Biological treatment method for acrylic acid wastewater

Abstract

The invention discloses a biological treatment method for acrylic acid wastewater, and belongs to the field of biological treatment of high-concentration acrylic acid wastewater. According to the treatment method, wastewater is sequentially subjected to activation and culture of an acrylic acid exclusive solid strain and wastewater treatment, the process is easy to operate and efficient in reaction, acrylic acid can be degraded and finally oxidized into CO2 and H2O, and acrylic acid is degraded. The wastewater with the inlet water acrylic acid concentration of 5000 mg / L or below can be treated, professional biodegradation can be carried out, and the acrylic acid degradation efficiency is higher than 95%. According to the method, a common biological method is upgraded and enhanced, and the application range of biological treatment of the acrylic acid wastewater is widened.

Description

Technical Field

[0001] The present invention belongs to the field of biological treatment of high-concentration acrylic acid wastewater, and particularly relates to a biological treatment method for acrylic acid wastewater. Background Art

[0002] Acrylic acid is an important organic synthesis raw material with the chemical formula C3H4O2. It is a colorless liquid with a pungent odor, miscible with water, and can be miscible with ethanol and ether. It has active chemical properties and is prone to polymerization in the air. It is widely used in many fields such as textiles, construction, medicine, and synthetic resins. Acrylic acid wastewater has the characteristics of high COD concentration, toxicity, and difficult biodegradation.

[0003] Currently, the main treatment methods for acrylic acid wastewater are incineration method, wet oxidation method, supercritical water oxidation method, etc. All of them have disadvantages such as high treatment costs and high energy consumption to varying degrees. While the ordinary biological method for treating acrylic acid wastewater has disadvantages such as low inlet concentration limit and unstable operation. Therefore, this patent discloses a biological treatment method for acrylic acid wastewater, which can treat acrylic acid wastewater with a maximum concentration of 5000 mg / L. This method is an upgrade and enhancement of the ordinary biological method, broadening the applicable range of biological treatment of acrylic acid wastewater. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention discloses a biological treatment method for acrylic acid wastewater. The process is simple to operate and highly efficient in reaction, enabling wastewater with an inlet acrylic acid concentration below 5000 mg / L to be professionally biodegradable, and the acrylic acid degradation efficiency is higher than 95%.

[0005] The present invention is realized as follows: A biological treatment method for acrylic acid wastewater, characterized in that the biological treatment method comprises the following steps: Step 1: Activation and cultivation of acrylic acid strains: 1.1 Add 0.5 - 1‰ acrylic acid exclusive composite bacteria, 1 - 1.5 g / L of glucose, tap water, pH 7 - 8, and aerobically cultivate at 25 - 35°C in a strain expansion tank for 48 h to activate the strains, with DO 2 - 4 mg / L; 1.2 After the activation of the strains is completed, detect the bacterial density. When the microscopic examination reaches 1×10 9 CFU / mL, the activation cultivation is completed.

[0006] Step 2: Wastewater treatment: 2.1 Introduce the acrylic acid process wastewater with the pH adjusted to 7 - 8 into the acrylic acid wastewater biological treatment pool, control the temperature at 25 - 35°C, control the reaction time and dissolved oxygen. 10% of the activated and cultivated acrylic acid exclusive degradation bacteria liquid is added to the acrylic acid wastewater biological treatment pool, and the acrylic acid exclusive degradation bacteria are immobilized on polyurethane fillers; 2.2. When the acrylic acid concentration in the influent is less than 1000 mg / L or the COD is less than 1500 mg / L at system startup, add a carbon source equivalent to 500 mg / L of COD. 2.3. Gradually increase the negative load according to the acrylic acid concentration gradient of 500 - 1000 mg / L or the COD gradient of 500 - 1000 mg / L, with priority given to COD. Change 50 - 60% of the water for each batch until the influent load reaches the target acrylic acid concentration in the influent. The maximum acrylic acid concentration at full load in the influent can reach 5000 mg / L. 2.3. The hydraulic retention time (HRT) is as follows: When the acrylic acid in the influent is 1000 - 2000 mg / L, HRT is 24 h; When the acrylic acid in the influent is 2000 - 3000 mg / L, HRT is 48 h; When the acrylic acid in the influent is 3000 - 5000 mg / L, HRT is 72 h.

[0007] 2.4. Treatment process: Adopt an aerobic biochemical process; the reaction tank has been inoculated with activated acrylic acid - specific degradation bacteria and 70% polyurethane fillers.

[0008] Furthermore, it is characterized in that during the strain domestication process of steps 2.1 - 2.3, the influent pH is 7 - 8, the reaction temperature is 25 - 35 °C; the optimal acrylic acid concentration in the influent is 1000 - 3000 mg / L. Furthermore, the acrylic acid - specific solid bacteria are characterized as follows: a microbial agent prepared from Lysinibacillus sphaericus, Pseudochrobactrum asaccharolyticum, Brevibacillus brevis, Pseudogracilibacillus aurantiacus, Brevundimonas diminuta, and Brevundimonas diminuta strains is proportioned according to the mass ratio of 1:1:1:1:1. Furthermore, the implementation method of immobilizing the acrylic acid - specific degradation bacteria and polyurethane fillers is as follows: the acrylic acid - specific degradation bacteria agent is added to the reaction tank filled with 70% polyurethane fillers in 2 - 3 batches according to a dosing amount of 10%, control the residence time to be 24 - 72 h, sample and measure the COD and TOC indexes. After the acrylic acid degradation rate is greater than 90%, the removal effect is stable for 5 - 10 d. Gradually increase the acrylic acid concentration in the influent according to the acrylic acid concentration gradient of 500 - 1000 mg / L, and change 50 - 60% of the water for each batch until the influent load reaches the target acrylic acid concentration in the influent. The beneficial effects of the present invention compared with the prior art are as follows: 1. The present invention can treat high - concentration acrylic acid wastewater by a completely biological method, with good effects, low cost, and no secondary pollution.

[0009] 2. The proprietary acrylic acid-degrading bacteria used in the present invention are formulated according to a unique formula for proprietary degrading bacteria, and can treat high-concentration acrylic acid wastewater. When the acrylic acid is less than 5000 mg / L, professional biodegradation can be carried out, and the acrylic acid degradation efficiency is higher than 95%.

[0010] 3. The present invention can treat high-concentration acrylic acid wastewater by a completely biological method, degrade acrylic acid, and finally oxidize it into CO2 and H2O, and the acrylic acid is degraded. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a graph of COD change in the embodiment of the present invention; Figure 2 It is a graph of TOC change in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] To make the purpose, technical solution and effects of the present invention clearer and more definite, the following examples are listed to further illustrate the present invention in detail. It should be noted that the specific implementation described here is only used to explain the present invention and is not used to limit the present invention.

[0013] A biological treatment method for acrylic acid wastewater, characterized in that in the treatment method, the wastewater sequentially passes through activation and cultivation of proprietary solid bacteria for acrylic acid and wastewater treatment, and the specific implementation plan is as follows: 1. Add 0.5-1‰ of proprietary composite bacteria for acrylic acid, 1-1.5 g / L of glucose, tap water, pH 7-8, and aerate (DO 2-4 mg / L) at 25-35 °C in the strain expansion tank for 48 h to activate the strain; the proprietary solid for acrylic acid is a microbial agent prepared from Lysinibacillus sphaericus, Pseudochrobactrum sp., Brevibacillus brevis, Pseudogracilibacillus aurantiacus, and Brevundimonas diminuta strains in a ratio of 1:1:1:1:1 (mass ratio); 2. After the strain activation is completed, detect the strain density, and when the microscopic examination reaches 1×10 9 CFU / mL, the activation culture is completed.

[0014] 3. Adjust the pH of the process wastewater to pH = 6-9 to adjust the pH of the wastewater. When the acrylic acid concentration in the system inlet water is less than 1000 mg / L (or the COD is less than 1500 mg / L, COD is preferred), 500 mg / L of COD equivalent carbon source can be added; 4. The implementation method of the acrylic acid-specific degrading bacteria and polyurethane filler immobilization is as follows: The acrylic acid-specific degrading bacteria agent is added into the reaction tank filled with 70% polyurethane filler in 2 - 3 batches according to the dosing amount of 10%. The residence time is controlled to be 24 - 72 h. Samples are taken to measure indexes such as COD and TOC. After the acrylic acid degradation rate is greater than 90%, the removal effect is stable for 5 - 10 d. The influent acrylic acid concentration is gradually increased in the acrylic acid concentration gradient of 500 - 1000 mg / L, and 50 - 60% of the water is changed in each batch until the influent load reaches the target influent acrylic acid concentration. 5. The acrylic acid biological treatment process can select a suitable biochemical treatment process (used alone or in combination with the ordinary activated sludge method) and residence time according to the acrylic acid concentration of the wastewater and the actual situation on site: The aerobic biochemical process can be adopted. The aerobic reaction tank has been inoculated with acrylic acid-specific degrading bacteria and 70% polyurethane filler. The hydraulic residence time is as follows: when the influent acrylic acid is 1000 - 2000 mg / L, HRT is 24 h; when the influent acrylic acid is 2000 - 3000 mg / L, HRT is 48 h; when the influent acrylic acid is 3000 - 5000 mg / L, HRT is 72 h.

[0015] The following lists specific examples to describe the application of the acrylic acid wastewater biological treatment method described above: Example

[0016] In a certain wastewater project, the target influent acrylic acid concentration is 5000 mg / L. The activated acrylic acid-specific degrading bacteria are added into the aerobic treatment reaction tank filled with 70% polyurethane filler according to the dosing amount of 10%. The residence time is controlled, and the influent acrylic acid concentration is gradually increased in the acrylic acid concentration gradient of 500 - 1000 mg / L, and 50 - 60% of the water is changed in each batch until the influent load reaches the target influent acrylic acid concentration. The analysis and detection results show that the aerobic effluent COD is less than 200 mg / L, and the removal rates of COD and TOC are both greater than 95% ( Figure 1 the acrylic acid COD treatment effect and Figure 2 the acrylic acid TOC treatment effect), and acrylic acid can be efficiently biodegradated.

[0017] The above is only the preferred implementation mode of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements can still be made, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A biological treatment method for acrylic wastewater, characterized in that, The described biological treatment method includes the following steps: Step 1, activation and cultivation of acrylic acid strains: Step 2, wastewater treatment: (2.1) Introduce the acrylic acid process wastewater with the pH adjusted to 7 - 8 into the wastewater biological treatment tank, control the temperature at 25~35°C, control the reaction time and dissolved oxygen at 2 - 4 mg / L. Add 10% of the activated and cultivated acrylic acid-specific degradation bacteria liquid into the wastewater biological treatment tank, and immobilize the acrylic acid-specific degradation bacteria on polyurethane fillers; (2.2) When the influent acrylic acid concentration is less than 1000 mg / L or the COD is less than 1500 mg / L at the start-up of the system, supplement 500 mg / L of COD equivalent carbon source; (2.3) Gradually increase the negative load according to the acrylic acid concentration gradient of 500 - 1000 mg / L or the COD gradient of 500 - 1000 mg / L, with COD taking priority. Change 50 - 60% of the water for 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 retention time HRT is: When the influent acrylic acid is 1000 - 2000 mg / L, HRT is 24 h; When the influent acrylic acid is 2000 - 3000 mg / L, HRT is 48 h; When the influent acrylic acid is 3000 - 5000 mg / L, HRT is 72 h; (2.4) Treatment process: Adopt aerobic biochemical process; the reaction tank has been inoculated with the activated acrylic acid-specific degradation bacteria and 70% polyurethane fillers.

2. The biological treatment method for acrylic acid wastewater according to claim 1, wherein, The specific content of the described Step 1 is: (1.1) Add 0.5 - 1‰ of acrylic acid-specific complex bacteria, 0.5 - 1 g / L of glucose, tap water, pH 7 - 8, aerobically cultivate in the strain expansion tank at 25 - 35°C for 48 h to activate the strain, DO 2 - 4 mg / L; (1.2) After the strain activation is completed, the bacterial density is detected. When the microscopic examination reaches 1×10 9 CFU / mL, the activation culture is considered completed.

3. A biological treatment method for acrylic acid wastewater according to claim 1, characterized in that, During the process of strain domestication in Steps 2.1~2.3, the influent PH is 7 - 8, and the reaction temperature is 25~35°C; the optimal influent acrylic acid concentration is 1000 - 3000 mg / L.

4. A biological treatment method for acrylic acid wastewater according to claim 1, characterized in that, The described acrylic acid-specific solid bacteria are characterized by: A microbial bactericide prepared from Lysinibacillus sphaericus, Pseudochrobactrum asaccharolyticum, Brevibacillus brevis, Pseudogracilibacillus aurantiacus, and Brevundimonas diminuta strains is formulated according to a mass ratio of 1:1:1:1:

1.

5. A biological treatment method for acrylic acid wastewater according to claim 1, characterized in that, The implementation method of immobilizing the acrylic acid-specific degradation bacteria and polyurethane fillers is: The acrylic acid-specific bactericide is added to the reaction tank filled with 70% polyurethane fillers in 2 - 3 batches according to a dosage of 10%, control the residence time at 24 - 72 h, sample and measure the COD and TOC indexes. After the acrylic acid degradation rate is greater than 90%, the removal effect is stable for 5 - 10 d, and gradually increase the influent acrylic acid concentration according to the acrylic acid concentration gradient of 500 - 1000 mg / L, and change 50 - 60% of the water for each batch until the influent load reaches the target influent acrylic acid concentration.

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