A municipal sewage treatment composite microbial agent and a treatment method thereof

Abstract

This invention belongs to the field of municipal wastewater treatment, specifically relating to a compound bacterial agent and treatment method for municipal wastewater. Addressing the problems of complex composition and limited treatment effectiveness of single bacterial strains in municipal wastewater, this invention provides a compound bacterial agent comprising *Paragonimella foenum-graecum* BJ-J1788 and *Acinetobacter calciacetate* TS2H with a viable bacteria ratio of 1:2-4. Compared to single bacteria, the two strains of this invention exert a synergistic effect through metabolic complementarity, significantly improving the treatment efficiency of municipal wastewater and possessing significant application value in the field of municipal wastewater treatment.

Description

Technical Field

[0001] This invention belongs to the field of municipal wastewater treatment and specifically relates to a compound bacterial agent for municipal wastewater treatment and its treatment method. Background Technology

[0002] Urban wastewater treatment involves the effective purification of wastewater generated from urban domestic and industrial activities through technological means to ultimately meet environmental discharge standards. This includes not only physical, chemical, and biological treatment processes but also the recycling of resources. This treatment process is not only an important component of urban infrastructure construction but also a key link in urban environmental governance and public health protection.

[0003] With the acceleration of global urbanization, urban infrastructure is facing unprecedented pressure, especially urban wastewater treatment systems. Urban wastewater treatment is not only related to the quality of life of urban residents, but also a key factor in environmental protection and sustainable development.

[0004] Urban wastewater treatment technology is a crucial component in addressing wastewater discharge and protecting the water environment. Common treatment technologies include biological, chemical, and physical treatment. Biological treatment utilizes microorganisms to degrade organic matter in wastewater, primarily employing methods such as activated sludge and oxidation ditch processes. It is characterized by high treatment capacity and excellent effluent quality. Chemical treatment uses chemical agents for precipitation and oxidation-reduction reactions to remove pollutants such as nitrogen and phosphorus from wastewater. It is characterized by high treatment efficiency and the ability to target specific pollutants. However, the use of chemical agents may lead to secondary pollution. Physical treatment technologies remove suspended particles and impurities from wastewater through physical means such as sedimentation, filtration, and separation. They offer advantages such as simple operation and low cost, but their ability to remove organic matter and dissolved pollutants is relatively weak.

[0005] The development of urban wastewater treatment technology faces numerous problems and challenges. The efficiency and effectiveness of traditional treatment processes have become more pronounced with the rapid increase in wastewater volume, and they struggle to meet increasingly stringent discharge standards. High energy consumption during treatment remains a limiting factor for the application of these technologies, while reducing pollutants and maintaining low energy consumption presents a dual challenge. The complexity of the technologies and their high operating costs also make them unaffordable for many cities. Therefore, improving the efficiency of municipal wastewater treatment has become an urgent problem to be solved. Summary of the Invention

[0006] In view of this, the present invention provides a compound bacterial agent for municipal wastewater treatment and a treatment method thereof. The compound bacterial agent comprises pantrophic paracoccus BJ-J1788 and calcium acetate Acinetobacter TS2H with a live bacteria ratio of 1:2-4. The combination of the two strains can achieve the purpose of efficient remediation of municipal wastewater.

[0007] The technical solution of the present invention is as follows:

[0008] A compound microbial agent for municipal wastewater treatment comprises *Paragonimus westermani* BJ-J1788 and *Acinetobacter calcareae* TS2H; the viable count ratio of *Paragonimus westermani* BJ-J1788 to *Acinetobacter calcareae* TS2H is 1:2-4, and the total viable count is ≥1×10⁻⁶. 9 cfu / g.

[0009] Furthermore, the ratio of viable counts of *Paragonimococcus pantrophicans* BJ-J1788 and *Acinetobacter calcareae* TS2H in the compound bacterial agent for municipal wastewater treatment is 1:2.5-3.5, and the total viable count is ≥1×10⁻⁶. 9 cfu / g.

[0010] Furthermore, the ratio of viable counts of *Paragonimococcus pantrophicans* BJ-J1788 and *Acinetobacter calcareae* TS2H in the compound bacterial agent for municipal wastewater treatment is 1:3, with a total viable count of 5 × 10⁻⁶. 9 cfu / g.

[0011] The present invention discloses a method for preparing a compound bacterial agent for municipal wastewater treatment, comprising the following steps:

[0012] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter TS2H were inoculated into LB liquid medium and cultured to obtain activated bacterial solutions.

[0013] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to seed culture medium to prepare paracoccal BJ-J1788 seed culture and calcium acetate Acinetobacter TS2H seed culture respectively.

[0014] (3) Fermentation culture: The seed liquid obtained in step (2) is transferred to the fermentation medium for fermentation culture, and the fermentation liquid of the two bacteria is collected respectively.

[0015] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) is mixed with the fermentation broth of *Acinetobacter calcitrinum* TS2H at a viable count ratio of 1:2-4, and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent is ≥1×10⁻⁶. 9 cfu / g.

[0016] Preferably, the activation culture conditions in step (1) are constant temperature shaking culture at 30℃ for 42h.

[0017] Preferably, the components and contents of the LB culture medium in step (1) are as follows: 10g sodium chloride, 10g tryptone, 5g yeast extract, 1L distilled water, pH 7.0.

[0018] Preferably, in step (2), the inoculum amount of activated bacterial solution is 8-12% (v / v); the culture conditions are constant temperature shaking culture at 30℃ for 28h, and the rotation speed is 180rpm.

[0019] Preferably, the seed liquid inoculation amount in step (3) is 8-12% (v / v).

[0020] More preferably, in step (3), the amount of strain seed liquid added is 10% of the total mass of the culture medium.

[0021] Preferably, the fermentation conditions in step (3) are constant temperature shaking culture at 30℃ for 26-32h, and the dissolved oxygen is controlled at 30-40%.

[0022] The components and contents of the culture medium in step (2) or step (3) are as follows: 4.78g disodium hydrogen phosphate, 1.5g potassium dihydrogen phosphate, 0.1g magnesium sulfate, 3.416g sodium acetate, 0.191g ammonium chloride, 0.361g potassium nitrate, 0.05g ethylenediaminetetraacetic acid, 5mg calcium chloride, 2.2mg zinc sulfate, 5.06mg manganese chloride, 5mg ferrous sulfate, 1.1mg ammonium molybdate, 1.57mg copper sulfate, 1.61mg cobalt chloride, 1L distilled water, pH 7.0.

[0023] The present invention also provides the application of the above-mentioned compound bacterial agent for municipal wastewater treatment in municipal wastewater treatment.

[0024] The beneficial effects achieved by this invention are as follows:

[0025] To address the problems of complex composition of municipal sewage and the limited treatment effect of single bacterial strains, this invention provides a compound bacterial agent comprising pantrophic paracoccus BJ-J1788 and calcium acetate Acinetobacter TS2H with a live bacteria ratio of 1:2-4.

[0026] The synergistic effect of multiple microorganisms leads to complex conditions for coordinating their growth characteristics, placing high technical demands on the types and quantities of microorganisms used. The applicant screened two strains from numerous strains—Pantrophic Paracoccus BJ-J1788 and Acinetobacter calciacetate TS2H—and prepared a compound microbial agent by mixing these two strains. This agent can withstand low temperature, low oxygen, and low nutrient conditions, accelerating the degradation of organic matter, significantly improving treatment efficiency, and demonstrating superior municipal wastewater treatment capabilities.

[0027] Compared to single bacteria, the two strains of this invention exert a synergistic effect through metabolic complementarity, significantly improving the efficiency of municipal wastewater treatment and providing more options for municipal wastewater treatment. This has important application value in the field of municipal wastewater treatment. Attached Figure Description

[0028] Figure 1This invention provides a comparison of COD removal rates after treating municipal wastewater with the compound microbial agent.

[0029] Figure 2 This invention provides a comparison of TN removal rates after treating municipal wastewater with the compound bacterial agent.

[0030] Figure 3 This invention provides a comparison of TP removal rates after treating municipal wastewater with the compound bacterial agent.

[0031] Figure 4 This invention provides a comparison of ammonia nitrogen removal rates after treating municipal wastewater with the compound bacterial agent. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to embodiments. However, the scope of protection of this invention is not limited to the scope of the embodiments. Variations that can be easily conceived by those skilled in the art within the technical scope disclosed in this invention are all within the scope of protection of this invention.

[0033] Paracoccus pantrophicus BJ-J1788, Acinetobacter calciacetate TS2H, and Paracoccus pantrophicus ATCC 35512 are commercially available strains and can be purchased.

[0034] The components and contents of LB medium are as follows: 10g sodium chloride, 10g tryptone, 5g yeast extract, 1L distilled water, pH 7.0.

[0035] The components and contents of the fermentation medium are as follows: 4.78g disodium hydrogen phosphate, 1.5g potassium dihydrogen phosphate, 0.1g magnesium sulfate, 3.416g sodium acetate, 0.191g ammonium chloride, 0.361g potassium nitrate, 0.05g ethylenediaminetetraacetic acid, 5mg calcium chloride, 2.2mg zinc sulfate, 5.06mg manganese chloride, 5mg ferrous sulfate, 1.1mg ammonium molybdate, 1.57mg copper sulfate, 1.61mg cobalt chloride, 1L distilled water, pH 7.0.

[0036] Example 1

[0037] A compound bacterial agent for municipal wastewater treatment and its preparation method, comprising the following steps:

[0038] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter sucraniosus TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0039] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 10% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788 and the seed culture of Acinetobacter sucraniosus TS2H.

[0040] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 35%. After 32 h of culture, the fermentation liquid of the two bacteria was collected.

[0041] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) and the fermentation broth of *Acinetobacter calcitrinum* TS2H were mixed at a viable count ratio of 1:3 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0042] Example 2

[0043] A compound bacterial agent for municipal wastewater treatment and its preparation method, comprising the following steps:

[0044] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter sucraniosus TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0045] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 12% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788 and the seed culture of Acinetobacter sucraniosus TS2H.

[0046] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 40%. After 28 h of culture, the fermentation liquid of the two bacteria was collected.

[0047] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) and the fermentation broth of *Acinetobacter calcitrinum* TS2H were mixed at a viable count ratio of 1:2.5 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0048] Example 3

[0049] A compound bacterial agent for municipal wastewater treatment and its preparation method, comprising the following steps:

[0050] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter sucraniosus TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0051] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 8% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788 and the seed culture of Acinetobacter sucraniosus TS2H.

[0052] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 35%. After 30 h of culture, the fermentation liquid of the two bacteria was collected.

[0053] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) and the fermentation broth of *Acinetobacter calcareae* TS2H were mixed at a viable count ratio of 1:3.5 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0054] Example 4

[0055] A compound bacterial agent for municipal wastewater treatment and its preparation method, comprising the following steps:

[0056] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter sucraniosus TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0057] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 10% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788 and the seed culture of Acinetobacter sucraniosus TS2H.

[0058] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 8% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 40%. After 26 hours of culture, the fermentation liquid of the two bacteria was collected.

[0059] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) and the fermentation broth of *Acinetobacter calcareae* TS2H were mixed at a viable count ratio of 1:2 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0060] Example 5

[0061] A compound bacterial agent for municipal wastewater treatment and its preparation method, comprising the following steps:

[0062] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter sucraniosus TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0063] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 8% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788 and the seed culture of Acinetobacter sucraniosus TS2H.

[0064] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 12% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 30%. After 26 h of culture, the fermentation liquid of the two bacteria was collected.

[0065] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) and the fermentation broth of *Acinetobacter calcitrinum* TS2H were mixed at a viable count ratio of 1:4 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0066] Example 6

[0067] A compound bacterial agent for municipal wastewater treatment and its preparation method, comprising the following steps:

[0068] (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter sucraniosus TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0069] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 12% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788 and the seed culture of Acinetobacter sucraniosus TS2H.

[0070] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 40%. After 32 h of culture, the fermentation liquid of the two bacteria was collected.

[0071] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) and the fermentation broth of *Acinetobacter calcareae* TS2H were mixed at a viable count ratio of 1:3.5 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0072] Comparative Example 1

[0073] The only difference from Example 1 is the use of a single strain – Paracoccus pantrophicus BJ-J1788.

[0074] (1) Activation: Paracoccus pantrophicus BJ-J1788 was inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0075] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 10% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus pantrophicus BJ-J1788.

[0076] (3) Fermentation culture: The seed culture obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v), and fermentation culture was carried out at 30℃. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 35%. After culturing for 32 h, the fermentation broth was collected. The total number of viable bacteria in the obtained inoculum was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0077] Comparative Example 2

[0078] The only difference from Example 1 is the use of a single strain – Acinetobacter calcium acetate TS2H.

[0079] (1) Activation: Acinetobacter TS2H of calcium acetate was inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0080] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 10% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain Acinetobacter Calcium Acetate TS2H seed culture.

[0081] (3) Fermentation culture: The seed culture obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v), and fermentation culture was carried out at 30℃. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 35%. After culturing for 32 h, the fermentation broth was collected. The total number of viable bacteria in the obtained inoculum was determined to be ≥5×10⁻⁶. 9 cfu / g.

[0082] Comparative Example 3

[0083] Compared with Example 1, the only difference is that Paracoccus pantrophicans ATCC 35512 is used instead of Paracoccus pantrophicans BJ-J1788.

[0084] (1) Activation: Paracoccus ATCC 35512 and Acinetobacter TS2H were inoculated into LB liquid medium and cultured at 30℃ and 180 rpm for 42 h to obtain activated bacterial solution.

[0085] (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to the seed culture medium at an inoculation rate of 10% (v / v) and cultured at 30℃ and 180 rpm for 28 h to obtain the seed culture of Paracoccus ATCC 35512 and Acinetobacter TS2H.

[0086] (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium at an inoculation rate of 10% (v / v) and fermented at 30°C. The stirring speed was controlled at 180 rpm and the dissolved oxygen (DO) was 35%. After 32 h of culture, the fermentation liquid of the two bacteria was collected.

[0087] (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* ATCC 35512 obtained in step (3) and the fermentation broth of *Acinetobacter calcitrinum* TS2H were mixed at a viable count ratio of 1:3 and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent was determined to be ≥5×10⁻⁶.9 cfu / g.

[0088] Verification Example

[0089] The municipal wastewater used in the experiment was selected from the aeration tank of a wastewater treatment plant in a certain city. After the wastewater was collected, it was allowed to stand for 2 hours. The clear water was then extracted using the siphon method and immediately passed through a 300-mesh screen. Before treatment, the organic matter (COD) value, total nitrogen (TN), total phosphorus (TP), and ammonia nitrogen in the wastewater were measured to be (483.15±20.48) mg / L, (65.37±3.19) mg / L, (2.61±0.21) mg / L, and (23.17±1.16) mg / L.

[0090] Take a conical flask containing 600 mL of municipal sewage and inoculate it with bacterial suspensions of the compound bacterial agents from Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 at a 5% (v / v) inoculation rate. Place the conical flasks in a constant temperature shaking incubator at 40°C and 160 rpm. Three replicates are set up for each treatment group.

[0091] On the 4th day of culture, 50 mL of culture medium was centrifuged at 5000 r / min for 8 min, and 5 mL of supernatant was taken. The contents of COD, TN, TP and ammonia nitrogen in the supernatant were determined according to the corresponding methods in "Methods for Monitoring and Analysis of Water and Wastewater".

[0092] The results are shown in Table 1. Figure 1 , Figure 2 , Figure 3 , Figure 4 After treating municipal sewage with the compound bacterial agents of Examples 1, 2, and 3 of this invention, the COD removal rates were 97.2%, 95.5%, and 96.5%, respectively. After treating municipal sewage with the bacterial agents of Comparative Example 1, Comparative Example 2, and Comparative Example 3, the COD removal rates were 65.4%, 55.6%, and 76.7%, respectively.

[0093] After treating municipal sewage with the compound bacterial agents of Examples 1, 2, and 3 of this invention, the TN removal rates were 98.2%, 96.3%, and 97.3%, respectively. After treating municipal sewage with the bacterial agents of Comparative Example 1, Comparative Example 2, and Comparative Example 3, the TN removal rates were 90.1%, 85.0%, and 95.5%, respectively.

[0094] After treating municipal sewage with the compound bacterial agents of Examples 1, 2, and 3 of this invention, the TP removal rates were 99.3%, 98.9%, and 98.2%, respectively. After treating municipal sewage with the bacterial agents of Comparative Example 1, Comparative Example 2, and Comparative Example 3, the TP removal rates were 86.9%, 74.6%, and 90.5%, respectively.

[0095] After treating municipal sewage with the compound bacterial agents of Examples 1, 2, and 3 of this invention, the ammonia nitrogen removal rates were 92.8%, 91.1%, and 90.7%, respectively. After treating municipal sewage with the bacterial agents of Comparative Example 1, Comparative Example 2, and Comparative Example 3, the ammonia nitrogen removal rates were 77.9%, 61.1%, and 84.0%, respectively.

[0096] Table 1. Removal rates of COD, TN, TP, and ammonia nitrogen under each treatment

[0097] Group Example 1 Group Example 2 group Example 3 Group Comparative Example 1 Comparative Example 2 Comparative Example 3 Groups COD removal rate (%) 97.2 95.5 96.5 65.4 55.6 76.7 TN removal rate (%) 98.2 96.3 97.3 90.1 85.0 95.5 TP removal rate (%) 99.3 98.9 98.2 86.9 74.6 90.5 Ammonia nitrogen removal rate (%) 92.8 91.1 90.7 77.9 61.1 84.0

[0098] Under the same dosage, the treatment effect of municipal sewage in Example 1 of this invention is significantly better than that of the compound bacterial agent in Comparative Example 1, Comparative Example 2, and Comparative Example 3. In Example 1, the compound bacterial agent contains pantrophic paracoccus BJ-J1788 and calcium acetate Acinetobacter TS2H, which work together synergistically to promote the removal of COD, total nitrogen, total phosphorus, and ammonia nitrogen. In contrast, the bacterial agents in Comparative Examples 1 and 2 use only a single strain, and Comparative Example 3 changes the type of bacterial strain, resulting in a significant decrease in the removal rates of COD, total nitrogen, total phosphorus, and ammonia nitrogen.

[0099] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0100] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A compound bacterial agent for municipal wastewater treatment, characterized in that, The bacteria include *Paragonimus westermani* BJ-J1788 and *Acinetobacter calcareae* TS2H; the viable count ratio of *Paragonimus westermani* BJ-J1788 to *Acinetobacter calcareae* TS2H is 1:2-4; the total viable count is ≥1×10⁻⁶. 9 cfu / g.

2. The method for preparing the compound bacterial agent for municipal wastewater treatment according to claim 1, characterized in that, Includes the following steps: (1) Activation: Paracoccus pantrophicus BJ-J1788 and Acinetobacter calcium acetate TS2H were inoculated into LB liquid medium and cultured to obtain activated bacterial solutions; (2) Seed culture: The activated bacterial solution obtained in step (1) was transferred to seed culture medium to prepare paracoccal BJ-J1788 seed culture and calcium acetate Acinetobacter TS2H seed culture, respectively. (3) Fermentation culture: The seed liquid obtained in step (2) was transferred to the fermentation medium for fermentation culture, and the fermentation liquid of the two bacteria was collected respectively; (4) Compound preparation: The fermentation broth of *Paragonimococcus pantrophicans* BJ-J1788 obtained in step (3) is mixed with the fermentation broth of *Acinetobacter calcitrinum* TS2H at a viable count ratio of 1:2-4, and stirred evenly to obtain the compound bacterial agent for municipal wastewater treatment. The total effective viable count of the obtained compound bacterial agent is ≥1×10⁻⁶. 9 cfu / g.

3. The preparation method according to claim 2, characterized in that, The activation culture conditions in step (1) are constant temperature shaking culture at 30℃ for 42h.

4. The preparation method according to claim 2, characterized in that, The components and contents of the LB medium in step (1) are as follows: 10g sodium chloride, 10g tryptone, 5g yeast extract, 1L distilled water, pH 7.

0.

5. The preparation method according to claim 2, characterized in that, In step (2), the inoculum amount of activated bacterial solution is 8-12% (v / v); the culture conditions are constant temperature shaking culture at 30℃ for 28h, and the rotation speed is 180rpm.

6. The preparation method according to claim 2, characterized in that, In step (3), the seed liquid inoculation amount is 8-12% (v / v).

7. The preparation method according to claim 2, characterized in that, In step (3), the fermentation conditions are constant temperature shaking culture at 30℃ for 26-32h, and the dissolved oxygen is controlled at 30-40%.

8. The preparation method according to claim 2, characterized in that, The components and contents of the culture medium in step (2) or step (3) are as follows: 4.78g disodium hydrogen phosphate, 1.5g potassium dihydrogen phosphate, 0.1g magnesium sulfate, 3.416g sodium acetate, 0.191g ammonium chloride, 0.361g potassium nitrate, 0.05g ethylenediaminetetraacetic acid, 5mg calcium chloride, 2.2mg zinc sulfate, 5.06mg manganese chloride, 5mg ferrous sulfate, 1.1mg ammonium molybdate, 1.57mg copper sulfate, 1.61mg cobalt chloride, 1L distilled water, pH 7.

0.

9. The application of the compound microbial agent for municipal wastewater treatment as described in claim 1 in municipal wastewater treatment.

Images