea and CaCl2 to form CaCO3 precipitation to repair the cracks. Then add slag, desulfurized gypsum, cement, urea and CaCl2 and stir evenly. Due to the fast rate of microbial mineralization reaction, the stirring time is controlled within 2 minutes. After mixing and stirring evenly, the sludge mixture is obtained.

[0034] S7, sludge mixture curing: put the sludge mixture into the mold, and after demoulding, wrap it with plastic wrap and place it in a constant temperature and humidity box for curing.

[0035] Embodiment 2:

[0036] Another implementation method of the sludge solidification method based on Example 1 is disclosed:

[0037] The sludge mixture includes: sludge to be treated, slag, desulfurized gypsum, cement, bentonite, urea and CaCl2; in terms of mass fractions, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement and 20-25 parts of bentonite are required for every 100 parts of sludge solidified. In this embodiment, 2g of bacterial sludge is added to 1000g of sludge mixture; it is calculated that 0.48g of beef extract, 0.80g of tryptone, 6.06g of calcium chloride and 3.28g of urea are required.

[0038] Embodiment 3:

[0039] Another implementation method of the sludge solidification method based on Example 1 is disclosed:

[0040] The sludge mixture includes: sludge to be treated, slag, desulfurized gypsum, cement, bentonite, urea and CaCl2; by weight, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement and 20-25 parts of bentonite are required for every 100 parts of sludge solidified. In this embodiment, 3g of bacterial sludge is added to 1000g of sludge mixture; it is calculated that 0.72g of beef extract, 1.20g of tryptone, 11.53g of calcium chloride and 6.24g of urea are required.

[0041] Embodiment 4:

[0042] Another implementation method of the sludge solidification method based on Example 1 is disclosed:

[0043] The sludge mixture includes: sludge to be treated, slag, desulfurized gypsum, cement, bentonite, urea and CaCl2; in terms of mass fractions, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement and 20-25 parts of bentonite are required for every 100 parts of sludge solidified. In this embodiment, 4g of bacterial sludge is added to 1000g of sludge mixture; it is calculated that 0.96g of beef extract, 1.60g of tryptone, 24.21g of calcium chloride and 13.10g of urea are required.

[0044] Embodiment 5:

[0045] This example verifies the effect of different microorganism (Bacillus pasteurianus) dosage on the unconfined compressive strength of sludge mixture (solidified body):

[0046] In this experiment, the unconfined compressive strength of the microbial-solid waste-based solidified sludge body (sludge mixture) that has reached the curing age is tested using the AGS-X-300KN Shimadzu electronic universal testing machine. In order to reduce the experimental error, 3 samples were measured in each group and the average value was taken, and the sample loading rate was 1 mm / min. The test was repeated for the ratios with a strength difference of more than 50% between the three samples, and the average value was taken after removing the data that was obviously too low or too high. The unconfined compressive strength of the sludge mixture obtained in different embodiments at 3 d, 7 d, and 28 d is shown in the following table:

[0047] Group 3 d unconfined compressive strength (kPa) 14 d unconfined compressive strength (kPa) 28 d unconfined compressive strength (kPa) Example 1 65 148 818 Example 2 67 158 883 Example 3 78 213 911 Example 4 81 216 913

[0048] The early strength (3 d, 7 d) of the solidified sludge body (sludge mixture) increased rapidly with the increase of the sludge content, and tended to be flat after the 0.3% sludge content, while the later strength (28 d) increased slowly compared with the 7-d age, and the strength of the solidified body with 0.4% dead bacteria content was extremely low at all ages. This shows that the improvement effect of microorganisms on solid waste-based solidified sludge bodies requires a certain amount of sludge content to take effect, and after exceeding a certain content, the strength improvement rate slows down. The CaCO3 produced by mineralization fills the internal pores of the solidified body and plays a role in cementing the internal particles, while the stabilization of heavy metal ions reduces the adverse effects of the sludge environment on the hydration of solid waste solidified materials, and indirectly promotes the hydration process of solid waste-based solidified materials, which is caused by the combined effect of the two. The improvement of the solidified body in the later stage may be that the solid waste-based solidified material continues to generate a large amount of hydration products on the basis of the large amount of CaCO3 produced by microbial mineralization, further filling the solidified body and cementing the internal particles, so that the strength is further improved.

[0049] Embodiment 6:

[0050] In this embodiment, the microorganism-solid waste-based solidified sludge (sludge mixture) cured to a specific age was crushed and passed through a 2 mm sieve. According to the method of solid waste leaching toxicity leaching method: horizontal oscillation method HJ 557-2010 specification, the solid-liquid ratio was 1:10, and it was shaken in a shaker at 30 r / min for 18 h and then allowed to stand for 6 h. The clear liquid was filtered through a filter paper with a pore size of 0.25 μm, and the heavy metal ions (Zn 2+ , Cu 2+ ) concentration. Compared with Cu 2+ , Pasteur's Zn 2+ The stabilization effect is better. It may be that Zn in the sludge 2+ The content is the highest, and the stabilization effect is the most obvious. The stabilization effect of heavy metals increases with the increase of the amount of bacterial sludge, but when the amount of bacterial sludge is small, the effect is not obvious. The CO3 produced by the mineralization of pasteurization 2- The heavy metal ions in the sludge are converted into stable carbonate precipitates, and the Pasteurella cells and extracellular polymers (EPS) adsorb heavy metal cations through negative charges, turning them into a stable state; in addition, a large amount of hydration products and CaCO3 may encapsulate the heavy metal ions in the sludge; and the stabilization of the heavy metal ions indirectly accelerates the hydration of the solid waste solidification material, making the heavy metal ions inside the solidified body more tightly encapsulated.

[0051] Embodiment 7:

[0052] In this example, a 7-day-old microorganism-solid waste-based solidified sludge body (sludge mixture) was pressed with a blade to form cracks with a depth of 30 mm and a width of 0.4±0.05 mm (measured by a GTJ-FKY crack width tester), and then immersed in water to wait for self-repair. The crack repair rate is expressed as the area repair rate of the crack. First, a digital camera is used to take a picture of the fracture surface of the repaired solidified body, and the image processing software (ImageJ) is used to process it (by adjusting the threshold, the crack area is distinguished from the non-crack area), and then the pixel points of the crack area are calculated using an ultra-depth optical microscope to obtain the area of ​​the crack area;

[0053] Crack repair rate =

[0054] Where S1 is the initial area of ​​the crack before repair (mm 2 ), unit; S2 is the area of ​​the crack after repair (mm 2 ).

[0055] The self-repairing effect of the microbial-solid waste-based solidified sludge body increases with the increase of the amount of bacterial sludge. The self-repairing effects of the sludge mixture (solidified body) of Example 1 to Example 4 are significantly different. The higher the amount of bacterial sludge, the better the self-repairing effect. Among them, the self-repairing rate of the solidified body with less bacterial sludge is slower in 0-14 days and faster in 14-28 days. The self-repairing rate of the solidified body with more bacterial sludge is faster in 0-14 days and slower in 14-28 days. It may be because the solidified body is lack of oxygen and water after forming, causing the pasteurization to enter a dormant state to achieve self-protection. The number of pasteurella inside the solidified body with less bacterial sludge is small, and the number of pasteurella that reawakens after cracking is also small, resulting in poor 0-14 d repair effect. After 14 days, pasteurella gradually adapted to the harsh environment, and its number increased exponentially, thereby increasing calcium production and accelerating the repair rate. When the amount of bacterial mud is higher, more Pasteurella is awakened inside the solidified body. After awakening, its number increases exponentially at the cracks, and then it quickly produces calcium to seal the cracks. After the cracks are sealed, the Pasteurella is re-sealed in the solidified body, which slows down the improvement of the repair effect.

[0056] In summary, the sludge solidification method provided in Examples 1-4 can produce a solidification effect in a very short time based on microbial mineralization technology (MICP), and the CaCO3 produced by mineralization can fill the solidified body (sludge mixture) in the later stage, making it more compact. MICP technology can also convert unstable heavy metal ions in the soil into a stable form, reduce the mobility, activity and biological toxicity of heavy metals, and greatly reduce the environmental risk of the solidified body. The stabilization of heavy metal ions in the sludge reduces the hindrance of the sludge environment to the hydration of the solid waste solidifying agent. Bacillus pasteurianus (Pasteurella) has better urease activity and heavy metal tolerance. When calcium chloride (CaCl2) is used as a calcium source, Pasteurella has the highest urease activity and calcium production rate in the culture medium environment, and the stability and mechanical properties of the induced CaCO3 are excellent. It overcomes the problem of low early strength and high heavy metal ion concentration of the solidified body obtained by the traditional solidification method, and greatly utilizes solid waste resources while treating sludge, solving the problem of large cement consumption and low economy in sludge treatment. At the same time, the final solidified sludge body has a good engineering application prospect. When applied to highway roadbed, it has a certain self-repairing effect on cracks caused by long-term use or external force.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sludge solidification method, characterized in that: include: Preparation of bacterial sludge: placing the liquid culture medium containing Bacillus pasteurianus into a centrifuge for treatment, discarding the supernatant, and obtaining Bacillus pasteurian bacterial sludge; Calculate the amount of nutrients added: take a certain mass of Bacillus pasteurianus sludge and dilute it, compare it by using the method of counting bacteria with super depth of field, and obtain the ratio of the number of bacteria per unit volume between the sludge dilution and the liquid culture medium. The nutrient content of the liquid culture medium is known, and the mass of nutrients required for the certain mass of Bacillus pasteurianus sludge is calculated according to the bacterial number ratio; Calculate the amount of mineralizer added: Mix the bacterial sludge with the corresponding amount of nutrients and add sufficient calcium chloride and urea for full reaction. Use the hydrochloric acid pickling method to obtain the amount of calcium carbonate produced. According to the principle of calcium ion conservation, calculate the amount of mineralizer added. Adding sludge solidification materials: adding the bacterial sludge and the nutrients required for the bacterial sludge to the sludge to be treated and stirring, then adding bentonite and stirring, and then adding slag, desulfurized gypsum, cement, urea and calcium chloride and stirring evenly to obtain a sludge mixture. In terms of mass parts, for every 100 parts of sludge solidified, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement, and 20-25 parts of bentonite are required, and each kilogram of the sludge mixture contains 1g~4g of the bacterial sludge.

2. The sludge solidification method according to claim 1, characterized in that: The process of culturing Bacillus pasteurianus includes: Prepare a liquid culture medium, wherein each 1 L of the liquid culture medium contains 5 g of peptone, 3 g of beef extract and sufficient deionized water, and sterilize the culture medium at 120° C. for 60 minutes; After cooling to room temperature in a sterile environment, 4% volume fraction of Bacillus pasteurianus seed solution was added; The culture was shaken at 36° C. and 140 r / min for 24 hours to obtain the liquid culture medium containing Bacillus pasteurianus.

3. The sludge solidification method according to claim 1, characterized in that: Also includes: Sludge sterilization: Before adding bacterial sludge to the sludge to be treated, the sludge to be treated is sterilized by irradiating it with ultraviolet light for 1 hour, during which time the sludge is stirred every 20 minutes.

4. The sludge solidification method according to claim 1, characterized in that: Also includes: Sludge mixture curing: the sludge mixture is loaded into a mold, wrapped with plastic wrap after demoulding, and placed in a constant temperature and humidity box for curing.

5. The sludge solidification method according to claim 1, characterized in that: The step of adding the bacterial sludge and the nutrients required for the bacterial sludge to the sludge to be treated and stirring, and then adding bentonite and stirring, specifically comprises: Add bacterial sludge, beef extract and trypsin to the sludge to be treated and stir thoroughly. Stir once every hour. After stirring 8 times, add bentonite and stir for 3 minutes.

6. The sludge solidification method according to claim 1, characterized in that: Add slag, desulfurized gypsum, cement, urea and calcium chloride and stir evenly. The stirring time should be controlled within 2 minutes.

7. The sludge solidification method according to any one of claims 1 to 6, characterized in that: The mass ratio of the sludge, the slag, the desulfurized gypsum, the cement, and the bentonite is 1:0.75:0.1:0.15:0.

2.

8. A solidifying material, characterized in that: include: Solid waste-based materials, microbial sludge and mineralizers; wherein the solid waste-based materials include sludge, slag, desulfurized gypsum, cement and bentonite. In terms of mass fractions, for every 100 parts of sludge solidified, 70-80 parts of slag, 10-15 parts of desulfurized gypsum, 15-20 parts of cement and 20-25 parts of bentonite are required. The microbial sludge is obtained by discarding the supernatant after centrifugation of a liquid culture medium of Bacillus pasteurianus. The mineralizers include calcium chloride and urea.

9. The solidifying material according to claim 8, characterized in that: The liquid culture medium of Bacillus pasteurianus contains 5g of peptone, 3g of beef extract and sufficient deionized water per 1L. The nutrients required by the bacterial sludge in the process of solidifying the sludge are calculated by the following steps: Every 1000g of the mixture of sludge and solidifying material contains 1-4g of bacterial sludge; The mass of nutrients required for the bacterial sludge is calculated by comparing the number of bacteria per unit volume of 1-4 g of diluted bacterial sludge with that of the liquid culture medium.

10. The solidifying material according to claim 9, characterized in that: The addition amount of the calcium chloride and the urea is calculated by the following steps: The bacterial sludge and the corresponding amount of nutrients are mixed and sufficient amounts of calcium chloride and urea are added for sufficient reaction. The amount of calcium carbonate generated is obtained by a hydrochloric acid pickling method, and the amount of mineralizer added is calculated based on the principle of calcium ion conservation.

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