A method for biological treatment of acrylic acid wastewater

Abstract

The application discloses a kind of acrylic acid wastewater biological treatment methods, belong to the field of biological method treatment high concentration acrylic acid wastewater.The treatment method in wastewater is sequentially activated and cultivated by acrylic acid special solid bacterial species→wastewater treatment, this process is simple in operation, reaction is efficient, can degrade acrylic acid, finally oxidized to CO2 And H2O, acrylic acid is degraded.Wastewater with acrylic acid concentration below 5000mg / L can be treated, professional biodegradation can be carried out, and the degradation efficiency of acrylic acid is higher than 95%.The method of the application is upgrading and strengthening of ordinary biological method, and widens the application range of biological treatment of acrylic acid wastewater.

Description

Technical Field

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

[0002] Acrylic acid is an important raw material for organic synthesis, with the chemical formula C3H4O2. It is a colorless liquid with a pungent odor, miscible with water, and also miscible with ethanol and ether. It is chemically reactive and readily polymerizes in air. It is widely used in textiles, construction, pharmaceuticals, synthetic resins, and many other fields. Acrylic acid wastewater is characterized by high COD concentration, toxicity, and difficulty in biological treatment.

[0003] Currently, the main methods for treating acrylic acid wastewater are incineration, wet oxidation, and supercritical water oxidation, all of which have drawbacks such as high treatment costs and high energy consumption. Conventional biological methods for treating acrylic acid wastewater also have disadvantages such as low influent concentration limits and unstable operation. Therefore, this patent discloses a biological treatment method for acrylic acid wastewater that can treat acrylic acid wastewater with a maximum concentration of 5000 mg / L. This method is an upgrade and enhancement of conventional biological methods, broadening the applicable scope of biological treatment of acrylic acid wastewater. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by disclosing a biological treatment method for acrylic acid wastewater. This process is simple to operate and highly efficient, enabling professional biodegradation of wastewater with an influent acrylic acid concentration of less than 5000 mg / L, with an acrylic acid degradation efficiency of over 95%.

[0005] This invention is implemented as follows: A biological treatment method for acrylic acid wastewater, characterized in that the biological treatment method includes the following steps: Step 1: Activation and cultivation of acrylic acid bacteria: 1.1 Add 0.5-1‰ acrylic acid-specific compound bacteria, glucose 1-1.5g / L, tap water, pH 7-8, and culture in a culture tank at 25-35℃ for 48h to activate the bacteria, DO 2-4 mg / L; 1.2 After the bacterial strain is activated, the bacterial density is measured, and it reaches 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that activation culture has been completed.

[0006] Step 2: Wastewater Treatment 2.1. The acrylic acid process wastewater with pH adjusted to 7-8 is introduced into the acrylic acid wastewater biological treatment tank. The temperature is controlled at 25-35℃, and the reaction time and dissolved oxygen are controlled. 10% activated and cultured acrylic acid-specific degrading bacteria solution is added to the acrylic acid wastewater biological treatment tank, and the acrylic acid-specific degrading bacteria are immobilized on polyurethane packing. 2.2 When the influent acrylic acid concentration is less than 1000 mg / L or COD is less than 1500 mg / L during system startup, add 500 mg / L COD equivalent carbon source. 2.3. Increase the load in a gradient of 500-1000 mg / L for acrylic acid concentration or 500-1000 mg / L for COD, with priority given to COD. Replace 50-60% of the water in each batch until the influent load reaches the target influent acrylic acid concentration; the maximum influent acrylic acid concentration at full load can reach 5000 mg / L. 2.3 The hydraulic residence time (HRT) is: Influent acrylic acid 1000-2000 mg / L, HRT 24h; Influent acrylic acid 2000-3000 mg / L, HRT 48h; Influent acrylic acid 3000-5000 mg / L, HRT 72h.

[0007] 2.4 Processing Technology: An aerobic biochemical process is adopted; the reaction tank has been inoculated with activated acrylic acid-specific degrading bacteria and 70% polyurethane packing.

[0008] Furthermore, the feature is that, during the strain domestication process in steps 2.1 to 2.3, the pH of the influent is 7-8, the reaction temperature is 25-35℃, and the optimal acrylic acid influent concentration is 1000-3000 mg / L; Furthermore, the acrylic acid-specific solid bacteria are characterized by being prepared by microbial agents using strains of Bacillus lysine, Bacillus pseudoanthraceae, Bacillus brevis, Bacillus obbinensis, Bacillus brevis, and Bacillus brevis strains in a mass ratio of 1:1:1:1:1. Furthermore, the implementation method of the acrylic acid-specific degrading bacteria and polyurethane packing is as follows: the acrylic acid-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, COD and TOC indicators are sampled and measured, and the removal effect is stable for 5-10 days after the acrylic acid degradation rate is greater than 90%. The acrylic acid concentration in the influent is gradually increased in a gradient of 500-1000 mg / L, and 50-60% of the water is replaced in each batch until the influent load is the target influent acrylic acid concentration. The advantages of this invention compared to the prior art are as follows: 1. This invention can treat high-concentration acrylic acid wastewater using a fully biological method, with good results, low cost, and no secondary pollution.

[0009] 2. The acrylic acid-specific degrading bacteria used in this invention are formulated according to a unique formula and can treat high-concentration acrylic acid wastewater. When the acrylic acid concentration is less than 5000 mg / L, it can perform professional biodegradation with an acrylic acid degradation efficiency of over 95%.

[0010] 3. This invention can treat high-concentration acrylic acid wastewater using a fully biological method, which can degrade acrylic acid and ultimately oxidize it into CO2 and H2O, thus degrading the acrylic acid. Attached Figure Description

[0011] Figure 1 This is a graph showing the change in COD in an embodiment of the present invention; Figure 2 This is a graph showing the change in TOC in an embodiment of the present invention. Detailed Implementation

[0012] 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.

[0013] A biological treatment method for acrylic acid wastewater is characterized in that the wastewater undergoes sequential activation and cultivation of acrylic acid-specific solid microbial strains, followed by wastewater treatment. The specific implementation scheme is as follows: 1. Add 0.5-1‰ acrylic acid-specific compound bacteria, 1-1.5 g / L glucose, tap water, pH 7-8, and culture in a culture tank at 25-35℃ with aeration (DO 2-4 mg / L) for 48 hours to activate the bacterial strain; the acrylic acid-specific solid is a microbial agent prepared from strains of Bacillus lysine, Bacillus pseudoanthraceae, Bacillus brevis, Bacillus obbenza, and Bacillus malformans in a ratio of 1:1:1:1:1 (mass ratio); 2. After the bacterial strain is activated, the bacterial density is measured, and it reaches 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that activation culture has been completed.

[0014] 3. Adjust the pH of the process wastewater to 6-9. If the acrylic acid concentration in the system influent is less than 1000 mg / L (or COD less than 1500 mg / L, COD preferred), a 500 mg / L COD equivalent carbon source can be added. 4. The implementation method of acrylic acid-specific degrading bacteria and polyurethane packing is as follows: The acrylic acid-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 and testing of indicators such as COD and TOC are performed. After the acrylic acid degradation rate is greater than 90%, the removal effect is stable for 5-10 days. The concentration of acrylic acid in the influent is gradually increased in a gradient of 500-1000 mg / L. 50-60% of the water is replaced in each batch until the influent load is the target influent acrylic acid concentration. 5. The appropriate biological treatment process for acrylic acid can be selected based on the concentration of acrylic acid in the wastewater and the actual site conditions (used alone or in combination with the conventional activated sludge process) and retention time: an aerobic biological process can be adopted, with the aerobic reactor already inoculated with acrylic acid-specific degrading bacteria and 70% polyurethane packing. The hydraulic retention times are: influent acrylic acid 1000-2000 mg / L, HRT 24h; influent acrylic acid 2000-3000 mg / L, HRT 48h; influent acrylic acid 3000-5000 mg / L, HRT 72h.

[0015] The following are specific examples illustrating the application of the described biological treatment method for acrylic acid wastewater: Example

[0016] The target influent acrylic acid concentration for a wastewater treatment project is 5000 mg / L. Activated acrylic acid-specific degrading bacteria were added at a dosage of 10% to an aerobic treatment reactor containing 70% polyurethane packing. The retention time was controlled, and the influent acrylic acid concentration was gradually increased in a gradient of 500-1000 mg / L, with 50-60% of the water replaced per batch, until the influent load reached the target influent acrylic acid concentration. Analysis results showed that the COD of the aerobic effluent was less than 200 mg / L, and the COD and TOC removal rates were both greater than 95%. Figure 1 The effect of acrylic COD treatment and Figure 2 (The TOC treatment effect of acrylic acid) Acrylic acid can be efficiently biodegraded.

[0017] 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 biological treatment method for acrylic acid wastewater, characterized in that the biological treatment method includes the following steps: Step 1, Activation and Cultivation of Acrylic Acid Microorganisms: Step 1 specifically involves: 1.1 Add 0.5-1‰ acrylic acid-specific compound bacteria, 0.5-1g / L glucose, tap water, pH 7-8, and culture in a culture tank at 25-35℃ for 48h to activate the bacteria, with DO of 2-4mg / L; 1.2 After the bacterial strain is activated, the bacterial density is measured, and it reaches 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that activation culture has been completed; Step 2: Wastewater Treatment 2.

1. The acrylic acid process wastewater with pH adjusted to 7-8 is introduced into the wastewater biological treatment tank. The temperature is controlled at 25-35℃, the reaction time and dissolved oxygen are controlled at 2-4mg / L. 10% activated culture of acrylic acid-specific degrading bacteria solution is added to the wastewater biological treatment tank, and the acrylic acid-specific degrading bacteria are immobilized on polyurethane packing. 2.2 When the influent acrylic acid concentration is less than 1000 mg / L or COD is less than 1500 mg / L during system startup, add 500 mg / L LCOD equivalent carbon source. 2.

3. Gradually increase the load according to the acrylic acid concentration of 500-1000 mg / L or the COD of 500-1000 mg / L, with priority given to COD. Replace 50-60% of the water in each batch until the influent load reaches the target influent acrylic acid concentration; the maximum influent acrylic acid concentration at full load can reach 5000 mg / L. 2.4 The hydraulic residence time (HRT) is: The influent acrylic acid concentration is 1000-2000 mg / L, and the HRT is 24h. The influent acrylic acid concentration is 2000-3000 mg / L, and the HRT is 48h. The influent acrylic acid concentration is 3000-5000 mg / L, and the HRT is 72h. 2.5 Treatment Process: An aerobic biochemical process is adopted; the reaction tank has been inoculated with activated acrylic acid-specific degrading bacteria and 70% polyurethane packing material; during the bacterial acclimatization process in steps 2.1 to 2.3, the influent pH is 7-8 and the reaction temperature is 25-35℃; the optimal acrylic acid influent concentration is 1000-3000 mg / L; the acrylic acid-specific solid bacteria are characterized by being prepared from microbial agents made from strains of Bacillus lysine, Bacillus pseudoanthraceae, Bacillus brevis, Bacillus obbenza, and Bacillus brevis in a mass ratio of 1:1:1:1:

1.

2. The biological treatment method for acrylic acid wastewater according to claim 1, characterized in that, The implementation method of acrylic acid-specific degrading bacteria and polyurethane packing is as follows: the acrylic acid-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. COD and TOC indicators are measured. After the acrylic acid degradation rate is greater than 90%, the removal effect is stable for 5-10 days. The acrylic acid concentration in the influent is gradually increased in a gradient of 500-1000mg / L. 50-60% of the water is replaced in each batch until the influent load is the target influent acrylic acid concentration.

Images