An anaerobic microorganism growth promoter and its application

Abstract

The present invention discloses an anaerobic microorganism growth promoter, which comprises, by weight, 10 - 20 parts of a carrier, 1 - 5 parts of sludge particle crystal nuclei, 30 - 80 parts of a bioflocculant, 50 - 100 parts of a thickener, and (1 - 10) × 10<supgt; - 3< / supgt; parts of trace elements; the anaerobic microorganism growth promoter provided by the present invention has the following beneficial effects: 1) promoting floc aggregation and accelerating sludge granulation; 2) improving the sludge sedimentation performance, reducing the turbidity of the effluent from the anaerobic reactor, and doubling the volume load of the anaerobic reactor; 3) promoting the growth and reproduction of methanogens in the anaerobic reactor and improving the activity of methanogens.

Description

Technical Field

[0001] The present invention relates to a compound anaerobic microorganism growth promoter, and particularly to a compound growth promoter capable of promoting the proliferation and aggregation of hydrolytic acidifying bacteria and methanogenic bacteria into granules in an anaerobic reactor and its application, belonging to the technical field of environmental protection. Background Art

[0002] The upflow anaerobic sludge bed (UASB) reactor promotes sludge retention through the aggregation of anaerobic microorganisms. The granular sludge formed by the aggregation of microorganisms results in high biomass and volumetric conversion rate of the UASB reactor. In particular, the presence of methanogenic bacteria promotes the chemical oxygen demand (COD) removal and methane production capacity of the UASB reactor. In addition, compared with flocs, granular sludge has higher sedimentation and strength, enabling the reactor to withstand high flow rates and produce less debris. Therefore, the cultivation of sludge granules determines the startup and further operation of the UASB reactor.

[0003] Microorganisms form aggregates by combining with inert compounds, inorganic substances or other substances through reversible adsorption and irreversible adhesion, thereby inducing sludge granulation. These initial aggregates will gradually grow and form dense granules under conditions suitable for the survival of microorganisms. Many physical, chemical and biological factors affect the process of forming dense granules, such as the composition and concentration of organic substrates, the supply of nutrients, inoculated sludge, pH value, temperature, and the induction of flocculating components, etc. During the sewage treatment process, the composition and concentration of organic substrates, temperature and other conditions need to be determined according to the actual situation on site.

[0004] Existing growth promoters usually use mineral components such as vermiculite powder and clay as carriers for sludge adsorption and granulation. The adsorption capacity of these inorganic carriers is limited, and they can only make microorganisms accumulate into granules through complexation, flocculation and other effects. They cannot increase the activity of anaerobic microorganisms and can only act on a specific type of wastewater. Summary of the Invention

[0005] Aiming at the deficiencies of existing anaerobic microorganism growth promoters, the present invention provides a compound anaerobic microorganism growth promoter, which has the characteristics of simple dosing and wide applicability to wastewater types, and can solve the problems of fluctuating influent load and unstable operation in the anaerobic system.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] An anaerobic microorganism growth promoter, by weight, comprises 10 - 20 parts of a carrier, 1 - 5 parts of sludge particle crystal nuclei, 30 - 80 parts of a biological flocculant, 50 - 100 parts of a thickener, and (1 - 10)×10 -3 parts;

[0008] The carrier is selected from one or a combination of vermiculite, clay, diatomaceous earth, bentonite, zeolite powder, medical stone powder, montmorillonite powder;

[0009] The sludge particle crystal nucleus is selected from one or a combination of iron powder, carbon powder, and tourmaline powder;

[0010] The biological flocculant is a microbial agent containing Pseudochrobactrum asaccharolyticum, wherein the viable count of Pseudochrobactrum asaccharolyticum is 10-50 billion CFU / g. Pseudochrobactrum asaccharolyticum is preserved in the China General Microbiological Culture Collection Center, with the address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing. The preservation number is: CGMCC No. 28059, and the preservation date is: July 28, 2023. Its 16S rDNA sequence is as shown in SEQ ID No: 1;

[0011] The trace elements include Fe 2+ , Co 2+ and Mn 2+ .

[0012] Preferably, the thickener is selected from one or a combination of starch and chitosan.

[0013] Preferably, the trace elements further include one or a combination of Cu 2+ , BO3 – , Zn 2+ , NH4 + , Na + and Ni 2+ .

[0014] The present invention also claims a method for promoting the regeneration of anaerobic granular sludge using the above anaerobic microorganism promoter, including the step of applying the anaerobic microorganism promoter to sludge or water.

[0015] Preferably, the application amount of the anaerobic microorganism promoter is 50 ppm or more, more preferably 50-800 ppm, further preferably 100-500 ppm, and most preferably 100-200 ppm.

[0016] Preferably, the temperature is controlled at 20-60 °C during the regeneration of anaerobic granular sludge, preferably 25-40 °C, and most preferably 30-35 °C.

[0017] Preferably, the salinity of the water is 3% or less, preferably 2.5% or less, and more preferably 1% or less.

[0018] The present invention also claims the application of the above anaerobic microorganism growth promoter in the field of water purification. Preferably, the anaerobic microorganism growth promoter is used to accelerate the degradation of COD in the water of the anaerobic system. Preferably, the COD is an organic acid.

[0019] The mechanism of action of the technical solution of the present invention to solve the problem of slow sludge granulation is as follows:

[0020] There are mainly two theories about the mechanism of sludge granulation, the inorganic matter action theory and the adhesion polymerization theory. The inorganic matter action theory refers to that inorganic ions or sediments such as calcium, iron, and silicon cause microorganisms to accumulate into granules through charge attraction, complexation, flocculation, etc. The inorganic part in the flocculation component accelerates the formation of granules in this way. For example, iron powder, carbon powder, etc. can also serve as sludge crystal nuclei by themselves. The adhesion polymerization theory is that the extracellular polymers or capsules of microorganisms bind to each other through forms such as hydrogen bonds, polar bonds, and polysaccharide-protein links to form stable granules.

[0021] The anaerobic microorganism growth promoter provided by the present invention has the following beneficial effects:

[0022] 1) Promote the aggregation of flocs and accelerate the realization of sludge granulation;

[0023] 2) Improve the sludge sedimentation performance, reduce the turbidity of the effluent from the anaerobic reactor, and can multiply the volume load of the anaerobic reactor;

[0024] 3) Promote the growth and reproduction of methanogens in the anaerobic reactor and improve the activity of methanogens. Description of the Drawings

[0025] Figure 1 is the flocculation effect of Pseudogulbenkiania asaccharolytica on kaolin;

[0026] Figure 2 is the comparison of sludge properties on the 1st, 2nd, and 5th days in Example 4;

[0027] Figure 3 is the comparison of the flocculation effect of the growth promoter in Example 5;

[0028] Figures 1 - 3 In, the left side is the blank group; the right side is the experimental group. Detailed Embodiments

[0029] The principles and features of the present invention will be described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0030] The composition and dosage of each component of the anaerobic microorganism growth promoter used in the examples are shown in Table 1.

[0031] Table 1 Composition and dosage of each component of the anaerobic microorganism growth promoter in the examples

[0032] substance Ratio per ton of water (mg) <![CDATA[FeCl2·4H2O]]> 6 <![CDATA[CoCl2·6H2O]]> 12 <![CDATA[MnCl2·4H2O]]> 3 <![CDATA[Copper(II) chloride dihydrate]]> 0.2 <![CDATA[HBO3]]> 0.3 <![CDATA[ZnCl2]]> 0.3 <![CDATA[(NH4)6Mo7O 24 ·4H2O]]> 0.55 <![CDATA[Na2SeO3·5H2O]]> 3 <![CDATA[NiCl2·6H2O]]> 0.3 Na Resazurin 3 vermiculite 5000 clay 3500 diatomaceous earth 1000 bentonite 2000 zeolite powder 2500 medical stone powder 1000 montmorillonite powder 500 carbon powder (iodine value above 800) 2000 iron powder 500 tourmaline powder 1000 starch 50000 chitosan 30000 bioflocculant 50000

[0033] Example 1. Isolation, purification and identification of Pseudochrobactrum asaccharolyticum

[0034] (1) Screening and isolation of strains:

[0035] Collect the sludge and mud suspension from a chemical plant. Take 10 mL of the mud-water mixture and inoculate it into a 250 mL headspace bottle containing 100 mL of enrichment medium (5 g of yeast powder, 10 g of peptone, 10 g of sodium chloride, 1 L of distilled water, pH = 7.0, sterilized at 121 °C for 20 min). Incubate it on a constant temperature shaker at 30 °C and 200 r / min for one week to obtain the enrichment solution.

[0036] Dilute the enrichment solution step by step to 10 -3 times, 10 -4 times, 10 -5 times and 10 -6 times. Then spread each dilution on the SOB solid selective medium (1 g of KH2PO4, 0.8 g of NH4Cl, 0.8 g of MgCl2·6H2O, 0.01 g of CaCl2·2H2O, 0.01 g of FeCl3·6H2O, 0.04 g of MnCl2·4H2O, 1.2 g of Na2S·9H2O, 2 g of beef extract, 10 g of peptone, 20 g of agar, 1 L of distilled water, pH = 7.0, sterilized at 121 °C for 20 min). Place the spread plates in a constant temperature incubator at 30 °C and incubate until single colonies grow. Pick the single colonies with different morphologies and transfer them to the test tube slant medium. Incubate them at 30 °C for about 48 h, and then transfer them to a 4 °C refrigerator for storage for later use.

[0037] According to the above method, a total of 6 strains were isolated and named BC-1, BC-2, BC-3, BC-4, BC-5 and BC-6 respectively.

[0038] (2) Evaluation of strains

[0039] The 6 obtained strains were respectively inoculated into the activation medium (5 g of yeast powder, 10 g of peptone, 10 g of sodium chloride, 1 L of distilled water, pH = 7.0). After culturing for 48 hours under the conditions of 200 r / min on a shaker and 30 °C, the activation solution was obtained. Then, a headspace bottle (250 mL) containing 100 mL of liquid selection medium (1 g of KH2PO4, 0.8 g of NH4Cl, 0.8 g of MgCl2·6H2O, 0.01 g of CaCl2·2H2O, 0.01 g of FeCl3·6H2O, 0.04 g of MnCl2·4H2O, 0.4 g of Na2S·9H2O, 2 g of beef extract, 10 g of peptone, 1 L of distilled water, pH = 7.0, sterilized at 121 °C for 20 min) was prepared. The activation solutions of each strain were respectively inoculated into the headspace bottle, and the inoculation amount of the activation solution was 100 ppm. They were cultured under the conditions of 200 r / min on a shaker and 30 °C. The LH-S3H sulfide analyzer produced by Beijing Lianhua Yongxing Technology Development Co., Ltd. was used in combination with a special measurement reagent to measure the change in sulfide content after 0, 24, 48, 72, 96, and 120 hours. The results are shown in Table 1.

[0040] Table 2 Degradation of sulfide by each strain obtained by screening

[0041] BC - 1 BC - 2 BC - 3 BC - 4 BC - 5 BC - 6 24h 97.92 269.01 269.55 272.00 217.60 269.28 48h 8.16 268.74 272.00 269.28 225.22 269.01 72h 0.00 268.74 272.00 272.00 214.61 272.00 96h 0.00 267.65 271.18 263.02 209.44 268.46 120h 0.00 268.46 272.00 265.74 207.81 270.10

[0042] It can be seen from the data in Table 1 that compared with other strains, the BC-1 strain has a fast onset and good effect on the removal of sulfide. The sulfide concentration of about 270 ppm in the evaluation medium can be completely removed in 72 h. The strain was re-inoculated into the LB medium to prepare the activation solution, and then stored at -80 °C in a glycerol tube.

[0043] (3) Detection and identification

[0044] The slant of the strain was detected and identified by 16S rDNA gene sequence, and the identification result was Pseudochrobactrum asaccharolyticum. The 16S rDNA gene sequence determination result of this strain is shown in SEQ ID No: 1.

[0045] Example 2: Flocculation effect of Pseudochrobactrum asaccharolyticum

[0046] 1.2 g of kaolin and 100 mL of pure water were prepared into a kaolin mud-water mixture. A blank group and an experimental group were set up. 1 mL of the fermentation broth of Pseudochrobactrum asaccharolyticum was added to the experimental group, and 1 mL of pure water was added to the blank group. Then, it was shaken well and left to stand, and the change of substances in the bottle was observed.

[0047] The states of the blank group and the experimental group after 24 h were as Figure 1As shown, it can be seen that Pseudochrobactrum asaccharolyticum can be used as a biological flocculant and has good flocculation effect.

[0048] Example 3: Fermentation process of Pseudochrobactrum asaccharolyticum

[0049] 1) Primary shake flask activation

[0050] In a sterile environment, pick 1 loop of Pseudochrobactrum asaccharolyticum BC-1 strain and inoculate it into a 250 mL Erlenmeyer flask containing 100 mL of enrichment medium (5 g of yeast powder, 10 g of peptone, 10 g of sodium chloride, pH = 7.0, sterilized at 121 °C for 20 min). Incubate at 30 °C and 180 r / min for 24 h to obtain the primary activated solution.

[0051] 2) Secondary shake flask culture

[0052] In a sterile environment, transfer 10 mL of the primary activated solution to each of four 1 L Erlenmeyer flasks containing 500 mL of enrichment medium (5 g of yeast powder, 10 g of peptone, 10 g of sodium chloride, 1 L of distilled water, pH = 7.0, sterilized at 121 °C for 20 min). Incubate at 30 °C and 180 r / min for 24 h to obtain the secondary activated solution.

[0053] 3) 20 L tank fermentation culture

[0054] Sterilize the fermentation medium at 121 °C for 20 min. The formula of the fermentation medium is: 10 g / L of glucose, 5 g / L of yeast powder, 0.4 g / L of MgSO4, 0.2 g / L of MnSO4, 3 g / L of CaCl2, 3 g / L of K2HPO4. Inoculate the secondary seed culture solution into the fermentation medium at an inoculation amount of 5 - 10 vol%. The liquid filling amount of the fermentation tank is 70%. Adjust the initial pH = 7.0 with sodium hydroxide. Ferment and culture at an aeration ratio of 1:1.25 (m 3 ·min / m 3 )), 180 rpm, and 30 °C. During the fermentation process, control the pH = 6.5 by adding ammonia water. The fermentation cycle is about 40 h. When the dissolved oxygen begins to rise, immediately stop the fermentation to obtain the fermentation broth of Pseudochrobactrum asaccharolyticum. At this time, the fermentation is at the end of the logarithmic phase, the viable bacteria count is as high as 30 billion cfu / mL, the cell viability is the strongest, the residual fermentation nutrients are the least, and the viable bacteria count decreases less during storage. The fermentation broth is freeze-dried to obtain the bacterial powder, and the bacterial powder is diluted with auxiliary materials to the target viable bacteria count to obtain the microbial inoculant containing Pseudochrobactrum asaccharolyticum.

[0055] Example 4: Exploration of the shock load resistance of anaerobic microbial growth promoters

[0056] Under the condition of increasing the COD influent concentration, test the relationship between the activity of methanogens and the growth promoter under the condition of partial acidification of the tank.

[0057] The experimental influent was simulated wastewater prepared by mixing glucose and tap water, with a COD concentration of 13,000 mg / L. The granular sludge was taken from the Qilu Petrochemical EGSB anaerobic tower. The experiment was divided into two groups. No chemicals were added to the blank group, and the experimental group added the calculated amount of anaerobic microbial growth promoter according to the volume of water. During the experiment, the sludge properties were continuously observed. The sludge properties were observed and the COD reduction level was measured on the 1st, 2nd, and 5th days. The sludge properties on the 1st, 2nd, and 5th days were respectively as Figure 2 shown. It was found that the sludge particles without the growth promoter were significantly disintegrated and broken, and the COD data are shown in Table 3.

[0058] Table 3 Changes in COD data over time

[0059] COD 0d 1d removal rate 2d removal rate 5d removal rate blank group 12650 12640 0 12150 4％ 11750 7％ experimental group 13250 12225 8％ 11000 17％ 10000 25％

[0060] As can be seen from Table 3, in the case of pure glucose substrate, with the passage of time, the COD decreased slowly, indicating that the granular sludge was not adapted to the high-concentration COD and began to break. Considering the experimental situation over 5 days, adding the growth promoter could increase the COD removal rate by 18%, and could maintain the sludge properties unchanged as much as possible in the acid tank.

[0061] Example 5: Small-scale experiment on the flocculation effect of the growth promoter

[0062] The granular sludge taken from the Qilu Petrochemical EGSB anaerobic tower was crushed. A muddy water mixture of the same volume of crushed granular sludge and water was respectively placed in 250 mL bottles numbered 1 and 2. The left side was the blank group, and the right side was the experimental group. The calculated amount of the microbial growth promoter of the present invention was added to the experimental group. The initial COD concentration was 4,500 mg / L. Then, both the blank group and the experimental group bottles were placed in a shaker at 30 °C. After 24 hours, the sludge properties were observed, and the comparison pictures are as Figure 3 shown.

[0063] From Figure 3 it can be seen that the sedimentation performance of the sludge in the right experimental group was much better than that of the left blank group, and the shear resistance was also better. After 24 h, the sludge particle size was measured, and the sludge flocs with a particle size greater than 0.5 mm were filtered through a sieve, and their sludge concentration was measured and calculated, as shown in Table 4.

[0064] Table 4 Sludge concentrations of the blank group and the experimental group

[0065] sludge concentration blank group 8.4 g / L experimental group 18.2 g / L

[0066] As can be seen from Table 4, the concentration of sludge flocs with a particle size greater than 0.5 mm in the experimental group was 2.2 times that of the blank group, indicating that the growth promoter of the present invention could turn a large amount of sludge debris into sludge flocs.

[0067] Example 6: Comparative Experiment with Similar Products

[0068] To test the sedimentation of sludge after adding different types of microbial growth promoters, two similar products on the market were selected for a comparative experiment. Product 1 is a biological growth promoter purchased from Jiangyin Huadong Water Treatment Company, and Product 2 is Anaerobic Sludge Granule King purchased from Weifang Fanxing Biotechnology Co., Ltd. Under the condition of the same rising flow rate, the sludge level was determined by caliper measurement.

[0069] In engineering, the rising flow rate designed for the UASB system is generally less than 0.8 m / h. Therefore, 0.8 m / h was selected as the rising flow rate for the experiment. In addition, considering the possible higher reflux flow rate of the EGSB system, the sludge level at a rising flow rate of 2.0 m / h was additionally detected. The experiment was stopped after the sludge level remained stable for 30 minutes. Comparing the height of the sludge level in the reactor can reflect the sedimentation of the sludge to a certain extent. The addition amounts of Product 1, Product 2, and the microbial growth promoter of the present invention are equal, and the experimental group without adding any product was used as a blank control. The results are shown in Table 5.

[0070] Table 5 Sludge Levels of Different Products

[0071] grouping Sludge level (cm) at 0.8 m / h Sludge level (cm) at 2.0 m / h blank control 70.0 81.0 Product 1 59.5 73.0 Product 2 56.0 69.0 Microbial growth promoter of the present invention 57.0 57.0

[0072] As can be seen from the results in Table 5, the anaerobic microbial growth promoter of the present invention can ensure a stable sludge level and reduce the suspended floc particles in the effluent whether at a lower or higher rising flow rate.

[0073] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An anaerobic microorganism growth promoter, characterized in that, By weight, it contains 10 - 20 parts of a carrier, 1 - 5 parts of sludge particle crystal nuclei, 30 - 80 parts of a biological flocculant, 50 - 100 parts of a thickener, and (1 - 10)×10 -3 parts; The carrier is selected from one or a combination of more than one of vermiculite, clay, diatomite, bentonite, zeolite powder, medical stone powder, and montmorillonite powder; The sludge particle crystal nucleus is selected from one or a combination of more than one of iron powder, carbon powder, and tourmaline powder; The biological flocculant is a microbial inoculum containing Pseudochrobactrum asaccharolyticum, wherein the viable count of Pseudochrobactrum asaccharolyticum is 10-50 billion CFU / g, and the Pseudochrobactrum asaccharolyticum is preserved in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms, with the preservation number: CGMCC No. 28059; The trace elements include Fe 2+ , Co 2+ and Mn 2+ .

2. The anaerobic microorganism growth promoter according to claim 1, wherein The thickener is selected from one or a combination of starch and chitosan.

3. The anaerobic microorganism growth promoter according to claim 1 or 2, characterized in that, The trace elements also include Cu 2 + , BO3 – , Zn 2+ , NH4 + , Na + and Ni 2+ in a compounding of one or more of them.

4. A method for promoting the regeneration of anaerobic granular sludge, comprising the step of applying the anaerobic microorganism promoter according to any one of claims 1-3 to sludge or water.

5. The method according to claim 4, characterized in that, The application amount of the anaerobic microorganism promoter is 50 ppm or more.

6. The method according to claim 5, wherein The application amount of the anaerobic microorganism promoter is 50-800 ppm.

7. The method according to claim 6, wherein The application amount of the anaerobic microorganism promoter is 100-500 ppm.

8. The method according to claim 7, wherein The application amount of the anaerobic microorganism promoter is 100-200 ppm.

9. The method according to any one of claims 4-8, characterized in that, During the regeneration process of the anaerobic granular sludge, the temperature is controlled at 20-60 °C.

10. The method according to claim 9, wherein During the regeneration process of the anaerobic granular sludge, the temperature is controlled at 25-40 °C.

11. The method according to claim 10, wherein During the regeneration process of the anaerobic granular sludge, the temperature is controlled at 30-35 °C.

12. The method according to any one of claims 4 to 8, characterized in that The salinity of the water body is 3% or less.

13. The method according to claim 12, wherein The salinity of the water body is 2.5% or less.

14. The method according to claim 13, wherein The salinity of the water body is 1% or less.

15. The application of the anaerobic microorganism promoter according to any one of claims 1-3 in the field of water purification.

16. The application according to claim 15, wherein The anaerobic microorganism promoter is used to accelerate the degradation of COD in the water of the anaerobic system.

17. The application according to claim 16, characterized in that, The COD is an organic acid.

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