Reusing device for PHA washing water

Abstract

The utility model discloses a PHA washing water recycling device which is characterized in that a fermentation tank is connected with a separator system through a fermentation liquor buffer tank, and the separator system is respectively connected with a clear water storage tank and a separation transfer tank through pipelines; the separator system comprises a first separator, a second separator and a third separator which are connected in series; the second separator is connected with the first separator through a pipeline, and the third separator is connected with the second separator through a pipeline. According to the utility model, the separated water generated by the third separator is recycled to the second separator, and the separated water generated by the second separator is recycled to the first separator, so that the use amount of PHA washing water is saved while the impurity content of PHA fermentation liquor is reduced, and the utilization efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of PHA production, and particularly relates to a device for recycling PHA washing water. Background Art

[0002] PHA (polyhydroxyalkanoate) is a general term for high molecular weight polyesters produced by microorganisms using various carbon sources. Due to its good biocompatibility, biodegradability and thermal processing properties, it can be used as an environmentally friendly alternative to traditional petroleum-based plastics and is thus widely used in fields such as packaging materials, medical supplies, and agricultural films. Currently, the production processes of PHA mainly include microbial fermentation and chemical synthesis methods. Among them, microbial fermentation technology has been able to significantly reduce the complexity and cost of downstream processing through strain breeding, transformation, and fermentation technology optimization, and has thus become the mainstream production process of PHA.

[0003] During the production of PHA by microbial fermentation, it is necessary to separate the cells containing PHA from the fermentation broth, and then release the PHA. In addition to PHA, a large amount of impurities are also released together with the cells. Therefore, separation and washing steps are also required to assist in the separation. It can be seen that the production process of PHA has a high dependence on the separation and washing process. However, separation and washing consume a large amount of washing water, which does not conform to the principle of water conservation, increases production costs, and generates a large amount of wastewater that needs further treatment, bringing great environmental pressure.

[0004] Chinese Patent CN103011504B discloses a method for recycling fermentation wastewater in the industrial production of nosiheptide. The filtrate after pressure filtration of the streptomyces tertiary fermentation broth and the tank cleaning liquid are used as fermentation wastewater, which is treated using a sludge pond and an MBR membrane biochemical reaction tank. Then, after adding the corresponding proportion of culture medium components to the treated wastewater, it is used for nosiheptide tertiary fermentation, solving problems such as high wastewater treatment costs and serious water resource waste in the nosiheptide industry, avoiding environmental pollution, saving the strict sewage treatment process required for direct wastewater discharge, and greatly reducing production costs, showing good economic and environmental benefits.

[0005] Chinese Patent CN108821467A discloses a purification treatment and recycling method for alcohol fermentation wastewater. After removing solid impurities from the alcohol fermentation wastewater using a centrifuge, the pH is adjusted with quicklime and then separated by filtration. Then, organic modified attapulgite clay is added for purification and solid-liquid separation to complete the crystallization treatment of the alcohol fermentation wastewater. After treatment, it can be reused for fermentation, reducing the cost of treating alcohol fermentation wastewater.

[0006] Chinese Patent CN202968224U discloses a device for recycling the washing wastewater of a taurine concentration tank. A circulating water pump is used to supply water to the primary concentration tank, secondary concentration tank, tertiary concentration tank, and centrifuge. After the concentration tanks are cleaned, the water is discharged uniformly from the tertiary concentration tank, and the centrifuge cleaning water is directly discharged. All the cleaning water is settled in the first sedimentation tank and then recycled. It has a simple structure, is easy to operate, reduces the consumption of raw water, recovers the reactants in the washing liquid, avoids environmental pollution, and ensures normal production.

[0007] In the prior art, wastewater generally needs to be treated through one or more steps of reagents or equipment before it can be recycled. The treatment efficiency is low, and there are still more or less treatment costs. Moreover, with the in-depth treatment of wastewater, although the substances that have a negative impact on recycling are removed, there will also be some loss of water resources. Summary of the Invention

[0008] In view of the above technical problems, the present utility model provides a device for recycling PHA washing water, which recycles the separated water generated by the third separator to the second separator, and the separated water generated by the second separator is recycled to the first separator, reducing the impurity content of the PHA fermentation broth while saving the consumption of PHA washing water and improving the utilization efficiency.

[0009] To achieve the above object, the present utility model provides a device for recycling PHA washing water. The fermentation tank is connected to the separator system through a fermentation broth buffer tank, and the separator system is respectively connected to the clear water storage tank and the separation transfer tank through pipelines; the separator system includes a first separator, a second separator, and a third separator connected in series; the second separator is connected to the first separator through a pipeline, and the third separator is connected to the second separator through a pipeline.

[0010] Preferably, the first separator is connected to the wastewater storage tank through a pipeline.

[0011] Preferably, the separation transfer tank is connected to the washing buffer tank, and the washing buffer tank is connected to the first separator.

[0012] More preferably, a first lift pump is provided on the pipeline connecting the separation transfer tank and the washing buffer tank; a second lift pump and a check valve are provided on the pipeline connecting the washing buffer tank and the first separator.

[0013] Even more preferably, a detector is provided on the pipeline connecting the separation transfer tank and the first lift pump.

[0014] Preferably, the washing buffer tank is connected to the clear water storage tank through a pipeline.

[0015] Preferably, a first filter is provided on the pipeline connecting the fermentation broth buffer tank and the first separator, a second filter is provided on the pipeline connecting the first separator and the second separator; a third filter is provided on the pipeline connecting the second separator and the third separator.

[0016] The beneficial effects of the present utility model are as follows:

[0017] 1. The three-stage separators are connected in series to form a separator system. With the improvement of separation accuracy, the washing and separating water with the lowest impurity content generated by the third separator is directly transported to the second separator for reuse, and the washing and separating water with a medium impurity content generated by the second separator is directly transported to the first separator to initially wash the product with a relatively high impurity content. The generated washing and separating wastewater is directly recycled. This process does not require any reagents or equipment to purify the wastewater, reducing costs, reducing sewage generation, improving the utilization rate of water resources, and since the washing and separating wastewater is directly recycled, there is no waste of water resources.

[0018] 2. Filters are provided in front of each separator to remove impurities in the water and / or solution entering the separator, avoiding clogging of the separator.

[0019] 3. The solution treated by the separator is stored in the separation transfer tank, and its impurity content and / or main content is detected by a detector. When the content is unqualified, it can be processed by the washing buffer tank and then re-entered into the separator system for cyclic processing until the content is qualified and then enters the next process, improving the processing efficiency of the separator and the product purity.

[0020] 4. The present utility model can be used in processes that require separation such as impurity removal of fermentation broth, separation and purification of products, etc. It has a wide range of applications, a simple structure, and can be widely promoted and applied on a large scale. Description of the Drawings

[0021] Figure 1 is a schematic diagram of the overall structure of the present utility model. In the figure, 1 is the buffer tank, 2 is the first filter, 3 is the first separator, 4 is the second separator, 5 is the third separator, 6 is the separation transfer tank, 7 is the wastewater storage tank, 8 is the detector, 9 is the first lift pump, 10 is the clean water storage tank, 11 is the second lift pump, 12 is the washing buffer tank, 13 is the check valve, 14 is the second filter, and 15 is the third filter. Detailed Embodiments

[0022] The technical solution of the present utility model will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only the preferred embodiments of the present utility model and should not be construed as a limitation of the present utility model. The protection scope of the present utility model shall be subject to the content recorded in the claims. Modifications and substitutions made by those skilled in the art to the technical solution of the present utility model without creative work fall within the protection scope of the present utility model.

[0023] Embodiment 1

[0024] As Figure 1 shown, a device for recycling PHA washing water. The buffer tank 1 is connected to the separator system, and the separator system is respectively connected to the clear water storage tank 10 and the separation transfer tank 6 through pipelines; the separator system includes a series-connected first separator 3, second separator 4, and third separator 5; the second separator 4 is connected to the first separator 3 through a pipeline, and the third separator 5 is connected to the second separator 4 through a pipeline. The solution containing PHA is separated and washed by the series-connected separator system, and the washing and separation water generated by the next-stage separator is transported to the previous-stage separator through a pipeline for direct recycling, improving the utilization efficiency of water resources and the separation and washing effect.

[0025] Preferably, the first separator 3 is connected to the waste water storage tank 7 through a pipeline to discharge the separation and washing waste water with the highest impurity content generated by the first separator 3 from the device and into the waste water storage tank 7, and then the waste water treatment process is carried out to avoid the negative impact of too high impurity content on the PHA product.

[0026] Preferably, the separation transfer tank 6 is connected to the washing buffer tank 12, and the washing buffer tank 12 is connected to the first separator 3 to separate and wash the solution containing PHA after being treated by the separator system again, improving the separation effect.

[0027] Further preferably, a first lift pump 9 is provided on the pipeline connecting the separation transfer tank 6 and the washing buffer tank 12 to assist in the transportation of the solution; a second lift pump 11 and a check valve 13 are provided on the pipeline connecting the washing buffer tank 12 and the first separator 3 to assist in transporting the solution to the first separator 3 and prevent the solution from flowing back.

[0028] Even more preferably, a detector 8 is provided on the pipeline connecting the separation transfer tank 6 and the first lift pump 9 to detect whether the solution containing PHA stored in the separation transfer tank 6 is qualified.

[0029] Further preferably, the washing buffer tank 12 is connected to the clear water storage tank 10 through a pipeline to transport clear water to the washing buffer tank 12 for dilution and washing.

[0030] Preferably, a first filter 2 is provided on the pipeline connecting the fermentation broth buffer tank 2 and the first separator 3, and a second filter 14 is provided on the pipeline connecting the first separator 3 and the second separator 4; a third filter 15 is provided on the pipeline connecting the second separator 4 and the third separator 5 to filter the solution entering the separator, avoid clogging the separator, and reduce the maintenance frequency and difficulty.

Claims

1. A device for recycling PHA washing water, characterized in that: The buffer tank (1) is connected to the separator system, and the separator system is respectively connected to the clear water storage tank (10) and the separation transfer tank (6) through pipelines; the separator system includes a first separator (3), a second separator (4) and a third separator (5) connected in series; the second separator (4) is connected to the first separator (3) through a pipeline, and the third separator (5) is connected to the second separator (4) through a pipeline.

2. The reuse device for PHA washing water according to claim 1, characterized in that: The first separator (3) is connected to the wastewater storage tank (7) through a pipeline.

3. The reuse device for PHA washing water according to claim 1, characterized in that: The separation transfer tank (6) is connected to the washing buffer tank (12), and the washing buffer tank (12) is connected to the first separator (3).

4. The reuse device for PHA washing water according to claim 3, characterized in that: A first lift pump (9) is provided on the pipeline connecting the separation transfer tank (6) and the washing buffer tank (12); a second lift pump (11) and a check valve (13) are provided on the pipeline connecting the washing buffer tank (12) and the first separator (3).

5. The reuse device for PHA washing water according to claim 4, characterized in that: A detector (8) is provided on the pipeline connecting the separation transfer tank (6) and the first lift pump (9).

6. The reuse device for PHA washing water according to claim 3, wherein: The washing buffer tank (12) is connected to the clear water storage tank (10) through a pipeline.

7. The reuse device for PHA washing water according to claim 1, wherein: A first filter (2) is provided on the pipeline connecting the buffer tank (1) and the first separator (3), a second filter (14) is provided on the pipeline connecting the first separator (3) and the second separator (4); a third filter (15) is provided on the pipeline connecting the second separator (4) and the third separator (5).

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