Three-phase separator based on bacteria-algae culture isotopic tracing N / P removal path

Abstract

The invention provides a three-phase separator based on a bacteria-algae culture isotope tracing N / P removal path, and belongs to the technical field of water pollution treatment. The three-phase separator comprises a body, the body is provided with a cavity, and a partition plate in the cavity divides the cavity into a liquid separation area and a gas separation area; a stirring device and a lighting device are arranged in the gas separation area, the body is connected with a gas outlet pipe, and the gas outlet pipe is connected with a gas collection tank; a filter membrane and a Buchner funnel plate are horizontally arranged in the liquid separation area, and an air pump is arranged on the body. The reaction and separation are integrated, the reaction process is closed and stable, a closed reaction space is provided, the isotope is relatively stable, solid, liquid and gas three-phase samples are well separated, three-phase separation is explored, and the removal and utilization approach and removal contribution rate of N and P are achieved through a method based on bacterial-algae system isotope tracing.

Description

Technical Field

[0001] The invention belongs to the technical field of water pollution treatment and relates to a three-phase separator based on bacteria and algae culture isotope tracing N / P removal path. Background Art

[0002] With the rapid development of the pig farming industry, the amount of wastewater generated in pig farms is huge. Anaerobic fermentation is the main method for treating pig farm wastewater. Traditional physical treatment methods are unable to deeply treat wastewater, while chemical treatment methods have high treatment costs and produce corresponding by-products. Although biological treatment methods can effectively remove organic matter, the treatment effect on N / P is poor and it is difficult to meet relevant emission standards.

[0003] Therefore, microalgae are introduced into the biological treatment process of pig farm wastewater to utilize the microalgae to remove inorganic ions (such as NH4 + ,NO3 - ,NO2 - and H2PO4 - The algae-bacteria symbiotic biological treatment technology, which was developed by the absorption of N / P elements in organic form (such as urea), effectively fills the gap in nitrogen and phosphorus removal in biological treatment. Wastewater treatment technology based on microalgae cultivation is also considered to be an ideal technology for solving energy and environmental problems. The application of microalgae in livestock and poultry wastewater has also received widespread attention.

[0004] Common microalgae photobioreactors can be divided into open and closed types. There are four main types of open types: shallow pools, circulating pools, raceway pools, and ponds. Closed photobioreactors include: pipeline type, flat plate type, columnar airlift type, stirred fermentation tank, floating film bag, etc. For isotope tracing, a fully closed photobioreactor is generally used. The closed environment recycles isotopes, avoiding the loss of expensive isotopes and making the utilization rate of isotopes reach 100%.

[0005] In this regard, this application proposes a three-phase separator based on the isotope tracing N / P removal path of bacteria and algae culture, so as to better achieve the separation of solid, liquid and gas samples, and explore the removal and utilization pathways and removal contribution rates of bacteria and algae to N / P in the system. Summary of the invention

[0006] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a three-phase separator based on the isotope tracing N / P removal path of bacteria and algae culture. The three-phase separator integrates reaction and separation, the reaction process is closed and stable, provides a closed reaction space, provides a relatively stable environment for isotopes, and better separates solid, liquid and gas three-phase samples, so as to better explore the removal and utilization pathways and removal contribution rates of bacteria and algae to N / P in the system.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The three-phase separator based on the isotope tracer N / P removal path of bacteria and algae culture comprises a body, the body has a liquid inlet and a liquid outlet, and is characterized in that: the body has a chamber, a partition is arranged in the chamber, the partition divides the chamber into a liquid separation area and a gas separation area, a scraping port is arranged in the gas separation area, and the scraping port is provided with a sealing cover connected by a thread; an opening is opened on the partition, a liquid outlet pipe is fixed at the opening, a valve is arranged on the liquid outlet pipe, and the other end of the liquid outlet pipe is a free end;

[0009] The three-phase separator is used to isotope trace the N / P removal path of bacteria and algae culture, using stable isotopes 15 N-labeled NH4 + -N, and 32 P-labeled PO4 3- The wastewater was used as the substrate, and the stable state of algal symbiotic solution, pure Scenedesmus stock solution and separated dominant bacteria were centrifuged and concentrated. These were used as inoculation objects to determine the algal cells and fungi in the process of single culture and algal symbiotic culture. 15 N and 32 The content of P markers and the content of markers in the culture medium were analyzed by stable isotope tracing technology combined with high-resolution mass spectrometry analysis technology to analyze the removal and utilization pathways and removal contribution rates of N / P by bacteria and algae in the bacteria-algae symbiotic system.

[0010] The gas separation area is provided with a stirring device and a lighting device, the main body is connected to an air outlet pipe, one end of the air outlet pipe is connected to the gas separation area of ​​the chamber, and the other end of the air outlet pipe is connected to the gas collecting tank; the liquid separation area is horizontally provided with a filter membrane and a Buchner funnel plate, and the main body is provided with an exhaust pump, which is connected to the exhaust pipe and is connected to the liquid separation area of ​​the main body chamber through the exhaust pipe.

[0011] In the above three-phase separator, the stirring device comprises a rotating shaft, stirring blades and a servo motor, the servo motor is arranged on the body, the rotating shaft is connected to the servo motor, and the stirring blades are arranged on the rotating shaft.

[0012] In the above three-phase separator, an annular plate is arranged in the gas separation area, and the material of the annular plate is one of organic glass, PVC and resin, and its texture is selected from transparent material.

[0013] In the above three-phase separator, the lighting device is an LED light strip, the annular plate is hollow, and the LED light strip is arranged inside the annular plate.

[0014] In the above three-phase separator, a scraper is arranged on the partition, an annular slide groove is opened on the partition, an annular slide groove is slidably provided with an annular slider, and the scraper is fixed on the annular slider.

[0015] In the above three-phase separator, the scraper is fixed with a connecting block, the connecting block is provided with a clamping groove, and the rotating shaft is fixed with a clamping block matching the clamping groove.

[0016] In the above three-phase separator, a push rod motor is fixed on the main body, a mounting seat is fixed on the end of the output shaft of the push rod motor, and the servo motor is fixed on the mounting seat.

[0017] The N / P removal method based on isotope tracing of bacteria and algae system is characterized by:

[0018] Maintain a closed environment in the gas separation area to obtain a bacterial-algal symbiotic solution;

[0019] The motor drives the stirring blades on the rotating shaft to rotate, stirring the bacteria-algae symbiotic liquid to make it fully react;

[0020] Open the gas valve, and the gas collecting tank collects all the gas in the gas collecting chamber in the gas separation area;

[0021] After the gas collection is completed, open the valve of the partition liquid outlet pipe, turn on the vacuum pump, and use the filtration principle to separate the bacteria and algae from the liquid.

[0022] Compared with the prior art, the present application divides the entire reaction process into a reaction stage and a separation stage, and separates the two stages in space. During the reaction stage, the cavity is closed to prevent interference from external gases and microorganisms, and the reaction process is more complete through a stirring device, and the generated gas is fully released and collected by a gas collecting tank to achieve gas separation. During the separation stage, the partition is opened, and the scraper can intercept the bacteria and algae attached to the partition, and the solid-liquid separation is achieved by using the principle of filtration. The entire process is not connected to the outside world, integrating reaction and separation. The reaction process is closed and stable, reducing the influence of external factors, and better exploring its N / P degradation pathway in three-phase separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the laboratory research device in the present invention.

[0024] Figure 2 It is a schematic diagram of the three-phase structure of the three-phase separator in the present invention.

[0025] Figure 3 The sectional view of the three-phase separator of the present invention is shown in FIG. Figure 1 .

[0026] Figure 4 The sectional view of the three-phase separator of the present invention is shown in FIG. Figure 2 .

[0027] Figure 5 It is a high-throughput sequencing diagram for verifying the interference of samples collected after separation by the three-phase separator in the present invention.

[0028] Figure 6 Middle a, Ps-C group high efficiency algae and bacteria system 15 N degradation pathway; b, pure bacteria of Ps group 15 N degradation pathway; c, pure Scenedesmus in group C 15 N degradation pathway.

[0029] Figure 7 It is a, Ps-C group of efficient algae and bacteria system 18 Op degradation pathway; b, pure bacteria of Ps group 18 Op degradation pathway; c, pure Scenedesmus in group C 18 Op degradation pathway.

[0030] In the figure, 1, main body; 2, partition; 3, vacuum pump; 4, liquid outlet pipe; 5, filter membrane; 6, Buchner funnel plate; 7, rotating shaft; 8, stirring blade; 9, servo motor; 10, push rod motor; 11, annular plate; 12, scraper; 13, annular slider; 14, clamping block; 15, connecting block; 16, air outlet pipe; 17, liquid inlet; 18, liquid outlet; 19, liquid separation area; 20, gas separation area. DETAILED DESCRIPTION

[0031] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0032] Embodiment 1

[0033] like Figure 1-4 As shown, the three-phase separator includes a main body 1, the main body 1 has a liquid inlet 17 and a liquid outlet 18, the main body 1 has a chamber, a partition 2 is arranged in the chamber, the partition 2 is detachably arranged on the main body 1 by a snap, the partition 2 divides the chamber into a liquid separation area 19 and a gas separation area 20, a scraping port is provided in the gas separation area 20, and the scraping port is provided with a sealing cover threadedly connected.

[0034] A stirring device and a lighting device are arranged in the gas separation area 20. The main body 1 is connected with an air outlet pipe 16. One end of the air outlet pipe 16 is connected with the gas separation area 20 of the chamber, and the other end of the air outlet pipe 16 is connected with the gas collecting tank.

[0035] The liquid separation area 19 is horizontally provided with a filter membrane 5 and a Buchner funnel plate 6. The main body 1 is provided with a vacuum pump 3, which is connected to a vacuum pipe and communicates with the liquid separation area 19 of the chamber of the main body 1 through the vacuum pipe.

[0036] The partition plate 2 is provided with an opening, at which a liquid outlet pipe 4 is fixed, and a valve is provided on the liquid outlet pipe 4 . The other end of the liquid outlet pipe 4 is a free end and is located above the filter membrane 5 .

[0037] The stirring device includes a rotating shaft 7, a stirring blade 8 and a servo motor 9. The servo motor 9 is arranged on the body 1, the rotating shaft 7 is connected to the servo motor 9, and the stirring blade 8 is arranged on the rotating shaft 7. The stirring blade 8 on the rotating shaft 7 is driven by the servo motor 9 to rotate, so that the reaction process can be more sufficient.

[0038] An annular plate 11 is provided in the gas separation area 20. The material of the annular plate 11 is selected from one of organic glass, PVC and polyethylene, and its texture is selected from transparent materials. The lighting device is an LED lamp. The annular plate 11 is hollow and the LED lamp is arranged in the annular plate 11. The annular plate 11 can prevent liquid foam from entering during the gas collection process.

[0039] The partition plate 2 is provided with a scraper 12, the partition plate 2 is provided with an annular slide groove, the annular slide groove is slidably provided with an annular slider 13, and the scraper 12 is fixed on the annular slider 13. The scraper 12 is provided with a clamping groove, and a clamping block 14 matching the clamping groove is fixed on the rotating shaft 7. A push rod motor is fixed on the body 1, and a mounting seat is fixed on the end of the output shaft of the push rod motor, and the servo motor 9 is fixed on the mounting seat.

[0040] Specifically, the main body 1 adopts a cylindrical glass cavity shell with a diameter of 10 cm and a height of 15 cm. The bacteria and algae reaction part (i.e., the distance from the partition 2 to the top) is 10 cm high. The volume parameter design is based on the volume of the bacteria and algae reaction liquid and the gas collection process. The reaction liquid is 300 ml (water depth 4 cm) simulated wastewater, and the gas rising space is 6 cm high to prevent liquid foam from entering during the gas collection process.

[0041] Light intensity is 8000Lux / cm 2 .

[0042] The rotation speed of the servo motor 9 in the stirring device is 60 r / min, and the spiral blade (single) is 2 cm long, which ensures that the reaction proceeds fully and the gas generated by the reaction is fully released.

[0043] The partition 2 is made of polyethylene material with a thickness of 1 cm and good sealing performance.

[0044] The area of ​​the slit portion of the gas collecting chamber in the body 1 should account for 15-20% of the total area of ​​the reactor, so as to collect the gas sufficiently and evenly.

[0045] The Buchner funnel plate 6 is made of ceramic material. The pore size of the filter membrane 5 is 0.45 μm.

[0046] like Figure 5As shown in the figure, biological samples were collected from the beginning to the end of the three-phase separator for high-throughput sequencing. It was found that the main body of the reactor was microalgae and Pseudomonas stutzeri, and other bacteria accounted for less than 1% during the whole process, indicating that the reactor was less disturbed during operation, the samples were pure, and the experimental results were relatively reliable. This provides a matching reaction device for the isotope tracing method of the bacteria-algae system to explore its N / P degradation pathway.

[0047] Embodiment 2

[0048] like Figure 6-7 As shown, the three-phase separator is used to isotope trace the N / P removal pathway of bacterial and algal cultures.

[0049] Using isotopes 15 N-labeled NH4 + -N, and 32 P-labeled PO4 3- Simulated swine wastewater was prepared as the substrate. Through static closed culture experiments, the stable state of bacteria-algae symbiotic solution, pure Scenedesmus stock solution and separated dominant bacteria were obtained by centrifugation and concentrated. These were used as inoculation objects. The removal and utilization pathways and removal contribution rates of N / P were analyzed by measuring the 15N and 32P marker contents in algal cells and fungi, the marker content in the culture solution and the marker content in the gas during the single culture and bacteria-algae symbiotic culture processes.

[0050] Specific:

[0051] 15 NH4 + -N

[0052] In a closed environment reactor, the bacteria-algae symbiotic solution, pure Scenedesmus stock solution and the above-isolated dominant bacteria were centrifuged and concentrated, and used as inoculation objects. 10% of the original total ammonia nitrogen concentration of the system was added. 15 NH4CI (99atom%) powder was dissolved in simulated wastewater. This concentration was chosen mainly to avoid shock to the system and to prevent it from correctly reflecting the actual operation of the experiment. After 8 days of adding the isotope, the system reached stability. Gas samples, water samples, and bacterial and algal biomass samples were collected from the bacterial and algal symbiotic system. At this time, it was considered that the isotope had been evenly mixed in the system. Water samples and gas samples were collected separately, and the TAN concentration in the samples was determined.

[0053] 32 PO4 3-

[0054] In a closed environment reactor, the bacterial-algal symbiotic solution, pure Scenedesmus stock solution and the above-isolated dominant bacteria were centrifuged and concentrated, and used as inoculation objects. K2H was added according to 10% of the original total ammonia nitrogen concentration of the system. 32PO4 (99atom%) powder was dissolved in simulated wastewater. This concentration was chosen mainly to avoid shock to the system and to prevent it from correctly reflecting the actual operation of the experiment. After the isotope was added, it reached stability 8 days later. Water samples, solid sediment samples, and bacterial and algal biomass samples were collected from the bacterial-algal symbiotic system. At this time, it was considered that the isotope had been evenly mixed in the system. Water samples and solid samples were collected separately, and the TAN concentration in the samples was determined.

[0055] Reference BG11 culture medium was prepared with simulated wastewater. The composition of 100 ml culture medium is as follows:

[0056]

[0057] Add 10% of the original total ammonia nitrogen concentration in the system 15 NH4CI (99atom%) powder was dissolved in the simulated wastewater to ensure uniform mixing. This concentration was selected mainly to avoid shock to the system.

[0058] Add 300 ml of simulated wastewater for reaction into the three-phase separator, keep the gas separation area 20 closed, and the light intensity is 8000 Lux / cm 2 The temperature was controlled at 24-26°C and the light cycle was 24h / d. After the system was balanced, the logarithmic phase Desmodesmus sp. CHX1 was inoculated into the culture bottle at an inoculation density of 0.1 mg / L, and a constant temperature and light reaction was carried out. The growth conditions of the photobioreactor were maintained for about 8 days, and the biomass of Desmodesmus reached saturation, and the degradation of ammonia nitrogen in the water also reached the highest level.

[0059] The motor drives the stirring blades on the rotating shaft 7 to rotate, stirring the bacteria-algae symbiotic liquid to make it fully react; after the reaction is completed, continue stirring for 1 hour to ensure that the gas in the system is fully released. After turning off the motor, open the gas valve, collect 100ml of gas, and seal it in an air bag for storage. After the gas collection is completed, remove the partition, turn on the vacuum pump, filter and separate the microalgae sample to the filter membrane, freeze-dry and seal it for storage. 20ml of the liquid sample is passed through a 0.22μm membrane and stored in a refrigerator at 4℃.

[0060] varioPYROcube elemental analyzer connected to ISOPRIME-100 15N isotope analysis. The solid sample is oxidized at 1120°C, and the gas formed in this process is passed into a reduction copper tube and reduced to N at 850°C. The gas then uses helium as a carrier gas and passes through a water trap (magnesium perchlorate), where N is separated by adsorption and desorption columns, and then enters an isotope mass spectrometer (IRMS) for isotope analysis. The ammonia nitrogen in the liquid sample is concentrated by diffusion absorption, and then measured using an element analyzer combined with an isotope mass spectrometer. The gas sample can be measured directly. In order to analyze the removal and utilization pathways and removal contribution rates of bacteria and algae in the bacterial-algal symbiotic system to N / P in the system.

[0061] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A three-phase separator based on bacterial and algae culture isotope tracing N / P removal path, comprising a body having a liquid inlet and a liquid outlet, characterized in that: The main body has a chamber, in which a partition is arranged, which divides the chamber into a liquid separation area and a gas separation area. The gas separation area is provided with a scraping port, and the scraping port is provided with a sealing cover connected by a thread; an opening is opened on the partition, and a liquid outlet pipe is fixed at the opening, and a valve is provided on the liquid outlet pipe, and the other end of the liquid outlet pipe is a free end.

2. According to the three-phase separator based on the isotope tracing N / P removal path of bacteria and algae culture according to claim 1, a stirring device and a lighting device are arranged in the gas separation area, the main body is connected with an air outlet pipe, one end of the air outlet pipe is connected with the gas separation area of ​​the chamber, and the other end of the air outlet pipe is connected with the gas collecting tank; the liquid separation area is horizontally provided with a filter membrane and a Buchner funnel plate, and an air pump is arranged on the main body, the air pump is connected with the air extraction pipe, and the air extraction pipe is connected with the liquid separation area of ​​the main body chamber.

3. The three-phase separator based on the isotope tracing N / P removal path of bacteria and algae culture according to claim 1 is characterized in that: The stirring device comprises a rotating shaft, stirring blades and a servo motor. The servo motor is arranged on the body, the rotating shaft is connected to the servo motor, and the stirring blades are arranged on the rotating shaft.

4. The three-phase separator based on the isotope tracing N / P removal path of bacteria and algae culture according to claim 1, characterized in that: An annular plate is arranged in the gas separation area. The material of the annular plate is one of organic glass, PVC and resin, and its texture is selected from transparent material.

5. The three-phase separator based on bacterial and algal culture isotope tracing N / P removal path according to claim 4, characterized in that: The lighting device is an LED lamp, the annular plate is hollow, and the LED lamp is arranged inside the annular plate.

6. The three-phase separator based on bacterial and algae culture isotope tracing N / P removal path according to claim 1, characterized in that: The partition is provided with a scraper, an annular slide groove is provided on the partition, an annular slide groove is slidably provided with an annular slider, and the scraper is fixed on the annular slider.

7. The three-phase separator based on bacterial and algae culture isotope tracing N / P removal path according to claim 6, characterized in that: The scraper is fixed with a connecting block, the connecting block is provided with a clamping groove, and the rotating shaft is fixed with a clamping block matching the clamping groove.

8. The three-phase separator based on bacterial and algal culture isotope tracing N / P removal path according to claim 7, characterized in that: A push rod motor is fixed on the main body, a mounting seat is fixed on the end of the output shaft of the push rod motor, and the servo motor is fixed on the mounting seat.

Images