Compound bacteria preparation for sludge treatment and preparation method thereof

Abstract

The invention provides a compound bacteria preparation for sludge treatment and a preparation method of the compound bacteria preparation. The preparation method comprises the following steps: S1, preparing stearamide propyl phosphate betaine-PVA microgel; s2, preparing stearamide propyl phosphate betaine-PVA (Polyvinyl Alcohol) microgel / SiO2 composite microspheres; s3, carrying out high-temperature carbonization on the stearamide propyl phosphate betaine-PVA microgel / SiO2 composite microspheres under the protection of inert gas, so as to obtain C / SiO2 composite microspheres; and S4, adding the C / SiO2 composite microspheres into the mixed bacterial liquid, introducing nitrogen, heating and stirring to obtain the composite bacterial preparation for sludge treatment. According to the method, sphybrid conjugate electrons of a porous carbon matrix are prepared, distribution of electron clouds of refractory organics in the sludge is adjusted through interface action, active sites are exposed, degradation activation energy is reduced, decomposition of the refractory organics into volatile fatty acid is accelerated, and microspheres of a porous structure can also reduce mass transfer obstruction caused by thallus aggregation, so that the degradation efficiency of the sludge is improved. The sludge treatment is facilitated.

Description

Technical Field

[0001] This invention relates to the field of sludge resource utilization technology, specifically to a compound microbial preparation for sludge treatment and its preparation method. Background Technology

[0002] Urbanization exacerbates sludge production, and anaerobic fermentation has become a mainstream treatment technology because it can convert organic matter in sludge into methane (clean energy) and reduce volume by 40% to 60%. In this system, Clostridium decomposes organic matter to produce volatile fatty acids, which are then converted into methane by Diplococcus methanogens. However, the high suspended solids in sludge and fluctuating pH levels cause free-floating bacteria to easily become inactive and be lost, hindering the industrialization of the technology. Therefore, it is necessary to develop a microbial immobilization technology.

[0003] Currently, common technologies for anaerobic fermentation of sludge mainly revolve around two major directions: "process optimization" and "microbial enhancement." Regarding process optimization, these include high-temperature anaerobic fermentation (50-55℃) and pretreatment enhancement (such as ultrasonic pretreatment and alkali pretreatment). While these can improve the efficiency of organic matter leaching from sludge, they cannot solve the fundamental problem of functional microbial communities being easily inactivated and lost. Regarding microbial enhancement, the mainstream technology is microbial immobilization, which uses carriers to immobilize functional microbial communities, reducing their loss in the fermentation system. Commonly used carriers can be divided into three categories: first, inorganic carriers (such as natural zeolite and SiO2 microspheres), which have high mechanical strength and are resistant to the complex environment of sludge, but have poor biocompatibility and low affinity with microbial communities. The first problem is the lack of biocompatibility, which leads to low bacterial load and an inability to provide a suitable metabolic microenvironment for the bacteria. The second problem is the use of organic carriers (such as sodium alginate gel and polyvinyl alcohol particles). These carriers have excellent biocompatibility and can form porous structures through cross-linking to accommodate bacteria. However, they have poor shock resistance and are prone to swelling and cracking in the high-suspended-solids stirring environment of sludge. Furthermore, organic carriers are easily degraded by other bacteria, resulting in a short lifespan for the immobilized system. The third problem is the use of simple composite carriers (such as sodium alginate-SiO2 mixed carriers). Although these carriers attempt to integrate the advantages of inorganic and organic carriers, they are mostly prepared by physical mixing. The pore size distribution inside the carrier is uneven, and the components are loosely bonded. This makes them prone to stratification during long-term anaerobic fermentation of sludge, which does not meet the actual needs of sludge use. Summary of the Invention

[0004] The technical problem to be solved: This invention provides a composite microbial preparation for sludge treatment and its preparation method. By preparing composite microspheres with porous structures and loading Clostridium difficile and Methanococcus methanans onto them, sludge treatment can be achieved.

[0005] Surgical plan: A compound microbial preparation for sludge treatment, wherein the preparation is a C / SiO2 composite microsphere loaded with two bacterial species, namely Clostridium and Methanococcus, and the C / SiO2 composite microsphere is obtained by high-temperature carbonization of stearamidopropyl betaine-PVA microgel / SiO2 composite microsphere.

[0006] Preferably, the preparation method includes the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under inert gas protection to obtain C / SiO2 composite microspheres; S4. Add C / SiO2 composite microspheres to the mixed bacterial solution, introduce nitrogen gas and heat and stir to obtain a composite bacterial preparation for sludge treatment.

[0007] Preferably, step S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1~3 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 2~5:1~3, heat and stir at 60~70℃ until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 2-4 drops / second, with a volume ratio of aqueous phase to oil phase of 1-5:1-8. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.5~0.8mol / L NaOH solution to the emulsion until the pH reaches 8~9, and continue stirring for 2~4h to obtain stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 8000~10000r / min for 6~10min, discard the upper oil phase, and wash the precipitate with deionized water 3~5 times to obtain stearamide propyl betaine-PVA microgel dispersion.

[0008] Preferably, step S2 includes the following steps: S21. Add stearamide propyl betaine phosphate-PVA microgel dispersion to a SiO2 microsphere suspension with a concentration of 0.05~1g / mL, and stir at room temperature for 4~6h to obtain a mixed solution; S22. Centrifuge the mixture at 8000~9000r / min for 10~15min, discard the supernatant, and dry the lower precipitate at 50~60℃ for 10~14h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0009] Preferably, the inert gas in S3 is nitrogen, the high-temperature carbonization temperature is 500~600℃, the heating rate is 3~5℃ / min, and the holding time is 1~2h.

[0010] Preferably, in step S4, the mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:5~10 g / mL, the mixed bacterial solution consists of Clostridium perfringens solution and Diplostomum methanogenum solution, the volume ratio of Clostridium perfringens solution to Diplostomum methanogenum solution is 1:1~2, and the concentration of Clostridium perfringens solution is 10. 8 ~10 9 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 ~10 9 CFU / mL.

[0011] Preferably, the heating temperature in step S4 is 30~40℃ and the heating time is 12~20h.

[0012] Preferably, the volume ratio of the SiO2 microsphere suspension to the stearamide propyl betaine-PVA microgel dispersion in S21 is 1:0.5~1.5.

[0013] Preferably, the method of using the compound microbial preparation is as follows: the sludge to be treated is added to the sludge anaerobic fermentation tank, then the compound microbial preparation is added, the pH of the sludge to be treated is adjusted to 7-8, and anaerobic fermentation is carried out at 33-37℃. After standing, the water and the treated sludge are separated.

[0014] Preferably, the concentration of the sludge to be treated is 15-100 g / L, the MLVSS / MLSS value in the sludge to be treated is greater than 0.5, the amount of compound microbial preparation added is 0.1-0.5 g of compound microbial preparation per gram of sludge to be treated, and the anaerobic fermentation time is 8-12 days.

[0015] Beneficial effects: The present invention has the following advantages: 1. In this invention, stearamide propyl betaine-PVA microgel is prepared via emulsion and then cross-linked in situ to form a three-dimensional porous network, which is subsequently loaded onto SiO2 microspheres. Through subsequent high-temperature calcination, the carbon layer retains the porous structure of the microgel, while the SiO2 framework further supports the pores to prevent collapse, ultimately forming C / SiO2 composite microspheres with hierarchical channels. During the subsequent bacterial loading process, Clostridium perfringens can attach to the surface of the micron-sized channels, and spores can be embedded in the nano-sized channels, preventing detachment caused by water erosion. Methanococcus methanans attaches stably through physical adsorption and electrostatic interactions within the channels. Furthermore, the porous structure reduces mass transfer obstacles caused by bacterial aggregation, which is beneficial for subsequent sludge treatment. 2. In this invention, after the stearamidopropyl phosphate betaine-PVA microgel is carbonized under an inert atmosphere, the amide group and phosphate betaine group of stearamidopropyl phosphate betaine, along with the hydroxyl group of PVA, will retain heteroatom active groups with oxygen, nitrogen, and phosphorus as their cores. Some hydroxyl groups of PVA are not completely broken, and together with the local oxidation products of the carbon chain, they form hydroxyl and carboxyl groups. The amide bond of stearamidopropyl phosphate betaine has high thermal stability and is converted into pyridine N, pyrrole N, and residual amide N. After demethylation of the quaternary ammonium nitrogen, a nitrogen-containing short chain is formed. The above-mentioned heteroatom active groups are... The formation of atomically active groups can be regarded as the chemical adsorption sites for the binding of the carrier and the bacteria. In addition, the carbonization process will also leave flexible short carbon chain fragments: the stearyl long chain of stearamidopropyl phosphate betaine and the PVA long chain undergo partial bond breaking at 550°C, eventually forming short alkyl chain and amide side chain fragments. These short chains are anchored to the surface of carbon materials through C-C bonds. They contain hydrophobic bonds and retain a small number of hydrophilic groups, which are compatible with the hydrophilic and hydrophobic regions of the bacterial cell membrane. At the same time, they increase the surface roughness of the carrier and provide physical anchoring space for the bacteria. 3. In this invention, the sp² hybridized conjugated electrons of the porous carbon matrix regulate the electron cloud distribution of recalcitrant organic matter in sludge through interfacial interactions, expose active sites and reduce the degradation activation energy, thereby accelerating its decomposition into volatile fatty acids. It can also act as an electron shuttle, mediating extracellular electron transfer between acid-producing bacteria and methanogenic taenia, promoting CO2 reduction to produce methanogens. At the same time, it maintains a suitable redox potential in the system through electron buffering, alleviating the metabolic inhibition caused by the accumulation of volatile fatty acids, and ultimately improving the sludge treatment capacity of the formulation. Detailed Implementation

[0016] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: Example 1

[0017] A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 500℃, the heating rate was 3℃ / min, and the holding time was 1h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:5 g / mL, and the concentration of the Clostridium perfringens solution is 10. 8The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 30℃ for 12 hours with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 2:1, heat and stir at 60°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 2 drops / second, with a volume ratio of aqueous phase to oil phase of 1:1. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.5 mol / L NaOH solution to the emulsion until the pH reaches 8, and continue stirring for 2 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 9000 r / min for 6 min, discard the upper oil phase, and wash the precipitate 4 times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Add stearamidopropyl betaine-PVA microgel dispersion to a SiO2 microsphere suspension with a concentration of 0.05 g / mL. The SiO2 microsphere suspension and stearamidopropyl betaine-PVA microgel dispersion are mixed at a ratio of 1:0.5 and stirred at room temperature for 4 h to obtain a mixture. S22. Centrifuge the mixture at 8000 r / min for 10 min, discard the supernatant, and dry the lower precipitate at 50℃ for 10 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres. Example 2

[0018] A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 600℃, the heating rate was 5℃ / min, and the holding time was 2h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:10 g / mL, and the concentration of the Clostridium perfringens solution is 10. 9 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 9 CFU / mL, nitrogen gas was introduced and heated at 40℃ for 20h with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:3 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 5:3, heat and stir at 70°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 4 drops / second, with a volume ratio of aqueous phase to oil phase of 5:8. Stir at 30℃ for 30 minutes to form an emulsion. S14. Add 0.8 mol / L NaOH solution to the emulsion until the pH reaches 9, and continue stirring for 4 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 10000 r / min for 10 min, discard the upper oil phase, and wash the precipitate 5 times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Add stearamide propyl betaine phosphate-PVA microgel dispersion to a SiO2 microsphere suspension with a concentration of 1 g / mL. The SiO2 microsphere suspension and stearamide propyl betaine phosphate-PVA microgel dispersion are mixed at a ratio of 1:1.5 and stirred at room temperature for 6 h to obtain a mixed solution. S22. Centrifuge the mixture at 9000 r / min for 15 min, discard the supernatant, and dry the lower precipitate at 60℃ for 14 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0019] Example 3 A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 550℃, the heating rate was 4℃ / min, and the holding time was 1.5h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:8 g / mL, and the concentration of the Clostridium perfringens solution is 10. 8 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 30℃ for 12 hours with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 3:2, heat and stir at 65°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 3 drops / second, with a volume ratio of aqueous phase to oil phase of 4:7. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.6 mol / L NaOH solution to the emulsion until the pH reaches 8, and continue stirring for 3 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 9000 r / min for 8 min, discard the upper oil phase, and wash the precipitate 4 times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Stearamidopropyl betaine-PVA microgel dispersion was added to a SiO2 microsphere suspension with a concentration of 0.08 g / mL. The SiO2 microsphere suspension and the stearamidopropyl betaine-PVA microgel dispersion were mixed at a ratio of 1:1.5 and stirred at room temperature for 6 hours to obtain a mixture. S22. Centrifuge the mixture at 8000 r / min for 15 min, discard the supernatant, and dry the lower precipitate at 50℃ for 14 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0020] Example 4 A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 550℃, the heating rate was 4℃ / min, and the holding time was 1h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution. The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:8 g / mL. The mixed bacterial solution consists of Clostridium perfringens solution and Diplostomum methanogenum solution, with a volume ratio of 1:1. The concentration of the Clostridium perfringens solution is 10. 8 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 30℃ for 18 hours with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 4:3, heat and stir at 65°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 3 drops / second, with a volume ratio of aqueous phase to oil phase of 3:7. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.5 mol / L NaOH solution to the emulsion until the pH reaches 8, and continue stirring for 3 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 9000 r / min for 8 min, discard the upper oil phase, and wash the precipitate three times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Add stearamidopropyl betaine-PVA microgel dispersion to a SiO2 microsphere suspension with a concentration of 0.05 g / mL. The SiO2 microsphere suspension and stearamidopropyl betaine-PVA microgel dispersion are mixed at a ratio of 1:0.5 and stirred at room temperature for 4 h to obtain a mixture. S22. Centrifuge the mixture at 8000 r / min for 1 min, discard the supernatant, and dry the lower precipitate at 50℃ for 10 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0021] Example 5 A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 550℃, the heating rate was 4℃ / min, and the holding time was 1.5h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:8 g / mL, and the concentration of the Clostridium perfringens solution is 10. 8 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 35℃ for 16 h with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Mix cyclohexane in a volume ratio of 10:2 with Span-80 until homogeneous to obtain the oil phase; S12. Dissolve PVA and stearamide propyl phosphate betaine in water at a mass ratio of 5:2, heat and stir at 65°C until completely dissolved. S13. Add the aqueous phase to the oil phase at a rate of 3 drops / second, with a volume ratio of aqueous phase to oil phase of 5:7, and stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.7 mol / L NaOH solution dropwise to the emulsion until the pH reaches 9, and continue stirring for 3 hours to obtain a stearamidopropyl betaine-PVA microgel mixture; thus obtaining the aqueous phase; S15. Transfer the mixture to a centrifuge tube, centrifuge at 8000 r / min for 9 min, discard the upper oil phase, and wash the precipitate 4 times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Stearamidopropyl betaine-PVA microgel dispersion was added to a SiO2 microsphere suspension with a concentration of 0.08 g / mL. The SiO2 microsphere suspension and the stearamidopropyl betaine-PVA microgel dispersion were mixed at a ratio of 1:1.5 and stirred at room temperature for 5 h to obtain a mixture. S22. Centrifuge the mixture at 8000 r / min for 14 min, discard the supernatant, and dry the lower precipitate at 55℃ for 14 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0022] Example 6 A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 600℃, the heating rate was 4℃ / min, and the holding time was 1.5h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:8 g / mL, and the concentration of the Clostridium perfringens solution is 10. 8 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 35℃ for 8 hours with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:3 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 3:2, heat and stir at 65°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 3 drops / second, with a volume ratio of aqueous phase to oil phase of 5:1. Stir at 30℃ for 30 minutes to form an emulsion. S14. Add 0.6 mol / L NaOH solution to the emulsion until the pH reaches 9, and continue stirring for 4 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 10000 r / min for 8 min, discard the upper oil phase, and wash the precipitate 4 times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Stearamidopropyl betaine-PVA microgel dispersion was added to a SiO2 microsphere suspension with a concentration of 0.08 g / mL. The SiO2 microsphere suspension and the stearamidopropyl betaine-PVA microgel dispersion were mixed at a ratio of 1:1.5 and stirred at room temperature for 5 h to obtain a mixture. S22. Centrifuge the mixture at 8000 r / min for 10 min, discard the supernatant, and dry the lower precipitate at 55℃ for 12 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0023] Example 7 A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 550℃, the heating rate was 4℃ / min, and the holding time was 1h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:8 g / mL, and the concentration of the Clostridium perfringens solution is 10. 8 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 35℃ for 18 hours with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 4:3, heat and stir at 65°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 3 drops / second, with a volume ratio of aqueous phase to oil phase of 4:7. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.6 mol / L NaOH solution to the emulsion until the pH reaches 9, and continue stirring for 3 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 8000 r / min for 8 min, discard the upper oil phase, and wash the precipitate 4 times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Stearamidopropyl betaine-PVA microgel dispersion was added to a SiO2 microsphere suspension with a concentration of 0.09 g / mL. The SiO2 microsphere suspension and the stearamidopropyl betaine-PVA microgel dispersion were mixed at a ratio of 1:1.5 and stirred at room temperature for 5 h to obtain a mixture. S22. Centrifuge the mixture at 8000 r / min for 10 min, discard the supernatant, and dry the lower precipitate at 55℃ for 12 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0024] Example 8 A method for preparing a compound microbial preparation for sludge treatment, the preparation method comprising the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under nitrogen protection. The high temperature carbonization temperature was 550℃, the heating rate was 4℃ / min, and the holding time was 1h to obtain C / SiO2 composite microspheres. S4. Add C / SiO2 composite microspheres to the mixed bacterial solution (Clostridium perfringens solution and Diplococcus methanans solution, with a volume ratio of 1:1). The mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:8 g / mL, and the concentration of the Clostridium perfringens solution is 10. 8 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 CFU / mL, nitrogen gas was introduced and heated at 35℃ for 18 hours with stirring to obtain a compound bacterial preparation for sludge treatment; S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 4:1, heat and stir at 65°C until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 3 drops / second, with a volume ratio of aqueous phase to oil phase of 4:7. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.8 mol / L NaOH solution to the emulsion until the pH reaches 8, and continue stirring for 3 hours to obtain a stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 9000 r / min for 8 min, discard the upper oil phase, and wash the precipitate three times with deionized water to obtain stearamide propyl betaine-PVA microgel dispersion. S2 includes the following steps: S21. Add stearamidopropyl betaine-PVA microgel dispersion to a SiO2 microsphere suspension with a concentration of 0.08 g / mL. The ratio of SiO2 microsphere suspension to stearamidopropyl betaine-PVA microgel dispersion is 1:1.2. Stir at room temperature for 4 h to obtain a mixed solution. S22. Centrifuge the mixture at 8000 r / min for 14 min, discard the supernatant, and dry the lower precipitate at 55℃ for 12 h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

[0025] Comparative Example 1 The difference between Comparative Example 1 and Example 8 is that only PVA gel was prepared in S1 without the addition of stearamidopropyl phosphate betaine.

[0026] Comparative Example 2 The difference between Comparative Example 2 and Example 8 is that stearamidopropyl betaine-PVA microgel was not loaded onto SiO2 microspheres, that is, only stearamidopropyl betaine-PVA microgel was prepared.

[0027] Comparative Example 3 The difference between Comparative Example 3 and Example 8 is that, in S4, the C / SiO2 composite microspheres were not added to the mixed bacterial solution, but only to the Clostridium difficile solution.

[0028] Comparative Example 4 The difference between Comparative Example 4 and Example 8 is that, in S4, C / SiO2 composite microspheres were not added to the mixed bacterial solution, but only to the methanogenic octopus solution.

[0029] Comparative Example 5 The difference between Comparative Example 5 and Example 8 is that the C / SiO2 composite microspheres were not added to the mixed bacterial solution, but were directly used for subsequent sludge treatment.

[0030] Comparative Example 6 The difference between Comparative Example 6 and Example 8 is that the carbonization process in S3 was not performed, and stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were directly added to the mixed bacterial solution.

[0031] Comparative Example 7 The difference between Comparative Example 7 and Example 8 is that the C / SiO2 microspheres are loaded only with Vibrio butyricum, that is, in S4, the C / SiO2 composite microspheres are added to the Vibrio butyricum solution.

[0032] Performance testing The method of using the compound microbial preparations obtained in Examples 1-8 and Comparative Examples 1-7 is as follows: the sludge to be treated is added to the sludge anaerobic fermentation tank, the concentration of the sludge is 30g / L, and then the compound microbial preparation is added. The amount of compound microbial preparation added is 0.3g of compound microbial preparation per gram of sludge to be treated. The pH of the sludge to be treated is adjusted to 8, and anaerobic fermentation is carried out at 35℃ for 10 days. After standing, the water and the treated sludge are separated.

[0033] Table 1

[0034] Table 2

[0035] Note: 1. The MLVSS removal rate was tested according to the determination method of MLVSS in the national standard "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB 18918-2002); 2. The methane yield and rate were determined according to the standard "Determination of the production of anaerobic biodegradable gases from organic matter in digested sludge" (GB / T 27857-2011).

[0036] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A compound microbial preparation for sludge treatment, characterized in that: The formulation is a C / SiO2 composite microsphere loaded with two bacterial strains, namely Clostridium and Methanococcus methanans. The C / SiO2 composite microspheres are obtained by high-temperature carbonization of stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres.

2. The method for preparing the compound microbial preparation for sludge treatment according to claim 1, characterized in that: The preparation method includes the following steps: S1. Preparation of stearamidopropyl betaine-PVA microgel; S2. Preparation of stearamidopropyl betaine-PVA microgels / SiO2 composite microspheres; S3. Stearamidopropyl betaine-PVA microgel / SiO2 composite microspheres were carbonized at high temperature under inert gas protection to obtain C / SiO2 composite microspheres; S4. Add C / SiO2 composite microspheres to the mixed bacterial solution, introduce nitrogen gas and heat and stir to obtain a composite bacterial preparation for sludge treatment.

3. The method for preparing the compound microbial preparation for sludge treatment according to claim 2, characterized in that: S1 includes the following steps: S11. Take cyclohexane with a volume ratio of 10:1~3 and mix it evenly with Span-80 to obtain the oil phase; S12. Dissolve PVA and stearamide propyl betaine in water at a mass ratio of 2~5:1~3, heat and stir at 60~70℃ until completely dissolved to obtain an aqueous phase; S13. Add the aqueous phase to the oil phase at a rate of 2-4 drops / second, with a volume ratio of aqueous phase to oil phase of 1-5:1-8. Stir at 30°C for 30 minutes to form an emulsion. S14. Add 0.5~0.8mol / L NaOH solution to the emulsion until the pH reaches 8~9, and continue stirring for 2~4h to obtain stearamide propyl betaine-PVA microgel mixture; S15. Transfer the mixture to a centrifuge tube, centrifuge at 8000~10000r / min for 6~10min, discard the upper oil phase, and wash the precipitate with deionized water 3~5 times to obtain stearamide propyl betaine-PVA microgel dispersion.

4. The method for preparing the compound microbial preparation for sludge treatment according to claim 2, characterized in that: S2 includes the following steps: S21. Add stearamide propyl betaine phosphate-PVA microgel dispersion to a SiO2 microsphere suspension with a concentration of 0.05~1g / mL, and stir at room temperature for 4~6h to obtain a mixed solution; S22. Centrifuge the mixture at 8000~9000r / min for 10~15min, discard the supernatant, and dry the lower precipitate at 50~60℃ for 10~14h to obtain stearamidopropyl betaine-PVA / SiO2 composite microspheres.

5. The method for preparing the compound microbial preparation for sludge treatment according to claim 2, characterized in that: The inert gas in S3 is nitrogen, the high-temperature carbonization temperature is 500~600℃, the heating rate is 3~5℃ / min, and the holding time is 1~2h.

6. The method for preparing the compound microbial preparation for sludge treatment according to claim 2, characterized in that: In S4, the mass-to-volume ratio of C / SiO2 composite microspheres to the mixed bacterial solution is 1:5~10 g / mL. The mixed bacterial solution consists of Clostridium perfringens solution and Diplostomum methanogenum solution, with a volume ratio of Clostridium perfringens solution to Diplostomum methanogenum solution of 1:1~2. The concentration of the Clostridium perfringens solution is 10. 8 ~10 9 The concentration of *Methanecrocarpa* culture was 10 CFU / mL. 8 ~10 9 CFU / mL.

7. The method for preparing the compound microbial preparation for sludge treatment according to claim 2, characterized in that: The heating temperature in S4 is 30~40℃, and the heating time is 12~20h.

8. The method for preparing the compound microbial preparation for sludge treatment according to claim 4, characterized in that: The volume ratio of the SiO2 microsphere suspension to the stearamide propyl betaine-PVA microgel dispersion in S21 is 1:0.5~1.

5.

9. The compound microbial preparation for sludge treatment prepared according to claims 1-4, characterized in that: The method of using the compound microbial preparation is as follows: add the sludge to be treated into the sludge anaerobic fermentation tank, then add the compound microbial preparation, adjust the pH of the sludge to be treated to 7-8, and carry out anaerobic fermentation at 33-37℃. After standing, separate the water and the treated sludge.

10. The method of using the compound microbial preparation according to claim 9, characterized in that: The concentration of the sludge to be treated is 15-100 g / L, the MLVSS / MLSS value in the sludge to be treated is greater than 0.5, the amount of compound microbial preparation added is 0.1-0.5 g of compound microbial preparation per gram of sludge to be treated, and the anaerobic fermentation time is 8-12 days.

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