CN108802336B - A steady-state cultivation device for measuring the nitrogen pollution efficiency and nitrogen cycle of wetlands - Google Patents

Abstract

The invention discloses steady-state culture equipment for measuring the purification nitrogen pollution efficiency and nitrogen circulation of a wetland, which is characterized in that a sampling tube at the inner layer of a reaction kettle is used for obtaining a wetland soil column sample, a jacket at the outer layer of the reaction kettle is sleeved on the outer wall of the sampling tube and is communicated with a temperature control system, the surface of the wetland soil column sample is filled with wetland surface water, the wetland surface water is respectively communicated with a gas supply system and a sampling system, and a cavity between the wetland surface water and a kettle top cover is respectively connected with a nutrient solution supply system and a nutrient solution discharge system; the parameter probe a and the parameter probe b of the detection system are respectively inserted into the wetland surface water and the wetland soil columnar sample. The invention can accurately simulate and control a plurality of environmental factors, has the advantages of good simulation effect, strong repeatability, no pollution in a totally-enclosed mode, ingenious sampling design and the like, and can be safely and reliably used for investigation of purification nitrogen pollution of wetland soil and surface water and development of related experimental study of wetland soil and water nitrogen circulation.

Description

A steady-state cultivation device for measuring the nitrogen pollution efficiency and nitrogen cycle of wetlands

Technical field

The invention belongs to the technical fields of coastal wetland science and biogeochemistry, and specifically relates to a steady-state cultivation equipment for measuring the nitrogen pollution efficiency and nitrogen cycle of wetlands.

Background technique

The nitrogen cycle is an ecosystem material cycle that describes the mutual conversion process between nitrogen element and nitrogen-containing compounds in nature. It is an important part of the global biogeochemical cycle. The "reactive" nitrogen added to the world every year through human activities has caused a serious imbalance in the global nitrogen cycle and caused a series of environmental problems such as water eutrophication, water acidification, and greenhouse gas emissions. The nitrogen content in wetland soil and its migration and transformation process also significantly affect the structure and function of wetland ecosystems and wetland productivity. The wetland nitrogen cycle includes a series of links such as the synthesis of organic nitrogen by wetland vegetation or phytoplankton in water areas, ammoniation, nitrification, denitrification and nitrogen fixation. In the past half century, due to the dual impact of human activities and global climate change, the nitrogen content in my country's waters (including lakes, rivers, oceans, etc.) has increased significantly. Take the Bohai Sea as an example. According to incomplete statistics, the dissolved inorganic nitrogen (DIN) content in the Bohai Sea has increased by at least 10 times in the past 50 years, which is much higher than that in other sea areas in the world (for example, the DIN content in the offshore waters of Louisiana, USA). (increased only about 3 times), therefore, sewage discharge and nitrogen removal has become an urgent environmental issue.

Wetlands have extremely strong self-purification capabilities and the ability to purify sewage. They are called the "kidneys of the earth". In recent years, many artificial and natural wetlands have begun to be used in sewage treatment systems. Because they are cheap, green and environmentally friendly, and can avoid the shortcomings of conventional sewage treatment plants such as high cost, high energy consumption, and complex operation and management, they are gradually becoming a An efficient method of sewage and nitrogen removal has attracted more and more attention from scientific researchers and government departments. However, it is worth noting that there is currently no very clear method to investigate and evaluate the nitrogen removal efficiency of soil and its microorganisms when nitrogen-containing water flows through wetland soil; moreover, there is also a lack of suitable methods to analyze the purification process and the nitrogen cycle. The many biochemical reactions and microbial action mechanisms that occur are systematically studied.

The nitrogen cycle in wetlands not only affects the structure, function, stability and health of the ecosystem, but also determines the evolution direction of the wetland ecosystem to a certain extent. It is also related to a series of global environmental problems such as global warming, ozone layer destruction and acid deposition. are closely related to each other, so it is an important research field in global change research; how to use the purification capacity of wetlands to serve nitrogen pollution treatment is the focus of scientific researchers and government departments from various countries.

Preliminary investigation found that the current existing technology has the following shortcomings and problems:

(1) The previous design needs to be improved in terms of the connection between the two steps of "obtaining soil columnar samples" and "reactor culture". In the past, experimental settings often involved setting up a reactor first, then going to the field to obtain soil columnar samples, and then transferring the columnar samples into the reactor for cultivation. On the one hand, it is easy to change important parameters such as the structure, particle size, moisture and oxygen content of the soil columnar sample. On the other hand, it is also easy to be contaminated by the surrounding environment during the transfer process, resulting in culture failure or unrealistic results.

(2) Previous designs lacked accurate simulation and control of environmental factors. In the past, experimental devices can only simulate and control limited environmental state parameters, and it is difficult to accurately control the temperature (T), salinity (S), light, dissolved oxygen (DO) concentration, water flow dynamics, and nutrients of wetland soil and surface water. All hydrological environmental conditions such as salt concentration. For example, it is difficult to control the nutrient input rate and concentration of wetlands, which may lead to unstable patterns and mechanisms of microbial biochemical reactions; and the lack of precise control of dissolved oxygen and temperature will make it difficult to control the ecosystem's anorexia. The biochemical reactions and microbial nitrogen cycle mechanisms in oxygen, anoxic and aerobic states are also very different, and the efficiency of sewage removal and nitrogen removal is also uncertain and unpredictable.

(3) Previous designs had poor stability and poor repeatability: Most of the previous experimental devices did not adopt steady-state culture methods. Even if problem culture methods were used, they could not fully simulate all possible changes in environmental factors. Therefore, differences between different experiments The repeatability is poor and it is difficult to repeatedly verify the experimental results. Especially when sampling a culture system, the sampling process can easily disturb the balance of the system, making it difficult to maintain the entire system in a stable state.

(4) In the past, most designs used non-sealed environments, which were prone to contamination and interference. Existing experimental designs mostly use open batch culture, which makes wetland soil and surface water systems susceptible to interference from external microorganisms and bacteria, resulting in the coexistence of internal biological systems in wetland soil and surface water with foreign bacteria, viruses and other microorganisms after culture. This creates difficulties for further analysis and testing. Moreover, due to pollution interference, the experimental results are also inaccurate, reducing the experimental reference value.

(5) Most previous designs did not adopt pollution-free sampling methods. In the past, sampling operations often took the form of one-time sampling after extraction or culture. These methods are not optimal because they easily disturb the continuous and steady-state growth of wetland soil microorganisms and surface water phytoplankton ecosystems, and can easily cause pollution. Stopping culture to take samples also disrupts the biochemical balance of wetland soil and surface water biological systems. Moreover, it is difficult to observe changes in hydrological environmental parameters in wetland soil and surface water biological systems in real time by sampling after cultivation, such as DO status, temperature conditions, number of phytoplankton cells in the water, changes in cell composition, cell growth mechanisms and parameter changes, etc.

Therefore, how to develop a new type of steady-state culture equipment for measuring the nitrogen pollution efficiency and nitrogen cycle of wetlands has important practical significance.

Contents of the invention

In view of the technical problems existing in the prior art such as poor device stability, poor repeatability, difficulty in sampling, difficulty in multi-parameter control, easy contamination, and lack of accurate simulation of environmental factors, the purpose of the present invention is to provide a method for measuring purified nitrogen in wetlands. Steady-state culture equipment for fouling efficiency and nitrogen cycling.

The technical solutions adopted by the present invention are:

A steady-state cultivation equipment for measuring the efficiency of purifying nitrogen pollution in wetlands and nitrogen circulation, including a reaction kettle, a temperature control system, a nutrient solution supply system, a nutrient solution discharge system, a gas supply system, a sampling system and a detection system; the reaction The inner layer of the cauldron is set as a hollow sampling cylinder. The sampling cylinder is rammed into the soil with top pressure, and the columnar samples of wetland soil naturally filled in it are taken out at the same time. The top and bottom ends of the sampling cylinder are respectively equipped with a top cover and a cauldron top cover. The bottom cover of the kettle is sealed; the outer layer of the reaction kettle is set as a jacket filled with a circulating water bath, and the jacket is set on the outer wall of the sampling cylinder and is connected to the temperature control system of the circulating water bath; the surface of the wetland soil columnar sample is filled with wetland surface Water and wetland surface water are connected to the gas supply system and sampling system respectively, and the cavity between the wetland surface water and the cauldron top cover is connected to the nutrient solution supply system and the nutrient solution discharge system respectively; the detection system includes parameter probe a and parameter probe b , parameter probe a and parameter probe b are inserted inside the wetland surface water and inside the wetland soil columnar sample respectively.

Further, the temperature control system includes a circulating water bath. The circulating water bath is configured as a hollow cylindrical barrel structure with limited through holes arranged at equal intervals around it in an annular shape. The reaction kettle is installed in the limited through holes.

Furthermore, the inner sampling tube and the outer jacket of the reaction kettle are made of transparent hard plastic material. The sampling tube is set as an upright columnar structure with an internal hollow. The wall thickness of the sampling tube is greater than the wall thickness of the jacket. , the jacket is provided with a circulating water bath outlet and a circulating water bath inlet respectively, and the circulating water bath is connected to the circulating water bath outlet and the circulating water bath inlet of the jacket respectively.

Further, the nutrient solution supply system includes a nutrient solution reserve chamber and a peristaltic pump. The top of the nutrient solution reserve chamber is connected to the trachea a. The liquid in the nutrient solution reserve chamber is connected to the peristaltic pump through a conduit. The peristaltic pump is connected to the nutrient solution conduit. The liquid conduit is extended and inserted on the top cover of the reaction kettle.

Further, the nutrient solution discharge system includes a graduated cylinder and an overflow guide tube. One end of the overflow guide tube is inserted into the top cover of the reaction kettle, and the other end of the overflow guide tube is inserted into the graduated cylinder.

Further, the gas supply system includes an air pump and an air pipe b, the air pump is connected to the air pipe b, and the end of the air pipe b is inserted into the wetland surface water.

Further, the sampling system includes a sampling tube, an air extraction sampling bottle, and a vacuum pump. The vacuum pump is connected to the air extraction sampling bottle through a pipeline. The air extraction sampling bottle is connected to the sampling tube. The end of the sampling tube extends to the wetland surface water. , the sampling pipe and the gas pipe b of the gas supply system are connected through a three-way plug valve.

Further, the parameter probe a and parameter probe b of the detection system are connected to the power supply, detector, and computer through wires respectively.

Furthermore, a stirrer and a sampling hole are provided. The sampling hole is provided through the top cover of the kettle. The stirrer extends through the top cover of the kettle into the surface water of the wetland. The stirrer is driven by the motor of the top cover of the kettle.

Furthermore, a lighting control system is provided. The lighting control system includes a light panel and a light source lamp. The light panel is embedded on the top cover of the kettle. The light source lamp is installed on the light panel. The light source lamp is connected to the power supply through a timer.

The beneficial effects of the present invention are:

In view of several problems existing in the prior art, the present invention is mainly solved through the following technical solutions:

(1) In view of the problem that the two links of "obtaining soil columnar samples" and "reactor culture" are not easy to connect: the inner layer of the reactor used in this design is a hollow upright columnar structure, and the inner wall is made of transparent hard plastic. It can be placed directly on the surface of the wetland soil, and then the inner layer of the reactor (sampling cylinder) is tamped into the soil using top pressure. When the inner layer of the reactor (sampling cylinder) is taken out, the naturally filled contents can be The wetland soil columnar sample is taken out at the same time, and the bottom cover and top cover of the reaction kettle are immediately covered for sealing; the outer layer (jacket) of the reaction kettle can be placed on the inner layer (sampling tube) of the reaction kettle after the soil columnar sample is taken. ), and then connected to the temperature control system of the circulating water bath. In addition, if necessary, the reactor can be cleaned or sterilized in advance to eliminate environmental pollution. It can be seen that this design makes sampling fast and convenient, and avoids disturbance and potential human pollution of wetland soil samples to the greatest extent.

(2) In response to the problem that previous designs lacked accurate simulation and control of environmental factors: this design uses the double-layer structure of the reactor and circulating water bath equipment to control the temperature of the reactor during the entire culture process; it uses a peristaltic pump to accurately control the temperature introduced into the reactor. Nutrient solution input rate; use a stirrer to stir the surface water of the wetland sample to simulate the flow fluctuations of the wetland; use an air pump to inflate sterile air flow to simulate air conditions, thereby controlling the dissolved oxygen content of the wetland surface water and soil; use a multi-parameter detector Monitor hydrological environmental parameters such as temperature, salinity, dissolved oxygen, and redox potential in wetland surface water and soil columnar samples to ensure accurate control and simulation of environmental factors.

(3) In view of the problems of poor stability and poor repeatability of previous designs, this design uses a fully enclosed steady-state chemostat culture mode, which refers to the cultivation of microorganisms and microorganisms in wetland soil and water in a system with relatively constant conditions. Plankton are cultured; the total amount of nutrient solution in the system remains constant, is supplied from the outside at a constant rate, and the culture is continuously extracted; the growth rate of the culture can be precisely controlled by limiting the supply rate of certain nutrients. This method can not only improve equipment utilization, but also facilitate the development of culture experiments with high precision requirements. Therefore, in this design, all environmental conditions and even the input and output rates of the nutrient solution are accurately controllable. The entire system is stable and reliable, and when the environmental conditions are properly controlled, the entire experiment is repeatable.

(4) In view of the problem that previous designs often adopt non-closed environments and are easily contaminated and interfered with, this design adopts a fully enclosed design. All conduits or outlets have on-off valves, and the air or oxygen entering the system is also filtered. Filtration (the filter sieve preferably has a pore size of 0.22 μm, which can filter impurities and microorganisms and ensure the injection of sterile air).

(5) In view of the problem that sampling methods in previous designs may lead to contamination, this patent designs two sampling methods: ① One is controlled by a three-way cock valve. When the cock is turned to a certain angle, the sterile air introduction will be closed tube (trachea b), and is connected with the sampling tube, so that negative pressure can be created through a sterile air sampling bottle and a vacuum pump to extract the surface water sample from the reaction kettle; ② The other is to set The overflow diversion pipe is installed. Since the nutrient solution is continuously added to the reactor, the surface water will inevitably increase and the water surface will rise. One end of the overflow diversion pipe is close to the surface water surface of the wetland surface water. When the water body increases to a certain extent, it will The overflow is exported to maintain the stability of the system. Since the reactor is always filled with sterile air, and one end of the overflow guide tube is always a unidirectional airflow and liquid outlet, there will be no problem of outside air flowing back and contaminating the surface water in the reactor. The above two methods can well avoid the problem of changing the system balance of chemostat culture in the reactor due to sampling. In addition, conventional parameters, such as temperature, salinity, pH, DO, etc., can be monitored in real time through multi-parameter probes placed in surface water and soil, and there is no problem of contaminating samples inside the reactor.

To sum up, compared with the existing technology, the beneficial effects of the present invention are reflected in:

This patent designs a steady-state chemostat cultivation system device that can simulate the nitrogen cycle of natural wetland soil and surface water. It uses the steady-state model to calculate the efficiency of wetland soil and wetland surface water in purifying nitrogen pollution. It can also be used to analyze the nitrogen cycle. Conduct systematic research on processes and mechanisms. This design cleverly uses the steady-state chemostat culture model to avoid a series of problems in previous designs, and can accurately simulate and control many environmental factors. It has good simulation effects, strong repeatability, no pollution in the fully closed mode, and clever sampling design. With other advantages, it can be safely and reliably used to investigate nitrogen pollution in wetland soil and surface water purification and carry out related experimental research on nitrogen cycle in wetland soil and water bodies.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

Figure 2 is a schematic diagram of the overall structure of the circulating water bath in the present invention.

Figure 3 is a schematic structural diagram of the lighting control system in the present invention.

Among them, 1. Nutrient solution reserve room; 2. Trachea a; 3. Peristaltic pump; 4. Nutrient solution conduit; 5. Parameter probe a; 6. Air pump; 7. Trachea b; 8. Three-way plug valve; 9. Sampling tube; 10. Air sampling bottle; 11. Vacuum pump; 12. Sampling hole; 13. Top cover of cauldron; 14. Mixer; 15. Wetland surface water; 16. Circulating water bath outlet; 17. Wetland soil column sample; 18a, jacket; 18b, sampling cylinder; 19, bottom cover of the kettle; 20, circulating water bath inlet; 21, parameter probe b; 22, overflow guide tube; 23, measuring cylinder; 24, circulating water bath; 25 , limit through hole; 26. light panel; 27. light source lamp.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Example 1

As shown in Figure 1, a steady-state culture equipment used to measure the efficiency of purifying nitrogen pollution in wetlands and nitrogen circulation includes a reactor, a temperature control system, a nutrient solution supply system, a nutrient solution discharge system, a gas supply system, a sampling system and Detection system; the inner layer of the reaction kettle is made of transparent hard plastic material and is set as a hollow sampling tube 18b. The sampling tube 18b is set as an upright columnar structure with an internal hollow, which can be directly placed on the surface of the wetland soil, and then pressurized at the top. Punch the inner layer of the reactor (sampling cylinder 18b) into the soil. When the inner layer of the reactor (sampling cylinder 18b) is taken out, the columnar sample 17 of wetland soil naturally filled in it can be taken out at the same time, and the reactor should be covered immediately. The bottom cover 19 is sealed; the outer layer of the reaction kettle (jacket 18a) can be placed on the inner layer of the reaction kettle (sampling cylinder 18b) after the wetland soil columnar sample 17 is taken, and then connected to the temperature control system of the circulating water bath; reaction The outer layer of the kettle (jacket 18a) can be made of thin transparent plastic material, on which a circulating water bath outlet 16 and a circulating water bath inlet 20 are respectively provided. The circulating water bath 24 is connected to the circulating water bath outlet 16 and 20 of the reaction kettle respectively. The circulating water bath inlet 20 is connected; the surface of the wetland soil columnar sample 17 is filled with wetland surface water 15, the wetland surface water 15 is connected to the gas supply system and the sampling system respectively, and the cavity between the wetland surface water 15 and the cauldron top cover 13 is respectively It is connected to the nutrient solution supply system and the nutrient solution discharge system; the detection system includes a parameter probe a5 and a parameter probe b21. The parameter probe a5 and the parameter probe b21 are inserted inside the wetland surface water 15 and the wetland soil columnar sample 17 respectively.

The bottom cover 19 of the reaction kettle is installed at the bottom of the reaction kettle by threading. The outer layer of the reaction kettle wall can be filled with the water flow from the circulating water bath to accurately control the temperature of the reaction kettle. The wetland surface water 15 is not covered. On the surface of the soil columnar sample placed in the reactor, the depth of the wetland surface water 15 is much lower than the depth of the soil columnar sample.

The top cover 13 of the reaction kettle has multi-functional features. First of all, it can be sealed on the reactor body. The kettle cover runs through the nutrient solution introduction pipe, the sterile air introduction pipe, the multi-parameter probe/detector, the stirrer 14 and the rotor, Sampling hole 12 (the top is sealed with rubber and can be opened, and liquid can be added with a syringe) and overflow guide tube.

As shown in Figure 2, the temperature control system includes a circulating water bath 24. The circulating water bath 24 is configured as a hollow cylindrical barrel structure with limited through holes 25 arranged at equal intervals around it. The reaction kettle is installed in the limited through holes. Within 25.

A circulating water bath outlet 16 and a circulating water bath inlet 20 are respectively provided on the outer layer of the reactor. The circulating water bath 24 is connected to the circulating water bath outlet 16 and the circulating water bath inlet 20 of the reactor respectively.

The circulating water bath outlet 16 and the circulating water bath inlet 20 are arranged relatively at the top and bottom of the reactor, respectively. The distance between them is relatively far, which can ensure the adequacy of water circulation in the outer layer of the reactor. The reaction kettle is preferably made of transparent materials, such as hard plastic or tempered glass, which facilitates observation of internal reactions at any time, and also facilitates the top light panel 26 to put light into the wetland surface water 15 .

A support frame is provided inside the circulating water bath 24, and a fastening clamp is provided on the support frame, and the fastening clamp is clamped at the joint between the reactor body and the reactor top cover 13.

The nutrient solution supply system includes a nutrient solution reserve chamber 1 and a peristaltic pump 3. The top of the nutrient solution reserve chamber 1 leads to the trachea a2. The liquid in the nutrient solution reserve chamber 1 is connected to the peristaltic pump 3 through a conduit. The peristaltic pump 3 and the nutrient solution conduit 4 Connect, the nutrient solution conduit 4 is extended and inserted on the top cover 13 of the reaction kettle.

The peristaltic pump 3 extracts the nutrient solution from the nutrient solution storage chamber 1 and inputs it into the reaction kettle through the nutrient solution conduit 4 at a set rate. The outlet of the nutrient solution conduit 4 should be higher than the liquid level to facilitate timely replenishment of the nutrient solution; the peristaltic pump 3 The rotation speed is adjustable and the diameter of the internal conduit is adjustable to control the rate of introducing the nutrient solution; the top of the nutrient solution storage chamber 1 is sealed with a rubber plug, and the first air filter screen is penetrated through the rubber plug, and the filter screen has a preferred aperture of 0.22 μm. , can filter impurities and microorganisms, etc., to ensure the injection of sterile air.

The nutrient solution discharge system includes a graduated cylinder 23 and an overflow guide tube 22. One end of the overflow guide tube 22 is inserted into the reaction kettle top cover 13, and the other end of the overflow guide tube 22 is inserted into the graduated cylinder 23.

The overflow guide tube 22 can lead excess liquid in the reaction kettle to the measuring cylinder 23 for subsequent analysis. As the nutrient solution is continuously added to the reactor, the surface water will inevitably increase and the water surface will rise. One end of the overflow diversion pipe 22 is close to the surface water surface. When the water body increases to a certain extent, the overflow will be directed out to maintain the stability of the system. Since the reactor is always filled with sterile air, and one end of the overflow guide tube 22 is always a unidirectional airflow and liquid outlet, there is no problem of outside air being poured back to contaminate the surface water in the reactor.

The gas supply system includes an air pump 6 and an air pipe b7. The air pump 6 is connected to the air pipe b7. The end of the air pipe b7 is inserted into the wetland surface water 15, that is, the air outlet of the air pipe b7 is below the liquid level of the wetland surface water 15. The air pipe b7 of the gas supply system is equipped with a gas filter screen. The preferred aperture of the filter screen is 0.22 μm, which can filter impurities and microorganisms and ensure the injection of sterile air. The air pump 6 introduces the air into the second air filter screen (the preferred aperture is 0.22 μm). 0.22 μm), after filtration, the sterile air is introduced into the wetland surface water 15 in the reaction kettle through the three-way stopcock 8 through the trachea b7.

The sampling system includes a sampling tube 9, an air extraction sampling bottle 10, and a vacuum pump 11. The vacuum pump 11 is connected to the air extraction sampling bottle 10 through a pipeline. The air extraction sampling bottle 10 is connected to the sampling tube 9. The end of the sampling tube 9 extends to Wetland surface water 15.

The trachea b7 of the gas supply system and the sampling pipe 9 of the sampling system are connected through a three-way plug valve 8. The three-way plug valve 8 has the function of flow regulation. When adjusted to the first angle, the sterile air can be Enter the reaction kettle, and the connection with the sampling tube 9 is closed at this time; when adjusted to the second angle, the trachea b7 for inputting sterile air is closed, and is connected to the sampling tube 9, and can be pumped through the air sampling bottle 10 and the vacuum pump The pump 11 forms a negative pressure and takes out the water flow from the reaction kettle.

The parameter probe a5 and parameter probe b21 of the detection system are connected to the power supply, detector and computer through wires respectively. One of the multi-parameter probes/detectors composed of parameter probe a5 and parameter probe b21 is inserted into the water body, and the other probe is inserted into the soil, which can monitor the temperature, salinity, pH, DO, and redox of the water body and soil in real time. Electric potential and other hydrological environment parameters, the detector is connected to the computer and power supply, and the results can be read from the computer in real time for monitoring.

A stirrer 14 and a sampling hole 12 are also provided. The sampling hole 12 is provided through the top cover 13 of the kettle. The stirrer 14 extends through the top cover 13 of the kettle into the wetland surface water 15. The stirrer 14 passes through the top cover 13 of the kettle. motor drive. The agitator 14 is in the shape of a single needle and has a rotor on the top, which can stir the wetland surface water 15 of the wetland soil according to a set rotation speed, thereby simulating the fluctuation conditions in natural water bodies.

The sampling hole 12 is a small glass tube hole. The top of the sampling hole 12 is usually capped or sealed with a rubber septum. The rubber plug is removable and can also be penetrated by an injection needle to inject liquid (such as tracer, etc.).

As shown in Figure 3, a lighting control system is also provided. The lighting control system includes a light panel 26 and a light source lamp 27. The light panel 26 is embedded in the cauldron top cover 13. The light source lamp 27 is installed on the light panel 26. The light source lamp 27 Connect via timer and power supply. The timer controls the illumination time and can be set to continuous illumination or alternating day and night illumination. It is used to detect the light intensity at any time to ensure that the light intensity value is accurate.

Before using the steady-state culture equipment for measuring the nitrogen pollution efficiency of wetland purification and nitrogen cycle, assemble the components of the reactor first, and then connect it with the temperature control system, nutrient solution supply system, nutrient solution discharge system, gas supply system, and sampling The system and detection system are assembled in sequence and then sterilized together. The inner layer of the reaction kettle (sampling tube 18b) is elongated, cylindrical, and has a very thick inner wall. It is used for direct drilling to obtain soil columnar samples. After obtaining, the bottom is sealed with the kettle bottom cover 19; and then the pre-designed The outer jacket 18a of the reactor is shorter than the inner wall of the reactor. After sealing, it is the jacket 18a of the circulating water bath. The entire reactor is placed in the circulating water bath 24. The circulating water bath 24 is connected to the circulating water bath 24. The circulating water bath outlet 16 of the reaction kettle is connected to the circulating water bath inlet 20. The culture solution in the nutrient solution storage room 1 is continuously dripped into the inside of the reaction kettle through the peristaltic pump 3, until the wetland surface water 15 on the upper surface of the soil columnar sample reaches the predetermined liquid level, the temperature control system, the stirrer 14, and the light are turned on. control system and gas supply system. When the temperature is constant and the system is stable, liquid (such as an isotope tracer, etc.) is injected by penetrating the sampling hole 12 with an injection needle. The working mode of each system is as follows: the temperature control system heats the water through the circulating water bath 24 (which can be used to simulate the warming effect or cooling caused by global climate change), and the heated (or cooled) water enters the water inlet of the circulating water bath. 20. After sufficient circulation in the interlayer, it flows out through the circulating water bath outlet 16 and returns to the circulating water bath 24 for heating (or cooling) again to maintain the temperature. The gas supply system inputs sterile air (or increases the CO ₂ content to simulate the increasing atmospheric carbon dioxide concentration) through a rate-controllable air pump 6. The sterile air is introduced into the reaction kettle after passing through the three-way stopcock 8-door switch. The gas is introduced into the wetland surface water 15 through the diversion pipe, and the gas overflows from the bottom of the wetland surface water 15 to the upper layer in the form of bubbles. The nutrient solution supply system uses a peristaltic pump 3 to continuously drip the culture solution in the nutrient solution storage chamber 1 into the interior of the reactor through the nutrient solution conduit 4 . The lower end of the nutrient solution overflow pipe of the nutrient solution discharge system is located on the surface of the wetland surface water 15 and is in close contact with the liquid surface. Due to the continuous filling of sterile gas, the upper space on the surface of the wetland surface water 15 of the reactor maintains a certain stable pressure; as As the nutrient solution continues to drip in, the internal pressure slightly increases, and a slight pressure difference is generated between the nutrient solution and the external pressure. This pressure difference can force the excess culture solution to continuously flow out into the measuring cylinder 23 through the nutrient solution overflow pipe. The stirrer 14 can stir the wetland surface water 15 in the reactor, thereby simulating the fluctuation conditions in natural water bodies. The sampling system controls the three-way plug valve 8 and uses a vacuum pump 11 to extract the wetland surface water 15 along the sampling pipe 9 into the air extraction sampling bottle 10; before sampling, the gas channel is changed through the three-way plug valve 8 and externally Use a vacuum pump 11 to extract the wetland surface water 15 for sampling. Since the entire process is a unidirectional flow of liquid, this can reduce pollution during the sampling process. During the entire culture process, keep the peristaltic pump 3 operating; in order to reduce the interference effect on the steady state of continuous culture during sampling, the volume of each sampling shall not exceed the volume of culture fluid filled into the reactor during the two sampling points. and shall not exceed 6% of the total volume of the reactor. The light panel 26 and light source lamp 27 of the lighting control system provide and reflect light, and can control the light intensity; the timer controls the light time, which can be set to continuous illumination, or day and night alternating illumination, for detecting light intensity at any time to ensure the light intensity. The values are accurate.

The above is not a limitation of the present invention. It should be pointed out that those skilled in the art can make several changes, modifications, additions or substitutions without departing from the essential scope of the present invention. Improvements and modifications should also be considered as the protection scope of the present invention.

Claims (10)

1. The steady-state culture equipment for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland is characterized by comprising a reaction kettle, a temperature control system, a nutrient solution supply system, a nutrient solution discharge system, a gas supply system, a sampling system and a detection system; the reaction kettle is of a double-layer structure formed by sleeving an inner layer and an outer layer, the inner layer of the reaction kettle is provided with a hollow sampling tube, the sampling tube is tamped into soil in a top pressurizing mode, a wetland soil columnar sample naturally filled in the sampling tube is taken out at the same time, and the top end and the bottom end of the sampling tube are respectively provided with a kettle top cover and a kettle bottom cover in a rotating mode for sealing; the outer layer of the reaction kettle is provided with a jacket for filling the circulating water bath, and the jacket is sleeved on the outer wall of the sampling tube and is communicated with a temperature control system of the circulating water bath; the surface of the wetland soil columnar sample is filled with wetland surface water, the wetland surface water is respectively communicated with the gas supply system and the sampling system, and a cavity between the wetland surface water and the kettle top cover is respectively connected with the nutrient solution supply system and the nutrient solution discharge system; the detection system comprises a parameter probe a and a parameter probe b, wherein the parameter probe a and the parameter probe b are respectively inserted into the wetland surface water and the wetland soil columnar sample.

2. The steady-state culture device for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 1, wherein the temperature control system comprises a circulating water bath which is arranged in a hollow cylindrical barrel body structure, limit through holes are formed in the periphery of the circulating water bath in an annular equidistant arrangement mode, and the reaction kettle is arranged in the limit through holes.

3. The steady-state culture equipment for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 2, wherein the sampling tube at the inner layer of the reaction kettle and the jacket at the outer layer are both made of transparent hard plastic materials, the sampling tube is arranged into an upright column structure with a hollow inside, the wall thickness of the sampling tube is larger than that of the jacket, a circulating water bath water outlet and a circulating water bath water inlet are respectively arranged on the jacket, and the circulating water bath pool is respectively connected with the circulating water bath water outlet and the circulating water bath water inlet of the jacket.

4. The steady state culture device for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 1, wherein the nutrient solution supply system comprises a nutrient solution storage chamber and a peristaltic pump, the top end of the nutrient solution storage chamber is communicated with the air pipe a, the liquid in the nutrient solution storage chamber is connected with the peristaltic pump through a conduit, the peristaltic pump is connected with the nutrient solution conduit, and the nutrient solution conduit is extended and inserted on the top cover of the reaction kettle.

5. The steady state culture device for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 1, wherein the nutrient solution discharge system comprises a measuring cylinder and an overflow flow guide pipe, one end of the overflow flow guide pipe is inserted on the top cover of the reaction kettle, and the other end of the overflow flow guide pipe is inserted in the measuring cylinder.

6. A steady state cultivation apparatus for measuring the efficiency of purifying nitrogen pollution and nitrogen circulation of a wetland according to claim 1, wherein said gas supply system comprises a gas pump and a gas pipe b connected to each other, and the tip of the gas pipe b is inserted into the surface water of the wetland.

7. The steady state culture apparatus for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 1 or 6, wherein the sampling system comprises a sampling tube, a suction sampling bottle and a vacuum pump, the vacuum pump is connected with the suction sampling bottle through a pipeline, the suction sampling bottle is communicated with the sampling tube, the tail end of the sampling tube extends into the surface water of the wetland, and the sampling tube is communicated with a gas pipe b of the gas supply system through a three-way plug valve.

8. The steady-state culture device for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 1, wherein the parameter probe a and the parameter probe b of the detection system are respectively connected with a power supply, a detector and a computer through wires.

9. The steady state culture apparatus for measuring the efficiency of purifying nitrogen pollution and recycling nitrogen in a wet land according to claim 1, further comprising a stirrer and a sample-adding hole, wherein the sample-adding hole is provided in the tank top cover, the stirrer extends into the surface water of the wet land through the tank top cover, and the stirrer is driven by a motor of the tank top cover.

10. The steady-state cultivation equipment for measuring the purification nitrogen pollution efficiency and the nitrogen circulation of the wetland according to claim 1, wherein the equipment is further provided with an illumination control system, the illumination control system comprises a light panel and a light source lamp, the light panel is embedded on a kettle top cover, the light source lamp is arranged on the light panel, and the light source lamp is connected with a power supply through a timer.