Method for treating wine-brewing yellow water and enriching PHA (polyhydroxyalkanoate)-producing bacteria by using activated sludge
By treating brewing wastewater with activated sludge and using the SBR (Sequencing Batch Reactor) model to domesticate mixed microbial communities to synthesize PHA, the problems of brewing wastewater pollution and high PHA production costs have been solved, achieving low-cost, high-efficiency production and resource utilization. This method is suitable for food packaging and agricultural films.
Patent Information
- Application Number
- CN202511137422.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-14
- Publication Date
- 2025-11-18
AI Technical Summary
Existing methods for treating yellow wastewater from brewing are ineffective in removing organic matter, resulting in poor water quality and environmental pollution. At the same time, traditional PHA production is costly, and relying on pure culture systems is also costly and has poor strain adaptability.
The method utilizes activated sludge to treat brewing wastewater, and employs an SBR (Sequencing Batch Reactor) model to acclimate a mixed microbial community. It then uses the organic matter in the brewing wastewater to synthesize PHA, including pretreatment, acclimatization, and synthesis steps, to achieve efficient cultivation of the mixed microbial community and low-cost production of PHA.
It effectively solves the problem of yellow water pollution in brewing, reduces the production cost of PHA, realizes resource utilization, synthesizes high-yield PHA, and is suitable for food packaging and agricultural film fields.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of biodegradable plastic production, in particular to a method for enriching PHA-producing bacteria in brewery yellow water using activated sludge treatment. BACKGROUND
[0002] Brewery yellow water is wastewater generated during the brewing process. The treatment method is generally anaerobic digestion. For example, the anaerobic digestion of liquor wastewater disclosed in "Influence of acidity on the effect of anaerobic digestion of liquor wastewater" (J. Environmental Protection and Circular Economy, 2024, 44(03): 45-48.) and the anaerobic treatment of beer wastewater disclosed in "Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture" (Journal of Environmental Sciences, Volume 78, April 2019, Pages 137-146). Both articles disclose the use of anaerobic bacteria for anaerobic digestion to produce methane. Although it can remove some organic matter in the water, the water quality after treatment is still poor. If not further treated by deep aerobic treatment to remove carbon, nitrogen and phosphorus, it will cause water eutrophication, ecological destruction and other problems. Therefore, how to effectively treat brewery yellow water has become an urgent environmental problem to be solved.
[0003] Polyhydroxyalkanoate (PHA) is a biodegradable and environmentally friendly plastic with good mechanical properties, thermal stability and biodegradability. It is widely used in food packaging, agricultural films and other fields. The production of PHA usually requires high-priced carbon sources such as glucose and glycerol, which makes the production cost high. In addition, traditional PHA production mainly relies on pure bacterial culture, but the cost of pure bacterial culture is high, and the adaptability of the strain is poor. In order to further reduce the production cost of PHA and improve the industrialization level, researchers are also exploring low-cost raw materials and mixed bacterial populations to replace pure bacterial systems.
[0004] In summary, if a large amount of organic matter such as alcohols, fatty acids, sugars and phenols contained in brewery yellow water can be used as raw material for the cultivation and domestication of mixed bacteria, and further used as carbon source to synthesize PHA, it not only effectively solves the problem of wastewater pollution, but also greatly reduces the production cost of PHA, realizes the resource utilization of brewery yellow water, and provides an innovative solution for wastewater treatment in the brewing industry and sustainable development in the plastic industry, with significant economic and environmental advantages. SUMMARY
[0005] In order to overcome the defects of the prior art, the present application aims to provide a method for treating brewery yellow water to enrich PHA-producing bacteria by using activated sludge, which can effectively utilize the organic matters in the activated sludge and brewery yellow water, and synthesize a mixture rich in PHA-producing bacteria at low cost, while solving the environmental pollution problem caused by brewery yellow water.
[0006] To achieve the above-mentioned purpose, the present application provides the technical solutions as follows:
[0007] A method for treating brewery yellow water to enrich PHA-producing bacteria by using activated sludge, comprising the following steps:
[0008] Step one, pretreatment of brewery yellow water: using a filter screen to remove large-particle solid impurities in the brewery yellow water, and adjusting the pH value of the filtered yellow water to 6.5-7.5, thereby completing the pretreatment of the brewery yellow water.
[0009] Step two, domestication of PHA mixed bacterial community: introducing activated sludge with biological phosphorus removal function into a reactor, regulating the reactor operation program to be SBR mode, using the pretreated brewery yellow water in step one as raw water, adjusting the concentration of the influent by diluting the raw water, starting from COD 100 mg / L, and increasing the COD concentration of the influent by 20%-50% during the SBR mode cycle process until the COD concentration reaches 5000 mg / L and the COD removal rate is >80%, thereby completing the domestication of the PHA mixed bacterial community.
[0010] Step three, PHA synthesis: aerating the PHA mixed bacterial community in step two to make it in a fully aerobic state, DO > 7 mg / L and continuous aeration for not less than 1 h, then adjusting the aeration amount to 1, i.e. the gas-water ratio is 1; whenever the DO rises to 8 mg / L, add brewery yellow water, the amount of which is 1%-10% of the total volume, until the DO remains unchanged and is kept above 8 mg / L, then stop, thereby obtaining a sludge-water mixture rich in PHA.
[0011] The filter screen in step one has a pore size of 0.5-2.0 mm.
[0012] The activated sludge introduced into the reactor in step two has a concentration of 3-5 g / L.
[0013] One cycle process of the SBR mode in step two is: influent for 5-20 min, anaerobic stirring for 60-120 min, aerobic for 100-300 min with DO controlled at 3-5 mg / L, sedimentation for 10-30 min, and effluent for 5-20 min.
[0014] The NP ratio of the yellow water when water is fed in the SBR mode is C:N:P=100:(5-20):(1-5) mg / L, and if the NP ratio is lower than the ratio, ammonium chloride (N) or potassium dihydrogen phosphate (P) agents are supplemented to meet the rapid proliferation of microorganisms.
[0015] The drainage ratio in the SBR mode is 10% to 50%.
[0016] The C:N:P ratio in the SBR mode is 100:5:1.
[0017] The PHA mixed bacterial population concentration in the second step is greater than or equal to 7000 mg / L to complete domestication.
[0018] The final COD removal rate in the second step is greater than or equal to 80%.
[0019] The PHA cell dry weight content is 30% to 35% DCW when the DO is constant in the third step.
[0020] Compared with the prior art, the present application has the following advantages and beneficial effects:
[0021] (1) The present application uses the organic components in the yellow water from brewing to cultivate and domesticate PHA mixed bacterial populations from activated sludge, and further uses the yellow water from brewing to synthesize PHA, thereby solving the pollution problem of the yellow water from brewing and realizing comprehensive utilization of resources.
[0022] (2) The present application uses mixed bacterial populations in activated sludge as the source of microorganisms for PHA synthesis, which can significantly reduce production costs compared with traditional PHA production methods.
[0023] (3) The SBR mode in the second step is a feast-famine cycle method in which the PHA mixed bacterial populations are reacted in an anaerobic and aerobic environment, which is used to fully select and enrich bacteria capable of synthesizing PHA and eliminate other bacteria incapable of synthesizing PHA. In addition, the "famine period" can promote endogenous respiration (reduction), deep treatment (denitrification and phosphorus removal, removal of refractory substances), improve sludge settling performance, optimize microbial community structure, inhibit filamentous bacteria expansion, and synthesize a higher yield of PHA in a shorter cultivation period, which has good industrial application potential and market prospects.
[0024] In summary, the present application uses the organic components in the yellow water from brewing to cultivate and domesticate PHA mixed bacterial populations from activated sludge, and synthesizes PHA at low cost, while solving the environmental pollution problem caused by the yellow water from brewing. DETAILED DESCRIPTION
[0025] The specific technical methods of the present application are described in detail and completely in connection with the specific embodiments below. The specific embodiments described are only part of the examples of the present application, but not all examples. All other examples obtained by those skilled in the art without creative labor are within the protection scope of the present application.
[0026] Embodiment one
[0027] The method for treating the PHA-producing bacteria enriched in the yellow water of liquor production by using activated sludge disclosed in the present embodiment comprises the following steps:
[0028] Step one, pretreatment of the yellow water of liquor production: the large-particle solid impurities in the yellow water of liquor production are removed by using a filter screen with a mesh size of 0.5 mm, and the pH value of the filtered yellow water is adjusted to 6.5, thereby completing the pretreatment of the yellow water of liquor production.
[0029] Step two, domestication of the PHA mixed bacterial population: the activated sludge with the biological phosphorus removal function from a sewage treatment plant in a certain city is selected and put into a 20 L reactor, and the sludge concentration is 5000 mg / L. The pretreated yellow water of liquor production is used as raw water, the influent concentration is adjusted by diluting the raw water, the influent amount is 10 L starting from the COD of 100 mg / L, when the COD removal rate of the reactor is greater than 80%, the COD concentration is increased by 20%, until the COD concentration is greater than 5000 mg / L and the COD removal rate is greater than 80%. The operation program of the reactor is controlled as SBR mode during the whole process: influent for 10 min-anaerobic stirring for 120 min (stirring rate 150 rpm)-aerobic for 300 min (DO control is 4.2 mg / L)-sedimentation for 30 min-drainage for 10 min. The influent C:N:P is controlled as 100:5:1, and the drainage ratio is 50% to meet the rapid proliferation of microorganisms.
[0030] On the second day of operation, the COD removal rate reached 92%, which was greater than 80%, and then the influent COD concentration was adjusted to 120 mg / L. On the third day of operation, the COD removal rate reached 93%, which was greater than 80%, and then the influent COD concentration was adjusted to 144 mg / L. On the fourth day of operation, the COD removal rate reached 93%, which was greater than 80%, and then the influent COD concentration was adjusted to 173 mg / L. On the fifth day of operation, the COD removal rate reached 93%, which was greater than 80%, and then the influent COD concentration was adjusted to 207 mg / L. On the sixth day of operation, the COD removal rate reached 93%, which was greater than 80%, and then the influent COD concentration was adjusted to 250 mg / L. After about 41 days of domestication, when the influent COD concentration reached 5100 mg / L, the COD removal rate was greater than 80%, at this time the PHA mixed bacterial population concentration was 7900 mg / L, and the domestication of the PHA mixed bacterial population was completed.
[0031] Step three, PHA synthesis: the PHA mixed bacteria group can metabolize the organic matter in the yellow water of the distillery to synthesize PHA. The PHA mixed bacteria group obtained by acclimation of activated sludge can metabolize the organic matter (such as alcohols, phenols, fatty acids, etc.) in the yellow water of the distillery to synthesize PHA. The PHA mixed bacteria group acclimated in the above step two is fully aerated to make it in a fully aerobic state (DO>7mg / L) for 1h, then the aeration amount is adjusted to 1 (gas-water ratio is 1), and the yellow water is supplemented, the supplementing amount is 5% of the total volume. When the DO rises to 8mg / L, continue to supplement the yellow water, the supplementing amount is 5% of the total volume. Repeat this process until the DO remains unchanged, maintaining at 8mg / L or above.
[0032] Specifically: enter the PHA synthesis stage, take 30g of acclimated PHA mixed bacteria group and place it in a 10L reactor, fully aerate, and when DO>8mg / L, continue to aerate for 1h. Adjust the gas amount to 10L / min, add 0.5L of pretreated yellow water of the distillery, and observe the change of DO concentration. When the DO rises to 8mg / L, add 0.5L of pretreated yellow water again. Repeat this process until the DO remains unchanged, maintaining at 8mg / L or above, then stop. After about 4.5 hours of synthesis, the PHA content in the reactor reaches a maximum, and the PHA content is about 32%DCW.
[0033] Performance advantages of the embodiment:
[0034]
[0035]
[0036] Example two
[0037] The method for enriching PHA-producing bacteria by treating yellow water of the distillery with activated sludge disclosed in this embodiment comprises the following steps:
[0038] Step one, pretreatment of yellow water of the distillery: use a 1mm filter screen to remove large particulate solid impurities in the yellow water of the distillery, and adjust the pH value of the filtered yellow water to 7.0 to complete the pretreatment of the yellow water of the distillery.
[0039] Step two, acclimation of PHA mixed bacteria: select a city sewage treatment plant with biological phosphorus removal function of activated sludge, put into 20L reactor, sludge concentration is 5000mg / L. With pretreated yellow water as raw water, by diluting the raw water to adjust the concentration of influent, from COD 100mg / L, the influent amount is 10L, when the reactor COD removal rate is greater than 80%, the COD concentration is increased by 30%, until the COD concentration is greater than or equal to 5000mg / L and the COD removal rate is greater than 80%. The whole process of regulating the reactor operation program is SBR mode: influent 5min-anaerobic stirring 50min(stirring speed 150rpm)-oxygen 200min(DO control is 3mg / L)-sedimentation 10min-discharge 5min. The influent C﹕N﹕P is adjusted to 100﹕10﹕2, and the discharge ratio is 20% to meet the rapid proliferation of microorganisms.
[0040] On the second day of operation, the COD removal rate reached 89%, which was greater than 80%, and the influent COD concentration was adjusted to 130mg / L. On the third day of operation, the COD removal rate reached 91%, which was greater than 80%, and the influent COD concentration was adjusted to 169mg / L. On the fourth day of operation, the COD removal rate reached 92%, which was greater than 80%, and the influent COD concentration was adjusted to 220mg / L. On the fifth day of operation, the COD removal rate reached 94%, which was greater than 80%, and the influent COD concentration was adjusted to 285mg / L. On the seventh day of operation, the COD removal rate reached 89%, which was greater than 80%, and the influent COD concentration was adjusted to 371mg / L. On the third day of operation, the COD removal rate reached 91%, which was greater than 80%, and the influent COD concentration was adjusted to 169mg / L. After about 50 days of acclimation, the influent COD concentration reached 5118mg / L, and the COD removal rate was greater than 80%. At this time, the PHA mixed bacteria concentration was 8850mg / L, and the PHA mixed bacteria acclimation was completed.
[0041] Step three, PHA synthesis: the PHA mixed bacteria acclimated in step two are fully aerated to make them in fully aerobic state(DO>7mg / L) and keep for 1h, then adjust the aeration amount to 1(gas-water ratio is 1), and add yellow water, the amount of addition is 1% of the total volume. Observe the change of DO, when the DO rises to 8mg / L, continue to add yellow water, the amount of addition is 1% of the total volume. Repeat this process until the DO remains unchanged, maintaining at 8mg / L or more.
[0042] Specifically, proceed to the PHA synthesis stage. Place 3g of the acclimatized PHA mixed microbial community into a 1L reactor and aerate thoroughly. When DO > 8mg / L, continue aeration for another 1 hour. Adjust the aeration rate to 1L / min and add 10mL of pretreated brewing yellow water, observing the change in DO concentration. When DO rises to 8mg / L, add another 10mL of pretreated yellow water, repeating this process until DO remains constant above 8mg / L, at which point the process can be stopped.
[0043] After about 5 hours of synthesis, the intracellular PHA content in the reactor reaches its maximum, at approximately 35% DCW.
[0044] Example 3
[0045] This embodiment discloses a method for treating brewing wastewater with activated sludge to enrich PHA-producing bacteria, comprising the following steps:
[0046] Step 1, Pretreatment of brewing yellow water: Use a 2mm filter to remove large solid particles from the brewing yellow water. Adjust the pH of the filtered yellow water to 7.5 to complete the pretreatment of the brewing yellow water.
[0047] Step 2, Acclimation of the PHA Mixed Microbial Community: Activated sludge with biological phosphorus removal function from a municipal wastewater treatment plant was selected and added to a 20L reactor at a concentration of 5000 mg / L. Pretreated brewing wastewater was used as the raw water. The influent concentration was adjusted by diluting the raw water, starting with a COD of 100 mg / L and an influent flow rate of 10L. When the reactor's COD removal rate was >80%, the influent COD concentration was increased by 50% until the COD concentration was ≥5000 mg / L and the COD removal rate was >80%. Throughout the process, the reactor operation was controlled in SBR mode: 20 min influent – 60 min anaerobic stirring (stirring speed 150 rpm) – 100 min aerobic (DO controlled at 5 mg / L) – 20 min sedimentation – 20 min effluent discharge. The influent C:N:P ratio was adjusted to 100:20:5, and the effluent ratio to 40% to facilitate rapid microbial proliferation.
[0048] On the second day of operation, the COD removal rate reached 90%, exceeding 80%, so the influent COD concentration was adjusted to 150 mg / L. On the third day of operation, the COD removal rate reached 93%, exceeding 80%, so the influent COD concentration was adjusted to 225 mg / L. On the fourth day of operation, the COD removal rate reached 95%, exceeding 80%, so the influent COD concentration was adjusted to 337.5 mg / L. On the sixth day of operation, the COD removal rate reached 90%, exceeding 80%, so the influent COD concentration was adjusted to 506 mg / L. On the eighth day of operation, the COD removal rate reached 91%, exceeding 80%, so the influent COD concentration was adjusted to 760 mg / L. Finally, after approximately 63 days of acclimatization, when the influent COD concentration reached above 5700 mg / L, the COD removal rate exceeded 80%, and the PHA mixed microbial community concentration was 12500 mg / L, indicating that the PHA mixed microbial community had completed its acclimatization.
[0049] Step 3, PHA synthesis: The PHA mixed bacterial community acclimatized in Step 2 is fully aerated to ensure it is in a fully aerobic state (DO>7mg / L) and maintained for 1 hour. Then, the aeration rate is adjusted to 1 (air-to-water ratio is 1), and yellow water is added, with the amount added being 10% of the total volume. The DO change is observed. When the DO rises to 8mg / L, yellow water is added again, with the amount added being 10% of the total volume. This process is repeated until the DO remains constant above 8mg / L.
[0050] Specifically, proceed to the PHA synthesis stage. Place 50g of the acclimatized PHA mixed microbial community into a 10L reactor and aerate thoroughly. When DO > 8mg / L, continue aeration for another 1 hour. Adjust the aeration rate to 10L / min and add 1L of pretreated brewing yellow water, observing the change in DO concentration. When DO rises to 8mg / L, add another 1L of pretreated yellow water, repeating this process until DO remains constant above 8mg / L, at which point the process can be stopped.
[0051] After about 3 hours of synthesis, the PHA content in the reactor reaches its maximum, at approximately 33% DCW.
[0052] In summary, because PHA is purified using chloroform, it is first dissolved in organic matter and then precipitated. Therefore, the source of PHA does not affect its final use, and it can be used in the food packaging field. Furthermore, there is a significant demand for PHA in agricultural mulch films, which are currently the primary application. The commercial price of PHA is 40,000-50,000 RMB / ton, indicating a promising market prospect.
Claims
1. A method for treating brewing wastewater with activated sludge and enriching PHA-producing bacteria, characterized in that, Includes the following steps: Step 1, Pretreatment of brewing yellow water: Use a filter to remove large solid particles from the brewing yellow water. Adjust the pH of the filtered yellow water to 6.5-7.5 to complete the pretreatment of brewing yellow water. Step 2, acclimatization of PHA mixed microbial community: Introduce activated sludge with biological phosphorus removal function into the reactor, adjust the reactor operation program to SBR mode, use the pretreated brewing yellow water from Step 1 as raw water, adjust the concentration of the influent by diluting the raw water, starting from COD 100mg / L, during the SBR mode circulation process, when the COD removal rate in the reactor is >80%, increase the COD concentration of the influent by 20% to 50%, until the COD concentration reaches 5000mg / L and the COD removal rate is >80%, then the acclimatization of PHA mixed microbial community is completed; Step 3, PHA synthesis: Aerate the PHA mixed microbial community from Step 2 to ensure it is in a fully aerobic state, with DO > 7 mg / L, and continue aeration for at least 1 hour. Then adjust the aeration rate to 1, i.e., the air-to-water ratio is 1. Whenever the DO rises to 8 mg / L, add brewing yellow water at a rate of 1% to 10% of the total volume until the DO remains constant and above 8 mg / L. This will result in a mud-water mixture rich in PHA.
2. The method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1, characterized in that, In step one, the filter mesh size is 0.5–2.0 mm.
3. The method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1, characterized in that, In step two, the concentration of active substances in the sludge entering the reactor is 3-5 g / L.
4. The method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1, characterized in that, In step two, one cycle of the SBR mode is as follows: water inlet 5-20 min - anaerobic stirring 60-120 min - aerobic 100-300 min, DO controlled at 3-5 mg / L - sedimentation 10-30 min - drainage 5-20 min.
5. A method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1 or 4, characterized in that, In the SBR mode, the NP ratio of the yellow water during influent is: C:N:P = 100:(5-20):(1-5), unit mg / L. If the NP ratio is lower than this value, ammonium chloride (N) or potassium dihydrogen phosphate (P) is added to meet the needs of rapid microbial proliferation.
6. A method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1 or 4, characterized in that, The drainage ratio in the SBR mode is 10% to 50%.
7. A method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1 or 4, characterized in that, In the SBR mode, the influent C:N:P = 100:5:
1.
8. The method for treating brewing wastewater and enriching PHA-producing bacteria using activated sludge according to claim 1, characterized in that, In step two, the acclimatization is completed when the concentration of the PHA mixed bacterial community is ≥7000 mg / L.
9. The method for treating brewing wastewater with activated sludge and enriching PHA-producing bacteria according to claim 1, characterized in that, In step two, the final COD removal rate is ≥80%.
10. The method for treating brewing wastewater with activated sludge and enriching PHA-producing bacteria according to claim 1, characterized in that, In step three, when DO remains constant, the dry weight content of PHA cells is 30%–35% DCW.