High-concentration pyridine wastewater full biological treatment method

Abstract

The application discloses a kind of high concentration pyridine wastewater full biological treatment method, belong to the field of biological method treatment high concentration pyridine wastewater.The treatment method in wastewater is sequentially through pyridine strain screening domestication culture strain optimization culture-wastewater treatment, this process is simple, reaction efficient, can be 4000mg / L below pyridine full biodegradation, pyridine degradation efficiency is higher than 99%;The application can be full biological method treatment high concentration pyridine wastewater, effect is good, cost is low, no secondary pollution.The method of the application is the upgrading of ordinary biological method, widen the scope of application of biological treatment pyridine wastewater.

Description

Technical Field

[0001] This invention belongs to the field of biological methods for treating high-concentration pyridine wastewater, and specifically relates to a biological treatment method for pyridine wastewater. Background Technology

[0002] Pyridine (C5H5N) is an organic compound, a six-membered heterocyclic compound containing one nitrogen atom. Industrially, pyridine is used as a denaturing agent, a dyeing auxiliary, and a raw material for synthesizing a range of products, including pharmaceuticals, disinfectants, and dyes. Currently, pyridine treatment methods include adsorption, distillation, and incineration. Adsorption and distillation methods involve complex equipment and high costs, while incineration generates secondary pollution from waste gas. Therefore, developing targeted microbial strains and application methods specifically for pyridine wastewater can efficiently and cost-effectively treat high-concentration pyridine wastewater, possessing significant application and promotion value.

[0003] Therefore, this patent discloses a fully biological treatment method for high-concentration pyridine wastewater. This method can rapidly and cost-effectively screen for pyridine-specific degrading bacteria, and by adding glucose for co-metabolism during the aerobic degradation process of pyridine, the degradation rate of pyridine can be improved and the degradation time shortened. This method is an upgrade and enhancement of ordinary biological methods, broadening the applicability of biological treatment of pyridine wastewater. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by disclosing a fully biological treatment method for high-concentration pyridine wastewater. This process is simple to operate and highly efficient, enabling professional biodegradation of wastewater with an influent pyridine concentration of less than 4000 mg / L, with a pyridine degradation efficiency of over 99%.

[0005] This invention is implemented as follows:

[0006] A fully biological treatment method for high-concentration pyridine wastewater, characterized in that the biological treatment method includes the following steps:

[0007] Step 1: Screening and acclimatization of pyridine strains:

[0008] 1.1 Take activated sludge from a pyridine-containing wastewater treatment plant, add glucose 1-1.5 g / L, tap water, pH 7-8, and culture in a microbial culture tank at 25-35℃ for 1-2 days with DO 2-4 mg / L;

[0009] 1.2 Under the condition that the culture conditions remain unchanged, gradually change the ratio of glucose solution and pyridine wastewater until the final pyridine concentration in the influent is half of the target concentration designed in the scheme.

[0010] 1.3. Measure COD, and after stabilization, change half of the water every 48 hours to maintain the nutrients required by the microorganisms in the activated sludge.

[0011] Step 2: Optimization of microbial strain cultivation:

[0012] 2.1 Take out the activated sludge from the wastewater in the expansion tank after completing step one, prepare a bacterial suspension, add distilled water and shake well, then centrifuge the bacterial suspension at 3000 r / min for 10 min and take the supernatant.

[0013] 2.2. Take one loopful of supernatant with an inoculation loop and inoculate it into a solid culture medium. Incubate at room temperature for 48-72 hours and observe for obvious bacterial growth on the surface of the culture dish.

[0014] 2.3. Use an inoculation loop to pick up microorganisms from colonies of different shapes in the solid culture medium, and use the streak plate method to incubate them in solid culture medium with 1 / 2 the target wastewater pyridine concentration and solid culture medium containing the target wastewater pyridine concentration, respectively, at 25-30℃ for 48-72h.

[0015] 2.4 Repeat step 2.3 as needed until only a single colony exists in the solid culture medium, thus completing the screening and purification of the microbial strain;

[0016] 2.5. Select colonies of different shapes from the solid culture medium and culture them in liquid culture medium at 25-30℃ on a shaker for 48-72h. Prepare optimized pyridine compound bacterial suspensions from the strains obtained from plates of different concentrations.

[0017] Step 3: Biological treatment of pyridine wastewater:

[0018] 3.1. Pyridine wastewater with pH adjusted to 7-8 is introduced into the biological treatment tank. The temperature is controlled at 25-35℃, and the reaction time and dissolved oxygen are controlled. 10% pyridine composite bacterial solution is added to the biological treatment tank, and pyridine-specific degrading bacteria are immobilized on polyurethane packing.

[0019] 3.2 When the influent pyridine concentration is less than 1500 mg / L or COD is less than 2000 mg / L during system startup, add 500 mg / L COD equivalent glucose as a carbon source.

[0020] 3.3. Increase the load in a gradient of pyridine concentration of 500-1000 mg / L or COD of 1000-1500 mg / L, with priority given to COD. Replace 50-60% of the water in each batch until the influent load reaches the target influent pyridine concentration; the maximum influent pyridine concentration at full load can reach 3000-4000 mg / L.

[0021] 3.4 The hydraulic residence time (HRT) is:

[0022] Influent pyridine 500-2000 mg / L, HRT 24h;

[0023] Influent pyridine 2000-3000 mg / L, HRT 48h;

[0024] The influent was pyridine 4000 mg / L, HRT 72 h, and 2 g / L glucose was added as a co-metabolized carbon source;

[0025] 3.5 Processing Technology:

[0026] An aerobic biological process is adopted, with a gas volume in the range of 4.5-5.0 L / h; the aerobic reaction tank has been inoculated with 10% pyridine compound bacteria solution and 70% polyurethane packing material;

[0027] Furthermore, in the biological treatment process of pyridine wastewater in steps 3.1 to 3.3, the influent pH is 7-8, and the optimal influent pyridine concentration is 500-3000 mg / L.

[0028] Furthermore, the target concentration for the domestication of the exclusive degrading bacteria is divided into two parts: half of the target wastewater pyridine concentration and the target wastewater pyridine concentration. This is to screen out as many exclusive complex bacterial groups as possible that can treat low-concentration and high-concentration pyridine.

[0029] Furthermore, the implementation method of the pyridine-specific degrading bacteria and polyurethane packing is as follows: the pyridine-specific degrading bacteria agent is added to the reaction tank containing 70% polyurethane packing in 2-3 batches at a dosage of 10%, the residence time is controlled at 24-72h, and samples are taken to measure indicators such as pyridine, TOC, and ammonia nitrogen. After the degradation rate is greater than 90%, the removal effect is stable for 5-10 days. The concentration of pyridine in the influent is gradually increased in a pyridine concentration gradient of 500-1000mg / L, and 50-60% of the water is replaced in each batch until the influent load is the target influent pyridine concentration.

[0030] The advantages of this invention compared to the prior art are as follows:

[0031] 1. This invention can treat high-concentration pyridine wastewater using a fully biological method, with good results, low cost, and no secondary pollution.

[0032] 2. The screening of pyridine-specific degrading bacteria used in this invention is based on a unique target concentration setting, with the aim of screening to obtain as many exclusive complex bacterial groups as possible that can process low-concentration and high-concentration pyridine.

[0033] 3. This invention selects glucose as a cometabolite carbon source, which can provide energy for microbial growth while inducing the synthesis or secretion of corresponding enzymes involved in substrate metabolism, and producing cofactors as electron donors in the metabolic pathway. Simultaneously, the cometabolites can also participate in the degradation process of recalcitrant compounds. Ultimately, this enables the complete biodegradation of pyridine wastewater when pyridine concentrations are below 4000 mg / L, with a pyridine degradation efficiency exceeding 99%. Attached Figure Description

[0034] Figure 1 This is a graph showing the TOC changes in Embodiment 1 of the present invention;

[0035] Figure 2 This is the GCMS spectrum of pyridine in the feed water in Example 1 of the present invention;

[0036] Figure 3 This is the GCMS spectrum of pyridine in the effluent from Example 1 of the present invention; Detailed Implementation

[0037] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following examples provide a more detailed description of the invention. It should be noted that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0038] A fully biological treatment method for high-concentration pyridine wastewater is characterized in that the wastewater undergoes sequential processes of screening and acclimatization of pyridine bacteria → optimized culture of the bacteria → wastewater treatment. The specific implementation scheme is as follows:

[0039] Take activated sludge from a pyridine-containing wastewater treatment plant, add 1-1.5 g / L glucose and tap water, pH 7-8, and culture in a microbial propagation tank at 25-35℃ for 1-2 days with DO 2-4 mg / L. Under constant culture conditions, gradually change the ratio of glucose to pyridine wastewater until the final influent pyridine concentration is half of the target concentration designed in the program. Measure COD, and after stabilization, replace half the water every 48 hours to maintain the nutrients required by the microorganisms in the activated sludge. Microscopic examination shows a COD level of 1×10⁻⁶. 9 CFU / mL indicates that the screening culture has been completed.

[0040] The activated sludge that has completed screening and culture is taken out and made into a bacterial suspension. Distilled water is added and shaken well. The bacterial suspension is centrifuged at 3000 r / min for 10 min and the supernatant is collected. One loopful of the supernatant is inoculated into a solid culture medium and cultured at room temperature for 48-72 h. The growth of the bacterial species on the surface of the culture dish is observed. Microorganisms of different shapes in the solid culture medium are picked up with an inoculation loop and cultured in solid culture medium with 1 / 2 concentration of target wastewater pyridine and solid culture medium containing the target wastewater pyridine concentration for 48-72 h at 25-30 ℃ using the streak plate method. The above steps are repeated as needed until only a single colony exists in the solid culture medium, which completes the screening and purification of microbial strains. Colonies of different shapes in the solid culture medium are picked and cultured in liquid culture medium at 25-30 ℃ in a shaker for 48-72 h. The strains obtained from the plates of different concentrations are used to prepare the optimized pyridine complex bacterial suspension.

[0041] After the bacterial culture was completed, the bacterial density was measured, and it reached 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that the bacterial strain has been optimized.

[0042] The biological treatment process for high-concentration pyridine wastewater can be selected according to the pyridine concentration in the wastewater and the actual site conditions: influent pyridine 500-2000 mg / L, HRT 24h; influent pyridine 2000-3000 mg / L, HRT 48h; influent pyridine 4000 mg / L, HRT 72h, with 2 g / L glucose added as a co-metabolism carbon source;

[0043] The following are specific examples illustrating the application of the biological treatment method for high-concentration pyridine wastewater:

[0044] Example 1

[0045] A wastewater treatment project had a pyridine concentration of 4000 mg / L. Pyridine-specific degrading bacteria, after optimized cultivation, were added at a dosage of 10% to an aerobic treatment reactor containing 70% polyurethane packing material. Aerobic reactions were conducted at influent pyridine concentrations of 2000 mg / L, 3000 mg / L, and 4000 mg / L, with controlled retention times. TOC (Total Organic Carbon) levels were measured. Analysis showed that the effluent TOC was 25 mg / L after 24 hours of aerobic treatment with 2000 mg / L pyridine, 29 mg / L after 48 hours with 3000 mg / L pyridine, and 23 mg / L after 72 hours with 4000 mg / L pyridine.

[0046] like Figures 1-3 As shown, Figure 1 This is a graph showing the TOC changes in Embodiment 1 of the present invention; Figure 2 This is the GCMS spectrum of pyridine in the feed water in Example 1 of the present invention; Figure 3 The above figure shows the GCMS spectrum of pyridine in the effluent from Example 1 of this invention. As can be seen from the figure, the process of this invention is simple to operate and highly efficient, capable of completely biodegrading pyridine concentrations below 4000 mg / L, with a degradation efficiency exceeding 99%.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A fully biological treatment method for high-concentration pyridine wastewater, characterized in that, The processing method includes the following steps: Step 1: Screening and domestication of pyridine strains; 1.1 Take activated sludge from a pyridine-containing wastewater treatment plant, add glucose 1-1.5 g / L, tap water, pH 7-8, and culture in a microbial culture tank at 25-35℃ for 1-2 days with DO 2-4 mg / L; 1.2 Under the condition that the culture conditions remain unchanged, gradually change the ratio of glucose solution and pyridine wastewater until the final pyridine concentration in the influent is half of the target concentration designed in the scheme. 1.

3. Measure COD, and after stabilization, change half of the water every 48 hours to maintain the nutrients required by the microorganisms in the activated sludge. Step 2: Optimization of bacterial strain cultivation; Step 3: Biological treatment of pyridine wastewater: 3.

1. Pyridine wastewater with pH adjusted to 7-8 is introduced into the biological treatment tank. The temperature is controlled at 25-35℃, and the reaction time and dissolved oxygen are controlled. 10% pyridine composite bacterial solution is added to the biological treatment tank, and pyridine-specific degrading bacteria are immobilized on polyurethane packing. 3.2 When the concentration of pyridine in the influent is less than 1500 mg / L or the COD is less than 2000 mg / L when the system is started, add 500 mg / L COD equivalent glucose as a carbon source. 3.

3. Increase the load in a gradient of pyridine concentration of 500-1000 mg / L or COD of 1000-1500 mg / L, with priority given to COD. Replace 50-60% of the water in each batch until the influent load reaches the target influent pyridine concentration; the maximum influent pyridine concentration at full load can reach 3000-4000 mg / L. 3.4 The hydraulic residence time (HRT) is: Influent pyridine 500-2000 mg / L, HRT 24h; Influent pyridine 2000-3000 mg / L, HRT 48h; The influent was pyridine 4000 mg / L, HRT 72h, and 2 g / L glucose was added as a co-metabolized carbon source; 3.5 Processing Technology: An aerobic biological process is adopted, with a gas flow rate in the range of 4.5-5.0 L / h; the aerobic reaction tank has been inoculated with 10% pyridine compound bacteria solution and 70% polyurethane packing material; The target concentration for the domestication of the specific degrading bacteria is divided into two parts: half of the target wastewater pyridine concentration and the target wastewater pyridine concentration. This is to screen out as many specific composite bacterial groups as possible that can treat low-concentration and high-concentration pyridine.

2. The method for the fully biological treatment of high-concentration pyridine wastewater according to claim 1, characterized in that, The second step is specifically as follows: 2.1 Take out the activated sludge from the wastewater in the expansion tank after completing step one, prepare a bacterial suspension, add distilled water and shake well, then centrifuge the bacterial suspension at 3000 r / min for 10 min and take the supernatant. 2.

2. Take one loopful of supernatant with an inoculation loop and inoculate it into a solid culture medium. Incubate at room temperature for 48-72 hours and observe for obvious bacterial growth on the surface of the culture dish. 2.

3. Use an inoculation loop to pick up microorganisms from colonies of different shapes in the solid culture medium, and use the streak plate method to incubate them in solid culture medium with 1 / 2 the target wastewater pyridine concentration and solid culture medium containing the target wastewater pyridine concentration, respectively, at 25-30℃ for 48-72h. 2.4 Repeat step 2.3 as needed until only a single colony exists in the solid culture medium, thus completing the screening and purification of the microbial strain; 2.

5. Select colonies of different shapes from the solid culture medium and culture them in liquid culture medium at 25-30℃ on a shaker for 48-72h. Prepare optimized pyridine compound bacterial suspensions from the strains obtained from plates of different concentrations.

3. The method for the fully biological treatment of high-concentration pyridine wastewater according to claim 1, characterized in that, In the biological treatment of pyridine wastewater in steps 3.1 to 3.3, the influent pH is 7-8, and the optimal influent pyridine concentration is 500-3000 mg / L.

4. The method for the fully biological treatment of high-concentration pyridine wastewater according to claim 1, characterized in that, The implementation method of pyridine-specific degrading bacteria and polyurethane packing is as follows: The pyridine-specific degrading bacteria agent is added to the reaction tank containing 70% polyurethane packing in 2-3 batches at a dosage of 10%. The residence time is controlled at 24-72h. Sampling is taken to measure the indicators of COD, TOC and ammonia nitrogen. After the degradation rate is greater than 90% and stabilized for 5-10 days, the pyridine concentration of the influent is gradually increased in a pyridine concentration gradient of 500-1000 mg / L. 50-60% of the water is replaced in each batch until the influent load is the target influent pyridine concentration.

5. The method for the fully biological treatment of high-concentration pyridine wastewater according to claim 1, characterized in that, The glucose, as a cometabolite carbon source, provides energy for microbial growth while inducing the synthesis or secretion of corresponding enzymes involved in substrate metabolism, and generates cofactors as electron donors in the metabolic pathway. At the same time, the cometabolites can also participate in the degradation process of recalcitrant compounds.

6. The method for the fully biological treatment of high-concentration pyridine wastewater according to claim 1, characterized in that, The implementation method of pyridine-specific degrading bacteria and polyurethane packing is as follows: The pyridine-specific degrading bacteria agent is added to the reaction tank containing 70% polyurethane packing in 2-3 batches at a dosage of 10%. The residence time is controlled at 24-72h. Samples are taken to measure pyridine, TOC and ammonia nitrogen. After the degradation rate is greater than 90% and stabilized for 5-10 days, the influent pyridine concentration is gradually increased in a pyridine concentration gradient of 500-1000 mg / L. 50-60% of the water is replaced in each batch until the influent load is the target influent pyridine concentration.

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