CN111362561A - Method for resource utilization of sludge - Google Patents
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- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
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Abstract
The invention belongs to the technical field of sludge treatment, and relates to a method for recycling sludge. The method comprises the following steps: sequentially carrying out thermal hydrolysis, cooling and dilution on the first excess sludge; mixing the diluted first excess sludge and the second excess sludge, and performing anaerobic fermentation to obtain an acid producing liquid; carrying out solid-liquid separation on the acid-producing liquid to obtain acid-producing filtrate and mud cakes; processing the mud cakes into nutrient soil; a part of the acid-producing filtrate is discharged into a water plant biological pond to be used as a carbon source of the water plant biological pond; taking the other part of the acid production filtrate as a substrate carbon source of the flora, enriching and activating the flora in a abundance-hunger mode to synthesize polyhydroxyalkanoate, and collecting the flora at the stable synthesis stage of the polyhydroxyalkanoate; extracting polyhydroxyalkanoate from the collected flora, and purifying to obtain polyhydroxyalkanoate product; and drying the polyhydroxyalkanoate product to obtain the polyhydroxyalkanoate product. The method improves the resource utilization rate of the sludge.
Description
Technical Field
The invention belongs to the technical field of sludge treatment, and particularly relates to a method for recycling sludge.
Background
Along with the faster and faster urbanization process, the generation amount and the treatment rate of urban domestic sewage are higher and higher, and the total amount of generated sludge is rapidly increased. Although various methods have been employed to reduce the production of municipal sludge, the total amount has been increasing at a rate of 10% per year. In 2015, the total amount of sludge with water content of 80% in China is about 4000 ten thousand tons. The yield of the sludge with the water content of 80 percent is estimated to break through 6000 million tons in 2020. And the national sludge overall harmless treatment and resource utilization rate are low, so that the sludge treatment task is more difficult. With the strengthening of the country to the final treatment management of municipal sludge, the treatment and the resource utilization of the municipal sludge become problems to be solved urgently in sewage treatment plants.
The excess sludge contains a large amount of organic matter, and the possibility of resource utilization exists. The residual sludge is used for anaerobic fermentation to produce Volatile Fatty Acids (VFAs) which can be used as an external carbon source of a water plant. The method is a way for recycling the sludge, and water plants pay more and more attention to the development and utilization of the sludge. However, this method has some problems: firstly, the conversion rate of VFAs carbon source produced by directly utilizing excess sludge to carry out anaerobic fermentation is lower; secondly, the residual activated sludge contains more pathogenic bacteria and has certain pathogenic risk when being directly or indirectly used as a carbon source; thirdly, the sludge treatment capacity of a water plant can be increased by directly utilizing the fermentation liquor as a carbon source; fourthly, a large amount of ammonia nitrogen is generated in the fermentation process, and the nitrogen and phosphorus concentration of the fermentation liquor is higher, so that the fermentation liquor cannot be directly reused by a water plant; fifthly, when the demand of the water plant is low, VFAs fermentation liquor generated by excess sludge cannot be directly output as a product. In view of these problems, the current production of VFAs as an external carbon source by anaerobic fermentation using excess sludge has certain obstacles and challenges.
The invention patent application with publication number CN101555314A discloses a method for synthesizing Polyhydroxyalkanoates (PHAs) by using excess sludge fermentation liquor as a carbon source, which comprises the steps of hydrolyzing the excess sludge under anaerobic conditions, and then synthesizing the PHAs by using the hydrolysis fermentation liquor under aerobic multiple feeding-draining process conditions. In the method, the residual sludge is utilized to ferment the VFAs liquid to further synthesize the PHAs, so that the production cost of the PHAs can be reduced. However, the concentration of the volatile fatty acid in the hydrolysis fermentation broth is only 2606mg COD/L, a large promotion space is provided, the problems of low carbon source conversion rate, pathogenic risk and the like cannot be solved, and the carbon source is inevitably wasted in part of energy sources in further conversion.
Therefore, a method for improving the resource utilization of sludge is needed.
Disclosure of Invention
The invention aims to provide a method for recycling sludge so as to improve the recycling utilization rate of the sludge.
In order to achieve the purpose, the invention provides a method for recycling sludge, which comprises the following steps:
s1, sequentially carrying out thermal hydrolysis, cooling and dilution on the first excess sludge;
s2, mixing the diluted first excess sludge and the diluted second excess sludge, and performing anaerobic fermentation to obtain an acid producing liquid;
s3, carrying out solid-liquid separation on the acid production liquid to obtain an acid production filtrate and a mud cake;
s4, processing the mud cakes into nutrient soil;
s5, discharging a part of the acid-producing filtrate into a water plant biological pond as a carbon source of the water plant biological pond;
s6, taking the other part of the acid production filtrate as a substrate carbon source of the flora, enriching and activating the flora in a abundance-hunger mode to synthesize polyhydroxyalkanoate, and collecting the flora at a stable synthesis stage of the polyhydroxyalkanoate;
s7, extracting the Polyhydroxyalkanoates (PHAs) from the collected flora, and purifying to obtain polyhydroxyalkanoate products;
and S8, drying the polyhydroxyalkanoate product to obtain Polyhydroxyalkanoate (PHAs) products.
In the present invention, the excess sludge refers to activated sludge in the activated sludge system discharged from the secondary sedimentation tank or the sedimentation zone outside the system. The excess sludge used in the present invention is preferably derived from municipal sludge. The municipal sludge contains a large amount of organic matters and has great potential of resource utilization.
In a preferred embodiment of the present invention, the method further comprises: and S9, recovering nitrogen and phosphorus from the acid production liquid obtained in the step S2 or the acid production filtrate obtained in the step S3.
In a specific embodiment of the invention, in step S9, a magnesium salt is added to the acid production solution obtained in step S2 or the acid production filtrate obtained in step S3 so that the molar ratio of Mg to P to N in the filtrate is 1:0.5:1 to 2:1:1, for example, 1.4:0.8:1, and the mixture is stirred, then left to stand for precipitation, and then nitrogen and phosphorus in the form of struvite are collected.
In an embodiment of the invention, in step S1, the first excess sludge is placed in a pyrohydrolysis reaction tank, heated to 150 to 250 ℃ and at 6 to 8bar, steam is maintained for 25 to 50 minutes, for example, 40 minutes, so as to pyrohydrolyze the first excess sludge, and the first excess sludge after pyrohydrolysis is decompressed to a flash tank, and then cooled and diluted. For the conditions of thermal hydrolysis, the temperature may be around 170 ℃ and the pressure 6bar, with steam hold for 30 minutes. The solid content of the first excess sludge after thermal hydrolysis is generally 15% -18%, then the temperature is reduced, a heat exchanger can be used for accelerating the temperature reduction, the temperature of the first excess sludge in the flash tank can be reduced to 20-35 ℃, and the subsequent anaerobic fermentation is facilitated. After dilution, the solids concentration of the first excess sludge is typically 8% to 12%. Through thermal hydrolysis, the contents of SCOD, soluble protein, soluble sugar and volatile fatty acid in the first excess sludge are obviously improved, and a favorable material basis is provided for the subsequent anaerobic fermentation acid production and PHAs synthesis.
In a preferred embodiment of the present invention, step S1 further includes preheating the first excess sludge in a slurrying tank, and preheating the first excess sludge by using the steam waste heat generated by thermal hydrolysis, so that the steam generated by thermal hydrolysis can be recycled, and thus, the efficiency of thermal hydrolysis can be improved, and waste of heat energy can be avoided.
The skilled person can select the preheating temperature and time according to the actual situation, the preheating temperature can be the same as or slightly lower than the thermal hydrolysis temperature, and the preheating time can be determined according to the amount of the first excess sludge, and generally the temperature of the first excess sludge is uniform.
In a specific embodiment of the present invention, the solid concentration of the diluted first excess sludge is 8% to 12%; in step S2, the solid content of the second excess sludge is 15% -18%, and the mass ratio of the diluted first excess sludge to the second excess sludge is 4: 1-1: 1; the anaerobic fermentation is to firstly carry out continuous anaerobic fermentation for a preset time and then carry out anaerobic fermentation in a semi-continuous state for more than 4 days, wherein the temperature of the anaerobic fermentation is 35-55 ℃, and the stirring speed is 100-200 rpm. The method can improve the content of volatile fatty acid in the high-yield acid liquor to 10000mg COD/L, thereby further improving the yield of the subsequent PHAs.
Further, the preset time for the continuous anaerobic fermentation can be 12-18 days, such as 15 days; the anaerobic fermentation time in the semi-continuous state can be 4-5 days; the stirring speed may be 150 to 200 rpm.
In a more specific embodiment of the present invention, in step S2, when the content of the volatile fatty acid in the acid generating solution remains stable for more than 3 days, the acid generating solution enters an acid generating stabilizing stage to obtain the acid generating solution. Therefore, the person skilled in the art can monitor the volatile fatty acid in the acid production liquid, and when the content of the volatile fatty acid fluctuates within a threshold range and keeps a stable state for more than 3 consecutive days, the acid production liquid is considered to enter an acid production stable stage. The threshold range of the content of volatile fatty acid can be determined by those skilled in the art according to actual conditions.
In a specific embodiment of the present invention, in step S3, when performing solid-liquid separation on the acid-producing liquid, the acid-producing liquid is directly filter-pressed for 1-2 hours by using a filter press without adding a flocculant or the like, and the acid-producing filtrate and the sludge cake are obtained by separation.
In a specific embodiment of the invention, in step S4, the mud cake is mixed with a nitrogen source and a carbon source, and then naturally composted and fermented in a ventilated place for 6-10 days to obtain the nutrient soil. The method can be used for obtaining the nutrient soil with the water content of 20-30%, and the mud cakes contain a large amount of bacteria, so that the nutrient soil does not need to be added with additional microbial inoculum.
In step S5, one skilled in the art can determine the amount of acid-forming filtrate discharged into the water plant biological pond according to the amount of carbon source required by the water plant biological pond.
In one embodiment of the present invention, in step S6, the method for preparing the flora comprises the following steps:
and (3) acclimating the bacteria in the activated sludge by using the activated sludge of the sewage plant as a seed source and using the acid-producing liquid in the step S2 and/or the acid-producing filtrate in the step S3 as a substrate to obtain the flora. The acclimation time can be 1-4 months, and the bacteria are acclimated by increasing the chemical oxygen demand in the substrate in a gradient manner within the acclimation time.
In a specific embodiment of the present invention, in step S6, the abundance-hungry mode is that after the flora is inoculated to the substrate carbon source, the chemical oxygen demand of the supernatant of the substrate carbon source is monitored, the lowest point of the consumption rate of the chemical oxygen demand is used as a mark for entering the hungry period, the abundance period is set before the initial inoculation of the substrate carbon source enters the hungry period, the abundance-hungry time ratio is controlled to be 1: 2-5, for example, 1:3, the material is fed again, and a period is from the last feeding to the next feeding; polyhydroxyalkanoate (PHAs) synthesis is considered to be in a stable phase when the time to reach the starvation phase and the chemical oxygen demand stabilize above two cycles. The abundance-starvation mode can improve the synthesis amount and synthesis rate of PHAs.
In step S7, the method for extracting polyhydroxyalkanoate from the flora includes: sodium hypochlorite method, SDS-EDTA method, SDS-sodium hypochlorite method, acid method or alkaline method.
In step S8, one skilled in the art can dry the resulting polyhydroxyalkanoate product using an oven or a dryer. According to different methods for extracting the polyhydroxyalkanoates, Polyhydroxyalkanoates (PHAs) products can be dried under the condition of freezing or 50-100 ℃.
According to the method for recycling the sludge, provided by the invention, the first excess sludge is subjected to heating high-temperature high-pressure treatment through thermal hydrolysis, the zoogloea of the first excess sludge, internal microorganisms and organic matters are subjected to hydrolysis wall breaking, so that cells are inactivated, meanwhile, the intracellular part organic matters, such as proteins, polysaccharides and the like, are released and enter the supernatant of an acid production liquid, so that the yield of the organic matters which can be utilized in the sludge can be improved, for example, the conversion rate of the sludge for producing Volatile Fatty Acid (VFAs) carbon sources through subsequent anaerobic fermentation is improved, the recycling utilization level of the sludge can be improved, and the pathogenic risk of realizing the recycling of the sludge is obviously reduced through inactivating pathogenic bacteria; and (3) carrying out solid-liquid separation on the acid-producing liquid to obtain mud cakes and acid-producing filtrate, processing the mud cakes into nutrient soil, and using one part of the acid-producing filtrate as a carbon source of a biological pond of a water plant and the other part of the acid-producing filtrate as a substrate carbon source for synthesizing PHAs by flora to obtain PHAs products, thereby improving the resource utilization of the sludge.
The method for recycling the sludge can recycle nitrogen and phosphorus in the acid production liquid or the acid production filtrate, and the nitrogen and phosphorus exist in a struvite form, so that the recycling utilization rate of the sludge is further improved.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings.
FIG. 1 shows a process flow diagram of a method for recycling sludge provided by the invention.
FIG. 2 shows a graph of the amount of volatile fatty acids as a function of time in one embodiment of the present invention.
Detailed Description
Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.
Example 1
The method of this embodiment is shown in fig. 1, and includes the following specific steps:
(1) sludge pyrohydrolysis: preheating the first residual sludge in a slurrying tank by using steam waste heat recycled by thermal hydrolysis, then heating the first residual sludge in a thermal hydrolysis reaction tank to about 170 ℃, maintaining 6bar steam for 40 minutes, performing thermal hydrolysis, discharging the sludge subjected to thermal hydrolysis to a flash tank through pressure relief, reducing the temperature of the sludge in the flash tank to 102 ℃, and further reducing the particle size of sludge particles; cooling and diluting to 8% -12% solid concentration through a heat exchanger. Table 1 shows the comparison results of biochemical indexes of the second excess sludge and the first excess sludge after thermal hydrolysis. As can be seen from Table 1, the contents of SCOD, soluble protein, soluble sugar and volatile fatty acid in the sludge are remarkably improved through thermal hydrolysis, and a rich material basis is provided for the subsequent fermentation acid production and PHAs synthesis.
TABLE 1 comparison of biochemical indicators for the second excess sludge and the first excess sludge after thermal hydrolysis
| Index (I) | Second excess sludge | First excess sludge after pyrohydrolysis |
| Solid content | 2.82％ | 6.71％ |
| SCOD(mg/L) | 734 | 18457 |
| Soluble protein | 135 | 8726 |
| |
20 | 2978 |
| Volatile fatty acid(s) | 778 | 1302 |
(2) Anaerobic fermentation of sludge to produce acid: the acid production research of the first residual sludge after thermal hydrolysis is carried out in a 5L fermentation tank, and the actual working volume is 4L. Taking first residual sludge and second residual sludge after thermal hydrolysis from a certain sewage treatment plant in Beijing, wherein 2L of the first residual sludge after thermal hydrolysis and 2L of the second residual sludge are added into a fermentation tank according to a ratio of 1:1, and a reactor is set to have a water bath circulation temperature of 55 ℃ and a stirring speed of 150 rpm. The continuous fermentation time is 8 days, then the reactor enters a semicontinuous state, the sludge retention time SRT in the reactor semicontinuous state is 4d, namely 1000mL of sludge is fed in and out every day, and the discharged sludge is stored in a refrigerator at 4 ℃. On day 15, the pH in the reactor started to decrease, the volatile fatty acid content gradually increased, and finally the pH stabilized at about 6.05, and the reactor was stably put into the acidogenic stabilization phase (see fig. 2), and then the acidogenic solution was collected.
As can be seen from FIG. 2, the content of VFAs in the fermentation liquid reaches 10000mg COD/L by performing acidogenic fermentation on the first excess sludge after thermal hydrolysis, and compared with the concentration of 2606mg COD/L of fatty acid in the patent document of the invention with publication No. CN101555314A, the concentration of fatty acid in the invention is increased by about 4 times, that is, the volatile fatty acid available for synthesis of PHAs in the subsequent process is 4 times that in the patent document of the invention.
(3) Solid-liquid separation: carrying out mud-water separation on the hydrolysis acidification liquid of the pyrohydrolysis sludge through a plate-and-frame filter press, directly carrying out filter pressing in the filter press for 1.5 hours without adding a flocculating agent additionally to obtain mud cakes and filtrate, wherein the content of volatile fatty acid in the collected filtrate is 9000-10000 mg COD/L, and the method has less energy consumption compared with a centrifugal method and can obtain more stable acid-producing liquid; the obtained mud cake has the water content of 60-75 percent and can be directly used for subsequent nutrient soil processing.
(4) Processing the mud cakes into nutrient soil: adding a nitrogen source and a carbon source into the mud cakes, stirring, then placing the mud cakes in a ventilated place for natural composting and fermentation for 8 days, and finally obtaining the nutrient soil with the water content of 20-30%. In the process, no microbial inoculum is required to be added additionally, and the microorganisms obtained in the anaerobic fermentation step are used for composting fermentation.
(5) And (3) recovering nitrogen and phosphorus: adding magnesium salt to the filtrate to make the ratio of Mg to P to N (molar) in the filtrate 1.4:0.8:1, stirring, standing for precipitation, adding MgCl2·6H2O (27.323g/L) and H2PO4·2H2O (11.763 g/L); adjusting the pH to 9.0; after stirring the precipitate was filtered again, the pH was then adjusted to 7.0 and the nitrogen and phosphorus were collected as struvite.
TABLE 2 Biochemical index of acid-producing liquid from thermal hydrolysis sludge at each treatment stage
| Supernatant of acid-producing mud | Centrifuging the supernatant | Denitrogenation dephosphorization liquid | Filtrate |
| SCOD(mg/L) | 16978 | 16715 | 17613 |
| NH4 +-N(mg/L) | 1338 | 1338 | 228 |
| COD/N(mg/mg) | 13:1 | 13:1 | 77:1 |
(6) And (3) collecting acidified filtrate: acid-producing filtrate is collected through a storage tank, part of the acid-producing filtrate is pumped back to a water plant biological pond to be used as a carbon source according to the requirement of a water plant after the acid-producing filtrate is collected, and the rest part of the acid-producing filtrate enters a PHAs synthesis system;
(7) PHAs synthetic fermentation: and (3) taking the activated sludge of the sewage plant as a seed source, taking the filtrate obtained in the previous step as a matrix carbon source, and performing enrichment activation on the flora by adopting a abundance-hunger mode, wherein the abundance-hunger time ratio is controlled to be 1: 3. The method comprises the following specific steps: diluting the acid production liquid to different degrees to acclimatize the COD of the acid production liquid in a gradient of 2000mg/L, 5000mg/L, 10000mg/L and 20000 mg/L; enriching and activating the flora by adopting a fullness-hunger mode; when the COD is not obviously reduced and is used as a mark for entering a hungry period, controlling the time ratio of the abundant period to the hungry period to be 1:3, finally obtaining an enriched seed solution, centrifuging part of the enriched seed solution after each round, and using the thalli obtained by centrifugation as the next round of inoculation strains. Gradually domesticating, when the time of reaching the hunger stage and the COD change are stable for at least two periods, considering that the flora is stable, and collecting the flora as the flora synthesized by PHAs.
(8) PHAs are collected and extracted: the collected cells were subjected to extraction and purification of PHAs by the SDS-sodium hypochlorite method. Adding water into the thallus collected after centrifugation for suspension, adding a certain amount of SDS (7g/L) and EDTA (10g/L), adjusting the pH to 11, performing magnetic stirring treatment at 50 ℃ for 15min, adjusting the pH to about 7.0, adding 2 times of distilled water for dilution, performing centrifugal treatment on the treated bacterial liquid at 4000rpm for 15min, precipitating, and washing with distilled water.
(9) Drying PHAs: the PHAs products are obtained by drying in an oven at 80 ℃. The PHAs obtained by the method has the accumulation rate of over 60 percent, the purity of over 80 percent and the extraction efficiency of over 90 percent.
Example 2
The main process of the embodiment 2 is not changed with the embodiment 1, the sludge fermentation acid production process in the step (2) is carried out, the water bath circulation temperature of the reactor is set to be 35 ℃, and other steps and process parameters are the same.
The content of VFAs obtained by the method can also reach 10000mg COD/L, which indicates that the anaerobic fermentation of the sludge at the temperature of 35-55 ℃ has less influence on the yield of the sludge, and also indicates that the method has wider application range.
Example 3
In example 3, the main process is not changed with the process of example 1, the extraction of poly-PHAs in the step (8) is different, and other steps and process parameters are the same. The detailed step in the step (8) is to extract and purify the polyhydroxy fatty acid ester from the collected thallus by an acid method. Adding HCl solution into the freeze-dried thalli for acidification, stirring for 60min at 100 ℃, adjusting pH, washing, centrifuging, drying, and drying to obtain PHAs products.
The polyhydroxyalkanoate obtained by the method has the accumulation rate of more than 60%, the purity of more than 97% and the extraction efficiency of more than 96%.
The embodiment proves that the method for recycling the sludge provided by the invention not only obviously improves the recycling utilization rate of the sludge, but also has high yield of the produced polyhydroxyalkanoate.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.
Claims (10)
1. A method for recycling sludge is characterized by comprising the following steps:
s1, sequentially carrying out thermal hydrolysis, cooling and dilution on the first excess sludge;
s2, mixing the diluted first excess sludge and the diluted second excess sludge, and performing anaerobic fermentation to obtain an acid producing liquid;
s3, carrying out solid-liquid separation on the acid production liquid to obtain an acid production filtrate and a mud cake;
s4, processing the mud cakes into nutrient soil;
s5, discharging a part of the acid-producing filtrate into a water plant biological pond as a carbon source of the water plant biological pond;
s6, taking the other part of the acid production filtrate as a substrate carbon source of the flora, enriching and activating the flora in a abundance-hunger mode to synthesize polyhydroxyalkanoate, and collecting the flora at a stable synthesis stage of the polyhydroxyalkanoate;
s7, extracting the polyhydroxyalkanoate from the collected flora, and purifying to obtain polyhydroxyalkanoate products;
and S8, drying the polyhydroxyalkanoate product to obtain the polyhydroxyalkanoate product.
2. The method of claim 1, further comprising: and S9, recovering nitrogen and phosphorus from the acid production liquid obtained in the step S2 or the acid production filtrate obtained in the step S3.
3. The method according to claim 2, wherein in step S9, magnesium salt is added to the acid production solution obtained in step S2 or the acid production filtrate obtained in step S3 so that the molar ratio of Mg to P to N in the filtrate is 1:0.5: 1-2: 1:1, the mixture is stirred and then left to stand for precipitation, and nitrogen and phosphorus in the form of struvite are collected.
4. The method according to claim 1, wherein in step S1, the first excess sludge is placed in a thermal hydrolysis reaction tank, heated to 150-250 ℃ and 6-8 bar, steam is maintained for 25-50 minutes to thermally hydrolyze the first excess sludge, and the thermally hydrolyzed first excess sludge is depressurized to a flash tank, and then cooled and diluted.
5. The method of claim 4, wherein the step S1 further comprises preheating the first excess sludge in a slurry tank and preheating the first excess sludge by using steam waste heat generated by thermal hydrolysis.
6. The method according to claim 1, wherein in step S1, the diluted first surplus sludge has a solid concentration of 8% to 12%; in step S2, the solid content of the second excess sludge is 15% -18%, and the mass ratio of the diluted first excess sludge to the second excess sludge is 4: 1-1: 1; the anaerobic fermentation is to firstly carry out continuous anaerobic fermentation for a preset time and then carry out anaerobic fermentation in a semi-continuous state for more than 4 days, wherein the temperature of the anaerobic fermentation is 35-55 ℃, and the stirring speed is 100-200 rpm.
7. The method as claimed in claim 6, wherein in step S2, when the content of volatile fatty acid in the acid production solution is stable for more than 3 days, the acid production solution enters an acid production stabilization stage to obtain the acid production solution.
8. The method of claim 1, wherein step S4 is to mix the mud cake with nitrogen source and carbon source, and then naturally compost-ferment in a ventilated place for 6-10 days to obtain the nutrient soil.
9. The method according to claim 1, wherein in step S6, the preparation method of the flora comprises the following steps:
and (3) acclimating the bacteria in the activated sludge by using the activated sludge of the sewage plant as a seed source and using the acid-producing liquid in the step S2 and/or the acid-producing filtrate in the step S3 as a substrate to obtain the flora.
10. The method according to claim 1, wherein in step S6, the abundance-hungry mode is that after the flora is inoculated to the substrate carbon source, the chemical oxygen demand of the supernatant of the substrate carbon source is monitored, the lowest point of the consumption rate of the chemical oxygen demand is used as a mark for entering the hungry period, the abundance period is set before the initial inoculation of the substrate carbon source, the replenishment is performed when the abundance-hungry time ratio is controlled to be 1: 2-5, and a period is from the last replenishment to the next replenishment; when the time to reach the starvation period and the chemical oxygen demand stabilize above two cycles, the polyhydroxyalkanoate synthesis is considered to be in a stable phase.
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Cited By (5)
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| CN112812280A (en) * | 2020-12-31 | 2021-05-18 | 清华大学 | Method for producing polyhydroxy fatty acid ester coupling denitrification |
| CN112961766A (en) * | 2021-02-02 | 2021-06-15 | 清华大学 | Reaction system for synthesizing polyhydroxyalkanoate from organic waste and using method thereof |
| CN114769296A (en) * | 2022-05-20 | 2022-07-22 | 中国环境科学研究院 | Method and system for culturing PHA (polyhydroxyalkanoate) granular sludge by using organic waste fermentation liquor |
| CN115488142A (en) * | 2022-07-28 | 2022-12-20 | 北京城市排水集团有限责任公司 | Method for synthesizing fully biodegradable plastic raw material by resourcing waste organic matters |
| CN115536232A (en) * | 2022-10-19 | 2022-12-30 | 北京城市排水集团有限责任公司 | Carbon source recovery method based on sludge pyrohydrolysis |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112812280A (en) * | 2020-12-31 | 2021-05-18 | 清华大学 | Method for producing polyhydroxy fatty acid ester coupling denitrification |
| CN112961766A (en) * | 2021-02-02 | 2021-06-15 | 清华大学 | Reaction system for synthesizing polyhydroxyalkanoate from organic waste and using method thereof |
| CN112961766B (en) * | 2021-02-02 | 2022-11-11 | 清华大学 | Reaction system for synthesizing polyhydroxyalkanoate by organic waste and using method thereof |
| CN114769296A (en) * | 2022-05-20 | 2022-07-22 | 中国环境科学研究院 | Method and system for culturing PHA (polyhydroxyalkanoate) granular sludge by using organic waste fermentation liquor |
| CN114769296B (en) * | 2022-05-20 | 2024-02-09 | 中国环境科学研究院 | Method and system for cultivating PHA (polyhydroxyalkanoate) granular sludge by utilizing organic waste fermentation liquor |
| CN115488142A (en) * | 2022-07-28 | 2022-12-20 | 北京城市排水集团有限责任公司 | Method for synthesizing fully biodegradable plastic raw material by resourcing waste organic matters |
| CN115488142B (en) * | 2022-07-28 | 2024-04-26 | 北京城市排水集团有限责任公司 | Method for synthesizing biodegradable plastic raw material by recycling waste organic matters |
| CN115536232A (en) * | 2022-10-19 | 2022-12-30 | 北京城市排水集团有限责任公司 | Carbon source recovery method based on sludge pyrohydrolysis |
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