Sea ice-water-sediment system denitrification simulation device and experimental method

Abstract

The application discloses a sea ice-water-sediment system denitrification simulation device and experimental method, relates to the field of water conservancy engineering and earth science technology, and comprises a water tank, a cylinder and a liquid receiving barrel. Two first connecting pipes are communicated with the side bottom of the water tank, and a water stop valve is arranged at the end of each first connecting pipe outside the water tank. Water inlet holes, water outlet holes and sampling holes are formed in the cylinder. The water inlet holes are connected with one of the first connecting pipes through a second connecting pipe, a peristaltic pump is arranged on the second connecting pipe, and a sealing cover is arranged at the sampling hole. The liquid receiving barrel is connected with the water outlet holes through a third connecting pipe, and the water tank, the cylinder, the first connecting pipes, the second connecting pipe and the third connecting pipe are all provided with heat preservation layers. The sea ice-water-sediment system denitrification simulation device and experimental method can solve the problems of denitrification process simulation and monitoring under the generation of sea ice.

Description

Technical Field

[0001] This invention relates to the fields of water conservancy engineering and earth science technology, and in particular to a denitrification simulation device for a sea ice-water-sediment system. Background Technology

[0002] In recent decades, increased human activity has led to a doubling of nitrogen input into terrestrial and marine ecosystems. Approximately 20-30% of this nitrogen is input into coastal areas as nitrate, posing a growing threat to the ecological health of nearshore marine environments. Previous studies have shown that nearshore water-sediment systems are crucial sites for denitrification; however, current research indicates that sea ice formation, to some extent, disrupts the exchange of water and air, alters the exchange of nutrients between nearshore waters, and significantly impacts nearshore water-sediment denitrification processes. Therefore, further in-depth research is needed to investigate the potential impacts of sea ice formation on denitrification.

[0003] Currently, research methods for water-sediment denitrification processes are relatively systematic, often requiring in-situ observations and analysis of river or ocean samples. However, in-situ sampling of water-sediment samples during sea ice formation is difficult to achieve. Furthermore, while laboratory simulations of sea ice physical processes are relatively mature, there is a lack of scientifically sound indoor simulation devices and methods for simulating integrated physical and geochemical processes involving sea ice, water, and sediment. Summary of the Invention

[0004] The purpose of this invention is to provide a denitrification simulation device and experimental method for a sea ice-water-sediment system to solve the problem of monitoring the denitrification process under sea ice formation.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a denitrification simulation device for a sea ice-water-sediment system, comprising a water tank with a top opening, a cylinder, and a receiving tank. Two first connecting pipes are sealed and connected to the bottom side of the water tank, arranged symmetrically. A stop valve is provided at one end of each first connecting pipe outside the water tank. The cylinder has an inlet, an outlet, and a sampling port. The inlet is sealed and connected to one of the first connecting pipes via a second connecting pipe, which is equipped with a peristaltic pump. A sealing cap is provided at the sampling port. The receiving tank is sealed and connected to the outlet via a third connecting pipe. An insulation layer is provided on the water tank, the cylinder, the first connecting pipes, the second connecting pipe, and the exterior of the second connecting pipe.

[0007] Preferably, the first connecting pipe includes an acrylic round tube that can extend into the water tank and an elastic silicone hose sleeved on one end of the acrylic round tube located outside the water tank, and the elastic silicone hose is provided with the water stop valve.

[0008] Preferably, the distance between each of the plexiglass tubes and the bottom of the water tank is 5cm.

[0009] Preferably, the distance between the end of the plexiglass tube inside the water tank and the axis of the water tank is 3cm, and the length of the end of the plexiglass tube outside the water tank is 5cm.

[0010] Preferably, the cylinder includes a cylindrical body and a top cover and a bottom cover respectively sealing the top and bottom ends of the cylindrical body. The top cover has a water inlet and a water outlet, and the cylindrical body has a sampling hole on its side wall.

[0011] Preferably, an elastic fluororubber tube is provided at both the water inlet and the water outlet, and a pressure-resistant capillary tube is inserted inside each elastic fluororubber tube. Each pressure-resistant capillary tube can extend into the cylinder. The pressure-resistant capillary tube at the water outlet forms the third connecting tube. The second connecting tube is a peristaltic pump tube that is sealed and connected to the elastic silicone hose. The other end of the peristaltic pump tube is sealed and connected to the pressure-resistant capillary tube at the water inlet, and the peristaltic pump is provided on the peristaltic pump tube.

[0012] Preferably, the length of the pressure-resistant capillary tube at the water inlet extending into the cylinder is 35mm, and the length of the pressure-resistant capillary tube at the water outlet extending into the cylinder is 5mm.

[0013] Preferably, the insulation layer is insulation cotton.

[0014] Preferably, the insulation layer has a thickness of 100 mm.

[0015] Preferably, an observation port is provided on the insulation cotton located on the outside of the water tank, and a detachable insulation cotton strip is provided at the observation port.

[0016] This invention also provides an experimental method for any of the above-described denitrification simulation devices for sea ice-water-sediment systems, comprising the following steps:

[0017] Step 1: Add sediment to the cylinder until it covers the sampling hole, and then add the collected in-situ water or artificial seawater to the cylinder to avoid leaving air inside the cylinder;

[0018] Step 2: Fill the water tank with the collected in-situ water or artificial seawater, open the stop valve connected to the peristaltic pump pipe and start the peristaltic pump to pump the water in the tank into the cylinder at a flow rate of 1.2 mL / min. Run the device in this state for 24 hours and test its operational stability.

[0019] Step 3: If the device does not leak water or liquid after 24 hours and its operation is stable, then fill the water tank to capacity and add water as needed. 15 N-KNO3 makes 15 N-NO3 - The final concentration is approximately 100 μmol / L. 15 The AT% of N is 90-99%;

[0020] Step 4: After completing the above experimental preparations, adjust the indoor temperature to the outdoor temperature, start simulating the sea ice formation process, periodically observe the sea ice thickness through the observation port, and collect samples according to the experimental design.

[0021] Step 5: When samples need to be collected, open the stop valve at the bottom of the tank to collect bottom water from the sea ice formation process for the measurement and analysis of water environmental indicators. Open the sealing cap at the sampling port and use a spatula to collect sediment for sediment environmental indicator determination, mud experiments, and microbial technical analysis. Remove the pressure-resistant capillary tube from the outlet of the receiving tank, collect the sample using a Labco glass bottle (12mL), and inject 0.2ml of saturated mercuric chloride solution to determine the concentration of mercuric chloride in the water. 29 N2 and 30 N2, further combined with the results of sediment mud experiments, to analyze the rates of denitrification and anaerobic ammonium oxidation processes;

[0022] Step Six: Periodically empty the receiving bucket. After the experiment, close the stop valve and peristaltic pump, adjust the temperature to above zero, and clean the experimental apparatus after the sea ice melts. It can be reused.

[0023] The present invention achieves the following technical effects compared to the prior art:

[0024] The denitrification simulation device and experimental method for the sea ice-water-sediment system provided by this invention utilizes peristaltic pumps and pipelines to continuously transport subglacial water to the upper sediment layer, thereby achieving continuous renewal of the overlying water and solving the problem of integrated sea ice-water-sediment simulation devices. Furthermore, this method allows for the addition of isotopes to seawater before the experiment and the collection and measurement of water and sediment samples at any time after the experiment begins, thus addressing the monitoring problem of denitrification processes during sea ice formation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the denitrification simulation device for the sea ice-water-sediment system provided by the present invention;

[0027] In the diagram: 1-Water tank; 2-Insulation cotton; 3-Elastic silicone hose; 4-Stop valve; 5-Acrylic round tube; 6-Removable insulation strip; 7-Peristaltic pump tube; 8-Peristaltic pump; 9-Inlet; 10-Outlet; 11-Pressure-resistant capillary tube; 12-Top cover; 13-Elastic fluororubber tubing; 14-Stop ring; 15-Cylinder; 16-Sampling hole; 17-Receiving container; 18-Bottom cover. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide a denitrification simulation device and experimental method for a sea ice-water-sediment system to solve the problem of monitoring the denitrification process under sea ice formation.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] This invention provides a nitrogen removal simulation device for a sea ice-water-sediment system, such as... Figure 1 As shown, in this embodiment, the system includes a water tank 1 with a top opening, a cylinder, and a liquid receiving tank 17. Two first connecting pipes are sealed and connected to the bottom side of the water tank 1. The two first connecting pipes are symmetrically arranged, and a stop valve 4 is provided at one end of each first connecting pipe outside the water tank 1. The cylinder has an inlet hole, an outlet hole, and a sampling hole 16. The inlet hole is sealed and connected to one of the first connecting pipes through a second connecting pipe. A peristaltic pump 8 is provided on the second connecting pipe, and a sealing cap is provided at the sampling hole 16. The liquid receiving tank 17 is sealed and connected to the outlet hole through a third connecting pipe. The water tank 1, the cylinder, the first connecting pipe, the second connecting pipe, and the outer surface of the second connecting pipe are all wrapped with a heat insulation layer.

[0032] The denitrification simulation device for the sea ice-water-sediment system provided by this invention includes a water tank 1 for simulating the sea ice formation process, which is a simulation device, and a cylinder for detecting the denitrification process of the water-sediment system, which is a culture device. The water tank 1 is preferably made of plexiglass, sealed at the bottom and open at the top, cylindrical in shape, 100cm high, 40cm inner diameter, and 7mm wall thickness. Two circular holes with an inner diameter of 4mm are symmetrically opened at a position 5cm from the bottom of the water tank 1 for horizontally inserting the first connecting tube.

[0033] Both first connecting pipes include an acrylic round tube 5 that can extend into the water tank 1 and an elastic silicone hose 3 that is sealed and fitted on the end of the acrylic round tube 5 located outside the water tank 1. The acrylic round tube 5 has an inner diameter of 3 mm and an outer diameter of 4 mm. The elastic silicone hose 3 is preferably 10 cm long, has an inner diameter of 4 mm, and an outer diameter of 6 mm. A stop valve 4 is provided on the elastic silicone hose 3. One of the elastic silicone hoses 3 is used to collect bottom water during the freezing process, and the other is used to connect with the second connecting pipe for flow culture.

[0034] Each acrylic tube 5 is inserted into the water tank 1 through a round hole, and the distance between the tube and the bottom of the water tank 1 is 5cm.

[0035] The distance between the end of the acrylic tube 5 inserted into the water tank 1 and the axis of the water tank 1 is 3cm, and the end of the acrylic tube 5 located outside the water tank 1 is 5cm long.

[0036] The cylindrical body includes a cylinder 15 with openings at both the top and bottom, and a top cover 12 and a bottom cover 18 respectively sealing the top and bottom ends of the cylinder 15. Both ends of the cylinder 15 have 20mm high internal threads. The top cover 12 and bottom cover 18 are both 80mm in diameter and 20mm high, and both have corresponding 20mm high external threads. The top cover 12 and bottom cover 18 can be threaded onto the cylinder 15. Both the top cover 12 and bottom cover 18 are equipped with water-stop rings 14 to ensure a tight seal between the top cover 12 / bottom cover 18 and the cylinder 15. Two through holes with a diameter of 3mm are symmetrically opened on the cylinder 12 at a position 25mm away from its center, namely the water inlet and the water outlet. The cylinder 15 is preferably made of plexiglass, with a height of 300mm, an inner diameter of 80mm, and a wall thickness of 5mm. A sampling hole 16 with a diameter of 30mm is opened on the side wall of the cylinder 15 at a position 60mm away from the top of the cylinder 15, and is equipped with a sealing cap with a silicone water-stop ring. The sealing cap has a diameter of 40mm and can be threaded to the sampling hole 16. Sediment collection can be carried out through the sampling hole 16.

[0037] A flexible fluororubber tube 13 with an inner diameter of 1.65 mm, an outer diameter of 3.4 mm, and a length of 60 mm is inserted into both the water inlet and outlet, penetrating the top cover 12. The tubes at both ends and the length of the tubes are 10 mm longer to ensure the airtightness of the device. Each flexible fluororubber tube 13 has a pressure-resistant capillary tube 11 with an inner diameter of 1 mm, an outer diameter of 1.59 mm, and a length of 1 m inserted inside. Each pressure-resistant capillary tube 11 can extend into the cylinder. The pressure-resistant capillary tube 11 at the water outlet forms a third connecting tube, which can be inserted into a 15 L liquid receiving tank 17. The liquid receiving tank 17 is used for sample collection and wastewater collection. The second connecting tube is a peristaltic pump tube 7 with one end sealed and connected to the flexible silicone tube 3. The other end of the peristaltic pump tube 7 is sealed and connected to the pressure-resistant capillary tube 11 at the water inlet. A peristaltic pump 8 is installed on the peristaltic pump tube 7.

[0038] The pressure-resistant capillary tube 11 at the water inlet extends 35mm into the cylinder and serves as the water inlet 9. The pressure-resistant capillary tube 11 at the water outlet extends 5mm into the cylinder and serves as the water outlet 10. Combined with the peristaltic pump 8, this achieves continuous renewal of the water in the upper layer of the cylinder.

[0039] The insulation layer is made of insulation cotton 2.

[0040] The insulation layer is 100mm thick.

[0041] An observation opening is cut into the insulation cotton 2 located on the outside of the water tank 1. A rectangular removable insulation cotton strip 6, 3cm wide and 60cm high, is installed at the observation opening so that it can be removed at any time to observe the sea ice formation in the water tank 1. The top of the water tank 1 is not covered with insulation cotton 2 to ensure that ice can form in the water tank 1 from top to bottom.

[0042] The present invention provides a denitrification simulation device for a sea ice-water-sediment system. It uses a peristaltic pump 8 to connect two separate experimental devices, realizing an integrated simulation of the sea ice-water-sediment system. The sea ice can achieve a top-down growth process, and the water and sediment under the ice can be collected at any time. This enables the monitoring and analysis of various physicochemical indicators and biological information during the sea ice formation process. At the same time, with the help of isotope labeling technology, the denitrification rate during the sea ice formation process can be monitored and analyzed.

[0043] This invention also provides an experimental method for simulating nitrogen removal in a sea ice-water-sediment system. This method can be carried out in a temperature-controlled laboratory and includes the following steps:

[0044] Step 1: Prepare several experimental devices, open the top cover 12 of the cylinder, add sediment into the cylinder until it covers the sampling hole 16, then add the collected in-situ water or artificial seawater into the cylinder, and then put the top cover 12 back on to avoid air remaining in the cylinder.

[0045] Step 2: Fill water tank 1 with the collected in-situ water or artificial seawater (adjusted to the in-situ environmental factor level), open the stop valve 4 connected to the peristaltic pump pipe 7 and start the peristaltic pump 8 to pump the water in water tank 1 into the cylinder at a flow rate of 1.2 mL / min. Run the device in this state for 24 hours to test the stability of the device. If leakage occurs, adjust or replace the parts in time and restart the device.

[0046] Step 3: If the device does not leak water or liquid after 24 hours and its operation is stable, then refill the water tank 1 and add water to it. 15 N-KNO3 makes 15 N-NO3 - The final concentration is approximately 100 μmol / L. 15 The AT% of N is approximately 90-99%, adding 15 After N-KNO3, the final products of the two different denitrification processes are different; the denitrification process will produce... 30 N2, while the anaerobic ammonium oxidation process will generate 29 N2 was used to study the changes in different denitrification processes;

[0047] Step 4: After completing the above experimental preparations, adjust the indoor temperature to the outdoor temperature, start simulating the sea ice formation process, periodically observe the sea ice thickness through the observation port, and collect samples according to the experimental design.

[0048] Step 5: When samples need to be collected, open the stop valve 4 at the bottom of tank 1 to collect bottom water samples from the sea ice formation process. These samples are used for measuring and analyzing water environmental indicators such as water temperature, dissolved oxygen, salinity, ammonia nitrogen, and nitrate nitrogen. Open the sealing cap at sampling port 16 and use a spatula to collect sediment samples for sediment environmental indicator determination, mud experiments, and microbiological analysis. Remove the pressure-resistant capillary tube 11 from the outlet of the receiving container 17, collect samples using a 12mL Labco glass bottle, and inject 0.2mL of saturated mercuric chloride solution to determine the concentration of certain substances in the water. 29 N2 and 30 N2, further combined with the results of sediment mud experiments, to analyze the rates of denitrification and anaerobic ammonium oxidation processes;

[0049] Step 6: Periodically empty the liquid collection tank 17. After the experiment, close the stop valve 4 and the peristaltic pump 8, adjust the temperature to above zero, and clean the experimental apparatus after the sea ice melts. It can be reused.

[0050] The present invention provides a denitrification simulation device and experimental method for a sea ice-water-sediment system. This device ensures that the sea ice, water, and sediment are interconnected during sea ice formation, and that the device is airtight, preventing substances generated during sea ice formation and denitrification from escaping. Simultaneously, the bottom water and sediments during sea ice formation can be collected and monitored at any time. Furthermore, the experimental device can adjust the initial environmental factors and experimental temperature conditions as needed to simulate the water-sediment denitrification process during sea ice formation under varying environmental climates.

[0051] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A nitrogen removal simulation device for a sea ice-water-sediment system, characterized in that: include: A water tank with an open top has two first connecting pipes sealed and connected to the bottom side of the water tank. The two first connecting pipes are symmetrically arranged, and a water stop valve is provided at one end of each first connecting pipe outside the water tank. The water tank is used to simulate the sea ice formation process. A cylinder is provided with an inlet hole, an outlet hole, and a sampling hole. The inlet hole is sealed and connected to one of the first connecting pipes through a second connecting pipe. A peristaltic pump is provided on the second connecting pipe. A sealing cap is provided at the sampling hole. The cylinder is used for detecting the denitrification process of water-sediment. The system includes a liquid receiving tank, which is sealed and connected to the water outlet via a third connecting pipe. The water tank, the cylinder, the first connecting pipe, the second connecting pipe, and the third connecting pipe are all equipped with an insulation layer. An elastic fluororubber tube is installed at both the water inlet and the water outlet. A pressure-resistant capillary tube is inserted inside each elastic fluororubber tube. The length of the pressure-resistant capillary tube extending into the cylinder at the water inlet is greater than the length of the pressure-resistant capillary tube extending into the cylinder at the water outlet.

2. The denitrification simulation device for a sea ice-water-sediment system according to claim 1, characterized in that: The first connecting pipe includes an organic glass tube that can extend into the water tank and an elastic silicone hose sleeved on one end of the organic glass tube located outside the water tank. The elastic silicone hose is equipped with the water stop valve.

3. The denitrification simulation device for a sea ice-water-sediment system according to claim 2, characterized in that: The distance between each of the organic glass tubes and the bottom of the water tank is 5cm.

4. The denitrification simulation device for a sea ice-water-sediment system according to claim 3, characterized in that: The distance between the end of the plexiglass tube inside the water tank and the axis of the water tank is 3cm, and the end of the plexiglass tube outside the water tank is 5cm long.

5. The denitrification simulation device for a sea ice-water-sediment system according to claim 2, characterized in that: The cylinder includes a cylindrical body and a top cover and a bottom cover respectively sealing the top and bottom ends of the cylindrical body. The top cover has a water inlet and a water outlet, and the side wall of the cylindrical body has a sampling hole.

6. The denitrification simulation device for a sea ice-water-sediment system according to claim 5, characterized in that: Each pressure-resistant capillary can extend into the interior of the cylinder. The pressure-resistant capillary at the water outlet forms the third connecting pipe. The second connecting pipe is a peristaltic pump pipe that is sealed and connected to the elastic silicone hose. The other end of the peristaltic pump pipe is sealed and connected to the pressure-resistant capillary at the water inlet. The peristaltic pump is installed on the peristaltic pump pipe.

7. The denitrification simulation device for a sea ice-water-sediment system according to claim 6, characterized in that: The pressure-resistant capillary tube at the water inlet extends 35 mm into the cylinder, and the pressure-resistant capillary tube at the water outlet extends 5 mm into the cylinder.

8. The denitrification simulation device for a sea ice-water-sediment system according to claim 1, characterized in that: The insulation layer is 100mm thick insulation cotton.

9. A denitrification simulation device for a sea ice-water-sediment system according to claim 8, characterized in that: An observation port is provided on the insulation cotton located on the outside of the water tank, and a detachable insulation cotton strip is provided at the observation port.

10. An experimental method based on the denitrification simulation device of the sea ice-water-sediment system according to any one of claims 1 to 9, characterized in that: The steps include the following: Step 1: Add sediment to the cylinder until it covers the sampling hole, and then add the collected in-situ water or artificial seawater to the cylinder to avoid leaving air inside the cylinder; Step 2: Fill the water tank with the collected in-situ water or artificial seawater, open the stop valve connected to the peristaltic pump pipe and start the peristaltic pump to pump the water in the tank into the cylinder at a flow rate of 1.2 mL / min. Run the device in this state for 24 hours and test its operational stability. Step 3: If the device does not leak water or liquid after 24 hours and its operation is stable, then fill the water tank to capacity and add water as needed. 15 N-KNO3 makes 15 N-NO3 - The final concentration was 100 μmol / L. 15 The AT% of N is 90-99%; Step 4: After completing the above experimental preparations, adjust the indoor temperature to the outdoor temperature, start simulating the sea ice formation process, periodically observe the sea ice thickness through the observation port, and collect samples according to the experimental design. Step 5: When samples need to be collected, open the stop valve at the bottom of the tank to collect bottom water from the sea ice formation process for the measurement and analysis of water environmental indicators. Open the sealing cap at the sampling port and use a spatula to collect sediment for sediment environmental indicator determination, mud experiments, and microbial technical analysis. Remove the pressure-resistant capillary tube from the outlet of the receiving tank, collect the sample using a 12mL Labco glass bottle, and inject 0.2mL of saturated mercuric chloride solution into it for the determination of the water's... 29 N2 and 30 N2, combined with the results of sediment mud experiments, was used to analyze the rates of denitrification and anaerobic ammonium oxidation processes; Step Six: Periodically empty the receiving bucket. After the experiment, close the stop valve and peristaltic pump, adjust the temperature to above zero, and clean the experimental apparatus after the sea ice melts. It can be reused.

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