A composite microbial agent for aerobic treatment of pesticide wastewater and its preparation method and application

Abstract

The invention relates to a composite microbial agent for aerobic treatment of pesticide wastewater, a preparation method and application thereof, and belongs to the technical field of microbial sewage treatment. The composite microbial agent comprises hymenium, chitinophage, rhizobium, lake desert river bacillus, sphingomonas, castellania and water microbacterium; in the composite microbial agent, the bacterial cell concentration percentages are: 35%-45%, 18%-25%, 9-15%, 6%-15%, 5%-15%, 5%-10% and 2%-5% in sequence; the agent can more effectively promote the growth of different strains through the synergistic effect between component populations, make the total number of bacteria in the bacterial solution reach the degradation standard in a shorter time, degrade pollutants in water more efficiently, accelerate the complete degradation of pollutants, and significantly reduce the chemical oxygen demand (COD) and the concentration of toxic substances in the wastewater by utilizing the metabolic activities of microorganisms.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial sewage treatment and relates to a composite microbial agent for aerobic treatment of pesticide wastewater and a preparation method and application thereof. Background Art

[0002] With the rapid development of the agricultural chemical industry, a large amount of wastewater generated during the production of pesticides has become a high-risk source of industrial pollution. This type of wastewater mainly comes from waste liquid discharged during pesticide synthesis, reaction processes and production processes. Its composition is complex and diverse, and it usually contains high concentrations of difficult-to-degrade organic matter, toxic by-products and some persistent pollutants. These pollutants are not only significantly toxic and environmentally persistent, but may also cause serious damage to surface water and groundwater systems through infiltration, runoff, etc., further threatening ecosystems and human health. Due to the high toxicity, complex composition and difficulty in treatment of pesticide wastewater, it is listed as one of the problems that need to be overcome in industrial wastewater treatment. Efficient and economical treatment of pesticide production wastewater has become an important technical challenge in the current field of environmental governance.

[0003] At present, the treatment methods for pesticide wastewater include three categories: physical, chemical and biological methods. Although physical methods (such as adsorption and membrane separation technology) can quickly remove some pollutants, it is difficult to completely decompose the pollutants and the operating costs are relatively high; although chemical methods (such as advanced oxidation and chemical precipitation) have high degradation efficiency, they often bring high reagent costs and the hidden dangers of secondary pollution. In contrast, biological treatment methods have become a research hotspot for pesticide wastewater treatment due to their advantages such as low operating costs and environmental friendliness. However, traditional biological methods (especially anaerobic treatment) face significant challenges in treating wastewater containing pesticides, including long reaction time, low treatment efficiency and the possible generation of foul-smelling gases. In this context, aerobic biochemical treatment has gradually become a more preferred treatment technology due to its efficient degradation ability for highly toxic organic pollutants.

[0004] Aerobic treatment utilizes the metabolic activity of microorganisms to significantly reduce the chemical oxygen demand (COD) and toxic substance concentrations in wastewater. However, the complexity and resistance to biodegradation of pollutants in pesticide wastewater place higher demands on aerobic biological treatment, such as the need to overcome technical difficulties such as the long microbial acclimatization cycle, low toxicity resistance, and poor adaptability.

[0005] In aerobic biochemical treatment, microorganisms are the core driving force for pollutant degradation, and their population composition and metabolic capacity directly affect the efficiency of wastewater treatment. Through targeted screening and cultivation of aerobic microbial communities, highly toxic organic matter (such as organophosphorus and organochlorine compounds) in pesticide wastewater can be specifically degraded into non-toxic or low-toxic small molecules, while efficiently removing nutrients such as nitrogen and phosphorus. In addition, some dominant strains also have strong drug resistance and stress resistance, and can still maintain high activity under highly toxic wastewater conditions.

[0006] Composite microbial agents can achieve significant synergy in the treatment of pesticide wastewater by integrating the advantages of multiple functional strains. Different strains can form a metabolic complementary relationship. For example, the intermediates decomposed by one strain can be used as an energy source for another strain, thereby accelerating the complete degradation of pollutants. Compared with a single strain, composite microbial agents can not only improve the degradation efficiency, but also significantly enhance the environmental adaptability and stress resistance of the microbial community, and are suitable for different types of pesticide wastewater. In addition, composite microbial agents can reduce the treatment system's dependence on external conditions (such as temperature and pH value), reduce operating costs, and have a wider range of practical application value. More importantly, composite microbial agents occupy a small area and are particularly suitable for decentralized or small-scale wastewater treatment scenarios.

[0007] Therefore, there is an urgent need for an efficient, economical and popularizable composite microbial agent for aerobic treatment of pesticide wastewater to solve the pollution problem of pesticide wastewater. Summary of the invention

[0008] In view of this, the present invention provides a composite microbial agent for aerobic treatment of pesticide wastewater and its preparation method and application in order to solve the problems of the above-mentioned background technology. The agent accelerates the complete degradation of pollutants through the synergistic effect between component populations, enhances the treatment efficiency of degradation substrates, and has the characteristics of strong pertinence, rapid response and convenient operation.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] A composite microbial agent for aerobic treatment of pesticide wastewater, comprising Hyphomicrobium, Chitinophagaceae, Rhizobiaceae, Moheibacter, Sphingomonadaceae, Castellaniella, and Aquamicrobium;

[0011] Hyphomicrobium is a type of actinomycetes with high metabolic capacity. It can secrete a variety of enzymes (such as cellulase, xylanase, etc.) and degrade complex organic compounds, especially aromatic and polycyclic compounds. It has a significant decomposition effect, which can effectively reduce the chemical oxygen demand (COD) and improve the biodegradability of wastewater.

[0012] Chitinophagaceae mainly secrete chitinase and chitinase, and are good at decomposing chitin and similar complex polysaccharide structures. In the treatment of pesticide wastewater, the bacteria have a significant degradation effect on organic pollutants containing polysaccharides or chitin structures by decomposing macromolecules into low molecular organic matter;

[0013] Rhizobiaceae: a type of nitrogen-fixing bacteria that live in symbiosis with plants, can secrete a variety of secondary metabolites, and has a certain ability to transform organic matter. In the treatment of pesticide wastewater, rhizobia have the potential to degrade nitrogen-containing organic compounds (such as amino compounds and nitrogen heterocyclic compounds), which helps to reduce the nitrogen pollution load in wastewater;

[0014] Moheibacter can secrete dehydrogenase and oxidoreductase to degrade some halogenated organic compounds and sulfur-containing compounds, significantly improving the biochemical degradation performance of wastewater;

[0015] Sphingomonadaceae has the ability to decompose high-concentration organic pollutants, especially polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds. By secreting monooxygenase and dioxygenase, it can effectively remove toxic and difficult-to-degrade aromatic compounds in pesticide wastewater treatment;

[0016] Castellaniella has a strong ability to degrade phosphate compounds;

[0017] Aquamicrobium has strong extracellular enzyme activity and can secrete lipase and protease.

[0018] Furthermore, in the composite microbial agent, the bacterial cell concentration percentages of Hyphobacterium, Chitinophage, Rhizobium, Bacillus, Sphingomonas, Castellania and Aquamicrobium are 35%-45%, 18%-25%, 9-15%, 6%-15%, 5%-15%, 5%-10% and 2%-5%, respectively.

[0019] Furthermore, the total viable count of the composite microbial agent is not less than 10 8 CFU / ml can make the composite microbial agent exert a stronger degradation effect.

[0020] Furthermore, the degradation rates of COD and ammonia nitrogen in pesticide wastewater by the composite microbial agent are both ≥85%.

[0021] Furthermore, a method for preparing a composite microbial agent for aerobic treatment of pesticide wastewater comprises the following steps:

[0022] S1: strain activation: inoculate Hyphomicrobium, Chitinophage, Rhizobium, Lactobacillum, Sphingomonas, Castellania and Aquamicrobium into nutrient agar plate medium respectively, culture at 30℃ for 24h, streak, separate and transfer until relatively uniform and regular colonies grow;

[0023] S2: Expanded culture: The seven single colonies activated in step S1 were inoculated into LB liquid culture medium respectively to form a mycelial microbial solution, a chitinophage solution, a rhizobium solution, a lake desert bacillus solution, a sphingomonas solution, a castellaniella solution and a water microbial solution, and aerobically cultured at 30°C and 200-400rpm for 24h-48h;

[0024] S3: Bacterial liquid mixing: the 7 bacterial liquids in step S2 are inoculated into a production tank at a 10% inoculation rate for culture, and the culture medium in the production tank is LB liquid culture medium;

[0025] S4: After the fermentation in the production tank, the number of bacteria is ≥10 8 CFU / ml, after fermentation is completed, the seven bacterial liquids are taken out of the tank separately, and the seven bacterial liquids are mixed according to the percentage of bacterial cell concentration to obtain the liquid bacterial agent of the composite microbial agent.

[0026] Furthermore, the nutrient agar plate culture medium in step S1 is: 10 g / L tryptone, 5 g / L yeast powder, 10 g / L sodium chloride, 15 g / L agar powder, the solvent is deionized water, and the pH is 6.5-8.

[0027] Furthermore, the LB liquid culture medium in step S2 and step S3 is: 10 g / L tryptone, 5 g / L yeast powder, 10 g / L sodium chloride, the solvent is deionized water, and the pH is 6.5-8.

[0028] Furthermore, the culture conditions in the production tank in step S4 are: a stirring speed of 100 to 150 r / min, a culture temperature of 30° C., and a culture time of 24 to 48 h.

[0029] Furthermore, a composite microbial agent for aerobic treatment of pesticide wastewater is used in the treatment of pesticide wastewater, wherein the inoculation amount of the composite microbial agent is 1-5%.

[0030] Furthermore, a composite microbial agent for aerobic treatment of pesticide wastewater is used in the degradation of organic matter.

[0031] Furthermore, an application of a composite microbial agent for aerobic treatment of pesticide wastewater in purifying water bodies is specifically: applying the composite microbial agent to the water body, wherein the addition amount of the composite microbial agent is more than 1%, more preferably 1%-10%, and most preferably 5%-8%.

[0032] The beneficial effects of the present invention are:

[0033] 1. The present invention discloses a composite microbial agent for aerobic treatment of pesticide wastewater. The agent can more effectively promote the growth of different strains through the synergistic effect between component populations, so that the total number of bacteria in the bacterial solution reaches the degradation standard in a shorter time, and the pollutants in the water are more efficiently degraded, thereby accelerating the complete degradation of pollutants.

[0034] 2. The present invention discloses a composite microbial agent for aerobic treatment of pesticide wastewater. The agent has a short microbial acclimation period, high toxicity resistance, and strong adaptability. It utilizes the metabolic activities of microorganisms to significantly reduce the chemical oxygen demand (COD) and the concentration of toxic substances in wastewater.

[0035] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0037] Example 1

[0038] A method for preparing a composite microbial agent for aerobic treatment of pesticide wastewater and application of the composite microbial agent in treating pesticide wastewater.

[0039] The preparation method of the composite microbial agent for aerobic treatment of pesticide wastewater comprises the following steps:

[0040] S1: Medium preparation: Nutrient agar plate medium is: 10g tryptone, 5g yeast powder, 10g sodium chloride, 15g agar, 1000mL deionized water; after high-pressure sterilization at 121℃, pour into the plate to make nutrient agar plate medium. LB medium: 10g tryptone, 5g yeast powder, 10g sodium chloride, 1000mL deionized water.

[0041] S2: Preparation of composite microbial agent: inoculate Hyphomicrobium, Chitinophage, Rhizobium, Bacillus, Sphingomonas, Castellaniella, and Aquamicrobium into the nutrient agar plate medium in S1, respectively, and culture at 30°C for 24h; streak, separate, and transfer until relatively uniform and regular colonies grow.

[0042] S3: Expanded culture: The uniform and regular colonies in step S2 were inoculated into LB liquid culture medium and cultured at 30°C for 48 hours until the bacterial cell concentration in each culture medium was ≥10 8 CFU / ml.

[0043] S4: mixing bacterial solutions, mixing the 7 bacterial solutions fermented separately in step S3 according to the bacterial cell percentage concentrations of 43% of Mycobacterium, 19% of Chitinophora, 11% of Rhizobium, 8% of Bacillus, 8% of Sphingomonas, 8% of Castellania, and 3% of Aquamicrobium to obtain a composite microbial agent.

[0044] Inoculation amount: 1g of composite microbial agent per liter of aquaculture wastewater.

[0045] At room temperature, the composite microbial agent was directly inoculated into the pesticide wastewater with pH = 7-8 for aerobic treatment, DO = 3-4 mg / L, COD detection was performed, and the COD degradation rate was calculated. Before degradation, the COD concentration in the pesticide wastewater was 3000 mg / L and the ammonia nitrogen concentration was 1000 mg / L.

[0046] The degradation efficiency of the composite microbial agent on pesticide wastewater is shown in Table 1.

[0047] Table 1: Degradation effect of bacterial agents on COD and ammonia nitrogen in pesticide wastewater

[0048]

[0049] Example 2

[0050] Example 2 is another preparation method and application of a composite microbial agent for aerobic treatment of pesticide wastewater. The composite microbial agent includes slope seeds-seed liquid-seed tank-liquid agent.

[0051] The preparation method comprises the following steps:

[0052] S1: The test tube cultures of the seven strains in Example 1 were inoculated into a fermentation medium and cultured to the logarithmic phase.

[0053] S2: Inoculate the above cultured bacteria into a 500L seed tank at a 10% inoculation rate and culture it aerobically until the logarithmic growth phase. The culture medium formula and mass content used in the seed tank are: 10g tryptone, 5g yeast powder, 10g sodium chloride, prepared with deionized water, pH 7.0.

[0054] S3: The seed liquid is inoculated into the production tank at a 10% inoculation rate for cultivation. The culture medium used in the production tank is the same as that in the seed tank.

[0055] S4: During the cultivation process of the seed tank and the production tank, the stirring speed is 100-150r / min, the cultivation temperature is 30°C, and the cultivation time of the entire process is 24-48h. After the fermentation is completed, the number of bacteria reaches 10 8 CFU / ml or above, after fermentation is completed, the culture liquid is discharged from the tank and the seven bacterial liquids are mixed according to the bacterial cell percentage concentration ratio of 43% of Mycena, 19% of Chitinophora, 11% of Rhizobium, 8% of Lake Desert Bacillus, 8% of Sphingomonas, 8% of Castellaniella and 3% of Aquamicrobium to obtain a composite microbial agent.

[0056] The composite microbial agent was directly inoculated into the aquaculture wastewater of Example 1 for detection, and the inoculation amount was the same as that of the composite microbial agent in Example 1.

[0057] At room temperature, the composite microbial agent was directly inoculated into the pesticide wastewater with pH = 7-8 for aerobic treatment, DO = 3-4 mg / L, COD detection was performed, and the COD degradation rate was calculated. Before degradation, the COD concentration in the pesticide wastewater was 3500 mg / L and the ammonia nitrogen concentration was 1200 mg / L.

[0058] The degradation efficiency of the composite microbial agent on pesticide wastewater is shown in Table 2.

[0059] Table 2: Degradation effect of bacterial agents on COD and ammonia nitrogen in pesticide wastewater

[0060]

[0061] The data in Tables 1 and 2 show that after the composite microbial agent prepared by the present invention is inoculated into pesticide wastewater, it has a significant effect on the removal efficiency of COD and ammonia nitrogen in the pesticide wastewater. Among them, the COD removal rate is as high as 87.6%, and the ammonia nitrogen removal rate can reach 90.6%. Specific analysis shows that this significant effect is due to the composite microbial agent of the present invention benefiting from the composition of multiple functionally complementary microorganisms. Its advantages lie in the diversity of bacterial species, the complementarity of metabolic pathways, and the manifestation of the synergistic effect of different strains, so that the composite microbial agent can quickly adapt to the highly polluted environment of pesticide wastewater and efficiently decompose organic pollutants.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A composite microbial agent for aerobic treatment of pesticide wastewater, characterized in that: It includes hymenophage, chitinophage, rhizobium, lake desert bacillus, sphingomonas, castellania and water microbacterium; in the composite microbial inoculant, the bacterial cell concentration percentages are: 35%-45%, 18%-25%, 9-15%, 6%-15%, 5%-15%, 5%-10% and 2%-5%.

2. A composite microbial agent for aerobic treatment of pesticide wastewater according to claim 1, characterized in that: The total viable count of the composite microbial agent is not less than 10 8 CFU / ml.

3. A composite microbial agent for aerobic treatment of pesticide wastewater according to claim 1, characterized in that: The degradation rates of COD and ammonia nitrogen of the composite microbial agent on pesticide wastewater are both ≥85%.

4. A method for preparing a composite microbial agent for aerobic treatment of pesticide wastewater according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: strain activation: inoculate Hyphomicrobium, Chitinophage, Rhizobium, Lactobacillum, Sphingomonas, Castellania and Aquamicrobium into nutrient agar plate medium respectively, culture at 30℃ for 24h, streak, separate and transfer until uniform and regular colonies grow; S2: Expanded culture: The seven single colonies activated in step S1 were inoculated into LB liquid culture medium to form a mycelial microbial solution, a chitinophage solution, a rhizobium solution, a lake desert bacillus solution, a sphingomonas solution, a castellaniella solution and a water microbial solution, and aerobically cultured at 30°C and 200-400rpm for 24h-48h; S3: Bacterial liquid mixing: the 7 bacterial liquids in step S2 are inoculated into a production tank at a 10% inoculation rate for culture, and the culture medium in the production tank is LB liquid culture medium; S4: After the fermentation in the production tank, the number of bacteria is ≥10 8 CFU / ml, after fermentation is completed, the seven bacterial liquids are taken out of the tank separately, and the seven bacterial liquids are mixed according to the percentage of bacterial cell concentration to obtain the liquid bacterial agent of the composite microbial agent.

5. The method for preparing a composite microbial agent for aerobic treatment of pesticide wastewater according to claim 4, characterized in that: The nutrient agar plate culture medium in step S1 is: 10 g / L tryptone, 5 g / L yeast powder, 10 g / L sodium chloride, 15 g / L agar powder, the solvent is deionized water, and the pH is 6.5-8.

6. The method for preparing a composite microbial agent for aerobic treatment of pesticide wastewater according to claim 4, characterized in that: The LB liquid culture medium in step S2 and step S3 is: 10 g / L tryptone, 5 g / L yeast powder, 10 g / L sodium chloride, the solvent is deionized water, and the pH is 6.5-8.

7. The method for preparing a composite microbial agent for aerobic treatment of pesticide wastewater according to claim 4, characterized in that: The culture conditions in the production tank in step S4 are: a stirring speed of 100 to 150 r / min, a culture temperature of 30° C., and a culture time of 24 to 48 h.

8. Use of a composite microbial agent for aerobic treatment of pesticide wastewater according to any one of claims 1 to 3 in treating pesticide wastewater, characterized in that: The inoculation amount of the composite microbial agent is 1-5%.

9. Use of the composite microbial agent for aerobic treatment of pesticide wastewater as claimed in any one of claims 1 to 3 in degrading organic matter.

10. Use of a composite microbial agent for aerobic treatment of pesticide wastewater according to any one of claims 1 to 3 in purifying water, characterized in that: The composite microbial agent is applied to the water body, and the dosage of the composite microbial agent is more than 1%.

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