Microflora for treating industrial wastewater

Abstract

The invention discloses a flora for treating industrial wastewater and application of the flora for treating the industrial wastewater or polluted soil, the flora comprises stenotrophomonas and at least two selected from the group consisting of comamonas, ochrobactrum, pseudomonas, brucella, citrobacter, salmonella, balloon and enterococcus, and wherein the industrial wastewater contains a bactericide.

Description

Technical Field

[0001] This invention relates to a microbial community for treating industrial wastewater and its uses. Background Technology

[0002] Metalworking fluids (MWFs) play a crucial role in machining. During processes such as cutting, drilling, and grinding, MWFs act as both lubricants and coolants to improve workpiece quality and extend tool life. Water-soluble MWFs are the most widely used due to their excellent performance and relatively low price.

[0003] The chemical composition of metalworking fluids (MWFs) is extremely complex, including surfactants, corrosion inhibitors, friction modifiers, and extreme pressure agents. Furthermore, to prevent microbial contamination during processing, a certain amount of bactericide is typically added to the formulation. Therefore, used metalworking fluids may still retain some antibiotics. In addition, the residual metal ions and complex components from metalworking processes result in highly biotoxic industrial wastewater containing MWFs, potentially posing harm to human health and the environment, and in severe cases, even causing cancer.

[0004] Therefore, industrial wastewater containing MWF must be treated safely and appropriately.

[0005] Incineration and landfill are traditional methods for treating industrial wastewater containing microwave-safe waste (MWF). However, incineration produces nitrogen oxides, sulfides, and hydrogen chloride, which severely impact the atmospheric environment, while landfill leachate poses a serious threat to soil and groundwater. Furthermore, EU directives (2000 / 76 / EC), the EU Water Directive (2000 / 60 / EC), and the Landfill Directive (2004) have imposed stricter standards on waste incineration and landfill treatment methods.

[0006] Therefore, numerous researchers have devoted their efforts to studying chemical, physical, and biological treatment methods for industrial wastewater containing microwave-forced fumes (MWF). Coagulation, evaporation, and ultrafiltration are the preferred processes for wastewater treatment; however, the sludge produced by coagulation and sedimentation increases the cost of additional treatment, while the high energy consumption and membrane scaling problems of evaporation and membrane separation increase investment costs, limiting their application.

[0007] Biological treatment is an option for treating industrial wastewater containing metallurgical fluids (MWFs), offering advantages such as sustainability, low cost, and the ability to treat wastewater in situ, thus achieving water resource recycling. The feasibility of biological methods for treating MWF-containing industrial wastewater has been studied and verified. In 2001, CJ van der Gast et al. conducted phenotypic and genetic analyses of bacterial communities isolated from used metalworking fluids and tested the pollutant degradation performance after inoculation into a bioreactor. Because MWF formulations typically include bactericides to prevent biofouling, they are often biotoxic and difficult to degrade. Toxic substances in MWF-containing industrial wastewater (such as bactericide residues) inhibit microbial growth, often resulting in low species diversity in the microbial community. Furthermore, different industrial wastewaters may have different chemical properties, making it difficult to obtain microbial communities suitable for the broad treatment of MWF-containing industrial wastewater.

[0008] Therefore, there is a need in the art for a microbial ensemble capable of treating industrial wastewater containing metalworking fluids, which can survive under various wastewater conditions and exhibit good pollutant degradation efficiency. This would advance the harmless treatment of industrial wastewater and water resource recycling. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, the present invention aims to provide a microbial community for treating industrial wastewater, comprising *Stenotrophomonas* sp. and at least two selected from the following: *Comamonas* sp., *Ochrobactrum* sp., *Pseudomonas* sp., *Brucella* sp., *Citrobacter* sp., *Salmonella* sp., *Aerococcus* sp., and *Enterococcus* sp., wherein the industrial wastewater contains a bactericide.

[0010] In some embodiments, the industrial wastewater contains a metalworking fluid, which contains a bactericide.

[0011] In some embodiments, the bactericide is a bactericide for metalworking fluids, for example, the bactericide includes at least one of triazine bactericides, morpholine bactericides, 1,2-benzisothiazolin-3-one (BIT) bactericides, 3-iodo-2-propynyl-butylcarbamate (IPBC) bactericides, 2-butyl-1,2-benzisothiazolin-3-one (BBIT) bactericides, and sodium pyridinethione bactericides.

[0012] In some embodiments, the concentration of the bactericide in the industrial wastewater, based on the total weight of the industrial wastewater, is 0.3% by weight or more, 0.4% by weight or more, 0.5% by weight or more, 0.6% by weight or more, 0.7% by weight or more, 0.8% by weight or more, 0.9% by weight or more, 1.0% by weight or more, 1.1% by weight or more, 1.2% by weight or more, 1.3% by weight or more, 1.4% by weight or more, 1.5% by weight or more, 1.6% by weight or more, 1.7% by weight or more, 1.8% by weight or more, 1.9% by weight or more, 2.0% by weight or more, 2.1% by weight or more, 2.2% by weight or more, 2.3% by weight or more, 2.4% by weight or more, 2.5% by weight or more, 2.6% by weight or more, 2.7% by weight or more, 2.8% by weight or more, 2.9% by weight or more, or 3.0% by weight or more. By utilizing the microbial community for treating industrial wastewater according to the present invention, harmless biological treatment of industrial wastewater can be achieved, enabling in-situ wastewater treatment without consuming large amounts of energy, and reducing the risk of secondary pollution due to the elimination of the need for transportation. The microbial community according to the present invention minimizes sludge production when degrading industrial wastewater containing metalworking fluids. Furthermore, the microbial community according to the present invention can function stably in highly biotoxic wastewater and is suitable for degrading industrial wastewater containing metalworking fluids with different formulations.

[0013] In some implementations, this bacterial group includes the genus *Panax*.

[0014] In some implementations, the microbial community includes Pseudomonas.

[0015] In some implementations, the bacterial group includes Pseudomonas and Paleobacterium.

[0016] In some implementations, the microbial community includes the genera *Oligotrophomonas*, *Trichophyton*, and *Parabacterium*.

[0017] In some implementations, the microbial community consists of the following genera: Oligotrophomonas, Trichomonas, and Paleobacterium.

[0018] In some implementations, the microbial community includes Oligotrophomonas, Pseudomonas, Brucella, and Citrobacter.

[0019] In some implementations, the microbial community consists of the following genera: Oligotrophomonas, Pseudomonas, Brucella, and Citrobacter.

[0020] In some implementations, the microbiota includes Oligotrophomonas, Pseudomonas, Salmonella, Gastroenterobacter, and Enterococcus.

[0021] In some implementations, the microbial community consists of the following genera: Oligotrophozoites, Pseudomonas, Salmonella, Gastroenterobacteria, and Enterococci.

[0022] In some implementations, the microbial community includes the genera *Oligotrophomonas*, *Citrobacter*, and *Aureobacterium*.

[0023] In some implementations, the microbial community consists of the following: Oligotrophomonas, Citric Acid Bacteria, and Paleobacterium.

[0024] In some implementations, the microbial community includes *Oligotrophomonas*, *Trichophyton*, *Aureobacter*, *Pseudomonas*, *Brucella*, *Citrobacter*, *Salmonella*, *Blephalosporium*, and *Enterococcus*.

[0025] In some implementations, the microbial community consists of the following genera: Oligotrophomonas, Trichomonas, Aristobacterium, Pseudomonas, Brucella, Citrobacter, Salmonella, Gastroenterobacter, and Enterococcus.

[0026] In some embodiments, the industrial wastewater includes organic matter, including at least one of mineral oil, polyols, esters, and emulsifiers. In some embodiments, the industrial wastewater includes metal salts, including at least one of iron salts and aluminum salts.

[0027] In some embodiments, the COD concentration of the industrial wastewater is above 10,000 mg / L, for example above 20,000 mg / L, above 30,000 mg / L, above 40,000 mg / L, above 50,000 mg / L, above 60,000 mg / L, above 70,000 mg / L, above 80,000 mg / L, above 90,000 mg / L, above 100,000 mg / L, above 110,000 mg / L, and above 120,000 mg / L.

[0028] In some embodiments, the industrial wastewater has a chromium equivalent biotoxicity of 100 μM or more, for example, the industrial wastewater has a chromium equivalent biotoxicity of 110 μM or more, 120 μM or more, 130 μM or more, 140 μM or more, 150 μM or more, 160 μM or more, 170 μM or more, 180 μM or more, 190 μM or more, 200 μM or more, 210 μM or more, 220 μM or more, 230 μM or more, 240 μM or more, 250 μM or more, 260 μM or more, 270 μM or more, 280 μM or more, 290 μM or more, or 300 μM or more.

[0029] The present invention also provides a method for treating industrial wastewater or contaminated soil, the method comprising the following steps:

[0030] (i) Provide a microbial community comprising Stenotrophomonas sp. and at least two of the following: Commonas sp. and Ochrobactrum sp.

[0031] sp., Pseudomonas sp., Brucella sp., Citrobacter sp., Salmonella sp., Aerococcus sp., Enterococcus sp.;

[0032] (ii) Providing industrial wastewater containing a bactericide;

[0033] (iii) Add the bacterial community to the industrial wastewater.

[0034] In some implementations, the number of each genera in the bacterial community is substantially the same, or the number of each genera in the bacterial community is not the same.

[0035] Another object of the present invention is to provide the use of the microbial community according to the present invention for treating industrial wastewater or contaminated soil. Attached Figure Description

[0036] Figure 1 The biofilm reactor used according to Example 9 is illustrated schematically;

[0037] Figure 2 The degradation rate of organic pollutants in Example 9 is illustrated schematically;

[0038] Figure 3 The changes in biotoxicity in Example 9 are illustrated schematically.

[0039] List of reference numerals

[0040] 1 tank

[0041] 2 packing

[0042] 3 Aeration Pumps

[0043] 4 aeration discs

[0044] 5 valves Detailed Implementation

[0045] The present application will be further described below with reference to specific embodiments. It should be understood that these specific embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0046] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0047] Unless otherwise stated, the terms used in this application have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this application).

[0048] The list of items connected by the terms "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

[0049] Test methods

[0050] Chemical oxygen demand (COD) concentration was tested using Hach COD(HR) reagent, a Hach DRB200 digester, and a Hach DR6000 UV spectrophotometer. 2 mL of sample was added to the Hach COD(HR) reagent and mixed thoroughly. The mixture was then digested at 150 °C for 2 h using a Hach DRB200, and the COD concentration was measured using a Hach DR6000 UV spectrophotometer.

[0051] Biotoxicity testing (as chromium equivalent concentration): Biosensors were used according to the method disclosed in Song, Y. et al., Optimization of Bacterial Whole Cell Bioreporters for Toxicity Assay of Environmental Samples. Environmental Science & Technology 43, 7931-7938 (2009). Potassium dichromate was used as the standard toxicant. Biotoxicity was assessed using luminescent bacteria and fluorescence intensity changes measured with a microplate reader. The acute biotoxicity of the samples was converted to an equivalent concentration relative to chromium. Batch testing was performed using a TECAN workstation (Instrument Fluent 780).

[0052] Example 1

[0053] Provided bacterial group 1, which consists of the genera *Oligotrophomonas*, *Trichophyton*, and *Aureobacter*.

[0054] The activated bacterial culture 1 was inoculated at a volume concentration of 2% or 2.5% into conical flasks containing 40 mL of industrial wastewater, which contained 0.3% by weight of a bactericide. The flasks were incubated at 30°C and 150 rpm for 7 days. The initial chemical oxygen demand (COD) concentration was measured to be 10000 mg / L. COD samples were taken on days 0, 1, 3, 5, and 7. After one week of operation, the COD concentration decreased by 54.3%.

[0055] Example 2

[0056] A microbial community 2 is provided, which consists of Oligotrophomonas, Pseudomonas, Brucella and Citrobacter.

[0057] After inoculating bacterial community 2 using the same method as in Example 1 and running for one week, the COD concentration decreased by 29.3%.

[0058] Example 3

[0059] A bacterial community 3 is provided, which consists of Oligotrophomonas, Pseudomonas, Salmonella, Gastroenterobacter, and Enterococcus.

[0060] After inoculating bacterial community 3 using the same method as in Example 1 and running for one week, the COD concentration decreased by 43%.

[0061] Example 4

[0062] A bacterial community 4 is provided, which consists of the genera *Oligotrophomonas*, *Citrobacter*, and *Aureobacterium*.

[0063] After inoculating bacterial community 3 with the same method as in Example 1 for one week, the COD concentration decreased by 43.1%.

[0064] Example 5

[0065] A bacterial community 5 is provided, which consists of the genera *Oligotrophomonas*, *Trichophyton*, *Aureobacter*, *Pseudomonas*, *Brucella*, *Citrobacter*, *Salmonella*, *Blephalosporium*, and *Enterococcus*.

[0066] Group 5 was used as the bacterial strain source and inoculated at a rate of 2% (v / v) in liquid medium containing TSB (30 g / L), and cultured at 30°C and 150 rpm for 12 h. The activated strain was then inoculated into 200 mL of wastewater, which contained 0.3% by weight of bactericide, and run at 30°C and 150 rpm for 7 days.

[0067] The initial chemical oxygen demand (COD) concentration was 10,000 mg / L. COD samples were taken and tested on days 0, 1, 3, 5, and 7. After one week of operation, the COD concentration decreased by 77%.

[0068] Example 6

[0069] The process was basically the same as in Example 5, except that after gradually increasing the working concentration to 30,000 mg / L and running for one cycle, the degradation rate of organic pollutants was 66%, and no biotoxicity was detected.

[0070] Example 7

[0071] The process was essentially the same as in Example 6, except that after gradually increasing the working concentration of the biofilm reactor to 50,000 mg / L and running it for one cycle, the degradation rate of organic pollutants was 57%, and no biotoxicity was detected.

[0072] Example 8

[0073] The process was basically the same as in Example 7, except that after gradually increasing the working concentration of the biofilm reactor to 80,000 mg / L and running it for one cycle, the degradation rate of organic pollutants was 48.3% and the biotoxicity decreased by 71.5%.

[0074] Example 9

[0075] A bacterial community 5 is provided, which consists of the genera *Oligotrophomonas*, *Trichophyton*, *Aureobacter*, *Pseudomonas*, *Brucella*, *Citrobacter*, *Salmonella*, *Blephalosporium*, and *Enterococcus*.

[0076] Bacterial group 5 was used as the strain source and inoculated at a rate of 2% (v / v) in liquid medium containing TSB (30 g / L), and cultured at 30°C and 150 rpm for 12 h. The biofilm reactor used was as follows: Figure 1 As shown, the aeration equipment includes, but is not limited to, the example aeration pump or aeration disc, to provide uniform aeration and ensure that the dissolved oxygen (DO) concentration is above 2 mg / L. The packing material includes, but is not limited to, plastic mesh cylinders. Impurities on the surface of the packing material are removed and sterilized during pretreatment to ensure the formation of a microbial biofilm. Pretreatment includes soaking in ethanol and rinsing with sterile water.

[0077] Industrial wastewater containing metal processing fluid was added to the biofilm reactor. Sterile water was added to the reactor's rated total volume of 5L. At the initial stage of reactor operation, the COD concentration of the industrial wastewater was 1000 mg / L and the pH range was 0 to 9. The aeration device was turned on, and the gas flow rate was controlled at 0.5 to 10 L / min. The biofilm reactor was operated at room temperature.

[0078] After 30 minutes of operation, samples were taken to test the initial COD, pH, and biotoxicity levels of the biofilm reactor. Samples were then taken every day to test COD, pH, and biotoxicity levels to monitor the degradation of industrial wastewater containing metalworking fluid within the reactor. Biotoxicity was expressed as chromium equivalent concentration. After 7 days of operation, three-quarters of the reactor liquid was discharged, and the pretreated industrial wastewater was added to the rated volume. The reactor was then operated for approximately 15 to 30 days to check the biofilm formation. Once the microbial degradation was confirmed to be effective and the biofilm formation normal, the initial COD concentration was gradually increased from 1000 mg / L to 10000 mg / L.

[0079] Once the initial COD concentration of the biofilm reactor reaches the working concentration of 10,000 mg / L, the reactor is continuously run in a sequencing batch manner for several cycles, with each cycle lasting 7 days. Between each cycle, 3 / 4 of the liquid volume in the reactor is discharged, and 3 / 4 of the industrial wastewater volume is added.

[0080] like Figure 2 As shown, after one cycle of operation, the degradation rate of organic pollutants (COD concentration change) in the reactor of Example 9 after inoculation with the dominant microbial community reached 69.3%, while the COD concentration of the blank group without inoculation with the dominant microbial community decreased by only 11.9% after 8 days.

[0081] from Figure 3 The biotoxicity test results showed that the biotoxicity of the industrial wastewater before treatment was greater than 150 μM, the biotoxicity of the pretreated industrial wastewater used as the reactor influent was 67 μM, and no biotoxicity was detected in the effluent treated by the reactor.

[0082] Example 10

[0083] The process is essentially the same as in Example 9, except that the industrial wastewater is from the processing of iron products. This wastewater contains mineral oil, polyols, esters, emulsifiers, bactericides, and residual iron. After one cycle of operation, the degradation rate of organic pollutants is 70%, and no biotoxicity can be detected.

[0084] It can be seen that despite the presence of a small amount of iron in the wastewater, the desired degradation rate of organic pollutants can still be achieved. Therefore, the microbial community according to the present invention can effectively treat wastewater from the processing of iron products.

[0085] Example 11

[0086] The process is essentially the same as in Example 9, except that the industrial wastewater is from the processing of aluminum products. This wastewater contains mineral oil, polyols, esters, emulsifiers, bactericides, and residual aluminum. After one cycle of operation, the degradation rate of organic pollutants is 70%, and no biotoxicity can be detected.

[0087] It can be seen that despite the presence of a small amount of aluminum in the wastewater, the desired degradation rate of organic pollutants can still be achieved. Therefore, the microbial community according to the present invention can effectively treat wastewater from aluminum and iron products processing.

[0088] While some exemplary embodiments of this application have been described and illustrated, this application is not limited to the disclosed embodiments. Rather, those skilled in the art will recognize that modifications and changes may be made to the described embodiments without departing from the spirit and scope of this application as described in the appended claims.

Claims

1. A bacterial flora for treating industrial wastewater, characterized in that, This bacterial group includes *Oligotrophomonas* and at least two of the following: *Trichophyton*, *Ailuropoda*, *Pseudomonas*, *Brucella*, *Citrobacter*, *Salmonella*, *Bacillus*, and *Enterococcus*. And among them, The industrial wastewater contains bactericides.

2. The microbial community according to claim 1, characterized in that, This bacterial group includes Pseudomonas and / or Paleobacterium.

3. The microbial community according to claim 1, characterized in that, This bacterial group includes or consists of the following: Oligotrophomonas, Trichomonas, and Paleobacterium.

4. The microbial community according to claim 1, characterized in that, This microbial community includes or is composed of the following: Oligotrophomonas, Pseudomonas, Brucella, and Citrobacter.

5. The microbial community according to claim 1, characterized in that, This microbial community includes or is composed of the following: Oligotrophozoites, Pseudomonas, Salmonella, Gastroenterobacteria, and Enterococcus.

6. The microbial community according to claim 1, characterized in that, This bacterial group includes or consists of the following: Oligotrophomonas, Citric Acid Bacteria, and Paleobacterium.

7. The microbial community according to claim 1, characterized in that, This microbial community includes or consists of the following genera: Oligotrophomonas, Trichomonas, Aristobacterium, Pseudomonas, Brucella, Citrobacter, Salmonella, Gastroenterobacter, and Enterococcus.

8. The microbial community according to claim 1, characterized in that, The industrial wastewater includes organic matter, which includes at least one of mineral oil, polyols, esters, and emulsifiers, and / or The industrial wastewater includes metal salts, which include at least one of iron salts and aluminum salts.

9. The microbial community according to claim 1, characterized in that, The industrial wastewater has a COD concentration of 10,000 mg / L or higher and / or the industrial wastewater has a chromium equivalent biotoxicity of 100 μM or higher.

10. Use of the microbial community according to any one of claims 1 to 9 for the treatment of industrial wastewater or contaminated soil.

Images