Method for treating high-salinity wastewater containing organic halide by using salt-tolerant microbial agent

Abstract

The invention provides a salt-tolerant microbial agent which is used for treating high-salt wastewater containing organic halide and comprises bacillus licheniformis and microbacterium. The preservation number of the microbacterium is CGMCC (China General Microbiological Culture Collection Center) No.25197; the preservation number of the bacillus licheniformis is CGMCC (China General Microbiological Culture Collection Center) No. 22532. The salt-tolerant microbial agent provided by the invention is used for treating the high-salinity wastewater containing the organic halide or preparing a product for treating the high-salinity wastewater containing the organic halide; the treatment effect is obvious and effective.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental pollution control, and specifically relates to a method for treating high-salt wastewater containing organic halides by using a salt-tolerant bacterial agent. Background Art

[0002] High-salinity wastewater has always been a difficult problem in the water treatment industry. Since most activated sludge systems have poor salt tolerance, wastewater needs to be desalted before entering the biochemical treatment stage, which requires high technical investment and treatment costs. If high-salinity wastewater can be biochemically treated without desalination, it will have huge economic benefits for subsequent processes and overall costs. In particular, a type of wastewater such as dye wastewater or epoxy resin wastewater not only has high salinity and COD, but also contains organic halides, which are very toxic to the activated sludge system and can easily cause the system to collapse. Therefore, before entering the biochemical treatment system, it is necessary not only to reduce the influent COD, but also to deeply degrade the organic halides in the water to relieve the inhibition and toxicity of the organic halides on the biological system.

[0003] For high-salinity wastewater containing organic halides, the commonly used treatment processes are mainly multi-effect evaporation, membrane treatment and biological methods. However, multi-effect evaporation is a high-energy consumption process with high treatment costs; and the membrane method also has the problem of easy membrane contamination and high costs due to frequent replacement. The biological treatment process is gentle, low in energy consumption, and has no secondary pollution. It is a low-carbon and green treatment process, but due to high salinity and the biological toxicity of halides, there is a lack of effective functional bacteria. Summary of the invention

[0004] The purpose of the present invention is to provide a method for treating high-salt wastewater containing organic halides with a salt-tolerant bacterial agent, thereby reducing the concentration of COD and organic halides in the water to facilitate effective treatment by a subsequent biological system.

[0005] The present invention first provides a salt-tolerant bacterial agent for treating high-salt wastewater containing organic halides, which contains Bacillus licheniformis and Microbacterium; The strain used is Microbacterium sp. K7 strain, which was deposited at the General Microbiology Center of China Culture Collection Administration at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing on June 27, 2022, with the deposit number CGMCC No.25197.

[0006] The Bacillus Licheniformis SX-1 (Bacillus Licheniformis) used was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration on May 17, 2021, with the deposit number CGMCC No. 22532.

[0007] The salt-tolerant bacterial agent provided by the present invention is used to treat high-salt wastewater containing organic halides or to prepare a product for treating high-salt wastewater containing organic halides; The present invention also provides a fixed bacterial agent for treating high-salt wastewater containing organic halides, which is prepared by fixing the above-mentioned salt-tolerant bacterial agent into a filler; The filler, as specifically described in the embodiment, is a polyurethane filler; Another aspect of the present invention provides a biofilter system for treating high-salinity wastewater containing organic halides, in which the fixed bacterial agent is used. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 : The effect diagram of the salt-tolerant bacteria agent of the present invention in treating high-salt wastewater containing organic halides. DETAILED DESCRIPTION

[0009] The salt-tolerant bacteria agent provided by the present invention can treat high-salt wastewater containing organic halides, and can treat wastewater with a COD concentration of about 7000 mg / L and a salinity of about 3% (in terms of sodium chloride).

[0010] The strain used is Microbacterium sp. K7 strain, which was deposited at the General Microbiology Center of China Culture Collection Administration at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing on June 27, 2022, with the deposit number CGMCC No.25197.

[0011] The Bacillus licheniformis SX-1 used was deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration on May 17, 2021, with the deposit number CGMCC No. 22532.

[0012] The present invention is described in detail below in conjunction with embodiments and drawings.

[0013] Example 1: Activation and expansion of bacterial strains Bacillus licheniformis SX-1 and Microbacterium K7 were activated in activation medium, the components of which were peptone 3g / L, yeast powder 1.5g / L, sodium chloride 0.5g / L, glucose 5g / L; inoculation amount 10%-20%, culture temperature 30°C, shaking culture at 180rpm. Activation was considered complete when OD>0.5.

[0014] The activated strains were inoculated into the expansion medium at a ratio of 10%-20%. The composition ratio of the expansion medium was as follows: 0.5g / L yeast extract, 0.5g / L peptone, 0.5g / L tryptone, 0.5g / L glucose, 0.5g / L soluble starch, 0.3g / L dipotassium hydrogen phosphate, 0.03g / L anhydrous magnesium sulfate, 0.5g / L sodium pyruvate, pH 7.2±0.2. The culture conditions were the same as above, and the expansion culture was considered complete when OD>0.5.

[0015] Example 2: Construction and immobilization of bacterial agents After the cultured bacteria are mixed in a volume ratio of 1:1, the mixed bacterial solution and the polyurethane filler are inoculated in an equal volume ratio into a biofilter device containing the diluted wastewater to be treated. The biofilter device used is a conventional device, in which the filler is a quick-separation ball. The quick-separation ball should be a quick-separation ball with a black polyurethane block inside. The diameter of the quick-separation ball is 80cm, and the size of the polyurethane block inside the ball is 1-8cm 3 , porosity greater than 98%, specific surface area greater than 4500m 2 / m 3 , filling rate 30%.

[0016] The wastewater to be treated is added to the biofilter to make the final COD concentration 1000-1500mg / L. The bacterial agent and filler are added to the biofilter together. The nutrient solution is added. The liquid volume is enough to cover the filler. The spraying volume is 50% of the filler volume per minute. The air enters from the bottom of the device and is discharged from the top. The air volume is 10-20% of the filler volume per minute. The pH is controlled in the range of 6.0-7.5. The liquid is circulated until the biofilm is clearly visible on the polyurethane filler to prepare the fixed bacterial agent.

[0017] Example 3: Effect of Immobilized Bacteria The fixed bacterial agent prepared in Example 2 is used to treat high-salt wastewater containing organic halides, and the final concentration of the influent COD of the high-salt wastewater is increased to 2000-3000 mg / L. The process is operated in the same manner, but the carbon source in the nutrient solution is no longer added. When the water COD is reduced to below 1000 mg / L, more than 50% of the liquid volume is discharged again, and the wastewater is replenished again to a final COD concentration of 3000-4000 mg / L, and so on until the final COD concentration of the water reaches 4000-5000 mg / L. When the water COD is <2000 mg / L, the wastewater can be introduced into the activated sludge treatment system for subsequent deep treatment.

[0018] The results are as follows Figure 1As shown in the figure, after the high-salt wastewater has undergone this pretreatment and enters the activated sludge treatment system, although the system salinity and COD load are gradually increasing, the effluent COD of the sludge treatment system can be stabilized below 500 mg / L, meeting the official discharge standards.

Claims

1. A salt-tolerant bacterial agent, characterized in that: The salt-tolerant bacterial agent contains Bacillus licheniformis and Microbacterium truncatum.

2. The salt-tolerant bacterial agent according to claim 1, characterized in that The deposit number of the Microbacterium is CGMCC No.25197.

3. The salt-tolerant bacterial agent according to claim 1, characterized in that The deposit number of the Bacillus licheniformis is CGMCC No. 22532.

4. Use of the salt-tolerant bacterial agent according to claim 1 in treating high-salt wastewater containing organic halides.

5. Use of the salt-tolerant bacterial agent according to claim 1 in the preparation of a product for treating high-salt wastewater containing organic halides.

6. The use according to claim 5, characterized in that The product is a fixed bacterial agent.

7. A fixed bacterial agent, characterized in that: The fixed bacterial agent is prepared by inoculating the salt-tolerant bacterial agent described in claim 1 into a fixed filler.

8. The fixed bacterial agent according to claim 7, characterized in that: The fixed filler is a polyurethane filler.

9. A biofilter system for treating high-salinity wastewater containing organic halides, characterized in that: The biofilter system contains the fixed bacterial agent according to claim 7.

10. A method for treating high-salinity wastewater containing organic halides, characterized in that: The method is to use the fixed bacterial agent according to claim 7 for treatment.

Images