Biological rotating disc rapid biofilm culturing technology based on quorum sensing and application of biological rotating disc rapid biofilm culturing technology

Abstract

The invention discloses a biological rotating disc rapid biofilm culturing technology based on quorum sensing and application thereof, and belongs to the technical field of biological sewage treatment. According to the biological rotating disc rapid biofilm culturing technology based on quorum sensing, the quorum sensing inducer with boron as the main component is adopted as the quorum sensing inducer, the adsorption and breeding environment of microorganisms can be remarkably optimized, the breeding rate of the microorganisms on the rotating disc is increased, the biofilm culturing time is greatly shortened, and the biofilm culturing time is about 38 days earlier than that of a traditional method; the quorum sensing inducer is added, so that bacteria can secrete AI-2 signal molecules, the bacteria can be promoted to secrete extracellular polymers, the agglomeration phenomenon among the bacteria can be promoted, and the biological rotating disc biofilm formation can be quickly and stably realized; meanwhile, the viscous extracellular polymer can also play a role of a biological adhesive between the bacteria and the disc carrier, so that the bacteria are easy to attach and fix on the surface of the carrier, and the formed biological membrane is effectively prevented from falling off.

Description

Technical Field

[0001] The invention relates to the technical field of sewage biological treatment, and in particular to a biological turntable rapid biofilm formation technology based on quorum sensing and an application thereof. Background Art

[0002] The biological turntable technology is a type of biofilm treatment technology in the field of sewage treatment. Its principle is: using microorganisms (usually including bacteria, fungi, algae, etc.) to reproduce with a turntable as a carrier, gradually forming a layer of biofilm on the surface of the turntable carrier. The microorganisms decompose the organic matter in the water by secreting enzymes and other substances. As the turntable slowly rotates in the water, the part of the biofilm exposed to the air comes into contact with oxygen, and the microorganisms in it undergo aerobic degradation; while the part immersed in the water is in an anaerobic or anoxic state, and the microorganisms in it undergo anaerobic or anoxic degradation. This microbial community in different environments allows the organic matter in the sewage to be effectively treated under different oxygen concentration conditions. The water flows on the turntable, carrying away the degraded pollutants. When the organic matter is consumed, the metabolites produced by the microorganisms can continue to be used, forming a stable ecological cycle.

[0003] Rotating biological contactor (RBC) is a sludge film mixed sewage treatment process, which is mainly composed of discs, oxidation tanks, rotating shafts and transmission devices. The discs are partially immersed in the mixed liquid and driven by the transmission device to alternately contact with the air and the mixed liquid, thereby constantly experiencing anoxic and aerobic states. This mode of operation not only allows a large amount of activated sludge to adhere to the discs to form a biofilm, but also allows the process to have both nitrification and denitrification functions. The biological rotary disc is usually used as a pre-treatment process when the water quality of the target wastewater fluctuates greatly, in order to stabilize the influent water quality and reduce the impact on subsequent conventional biological treatment processes (such as A / O or A 2 O, etc.). In the bio-rotating disc reactor, since the microorganisms are fixed on the carrier, the SRT (sludge retention time) and HRT (hydraulic retention time) are separated, so that microorganisms with slow proliferation rates can also grow and reproduce. Therefore, the biofilm is a stable and diverse microbial ecosystem. However, when the bio-rotating disc is faced with target wastewater with poor water quality such as landfill leachate and high organic content industrial wastewater, problems such as long biofilm formation period and easy detachment of biofilm usually occur, making it difficult for the bio-rotating disc to achieve the expected treatment effect.

[0004] Quorum sensing (QS) is a communication mechanism between bacteria that regulates the behavior of microbial communities by secreting and sensing exogenous signal molecules (such as autoinducers). When the number of bacteria reaches a certain concentration, the concentration of quorum sensing signal molecules will increase, thereby activating gene expression and promoting coordinated activities of microbial communities, such as biofilm formation, enhanced drug resistance, and the release of virulence factors. In the bio-rotor, the quorum sensing response of microorganisms can be effectively promoted by adding exogenous stimulants (such as specific quorum sensing signal molecules or compounds that promote quorum sensing). These stimulants can enhance the coordination of microbial communities, thereby promoting the growth and stability of biofilms. Summary of the invention

[0005] The purpose of the present invention is to provide a quorum sensing-based rapid biofilm growth technology for a biological turntable and its application, so as to solve the problems of the existing biological turntable biofilm growth technology, such as slow initial microbial growth and adsorption, resulting in a long biofilm growth period, and lack of diversified bacterial flora, which makes the biofilm easy to fall off and unstable treatment effect.

[0006] To achieve the above object, the present invention provides a rapid biofilm growth technology based on quorum sensing, comprising the following steps: S1. Fill the structure of the biological turntable with aerobic activated sludge, add a quorum sensing inducer at one time, and start the biological turntable; S2. Inject the sewage to be treated into the structure where the biological rotary table is located by continuous flow water inlet; S3, adding quorum sensing inducer and carbon source by continuous addition; The components and concentrations of the quorum sensing inducer in the S1 are: H3BO3 15.46 g / L, EDTA 15.0 g / L, MnCl2·4H2O 0.99 g / L, CuSO4·5H2O 0.25 g / L, ZnSO4·7H2O 0.43 g / L, NiCl2·6H2O 0.19 g / L, NaSeO4·10H2O 0.21 g / L, NaMoO4·2H2O 0.22 g / L and NaWO4·2H2O 0.05 g / L.

[0007] Preferably, the material of the biological turntable in S1 is a mesh structure made of polyethylene-based resin, polypropylene, polyethylene, polyvinyl chloride, polystyrene or unsaturated resin fiberglass; the rotation speed of the biological turntable is 4r / min.

[0008] Preferably, the amount of quorum sensing inducer added in S1 is 1 L quorum sensing inducer / m³ aerobic activated sludge.

[0009] Preferably, the sewage in S2 is landfill leachate, landfill filtrate from a landfill transfer station, or kitchen waste liquid.

[0010] Preferably, the carbon source in S3 is one or more of methanol, glucose and sodium acetate; the carbon source is added in a continuous manner, and the daily dosage is adjusted according to the total nitrogen mass concentration of the influent, and is added at C / N=2~5.

[0011] Preferably, the dosage of the quorum sensing inducer in S3 is adjusted according to the daily sewage inflow, and the addition ratio is 1 mL quorum sensing inducer / L sewage.

[0012] Preferably, the quorum sensing inducer in S3 is added directly into the biological rotary disk pool through a metering pump, or mixed with the sewage to be treated in advance according to proportion.

[0013] An application of the above-mentioned biological turntable rapid biofilm formation technology based on quorum sensing in sewage treatment.

[0014] Therefore, the present invention provides a biological turntable rapid biofilm growth technology based on quorum sensing and its application, and its specific technical effects are as follows: (1) The rapid biofilm formation technology based on quorum sensing provided by the present invention uses a quorum sensing inducer with boron as the main component, which can significantly optimize the adsorption and reproduction environment of microorganisms, increase the reproduction rate of microorganisms on the turntable, and significantly shorten the biofilm formation time, which is about 38 days earlier than the traditional method; (2) The quorum sensing-based rapid biofilm formation technology provided by the present invention has a quorum sensing inducer whose main component is boric acid, which can cause bacteria to secrete AI-2 signal molecules, promote bacteria to secrete extracellular polymers, and promote bacterial aggregation, thereby achieving rapid and stable biofilm formation on the bio-turntable; at the same time, this sticky extracellular polymer can also act as a biological adhesive between the bacteria and the disc carrier, making it easy for the bacteria to adhere and fix on the carrier surface, effectively preventing the formed biofilm from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0016] Figure 1 is a photo of the biological turntable experimental device used in the experiment in the embodiment of the present invention; Figure 2 The following are photos of the bio-rotating disks at different treatment times during the test process of the embodiments of the present invention; wherein part (a) is the bio-rotating disk in embodiment 1, and part (b) is the bio-rotating disk in comparative example 1; Figure 3 It is a dynamic curve of nitrogen concentration at the water inlet and water outlet, ammonia nitrogen and total nitrogen removal rate in the test process of the embodiment of the present invention; wherein part (a) is the dynamic curve of nitrogen concentration at the water inlet and water outlet of the biological rotary disk in Example 1; part (b) is the dynamic curve of nitrogen concentration at the water inlet and water outlet of the biological rotary disk in Comparative Example 1; part (c) is the dynamic curve of ammonia nitrogen and total nitrogen removal rate in Example 1; part (d) is the dynamic curve of ammonia nitrogen and total nitrogen removal rate in Comparative Example 1; Figure 4 These are the statistical results of the average ammonia nitrogen and total nitrogen removal rates of the bio-rotating disks in Example 1 and Comparative Example 1 during the 64-day test in the embodiments of the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0018] In order to make the purpose, technical scheme and advantages of the present application clearer, more thorough and more complete, the technical scheme of the present invention is clearly and completely described below through the accompanying drawings and examples. The following detailed descriptions are all descriptions of the embodiments, and are intended to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present application belongs.

[0019] The instruments, equipment, reagents and materials used in the examples were obtained through commercial channels. The experiments in the examples were carried out in a leachate treatment plant of a landfill in urban Huizhou City. The influent was real old landfill leachate. The influent water quality had certain fluctuations. The ammonia nitrogen in the inlet and outlet water of the biological turntable was measured every two days using Nessler's reagent spectrophotometry. During the entire test process, the ammonia nitrogen content of the influent (sewage) was 200-600 mg / L.

[0020] The biological turntable used in the embodiment is as follows Figure 1 As shown, there are two biological turntable tanks arranged side by side, with an effective volume of 200 L. The tanks use disks of the same size and material, and the disks are all made of polyethylene-based resin (PVDC).

[0021] The composition of the quorum sensing inducer used in the example is (g / L): H3BO3 15.46, EDTA 15.0, MnCl2·4H2O 0.99, CuSO4·5H2O 0.25, ZnSO4·7H2O 0.43, NiCl2·6H2O 0.19, NaSeO4·10H2O 0.21, NaMoO4·2H2O 0.22 and NaWO4·2H2O 0.05.

[0022] Example 1 A method for rapid biofilm growth on a biological turntable based on quorum sensing is as follows: The structure of the biological turntable was filled with aerobic activated sludge, 200mL of quorum sensing inducer was added, and the biological turntable was started at a speed of 4r / min. The sewage to be treated was injected into the structure where the biological turntable was located by continuous flow inflow, and the sewage treatment capacity was 48L / d. Methanol and quorum sensing inducer were added simultaneously by continuous addition. The daily methanol addition amount was adjusted according to the total nitrogen mass concentration of the influent (the total nitrogen concentration in this case was replaced by the total inorganic nitrogen concentration (TIN) because the organic nitrogen content in the old garbage leachate was low), and the addition was based on C / N=2, the hydraulic retention time was 5d, and the quorum sensing inducer was added in an amount of 48mL / d.

[0023] Comparative Example 1 The traditional process of film hanging is adopted, and the specific steps are as follows: Fill the structure of the biological turntable with aerobic activated sludge, start the biological turntable, and the turntable speed is 4r / min. Use continuous flow water inlet to inject the sewage to be treated into the structure where the biological turntable is located, and the sewage treatment capacity is 48L / d. Use continuous dosing to add methanol at the same time. The daily methanol dosage is adjusted according to the total nitrogen mass concentration of the influent (in this case, the total nitrogen concentration is replaced by the total inorganic nitrogen concentration (TIN) because the organic nitrogen content in the old garbage leachate is low), and the addition is based on C / N=2, and the hydraulic retention time is 5d.

[0024] The results are as follows Figure 2 As shown, on the 7th day after the start-up operation, some black mud spots appeared on the surface of the biological turntable in Example 1, while the surface of the biological turntable in Comparative Example 1 was brown without obvious mud spots. On the 10th day, a thin black biofilm had formed on the surface of the biological turntable in Example 1, and on the 12th day, the turntable surface was covered with a dense black biofilm. In contrast, only a few black mud spots appeared on the surface of the biological turntable in Comparative Example 1 on the 19th day, a thin black biofilm was formed on the 37th day, and a dense black biofilm was formed on the 50th day.

[0025] It can be seen that the method provided by the present invention can form a dense black biofilm on the surface of the biological turntable in only about 12 days, while the conventional method requires nearly 50 days, indicating that the method provided by the present invention can significantly reduce the biofilm formation time of the biological turntable.

[0026] The ammonia nitrogen (NH4) in the inlet and outlet water of the biological rotary disk in Example 1 (R1) and Comparative Example 1 (R2) was measured by Nessler's reagent spectrophotometry, thymol spectrophotometry and N-(1-naphthyl)-ethylenediamine spectrophotometry. + -N) concentration, nitrate nitrogen (NO3 - -N) concentration and nitrite nitrogen (NO2 --N) concentration was measured every 2 days, and the dynamic curves of ammonia nitrogen concentration, nitrate nitrogen concentration and nitrite nitrogen concentration in the inlet and outlet water of the biological rotary table in Example 1 and Comparative Example 1 were drawn, respectively as shown in Figure 3 Part (a) and Figure 3 The dynamic curves of the ammonia nitrogen removal rate (ARE) and the total nitrogen removal rate (TINRE) in the influent and effluent of the biological rotary disk in Example 1 and Comparative Example 1 are shown in FIG. Figure 3 Part (c) and Figure 3 As shown in part (d) Depend on Figure 3 Part (a) and Figure 3 Part (c) shows that the nitrite in the effluent of R1 increased rapidly from the 1st to the 7th day, and the nitrite concentration in the effluent of R1 was 215 mg / L on the 7th day. At the same time, the ammonia nitrogen in the effluent of R1 continued to decrease, and the ARE increased accordingly. On the 7th day, the ARE was 62.49%. The ARE of R1 reached a maximum of 66.13% on the 11th day, which is similar to the time when the black dense biofilm was formed in Example R1 (12th day). Figure 3 Part (b) and Figure 3 It can be seen from part (d) that although the ammonia nitrogen in the effluent of comparative example R2 also showed a decreasing trend in the first 7 days, the highest ARE was only 22.12%, which was much lower than the ARE in Example 1. At the same time, because the ARE was lower than that of R1, the effluent of R2 did not show the accumulation of nitrite or nitrate due to nitrification, and the ARE was always close to TINRE, ranging from 10% to 20% from the 1st to the 29th day. This shows that the quorum sensing inducer with boron as the main component added by R1 when the biological turntable was started can effectively promote the biofilm formation of the biological turntable and enhance its nitrification effect. In the 30 days after the experiment, the ARE and TINRE removal rates of R1 finally stabilized and decreased slightly, which may be related to the change in the matrix transfer efficiency in the turntable. The dense biofilm may hinder the transfer of oxygen. However, the overall effluent ammonia nitrogen concentration of R1 was always maintained at around 200 mg / L, indicating that the turntable was stably exerting its effect. The ammonia nitrogen concentration in the effluent of comparative example R2 was always similar to that in the inlet water, indicating that there was no quorum sensing enhancement promoted by the quorum sensing inducer. Even if there was a biofilm in R2, the functional bacteria related to ammonia nitrogen removal were still difficult to function.

[0027] The ammonia nitrogen removal efficiency (ARE) and total nitrogen removal efficiency (TINRE) were calculated using the following formula: 100%; ; Where: —Ammonia nitrogen removal rate, %; —Total nitrogen removal rate, %; —Influent ammonia nitrogen concentration, mg / L; —Effluent ammonia nitrogen concentration, mg / L; —Total concentration of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in effluent, mg / L; —The sum of the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the influent, mg / L.

[0028] The average ARE and TINRE of the bio-rotating disks in Example 1 (R1) and Comparative Example 1 (R2) during the 64 days of the statistical test were as follows: Figure 4 As shown in Figure 2, the average ARE and TINRE of R1 were 38.1±15.1% and 26.5±10.4%, respectively, both significantly higher than ( p< 0.05) R2 is 14.1±6.5% and 13.7±6.2%. The results show that the removal effect of ammonia nitrogen and total nitrogen by the biological rotary disc is better and more stable by using the method provided by the present invention.

[0029] Therefore, the rapid biofilm formation technology based on quorum sensing provided by the present invention adopts a quorum sensing inducer with boron as the main component as a quorum sensing inducer, which can significantly optimize the adsorption and reproduction environment of microorganisms, increase the reproduction rate of microorganisms on the turntable, and greatly shorten the biofilm formation time, which is about 38 days earlier than the traditional method; the added quorum sensing inducer can cause bacteria to secrete AI-2 signal molecules, promote bacteria to secrete extracellular polymers, and promote the aggregation phenomenon between bacteria, thereby achieving rapid and stable biofilm formation on the bioturntable; at the same time, this sticky extracellular polymer can also play the role of a biological adhesive between the bacteria and the disc carrier, making it easy for the bacteria to adhere and fix on the carrier surface, effectively preventing the formed biofilm from falling off.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A rapid biofilm growth technology based on quorum sensing, characterized in that: The steps include: S1. Fill the structure of the biological turntable with aerobic activated sludge, add a quorum sensing inducer at one time, and start the biological turntable; S2. Inject the sewage to be treated into the structure where the biological rotary disc is located by continuous flow water inlet; S3, adding quorum sensing inducer and carbon source by continuous addition; The components and concentrations of the quorum sensing inducer in the S1 are: H3BO3 15.46 g / L, EDTA 15.0 g / L, MnCl2·4H2O 0.99 g / L, CuSO4·5H2O 0.25 g / L, ZnSO4·7H2O 0.43 g / L, NiCl2·6H2O 0.19 g / L, NaSeO4·10H2O 0.21 g / L, NaMoO4·2H2O 0.22 g / L and NaWO4·2H2O 0.05 g / L.

2. The rapid biofilm growth technology based on quorum sensing according to claim 1 is characterized by: The material of the biological turntable in S1 is a mesh structure made of polyethylene resin, polypropylene, polyethylene, polyvinyl chloride, polystyrene or unsaturated resin fiberglass; the rotation speed of the biological turntable is 4r / min.

3. The rapid biofilm growth technology based on quorum sensing according to claim 1 is characterized by: The amount of quorum sensing inducer added in S1 is 1L quorum sensing inducer / m³ aerobic activated sludge.

4. The rapid biofilm growth technology based on quorum sensing according to claim 1 is characterized in that: The sewage in S2 is landfill leachate, landfill filtrate from a landfill transfer station, or kitchen waste liquid.

5. The rapid biofilm growth technology based on quorum sensing according to claim 1 is characterized by: The carbon source in S3 is one or more of methanol, glucose, and sodium acetate; the carbon source is added in a continuous manner, and the daily addition amount is adjusted according to the total nitrogen mass concentration of the influent, and is added at C / N=2~5.

6. The rapid biofilm growth technology based on quorum sensing according to claim 1 is characterized by: The dosage of the quorum sensing inducer in S3 is adjusted according to the daily sewage inflow, and the addition ratio is 1 mL quorum sensing inducer / L sewage.

7. The rapid biofilm growth technology based on quorum sensing according to claim 1 is characterized by: The quorum sensing inducer in S3 is added directly into the biological rotary tank through a metering pump, or mixed with the sewage to be treated in advance according to a proportion.

8. An application of the quorum sensing-based bio-rotating disk rapid biofilm formation technology as described in any one of claims 1 to 7 in sewage treatment.

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