Slow-release fungicide and preparation method thereof

Abstract

The invention relates to the technical field of environmental biology, in particular to a slow-release fungicide and a preparation method thereof. The slow-release microbial inoculum comprises 60%-90% of polycaprolactone, 10%-20% of a carbon source and 10%-30% of compound bacteria; the compound bacteria are prepared from the following five functional strains in parts by weight: sphingomyza sp. CY-10 (sphingomyza sp. CY-10), Shinella sp. CY-9 (Shinella sp. CY-9), Ochrobactrum sp. TAC-2 (Ochrobactrum sp. TAC-2), Halomonas denitrificans (Halomonas denitrificans) and Acinetobacter (Acinetobacter), and the compound bacteria are prepared from the following five functional strains in parts by weight: Sphingomyza sp. CY-10), Shinella sp. CY-9 (Sphingomyza sp. CY-10), Shinella sp. CY-9 (Sphingomyza sp. CY-9), Ochrobactrum sp. The slow-release bacterial agent provided by the invention is long in release period and stable in release amount, all substances in the slow-release carbon source can be utilized by microorganisms, secondary pollution to the natural environment cannot be caused, and the slow-release bacterial agent can be suitable for sewage treatment and river and lake remediation to promote removal of pollutants such as ammonia nitrogen, chemical oxygen demand, total nitrogen and the like.

Description

Technical Field

[0001] The present invention relates to the field of environmental biotechnology, and in particular to a slow-release bacterial agent and a preparation method thereof. Background Art

[0002] Since the 20th century, industry and agriculture have developed rapidly, and people's living standards have gradually improved. This has led to the generation of large amounts of industrial wastewater, livestock and poultry wastewater, and domestic sewage. If this wastewater is not effectively treated, it will have serious negative impacts on the natural environment, such as black and odorous water bodies, red tide outbreaks, groundwater pollution, and soil fertility loss. With the rise of environmental awareness, ecological and environmental protection and water environment management technologies have also developed. Among them, biological wastewater treatment has the advantages of no secondary pollution and low cost compared to physical and chemical methods, and has become a research hotspot for wastewater treatment.

[0003] Biological methods are widely used in urban sewage treatment, river and lake restoration, industrial wastewater treatment, and livestock and poultry wastewater treatment. Large cities generally have separate rainwater and sewage systems, resulting in relatively stable operation. Smaller cities, however, lack such systems and experience significant fluctuations in water quality and quantity. Industrial and livestock wastewater are also affected by seasonal factors and production, resulting in significant variations in both quality and quantity. Numerous natural environmental influences on rivers and lakes, such as ultraviolet rays, heavy rain, and drought, can cause microbial loss or death.

[0004] Any fluctuations in water quality or quantity, or changes in the natural environment, can cause the loss or death of functional microorganisms. Continuously replenishing these microorganisms can ensure wastewater treatment effectiveness and quickly restore the water's self-purification capacity. Therefore, the development of slow-release microbial agents can continuously replenish functional microorganisms, increasing their numbers in wastewater treatment processes or in rivers and lakes, and maintaining pollutant removal effectiveness. Summary of the Invention

[0005] The present invention aims to provide a slow-release microbial agent and its preparation method, which are used to maintain the abundance of functional microorganisms and improve the shock resistance and treatment efficiency of sewage treatment processes. The slow-release microbial agent of the present invention can release bacteria over a long period of time, exceeding 120 days, and can remove ammonia nitrogen, total nitrogen, and organic matter from water.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a sustained-release bacterial agent, which comprises the following components in parts by weight:

[0008] 60% to 90% polycaprolactone, 10% to 20% carbon source, 10% to 30% composite bacteria;

[0009] The composite bacteria includes five functional strains in the following weight proportions:

[0010] 10% to 30% of Sphingopyxis sp.CY-10, 5% to 10% of Shinella sp.CY-9, 10% to 30% of Ochrobacterum sp.TAC-2, 5% to 20% of Halomonas denitrificans, and 10% to 30% of Acinetobacter.

[0011] Furthermore, the carbon source includes at least one of the following: glucose, sodium acetate, sodium succinate, and sodium citrate.

[0012] Furthermore, the Sphingopyxis sp. CY-10 is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2021682;

[0013] The Shinella sp. CY-9 is deposited in China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2021681.

[0014] The Ochrobacterum sp. TAC-2 is deposited in China Center for Type Culture Collection with the deposit number CCTCC NO: M 2018028.

[0015] The denitrifying Halomonas (Halomonas denitrificans) is a deposited bacterium of the China Industrial Microorganism Culture Collection Center, with the number CICC 10554;

[0016] The Acinetobacter is a preserved bacterium of the China Industrial Microorganism Culture Collection Center, with the number being CICC 10695.

[0017] Furthermore, the composite bacteria also includes a composite bacteria protective agent, and the mass ratio of the total mass of the five functional strains to the composite bacteria protective agent is 6-8:2-4.

[0018] Furthermore, the composite bacteria protective agent includes trehalose, skim milk powder, corn flour and glycerin in a mass ratio of 1:6:7:1.

[0019] The present invention provides a method for preparing a sustained-release bacterial agent, comprising the following steps:

[0020] Step 1. Preparation of composite bacteria

[0021] 1.1 Prepare the culture medium using (NH4)2SO4, Na3C6H5O7, and Weiss salt solution;

[0022] Then the culture medium is divided into Erlenmeyer flasks, sterilized and cooled;

[0023] 1.2 The strains including Sphingopyxis sp.CY-10, Shinella sp.CY-9, Ochrobacterum sp.TAC-2, Halomonas denitrificans, and Acinetobacter were inoculated into triangular flasks and cultured in a shaker at 25-35°C and 150-200 rpm until the OD of the strains reached 0. 600 ≥1.0;

[0024] 1.3 Take out the flask and centrifuge the strains at 4000 rpm for 5-10 minutes. Discard the supernatant to obtain the bacterial slurry of the five functional strains.

[0025] 1.4 Mix the five types of bacterial mud in a mass ratio of 10% to 30%: 5% to 10%: 10% to 30%: 5% to 20%: 10% to 30%;

[0026] 1.5 Preparation of composite bacterial protective agent: Weigh trehalose, skim milk powder, corn starch, and glycerol according to the mass ratio of 1:6:7:1;

[0027] 1.6 The mixed bacterial sludge and the composite bacterial protective agent are evenly mixed in a mass ratio of 6-8:2-4, and prepared into composite bacteria by freeze-drying;

[0028] Step 2: Prepare sustained-release bacterial agent

[0029] 2.1 Weigh polycaprolactone, carbon source and composite bacteria in a mass ratio of 60% to 90%: 10% to 20%: 10% to 30% respectively;

[0030] 2.2 Add polycaprolactone to container 1 and heat to 80-90°C in a water bath until PCL is completely dissolved;

[0031] 2.3 Add the carbon source to container 2, add appropriate amount of water, heat to 80-90℃, dissolve the carbon source completely, stir into a paste, then pour into container 1 and stir evenly. Then cool container 1 to 65-75℃;

[0032] 2.4 Preheat the composite bacteria powder to 40-50°C, immediately add it to container 1, stir evenly, pour it into a mold, and cool it to room temperature to obtain a sustained-release bacterial agent.

[0033] Furthermore, the concentrations of the components of the culture medium are as follows:

[0034] (NH4)2SO4: 1.0 g / L; Na3C6H5O7: 10.64 g / L; Vickers salt solution: 50 mL / L.

[0035] Furthermore, the concentrations of the components of the Vickers salt solution are as follows: K2HPO4: 5.0 g / L, MgSO4·7H2O: 2.5 g / L, NaCl 2.5 g / L, FeSO4·7H2O: 0.05 g / L, MnSO4·4H2O: 0.05 g / L; the pH of the Vickers salt solution is 7.0.

[0036] The present invention provides application of the slow-release bacterial agent in sewage treatment.

[0037] The present invention provides any of the following applications of the sustained-release bacterial agent:

[0038] Remove ammonia nitrogen content in water;

[0039] Remove total nitrogen content from water;

[0040] Remove organic matter from water;

[0041] Maintain the abundance of functional microorganisms in water.

[0042] The present invention has at least the following beneficial effects:

[0043] The slow-release bacterial agent provided by the present invention has a long release cycle and a stable release amount, and the shape and size of the slow-release carbon source are determined by the mold and can be customized according to needs; all substances in the slow-release carbon source can be utilized by microorganisms and will not cause secondary pollution to the natural environment; the present invention can be effectively applied to sewage treatment and river and lake restoration, promote the removal of pollutants such as ammonia nitrogen, chemical oxygen demand, and total nitrogen, increase the number of functional microorganisms in sewage treatment processes or rivers and lakes, and maintain the pollutant removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 The quality change of the slow-release bacteria agent and the COD and OD of the effluent from the reaction system over 120 days 600 ;

[0046] Figure 2 The changes in ammonia nitrogen and total nitrogen concentrations in the effluent of the slow-release bacterial agent reaction system over 120 days;

[0047] Figure 3The change of ammonia nitrogen concentration in the effluent of the single strain slow-release bacterial agent reaction system;

[0048] Figure 4 The total nitrogen concentration change of the effluent from the reaction system of a single strain slow-release microbial agent;

[0049] Figure 5 This is a physical picture of the sustained-release bacterial agent of the present invention;

[0050] Figure 6 Schematic diagram of the rupture during the release of the sustained-release bacterial agent. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0052] Example 1: This example is used to disclose the main components of the slow-release microbial agent of the present invention.

[0053] The sustained-release bacterial agent of the present invention comprises the following components in parts by weight:

[0054] 60% to 90% polycaprolactone (PCL), 10% to 20% carbon source, and 10% to 30% composite bacteria.

[0055] The carbon source can be a single component of glucose, sodium acetate, sodium succinate, sodium citrate or the like, or a mixture of several of them.

[0056] The composite bacteria include 5 functional strains, and the weight proportions of the 5 functional strains are as follows:

[0057] 10% to 30% of Sphingopyxis sp.CY-10, 5% to 10% of Shinella sp.CY-9, 10% to 30% of Ochrobacterum sp.TAC-2, 5% to 20% of Halomonas denitrificans, and 10% to 30% of Acinetobacter.

[0058] In the above, the Sphingopyxis sp. CY-10 is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2021682 (see patent CN113388553B).

[0059] In the above, the Shinella sp. CY-9 is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2021681. (See patent CN113388553B)

[0060] In the above, the Ochrobacterum sp. TAC-2 is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2018028. (See patent CN109337832B)

[0061] In the above, the denitrifying Halomonas (Halomonas denitrificans) was purchased from the China Industrial Microbiological Culture Collection Center with the number CICC 10554.

[0062] In the above, the Acinetobacter was purchased from the China Industrial Microbiological Culture Collection Center with the license number CICC 10695.

[0063] In one embodiment, the composite bacteria further includes a composite bacteria protective agent, and the mass ratio of the five functional strains to the composite bacteria protective agent is 6-8:2-4.

[0064] The composite bacteria protective agent comprises trehalose, skim milk powder, corn flour and glycerin in a mass ratio of 1:6:7:1.

[0065] Please see for details Figure 5 The sustained-release bacterial agent prepared by the present invention is in the form of a solid, off-white block. In a specific embodiment, each block of the sustained-release bacterial agent is about 20 grams. Figure 6 As shown in FIG, the sustained-release microbial agent in Example 1 breaks after about 45 days of continuous release, further increasing the contact area of ​​the sustained-release microbial agent. Figure 5 and Figure 6 By comparison, we can see that Figure 5 The surface of the newly prepared sustained-release bacterial agent is smooth. Figure 6 Under the dual effects of water scouring and microbial erosion, the surface of the slow-release bacterial agent becomes uneven, which increases the contact area of ​​the slow-release bacterial agent.

[0066] Example 2: This example provides a method for preparing the sustained-release bacterial agent of Example 1.

[0067] Specific methods include:

[0068] Step 1: Preparation of compound bacteria

[0069] 1.1 Prepare the culture medium: The culture medium consists of 1.0 g / L (NH4)2SO4, 10.64 g / L Na3C6H5O7, and 50 mL / L Weiss salt solution.

[0070] The concentrations of the components of the Vickers salt solution are as follows: K2HPO4 5.0 g / L, MgSO4·7H2O 2.5 g / L, NaCl 2.5 g / L, FeSO4·7H2O 0.05 g / L, MnSO4·4H2O 0.05 g / L, pH=7.0.

[0071] The culture medium is then divided into Erlenmeyer flasks for sterilization and cooling.

[0072] 1.2 The five functional strains of the composite bacteria (Sphingopyxis sp.CY-10, Shinella sp.CY-9, Ochrobacterum sp.TAC-2, Halomonas denitrificans, Acinetobacter) were inoculated into triangular flasks and cultured in a shaker at 25-35°C and 150-200 rpm until the OD of the strains reached 0. 600 ≥1.0.

[0073] 1.3 Take out the Erlenmeyer flask and centrifuge the strains at 4000 rpm for 5-10 minutes. Discard the supernatant to obtain bacterial sludge of the five functional strains.

[0074] 1.4 The five types of bacterial mud were mixed according to the mass ratio in Example 1 (10% to 30%: 5% to 10%: 10% to 30%: 5% to 20%: 10% to 30%).

[0075] 1.5 Preparation of composite bacterial protective agent: Weigh trehalose, skim milk powder, corn starch and glycerol according to the mass ratio of 1:6:7:1 respectively.

[0076] 1.6 The mixed bacterial mud and the composite bacterial protective agent are evenly mixed in a mass ratio of 6-8:2-4, and prepared into composite bacteria by freeze-drying.

[0077] Step 2: Prepare sustained-release bacterial agent

[0078] 2.1 Weigh polycaprolactone (PCL), carbon source and composite bacteria according to the mass ratio of 60% to 90%: 10% to 20%: 10% to 30%.

[0079] 2.2 Add PCL to container 1 and heat in a water bath to 80-90°C until PCL is completely dissolved;

[0080] 2.3 Add the carbon source to container 2, add appropriate amount of water, heat to 80-90℃, dissolve the carbon source completely, stir into a paste, then pour into container 1 and stir evenly. Then cool container 1 to 65-75℃.

[0081] 2.4 Preheat the composite bacteria powder to 40-50°C, immediately add it to container 1, stir evenly, pour it into a mold, and cool it to room temperature. This will give a sustained-release bacterial agent.

[0082] Example 3: This example provides a specific example of the preparation of a sustained-release bacterial agent.

[0083] Step 1: Preparation of sustained-release bacterial agent

[0084] Prepare 5L culture medium and evenly divide it into 5 triangular flasks, sterilize and cool. Inoculate 10 ml of Sphingopyxis sp.CY-10, Shinella sp.CY-9, Ochrobacterum sp.TAC-2, Halomonas denitrificans and Acinetobacter into the triangular flasks respectively. Place the inoculated triangular flasks in a shaking incubator and set the culture conditions to 30℃ and 170rpm. Take samples every 12 hours to test the concentration of the bacterial solution in the triangular flasks. Under normal circumstances, the OD value of the bacterial solution will be 0.05 after 24 hours. 600 When it reaches above 1.0, the cultivation is complete.

[0085] The cultured bacterial liquids were placed in a centrifuge respectively and centrifuged at 4000 rpm for 5 minutes. Then, the centrifuged bacterial liquid mud was evenly mixed according to the mass ratio of Sphingopyxis sp.CY-10, Shinella sp.CY-9, Ochrobacterum sp.TAC-2, Halomonas denitrificans, and Acinetobacter in a ratio of 25%:10%:20%:20%:25% to obtain a mixed bacterial mud.

[0086] Weigh 100 g of trehalose, 600 g of skim milk powder, 700 g of corn flour, and 100 g of glycerol respectively, mix them evenly to prepare a bacterial agent protective agent.

[0087] Weigh 700 g of mixed bacterial mud and 300 g of bacterial agent protective agent, mix them evenly, put them in a 4°C refrigerator for precooling, and then freeze-dry them to prepare a composite bacteria.

[0088] Weigh 700 g of polycaprolactone (PCL), add it into container 1, and heat it to 80-90° C. in a water bath to completely melt the PCL.

[0089] Weigh 100g of anhydrous sodium acetate and add it to container 2. Dissolve the anhydrous sodium acetate in 100g of water and heat container 2 to 80-90°C. Then pour the carbon source in container 2 into container 1, stir evenly, and maintain the temperature for 30 minutes. Then cool to 65-75°C.

[0090] Weigh 200g of the composite bacteria and preheat it to 40-50°C in an oven. Immediately add it to container 1 and stir evenly. Immediately pour it into a 2.5cm x 2.5cm x 2.5cm container and cool it to obtain a square sustained-release bacterial preparation with a length, width, and height of 2.5cm.

[0091] Example 4: This example provides data verification of the sustained-release bacterial agent release cycle of Example 3 above.

[0092] Place 5 pieces of the slow-release bacteria agent prepared in Example 1 in a 2L container. Set an aeration plate at the bottom of the beaker, and set the aeration volume to 1-2L / min so that the gas can directly impact the slow-release bacteria agent. Then set continuous water inlet and outlet (the basic water inlet of the test device is taken from an artificial water body in Chongqing, and the water quality is adjusted to have ammonia nitrogen concentration of 2.5mg / L and total nitrogen concentration of 5mg / L), with a water inlet volume of 2L / d. Detect the pollutant concentration and bacterial solution OD in the test device every 3 days. 600 , weigh the mass of the sustained-release bacterial agent every 15 days.

[0093] like Figure 1 As shown in the figure, with the continuous release of the slow-release bacteria, the effluent COD showed a downward trend. The average effluent COD for 120 days was about 18.7 mg / L. 600 It also maintains around 0.018, which is 9 times higher than the incoming water.

[0094] like Figure 2 As shown in the figure, the concentration of ammonia nitrogen and total nitrogen in the water was significantly removed. From the 6th day on, the concentration of ammonia nitrogen in the effluent was always maintained at the requirement of surface water class II (<0.5mg / L), and the concentration of total nitrogen was always maintained at the requirement of surface water class III (<1.0mg / L).

[0095] Example 5: This example provides a verification of the advantages of the composite bacteria of the sustained-release bacterial agent of the present invention over a single strain.

[0096] According to the preparation method of the sustained-release agent of Example 3, the composite bacteria were replaced with a single strain to produce the sustained-release agents of Sphingobacterium, Shen's bacteria, Ochrobacter, Denitrifying Salt Mononas, and Acinetobacter. The experiment was carried out under the experimental conditions of Example 4. Figure 3 、 Figure 4 As shown, after 21 days of continuous operation, the single-species system with the Acinetobacter slow-release agent showed the best ammonia nitrogen and total nitrogen removal efficiency compared to the slow-release agent of the present invention, with an ammonia nitrogen removal rate of 87.6% and a total nitrogen removal rate of 81.6%. Over the same period, the slow-release agent of the present invention achieved an ammonia nitrogen removal rate of 94.4% and a total nitrogen removal rate of 93.1%, significantly higher than the slow-release agent made from a single bacterial species.

[0097] Experiments have shown that the composite bacterial system of the present invention is more effective than the sustained-release bacterial agent prepared from a single bacterial strain.

[0098] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A sustained-release bacterial agent, characterized in that: The sustained-release bacterial agent comprises the following components in parts by weight: 60% to 90% polycaprolactone, 10% to 20% carbon source, 10% to 30% composite bacteria; The composite bacteria includes five functional strains in the following weight proportions: 10% to 30% of Sphingopyxis sp.CY-10, 5% to 10% of Shinella sp.CY-9, 10% to 30% of Ochrobacterum sp.TAC-2, 5% to 20% of Halomonas denitrificans, and 10% to 30% of Acinetobacter.

2. A sustained-release bacterial agent according to claim 1, characterized in that The carbon source includes at least one of the following: glucose, sodium acetate, sodium succinate, and sodium citrate.

3. A sustained-release bacterial agent according to claim 1, characterized in that: The Sphingopyxis sp. CY-10 is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2021682. The Shinella sp. CY-9 is deposited in China Center for Type Culture Collection with a deposit number of CCTCCNO: M 2021681. The Ochrobacterum sp. TAC-2 is deposited in China Center for Type Culture Collection with the deposit number CCTCC NO: M 2018028. The denitrifying Halomonas (Halomonas denitrificans) is a deposited bacterium of the China Industrial Microorganism Culture Collection Center, with the number CICC 10554; The Acinetobacter is a preserved bacterium of the China Industrial Microorganism Culture Collection Center, with the number being CICC 10695.

4. A sustained-release bacterial agent according to claim 1, characterized in that The composite bacteria also includes a composite bacteria protective agent, and the mass ratio of the total mass of the five functional strains to the composite bacteria protective agent is 6-8:2-4.

5. A sustained-release bacterial agent according to claim 4, characterized in that: The composite bacteria protective agent comprises trehalose, skim milk powder, corn flour and glycerin in a mass ratio of 1:6:7:

1.

6. A method for preparing a sustained-release bacterial agent, characterized in that: The following steps are involved: Step 1. Preparation of composite bacteria 1.1 Prepare the culture medium using (NH4)2SO4, Na3C6H5O7, and Weiss salt solution; Then the culture medium is divided into Erlenmeyer flasks, sterilized and cooled; 1.2 The strains including Sphingopyxis sp.CY-10, Shinella sp.CY-9, Ochrobacterum sp.TAC-2, Halomonas denitrificans and Acinetobacter were inoculated into triangular flasks respectively and cultured in a shaker at 25-35°C and 150-200 rpm until the OD of the strains reached 0. 600 ≥1.0; 1.3 Take out the Erlenmeyer flask and centrifuge the strains at 4000 rpm for 5% to 10 minutes. Discard the supernatant to obtain the bacterial slurry of the five functional strains. 1.4 Mix the five types of bacterial mud in a mass ratio of 10% to 30%: 5% to 10%: 10% to 30%: 5% to 20%: 10% to 30%; 1.5 Preparation of composite bacterial protective agent: Weigh trehalose, skim milk powder, corn starch, and glycerol according to the mass ratio of 1:6:7:1; 1.6 The mixed bacterial sludge and the composite bacterial protective agent are evenly mixed in a mass ratio of 6-8:2-4, and prepared into composite bacteria by freeze-drying; Step 2: Prepare sustained-release bacterial agent 2.1 Weigh polycaprolactone, carbon source and composite bacteria in a mass ratio of 60% to 90%: 10% to 20%: 10% to 30% respectively; 2.2 Add polycaprolactone to container 1 and heat to 80-90°C in a water bath until PCL is completely dissolved; 2.3 Add the carbon source to container 2, add appropriate amount of water, heat to 80-90°C, dissolve the carbon source completely, stir into a paste, then pour into container 1, stir evenly, and then cool container 1 to 65-75°C; 2.4 Preheat the composite bacteria powder to 40-50°C, immediately add it to container 1, stir evenly, pour it into a mold, and cool it to room temperature to obtain a sustained-release bacterial agent.

7. The method for preparing a sustained-release bacterial agent according to claim 6, characterized in that: The concentrations of the components of the culture medium are as follows: (NH4)2SO4: 1.0 g / L; Na3C6H5O7: 10.64 g / L; Vickers salt solution: 50 mL / L.

8. The method for preparing a sustained-release bacterial agent according to claim 7, characterized in that: The concentrations of the components of the Vickers salt solution are as follows: K2HPO4: 5.0 g / L, MgSO4·7H2O: 2.5 g / L, NaCl 2.5 g / L, FeSO4·7H2O: 0.05 g / L, MnSO4·4H2O: 0.05 g / L; the pH of the Vickers salt solution is 7.

0.

9. Use of the slow-release bacterial agent according to claim 1 in sewage treatment.

10. Any of the following uses of the sustained-release bacterial agent according to claim 1: Remove ammonia nitrogen content in water; Remove total nitrogen content from water; Remove organic matter from water; Maintain the abundance of functional microorganisms in water.

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