Thermosensitive sustained-release carrier with activity regulating function and preparation method thereof

Abstract

The present invention discloses a method for preparing a thermosensitive sustained-release carrier with an activity regulating function, comprising the following steps: step 1, preparing a polyurethane porous carrier loaded with poly(N-isopropylacrylamide-co-butyl acrylate) on the surface; step 2, dispersing the polyurethane porous carrier loaded with poly(N-isopropylacrylamide-co-butyl acrylate) obtained in step 1 in an aqueous solution containing a cryoprotectant, reacting in a water bath shaker after ultrasound, separating solids, and drying to constant weight to obtain a thermosensitive sustained-release carrier with an activity regulating function. The present invention also discloses a thermosensitive sustained-release carrier with an activity regulating function prepared by the above-mentioned preparation method. The thermosensitive sustained-release carrier prepared by the present invention can ensure the stable release of the cryoprotectant for a long time through the slow release mechanism of the thermosensitive polymer, avoiding the loss problem of traditional additives in a continuous process, and reducing the introduction of pollution sources.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, relates to a temperature-sensitive slow-release carrier with an activity regulating function, and also relates to a preparation method of the temperature-sensitive slow-release carrier with an activity regulating function. Background Art

[0002] The moving bed biofilm reactor (MBBR) process is to increase the biomass and biological species in the reactor by adding functional biological carriers to the reactor, thereby increasing the system's processing load and capacity. The MBBR process is currently the core and essential main process of water treatment plants and the best upgrading and transformation technology for activated sludge tanks. As the core part of the MBBR process, the biological carrier determines the treatment efficiency and treatment capacity of the sewage / wastewater treatment system. Adding biological carriers to the core and essential processes of engineering applications to form an efficient biofilm system is currently the most popular and efficient in-situ upgrading and transformation method. The key to this process is the development and optimization of the carrier.

[0003] Although the existing wastewater biological treatment system has achieved remarkable results, it still faces many challenges, such as the biological activity is greatly affected by environmental temperature fluctuations, the microbial community structure is easily unbalanced, and the degradation efficiency of specific pollutants is low. Due to the differences in geographical regions (high latitudes) and seasonal changes (entering winter / spring) in my country, the wastewater temperature can often drop to 0-15°C, which is far below the suitable temperature for microbial growth, seriously inhibiting microbial activity, substrate utilization and cell growth, resulting in deterioration of wastewater biological treatment process performance and a significant reduction in wastewater removal efficiency. The inhibition of microbial metabolic activity in low-temperature biological systems has become a major problem in biological water treatment processes. The fundamental reason for the reduction in microbial activity is the reduction in enzyme activity or the deterioration of biofilm fluidity and the obstruction of mechanism exchange under environmental conditions. In addition, there is symbiotic metabolism between microorganisms. Building an ecological environment of harmonious symbiosis and long food chains is crucial to the stability of biological systems.

[0004] At present, the solutions to the inhibition of microbial activity caused by low temperature shock of sewage and wastewater include: ① installing an insulation jacket outside the biological system to maintain a constant water environment temperature; this method is only applicable to small reactors and greatly increases equipment costs and energy consumption; ② directly adding exogenous cryoprotectants such as betaine, trehalose and ethylene glycol to the biological system to ensure the permeability and rheology of microbial cell membranes at low temperatures, so that the metabolic activities of microorganisms can proceed normally. However, these exogenously added cryoprotectants are easily lost in the continuous process, the effect cannot be sustained, and if they are not used sufficiently, they will cause secondary pollution of the effluent. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a temperature-sensitive sustained-release carrier with activity regulation function, which solves the problem that the existing sewage and wastewater biological treatment process is difficult to maintain high biological activity under low temperature conditions, affecting the sewage treatment effect, and has low energy consumption.

[0006] Another object of the present invention is to provide a temperature-sensitive sustained-release carrier with activity regulation function.

[0007] The first technical solution adopted by the present invention is a method for preparing a thermosensitive sustained-release carrier with activity regulation function, comprising the following steps:

[0008] Step 1, preparing a polyurethane porous carrier with poly(N-isopropylacrylamide-co-butyl acrylate) loaded on the surface;

[0009] Step 2, dispersing the polyurethane porous carrier loaded with poly (N-isopropylacrylamide-co-butyl acrylate) obtained in step 1 in an aqueous solution containing a cryoprotectant, reacting in a water bath shaker after ultrasonication, separating the solid, and drying to constant weight to obtain a thermosensitive sustained-release carrier with activity regulation function.

[0010] The first technical solution of the present invention is also characterized in that:

[0011] The specific process of step 1 is:

[0012] Step 1.1, dispersing the polyurethane porous cubes in ethanol containing ammonia water, wherein the amount of the polyurethane porous cubes added is 30-50% of the volume of the ethanol, and the concentration of the ammonia water is 2 mol / L-4 mol / L;

[0013] Step 1.2, adding N-isopropylacrylamide, butyl acrylate, and coupling agent 3-aminopropyltriethoxysilane to the product obtained in step 1.1, and dispersing by mechanical stirring, wherein the amount of N-isopropylacrylamide is 50 to 150 mg; the amount of butyl acrylate is 0.02 to 0.10 mL; and the amount of coupling agent 3-aminopropyltriethoxysilane is 100 to 200 mg;

[0014] Step 1.3, adding the initiator azobisisobutyronitrile to the product obtained in step 1.2, controlling the temperature at 10-20° C. and continuously stirring, and passing nitrogen to deoxygenate during the entire reaction process; washing the product with deionized water, and vacuum drying to constant weight to obtain a polyurethane porous carrier with a surface loaded with poly(N-isopropylacrylamide-co-butyl acrylate).

[0015] In step 1.1, the size of the polyurethane porous cube is: 0.5 cm×0.5 cm×0.5 cm to 1 cm×1 cm×1 cm.

[0016] In step 1.3, the drying temperature during vacuum drying is 30 to 60°C.

[0017] In step 2, the cryoprotectant is at least one of betaine, trehalose, ethylene glycol, and proline, and the concentration of the cryoprotectant is 50 mg / L to 100 mg / L.

[0018] In step 2, the ultrasonic time is 20 to 40 minutes.

[0019] In step 2, the reaction is carried out in a water bath shaker for 1 to 3 hours, and the water bath temperature is maintained at 10 to 20°C.

[0020] In step 2, the drying temperature is 30-60°C.

[0021] The second technical solution adopted by the present invention is that the thermosensitive sustained-release carrier with activity regulating function is prepared by the preparation method of the thermosensitive sustained-release carrier with activity regulating function.

[0022] The beneficial effects of the present invention are as follows:

[0023] (1) The present invention utilizes in-situ grafting technology to firmly bond LCST (low critical solution temperature) type thermosensitive polymers (such as poly (N-isopropylacrylamide-co-butyl acrylate)) to the polyurethane porous bio-carrier, which is not only simple to synthesize but also ensures the stability and durability of the carrier.

[0024] (2) The surface of the carrier prepared in the present invention is grafted with a cold-responsive polymer (pNIPAM-BA) containing a microbial cryoprotectant. When the temperature of the aqueous solution is lower than its minimum critical solution temperature, the thermosensitive monomer stretches and becomes hydrophilic, and the cryoprotectant contained therein is released and acts on the microorganisms.

[0025] (3) The thermosensitive sustained-release carrier prepared by the present invention can ensure the stable release of the cryoprotectant over a long period of time through the slow release mechanism of the thermosensitive polymer, thereby avoiding the loss problem of traditional additives in the continuous process and reducing the introduction of pollution sources.

[0026] (4) The active substances released by the carrier can regulate the activity of microorganisms on the carrier surface and enhance their adaptability to environmental stresses such as low temperature, thereby improving the efficiency and stability of wastewater treatment.

[0027] (5) The slow-release carrier prepared by the present invention is particularly suitable for use in cold regions or during periods of seasonal temperature changes. It can significantly improve the efficiency and stability of wastewater biological treatment processes such as MBBR under low temperature conditions, and promote its widespread application in the field of environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the MBBR device used in the experimental process of the present invention;

[0029] Figure 2 It is a comparison diagram of COD inlet and outlet water concentrations of the unmodified carrier bioreactor R1 and the carrier bioreactor R2 in Example 3 under the same inlet water and operating conditions;

[0030] Figure 3 It is a comparison chart of the inlet and outlet concentrations of ammonia nitrogen in the unmodified carrier bioreactor R1 and the carrier bioreactor R2 in Example 3 under the same inlet and operating conditions;

[0031] Figure 4 It is a comparison chart of TN inlet and outlet water concentrations of the unmodified carrier bioreactor R1 and the carrier bioreactor R2 in Example 3 under the same inlet water and operating conditions;

[0032] Figure 5 The figure is a comparison of the dehydrogenase activity (DHA) and specific oxygen consumption rate (SOUR) of the biofilm on the carrier in the unmodified carrier bioreactor R1 and the carrier bioreactor R2 in Example 3 which were operated for 41 days.

[0033] In the figure, 1. water storage tank, 2. peristaltic pump, 3. interlayer outlet, 4. carrier, 5. reactor interlayer, 6. MBBR reactor, 7. wastewater inlet, 8. wastewater outlet, 9. interlayer inlet, 10. aeration device. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The method for preparing a thermosensitive sustained-release carrier with activity regulating function of the present invention comprises the following steps:

[0036] Step 1, dispersing polyurethane porous cubes with a size of (0.5-1) cm×(0.5-1) cm×(0.5-1) cm in ethanol containing ammonia water, with the addition amount being 30-50% of the volume of the ethanol liquid and the ammonia water concentration being 2-4 mol / L; adding N-isopropylacrylamide (NIPAM), butyl acrylate (BA), and coupling agent 3-aminopropyltriethoxysilane (APTES) thereto, and dispersing by mechanical stirring, wherein the amount of N-isopropylacrylamide is 50-150 mg; the amount of butyl acrylate is 0.02-0.10 mL; and the amount of coupling agent 3-aminopropyltriethoxysilane is 100-200 mg. Subsequently, an initiator azobisisobutyronitrile (AIBN) is added in an amount of 4 to 10 mg. The temperature is controlled at 10 to 20°C and stirring is continued for 6 to 8 hours. Nitrogen is passed through the entire process to deoxygenate. The product is washed with deionized water and vacuum dried (at a temperature of 30 to 60°C) to constant weight to obtain a polyurethane porous carrier with a surface loaded with poly(N-isopropylacrylamide-co-butyl acrylate), namely a PU / pNIPAM-BA carrier.

[0037] Step 2, the polyurethane porous carrier loaded with poly (N-isopropylacrylamide-co-butyl acrylate) obtained in step 1 is completely dispersed in an aqueous solution containing a cryoprotectant (including any one or more of betaine, trehalose, ethylene glycol, and proline; the amount of the cryoprotectant is 50-100 mg / L), the volume ratio of PU / pNIPAM-BA carrier to the solution is 30-50%, after ultrasonication for 20-40 minutes, react in a water bath shaker for 1-3 hours (the water bath temperature is maintained at 10-20° C.), separate the solid, and dry at 30-60° C. to constant weight to obtain the final product-a temperature-sensitive sustained-release carrier with activity regulation function.

[0038] Example 1

[0039] A polyurethane porous cube with a size of 0.5 cm×0.5 cm×0.5 cm was dispersed in 1 L of ethanol containing 4.0 mol of ammonia water, and 150 mg of NIPAM, 0.1 mL of BA, and 200 mg of coupling agent APTES were added thereto. The mixture was dispersed by mechanical stirring, and then 10 mg of initiator AIBN was added. The temperature was controlled at 20°C and stirring was continued. Nitrogen was passed through the whole process to deoxygenate. The product was washed with deionized water for 5 times and dried in vacuo at 60°C to constant weight to obtain a polyurethane porous carrier of poly(N-isopropylacrylamide-co-butyl acrylate), namely, a PU / pNIPAM-BA carrier.

[0040] The PU / pNIPAM-BA carrier was dispersed in 1L of aqueous solution containing 100mg of betaine-TMG, and after ultrasonication for 40min, it was reacted in a water bath shaker at 20°C for 3h. The solid was separated and dried to constant weight at 60°C to obtain the final product - a thermosensitive sustained-release carrier with activity regulation function.

[0041] Example 2

[0042] A polyurethane porous cube with a size of 0.5 cm×0.5 cm×0.5 cm was dispersed in 1 L of ethanol containing 2.0 mol of ammonia water, and 50 mg of NIPAM, 0.02 mL of BA, and 100 mg of coupling agent APTES were added thereto. The mixture was dispersed by mechanical stirring, and then 4 mg of initiator AIBN was added. The temperature was controlled at 10°C and stirring was continued. Nitrogen was passed through the whole process to deoxygenate. The product was washed with deionized water for 5 times and dried in vacuo at 30°C to constant weight to obtain a polyurethane porous carrier of poly(N-isopropylacrylamide-co-butyl acrylate), namely, a PU / pNIPAM-BA carrier.

[0043] The PU / pNIPAM-BA carrier was dispersed in 1L of aqueous solution containing 50mg betaine-TMG, and after ultrasonication for 20min, it was reacted in a water bath shaker at 10°C for 1h. The solid was separated and dried to constant weight at 30°C to obtain the final product - a thermosensitive sustained-release carrier with activity regulation function.

[0044] Example 3

[0045] A polyurethane porous cube with a size of 0.5 cm×0.5 cm×0.5 cm was dispersed in 1 L of ethanol containing 3.0 mol of ammonia water, and 100 mg of NIPAM, 0.06 mL of BA, and 150 mg of coupling agent APTES were added thereto. The mixture was dispersed by mechanical stirring, and then 7 mg of initiator AIBN was added. The temperature was controlled at 15°C and stirring was continued. Nitrogen was passed through the whole process to deoxygenate. The product was washed with deionized water for 5 times and dried in vacuo at 40°C to constant weight to obtain a polyurethane porous carrier of poly(N-isopropylacrylamide-co-butyl acrylate), namely, a PU / pNIPAM-BA carrier.

[0046] The PU / pNIPAM-BA carrier was dispersed in 1L of aqueous solution containing 75mg betaine-TMG, and after ultrasonication for 30min, it was reacted in a water bath shaker at 15°C for 2h. The solid was separated and dried to constant weight at 40°C to obtain the final product - a thermosensitive sustained-release carrier with activity regulation function.

[0047] Two identical MBBR reactors (inner diameter 10 cm, effective height 20 cm, effective volume 1.6 L) were used to investigate the effect of the thermosensitive slow-release carrier on the system (wherein, the reactor R1 was added with a polyurethane carrier (PU) without the thermosensitive polymer and low-temperature protective agent of the present invention, and the reactor R2 was added with the thermosensitive slow-release carrier prepared in Example 3 of the present invention). The sludge in the MBBR reactor was taken from the activated sludge in the aerobic tank of a wastewater treatment station of a certain university, and the relevant parameters are shown in Table 1. The experimental water was artificially prepared simulated wastewater, and glucose, ammonium chloride and potassium dihydrogen phosphate were added to the water according to the nutrient ratio of COD: N: P = 100: 5: 1.

[0048] Table 1

[0049]

[0050] like Figure 1 The device used is composed of a water storage tank 1 and an MBBR reactor 6 connected in series. The water storage tank 1 is connected to the MBBR reactor 6 through a water inlet pipe and a peristaltic pump 2; the MBBR reactor 6 is provided with an interlayer water outlet 3, a wastewater outlet 8, an interlayer water inlet 9 and a wastewater inlet 7 from top to bottom; a carrier 4 (filling ratio is 25%) and an interlayer 5 are provided inside, and aeration is performed by an aeration device 10.

[0051] During operation, aerobic activated sludge is added into the reactor, and a rapid biofilm formation method is used to form biofilm on the surface of the carrier. Experimental water enters the MBBR reactor 6 from the water tank 1 through the peristaltic pump 2 from the water inlet 7, and then the aeration device 10 starts aeration to make the dissolved oxygen inside the reactor between 5 and 6 mg / L; during biofilm formation and stable operation, the reaction temperature is controlled by the water inlet of the interlayer 5; the supernatant is discharged from the water outlet 8.

[0052] The reactor was operated for a total of 42 days (d represents days), including three stages (see Table 2 for relevant operating parameters). Stage 1 (1-12 days) is the biofilm stage, and biofilm formation is successful when the system TN and COD maintain a certain removal rate; Stage 2 (13-24 days) is the stabilization stage; Stage 3 (25-42 days) is the cooling stage, and the operating temperature is reduced to 15°C without changing other conditions to explore the effect of temperature-sensitive slow-release carriers on the system denitrification performance at low temperatures.

[0053] Table 2 Changes in reactor operating parameters

[0054]

[0055] At each stage, samples were taken to measure the effluent COD (chemical oxygen demand), NH 4 + -N (ammonia nitrogen), NO 2 - -N (nitrite nitrogen), NO 3 - -N (nitrate nitrogen) concentration, calculate TN (total nitrogen, NH 4 + -N, NO 2 - -N and NO 3 - The total removal rate of -N) was determined, and the dehydrogenase activity (DHA) and specific oxygen consumption rate (SOUR) were used to reflect the microbial activity on the biofilm.

[0056] Figure 2 The data of COD inlet and outlet water concentration (☆ is the inlet COD concentration, ◇ is the outlet COD concentration of R1, △ is the outlet COD concentration of R2) and COD degradation efficiency (● is the COD removal rate of R1, ◆ is the COD removal rate of R2) of the unmodified carrier bioreactor R1 and the modified carrier (carrier in Example 3) bioreactor R2 under the same inlet and operating conditions are shown. Figure 2It can be seen that the COD removal efficiency in the two groups of reactors is not much different in the startup stage (1-12 days) and the stable stage (13-24 days), indicating that the selected thermosensitive polymer grafted on the polyurethane surface has little effect on the hydrophilicity, bioaffinity and matrix transmission efficiency of polyurethane as a biological carrier. In the cooling stage (25-42 days), the COD removal rate of the simple polyurethane carrier system R1 is significantly lower than that of the R2 system in which the thermosensitive polymer is embedded with the betaine low-temperature cell permeabilizer. This is because at this temperature (15°C), the pNIPAM-BA on the PU surface stretches and releases the betaine aggregated at 40°C. The betaine diffuses to the surface of the microbial cells, regulates the fluidity and permeability of the cell membrane, and maintains the normal cell metabolic activity, thereby ensuring the continuous and stable metabolism of the microorganisms at this temperature and maintaining the stability of the biological system. However, this mechanism is lacking in R1. When the temperature drops, the metabolic activity of the microorganisms in the biological system is severely inhibited, and the COD removal efficiency decreases.

[0057] Figure 3 The data of ammonia nitrogen inlet and outlet water concentrations (☆ is the inlet ammonia nitrogen concentration, ◇ is the R1 effluent ammonia nitrogen concentration, △ is the R2 effluent ammonia nitrogen concentration) and ammonia nitrogen removal efficiency (● is the ammonia nitrogen removal rate of R1, ◆ is the ammonia nitrogen removal rate of R2) of the unmodified carrier bioreactor R1 and the modified group carrier (carrier in Example 3) bioreactor R2 under the same inlet and operating conditions are shown.

[0058] from Figure 3 It can be seen that at the reactor temperature T 1 =30℃, through rapid biofilm formation and stable operation, the unmodified (pure polyurethane) group R1 and modified group R2 carrier (Example 3) biological system has a high removal rate of ammonia nitrogen, and the microbial activity is not affected by the modification, which is basically equivalent to the unmodified group; however, when the temperature drops below 15℃, the average ammonia nitrogen of R2 is 87.41%, which is significantly higher than R1 (71.42%). It shows that the temperature response release of betaine has a significant effect on alleviating the low temperature shock of the biological system.

[0059] Figure 4 The data of TN inlet and outlet water concentrations (☆ is the inlet TN concentration, ◇ is the R1 effluent TN concentration, △ is the R2 effluent TN concentration) and ammonia nitrogen removal efficiency (● is the TN removal rate of R1, ◆ is the TN removal rate of R2) of the unmodified carrier bioreactor R1 and the modified group carrier (carrier in Example 3) bioreactor R2 under the same inlet and operating conditions are shown.

[0060] from Figure 4 It can be seen that at the reactor temperature T 1=30℃, through rapid biofilm formation and stable operation, both the unmodified group R1 and the modified group R2 carrier biological system have a high removal rate of total nitrogen (TN); however, when the temperature drops below 15℃, the average TN removal rate of R2 reaches 86.30%, which is significantly higher than R1 (71.00%). This shows that the modified polyurethane carrier can maintain good stability when facing low temperature shock, and the thermosensitive polymer-embedded betaine is effectively released under low temperature conditions, helping microorganisms resist low temperature shock.

[0061] Figure 5 The dehydrogenase activity (DHA) and specific oxygen consumption rate (SOUR) data of the biofilm on the carrier in the unmodified carrier bioreactor R1 and the carrier bioreactor R2 in Example 3 which were operated for 41 days are shown, wherein ◇ is the DHA of the biofilm on the R1 carrier, △ is the DHA of the biofilm on the R2 carrier, ● is the SOUR of the biofilm on the R1 carrier, and ◆ is the SOUR of the biofilm on the R2 carrier.

[0062] from Figure 5 It can be seen that at the reactor temperature T 1 =30℃, through rapid biofilm formation and stable operation, the microbial activity in the unmodified group R1 and the modified group R2 carrier biological system was not affected by the modification and was basically equivalent to the unmodified group; however, when the temperature dropped below 15℃, the microbial activity of R2 (average value in the cooling stage) was about 2.2 times that of R1. This once again verified the effectiveness of the invention of thermosensitive polymer embedded cryoprotectant.

[0063] The experimental results according to the present invention show that when the external environment temperature drops sharply, adding a thermosensitive slow-release carrier is more conducive to maintaining the activity of the bacteria and is helpful for the treatment of sewage and wastewater at low temperatures.

[0064] The present invention utilizes a LCST (lower critical solution temperature) type thermosensitive polymer (poly N-isopropylacrylamide-co-butyl acrylate), which is grafted in situ on a polyurethane porous biological carrier, and combined with a bacterial cryoprotectant solution to prepare a thermosensitive slow-release carrier with activity regulation function. After the bacteria are enriched and biofilmed on the functional carrier, when the ambient temperature is lower than its lowest critical solution temperature, the thermosensitive monomer stretches and releases the internal bacterial cryoprotectant, significantly improving the resistance of the surface microorganisms to low temperature shock. This method is expected to solve the problem of reduced wastewater biological treatment efficiency in cold areas or during seasonal temperature changes, and promote the wider application of MBBR technology in my country.

[0065] The preparation method of the thermosensitive sustained-release carrier with activity regulation function provided by the present invention is to combine thermosensitive polymer materials with biological activity regulators, and form a carrier structure with temperature perception and response capabilities through a specific preparation process. The carrier can autonomously release the encapsulated biologically active substances at low temperatures, protect microorganisms from low temperature shock, and solve the problem that the existing sewage and wastewater biological treatment process is difficult to maintain high biological activity under low temperature conditions, which affects the sewage treatment effect.

Claims

1. A method for preparing a thermosensitive sustained-release biological carrier with activity regulation function, characterized in that: The steps include: Step 1, preparing a polyurethane porous carrier with poly(N-isopropylacrylamide-co-butyl acrylate) loaded on the surface; The specific process of step 1 is as follows: Step 1.1, disperse the polyurethane porous cubes in ethanol containing ammonia water, the dosage of the polyurethane porous cubes is 30-50% of the volume of the ethanol, and the concentration of ammonia water is 2 mol / L-4 mol / L; Step 1.2, adding N-isopropylacrylamide, butyl acrylate, and coupling agent 3-aminopropyltriethoxysilane to the product obtained in step 1.1, and dispersing by mechanical stirring, wherein the amount of N-isopropylacrylamide is 50-150 mg; the amount of butyl acrylate is 0.02-0.10 mL; and the amount of coupling agent 3-aminopropyltriethoxysilane is 100-200 mg; Step 1.3, adding an initiator azobisisobutyronitrile to the product obtained in step 1.2, controlling the temperature at 10-20° C. and continuously stirring, and passing nitrogen to remove oxygen during the entire reaction process; washing the product with deionized water, and vacuum drying to constant weight to obtain a polyurethane porous carrier with poly(N-isopropylacrylamide-co-butyl acrylate) loaded on the surface; In the step 1.3, the drying temperature during vacuum drying is 30-60°C; Step 2, dispersing the polyurethane porous carrier loaded with poly (N-isopropylacrylamide-co-butyl acrylate) obtained in step 1 in an aqueous solution containing a cryoprotectant, reacting in a water bath shaker after ultrasonication, separating the solid, and drying to constant weight to obtain a thermosensitive sustained-release bio-carrier with activity regulation function; In step 2, the ultrasonic time is 20 to 40 min; In step 2, the reaction is carried out in a water bath shaker for 1 to 3 hours, and the water bath temperature is maintained at 10 to 20° C.; In step 2, the drying temperature is 30-60°C.

2. The method for preparing a thermosensitive sustained-release biological carrier with activity regulation function according to claim 1, characterized in that: In the step 1.1, the size of the polyurethane porous cube is: 0.5 cm×0.5 cm×0.5 cm~1 cm×1 cm×1 cm.

3. The method for preparing a thermosensitive sustained-release biological carrier with activity regulation function according to claim 1, characterized in that: In step 2, the cryoprotectant is at least one of betaine, trehalose, ethylene glycol, and proline, and the concentration of the cryoprotectant is 50 mg / L to 100 mg / L.

4. A thermosensitive sustained-release biological carrier with activity regulation function, characterized in that: The method for preparing the thermosensitive sustained-release biological carrier with activity regulating function described in any one of claims 1 to 3 is adopted.

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