A device and method for measuring in-situ sediment oxygen consumption rate of a reservoir

Abstract

The application discloses a kind of reservoir in-situ sediment oxygen consumption rate measuring device and method, and technical scheme points are as follows: wherein, reservoir in-situ sediment oxygen consumption rate measuring device includes sediment oxygen consumption rate measuring component, sediment oxygen consumption rate measuring component is used to determine reservoir in-situ sediment oxygen consumption rate, sediment oxygen consumption rate measuring component includes cylinder, circular ring transverse plate and DO measuring probe, wherein: cylinder includes upper half cylinder and lower half cylinder, upper half cylinder is made of PVC material, and lower half cylinder is made of stainless steel material;The bottom end outer periphery of upper half cylinder is fixedly installed with a flange, the upper end outer periphery of lower half cylinder is fixedly installed with a flange, and a headless screw is inserted between the two flanges, and a plurality of nuts are threadedly sleeved on the headless screw.The present application has the advantages of compact structure, simple operation, and can accurately reflect the oxygen consumption characteristics of reservoir sediments.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring technology, specifically to a device for measuring the oxygen consumption rate of in-situ sediments in a reservoir. Background Technology

[0002] As important water resource storage and regulation facilities, the water quality of reservoirs directly affects the production and lives of surrounding residents and the ecological balance. Sediment oxygen consumption is one of the important factors affecting reservoir water quality changes. Therefore, accurately measuring the oxygen consumption rate of in-situ sediments in reservoirs is of great significance for assessing reservoir water quality, predicting water quality change trends, and formulating corresponding water quality management measures.

[0003] Traditional methods for measuring sediment oxygen consumption rates mostly rely on laboratory simulations. While these methods can mimic the oxygen consumption process of sediments in reservoirs, the differences between laboratory conditions and the actual reservoir environment often result in inaccurate measurements reflecting the in-situ oxygen consumption rate of sediments. To overcome this limitation, it is necessary to develop a device and method for directly measuring sediment oxygen consumption rates in in-situ within reservoirs. Summary of the Invention

[0004] In view of the problems mentioned in the background art, the purpose of this invention is to provide a device and method for measuring the oxygen consumption rate of in-situ sediments in reservoirs, so as to solve the problem that traditional laboratory simulation experiments cannot accurately reflect the oxygen consumption rate of in-situ sediments in reservoirs.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A device for measuring the oxygen consumption rate of in-situ sediments in a reservoir includes a sediment oxygen consumption rate measuring component. The sediment oxygen consumption rate measuring component is used to measure the oxygen consumption rate of in-situ sediments in the reservoir. The sediment oxygen consumption rate measuring component includes a cylindrical tube, a circular transverse plate, and a DO (displacement oxygen) measuring probe, wherein:

[0007] The cylindrical tube has a diameter of 0.2 m and includes an upper cylindrical tube and a lower cylindrical tube. The upper cylindrical tube has a height of 0.2 m and is made of lightweight PVC material. The lower cylindrical tube has a height of 0.1 m and is made of heavy-duty stainless steel material, weighing 5 kg. The bottom edge is sharp and can be easily inserted into the sediment under its own weight.

[0008] A flange is fixedly installed on the outer periphery of the bottom end of the upper cylindrical section, and a flange is fixedly installed on the outer periphery of the upper end of the lower cylindrical section. A headless screw is inserted between the two flanges, and several nuts are threaded onto the headless screw. The headless screw is fixedly connected to the two flanges respectively through the nuts. A circular horizontal plate is fitted on the headless screw and is located between the two flanges. The headless screw is fixedly connected to the circular horizontal plate through the nuts. Two nuts are distributed on the upper and lower surfaces of the circular horizontal plate and the two flanges.

[0009] The upper end of the upper cylindrical section is sealed with PVC material to seal the upper end of the upper cylindrical section and prevent external water from entering the interior of the upper cylindrical section through the upper end of the upper cylindrical section.

[0010] The DO measuring probe is installed inside the upper part of the upper cylindrical section and is connected to an external dissolved oxygen meter to monitor the DO concentration of the water inside the upper cylindrical section in real time.

[0011] The in-situ sediment oxygen consumption rate measuring device for reservoirs is divided into an experimental group and a control group when measuring the in-situ sediment oxygen consumption rate of the reservoir, wherein:

[0012] A bottom water pumping pipe is fixed to the upper cylindrical section of the experimental group by wire. The bottom end of the bottom water pumping pipe is located above the circular cross plate. When the upper end of the bottom water pumping pipe is connected to the inlet of the peristaltic pump and the end of the circulating water inlet pipe away from the upper cylindrical section is connected to the outlet of the peristaltic pump, the peristaltic pump is started to replace the water inside the upper cylindrical section of the experimental group with the bottom water.

[0013] In the control group, the upper half of the cylindrical tube is symmetrically provided with a second circulating water inlet pipe and a second circulating water outlet pipe connected to its interior. When the end of the second circulating water inlet pipe away from the upper half of the cylindrical tube and the end of the first circulating water outlet pipe away from the upper half of the cylindrical tube are respectively connected to the inlet and outlet of the second peristaltic pump, the second peristaltic pump is activated to pump the renewed bottom water in the upper half of the cylindrical tube in the experimental group into the upper half of the cylindrical tube in the control group, thereby renewing the water in the upper half of the cylindrical tube in the control group to the bottom water. When water comes out from the end of the second circulating water outlet pipe away from the upper half of the cylindrical tube, it indicates that the water in the upper half of the cylindrical tube in the control group has been renewed.

[0014] After the water inside the upper cylindrical section in the control group is completely replaced, a circulating water inlet pipe and a circulating water outlet pipe are symmetrically arranged on the upper side of the upper cylindrical section in the experimental group and connected to its interior. When the end of the circulating water outlet pipe away from the upper cylindrical section and the end of the circulating water inlet pipe away from the upper cylindrical section are respectively connected to the outlet and inlet of the peristaltic pump, the peristaltic pump is started to circulate and pump water to uniformly mix the water inside the upper cylindrical section. In the control group, when the end of the circulating water inlet pipe away from the upper cylindrical section and the end of the circulating water outlet pipe away from the upper cylindrical section are respectively connected to the inlet and outlet of the peristaltic pump, the peristaltic pump is started to circulate and pump water to uniformly mix the water inside the upper cylindrical section in the control group.

[0015] The aforementioned reservoir in-situ sediment oxygen consumption rate measuring device further includes a float made of high molecular weight high-density polyethylene material, positioned above the cylindrical tube. Both peristaltic pump one and peristaltic pump two are fixedly installed inside the float. The float provides constraint force to the cylindrical tube through the traction of circulating water outlet pipe one, circulating water inlet pipe one, circulating water inlet pipe two, and circulating water outlet pipe two, ensuring that the bottom end of the lower half of the cylindrical tube is stably inserted into the bottom sediment.

[0016] The above-mentioned reservoir in-situ sediment oxygen consumption rate measuring device further includes a plumb bob, which is connected to the float via a plumb line. The plumb bob is used to position the float to ensure that the float does not drift or move with the water flow, so as to keep it at the set measuring position.

[0017] The above-mentioned in-situ sediment oxygen consumption rate measuring device for reservoirs, wherein: the circulating water outlet pipe 1, the circulating water inlet pipe 1, the circulating water inlet pipe 2, and the bottom pumping pipe are all made of corrosion-resistant, high-strength, elastic, and low-cost flexible hoses, such as rubber hoses, which are not prone to air or water leakage due to aging and hardening, and are easy to replace, to ensure that they will not be damaged by water flow during the experiment.

[0018] The above-mentioned reservoir in-situ sediment oxygen consumption rate measuring device includes an isolation baffle installed inside the lower half of the cylindrical tube in the control group. The isolation baffle is made of stainless steel and is used to isolate the sediment inside the lower half of the cylindrical tube from the water inside the upper half of the cylindrical tube so as to measure the oxygen consumption rate of the water body separately.

[0019] This invention also proposes a method for measuring the oxygen consumption rate of in-situ sediments in a reservoir, wherein: the oxygen consumption rate of in-situ sediments in a reservoir is measured using the aforementioned device, specifically including the following steps:

[0020] S1: Set up sediment oxygen consumption rate measurement component

[0021] At the experimental site, the cylindrical tube was placed vertically at the bottom of the reservoir, ensuring that the bottom of the lower half of the cylindrical tube was inserted into the sediment. By adjusting the height of the circular cross plate, the interior of the lower half of the cylindrical tube was filled with sediment.

[0022] S2: Design the experimental group and the control group

[0023] Six cylindrical tubes were set up at each experimental site. Before the experiment, it was ensured that there was a sufficiently thick sediment at the experimental site. If the sediment thickness was insufficient, the height of the circular cross plate was adjusted to ensure that the interior of the lower half of the cylindrical tube was filled with sediment. In the experimental group, the bottom of the lower half of the cylindrical tube was unobstructed, and the 0.1 m cylinder of the lower half of the cylindrical tube was filled with sediment to simulate the oxygen consumption of sediment and the total oxygen consumption of water. In the control group, the lower half of the cylindrical tube was equipped with an isolation baffle to isolate sediment from water, and only simulated the total oxygen consumption of water.

[0024] S3: Record experimental data

[0025] A 24-hour oxygen consumption experiment was conducted. The sediment oxygen consumption rate measuring device was placed at the bottom of the reservoir. Before the experiment began, the upper end of the bottom water pump pipe was connected to the inlet of peristaltic pump one, and the end of the circulating water inlet pipe one away from the upper cylindrical section was connected to the outlet of peristaltic pump one. The peristaltic pump one was then started to replace the water inside the upper cylindrical section of the experimental group with the bottom water. At the same time, the end of the circulating water inlet pipe two away from the upper cylindrical section and the circulating outlet were connected... When the end of pipe one away from the upper cylindrical section is connected to the inlet and outlet of peristaltic pump two, the peristaltic pump two is started to pump the renewed bottom water in the upper cylindrical section of the experimental group into the upper cylindrical section of the control group, thus renewing the water in the upper cylindrical section of the control group as bottom water. When water comes out from the end of the circulating outlet pipe two away from the upper cylindrical section, it indicates that the water in the upper cylindrical section of the control group has been renewed.

[0026] The experiment was started 5 minutes after water was discharged from the end of the circulating water outlet pipe away from the upper cylindrical section. The DO concentration change was recorded once per hour during the experiment.

[0027] During the experiment, when the end of the circulating water outlet pipe away from the upper cylindrical section and the end of the circulating water inlet pipe away from the upper cylindrical section are connected to the outlet and inlet of the peristaltic pump, respectively, the peristaltic pump is started to circulate and pump water to keep the water inside the upper cylindrical section uniformly mixed.

[0028] At the same time, when the end of the second circulating water inlet pipe away from the upper cylindrical section and the end of the second circulating water outlet pipe away from the upper cylindrical section are respectively connected to the inlet and outlet of the second peristaltic pump, the peristaltic pump is started to circulate and pump water so that the water inside the upper cylindrical section in the control group is kept uniformly mixed.

[0029] S4: Analyze experimental data

[0030] Based on the DO concentration data recorded during the experiment, the sediment oxygen consumption rate was calculated. The specific calculation method is as follows:

[0031] First, based on the change in DO concentration before and after the experiment, the amount of DO consumed in the water during the experiment was calculated.

[0032] Then, based on the volume of water and the area of ​​sediment inside the upper cylindrical section of the experimental group, the oxygen consumption rate per unit area of ​​sediment was calculated.

[0033] Finally, based on the experimental data of the control group, the oxygen consumption rate of the water body was calculated and subtracted from the oxygen consumption rate of the experimental group to obtain the oxygen consumption rate of the sediment itself.

[0034] The above-mentioned method for determining the oxygen consumption rate of in-situ sediments in reservoirs also includes S5: correcting the experimental results. Based on the changes in the concentrations of BOD5 (five-day biochemical oxygen demand), ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen in the in-situ experimental water body before and after the test, the degradation rate is calculated using the first-order reaction kinetic equation for pollutant degradation, which serves as a supplement and correction to the above calculation results.

[0035] The above-mentioned method for determining the oxygen consumption rate of in-situ sediments in reservoirs includes the following formula for calculating the oxygen consumption rate of the sediments: (1) (2)

[0036] In the formula: Oxygen production rate (d) of primary productivity in water bodies -1 ); The oxygen consumption rate of aquatic algae and other microorganisms during respiration (d) -1 ); The rate of oxygen consumption for the oxidation of carbon-containing organic matter (d) -1 ); The oxygen consumption rate of nitrification (d -1 ); AOCR is the ratio of dissolved oxygen to carbon during respiration (2.67 g O2 / g C); The amount required for nitration of ammonium ions per unit mass (4.33 g O2 / g N), see Wezernak (1968) for details; The oxygen consumption rate of ammonia nitrogen oxidation (d-1 ); The amount required for oxidation of ammonia nitrogen per unit mass (g O2 / g N); The oxygen consumption rate of nitrite oxidation (d) -1 ); The amount required for oxidation of nitrite per unit mass (g O2 / g N); S is the sediment area at the bottom of the sediment experimental cylinder (m²). 2 V is the volume of water inside the sediment experiment cylinder (m³). 3 ).

[0037] In summary, the present invention has the following main beneficial effects:

[0038] 1. Accurately reflects the oxygen consumption characteristics of sediments: This invention can accurately simulate the oxygen consumption process of reservoir sediments through in-situ experiments, thereby improving the accuracy and reliability of experimental results.

[0039] 2. Easy to operate: The experimental apparatus has a compact structure and is easy to operate, which reduces the difficulty and cost of the experiment.

[0040] 3. Comprehensive data: By combining the changes in pollutant concentration in the water body, the experimental results are supplemented and corrected using the first-order reaction kinetic equation of pollutant degradation, making the experimental results more comprehensive and accurate. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of the reservoir in-situ sediment oxygen consumption rate measuring device of the present invention.

[0042] Figure label:

[0043] 1. Float; 2. Circulating water outlet pipe 1; 3. Circulating water inlet pipe 1; 4. Circulating water outlet pipe 2; 5. Circulating water inlet pipe 2; 6. Isolation baffle; 7. Circular ring plate; 8. Plumb bob; 9. Upper cylindrical section; 10. Lower cylindrical section; 11. Headless screw; 12. Nut; 13. Bottom water pumping pipe. Detailed Implementation

[0044] 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.

[0045] Example 1

[0046] refer to Figure 1This embodiment provides a device for measuring the oxygen consumption rate of in-situ sediments in a reservoir, including a sediment oxygen consumption rate measuring component. The sediment oxygen consumption rate measuring component is used to measure the oxygen consumption rate of in-situ sediments in a reservoir, and the sediment oxygen consumption rate measuring component includes a cylindrical tube, a circular transverse plate 7, and a DO measuring probe.

[0047] The cylindrical tube has a diameter of 0.2 m and includes an upper cylindrical tube 9 and a lower cylindrical tube 10. The upper cylindrical tube 9 has a height of 0.2 m and is made of lightweight PVC material. The lower cylindrical tube 10 has a height of 0.1 m and is made of heavy-duty stainless steel material, weighing 5 kg. The bottom edge is sharp and can be easily inserted into the sediment under its own weight.

[0048] To facilitate adjustment of the height of the circular horizontal plate 7, the following scheme is adopted:

[0049] A flange is fixedly installed on the outer periphery of the bottom end of the upper cylindrical tube 9, and a flange is fixedly installed on the outer periphery of the upper end of the lower cylindrical tube 10. A headless screw 11 is inserted between the two flanges. Several nuts 12 are threaded on the headless screw 11. The headless screw 11 is fixedly connected to the two flanges through the nuts 12. A circular horizontal plate 7 is fitted on the headless screw 11 and is located between the two flanges. The headless screw 11 is fixedly connected to the circular horizontal plate 7 through the nuts 12. Two nuts 12 are distributed on the upper and lower surfaces of the circular horizontal plate 7 and the two flanges.

[0050] If the sediment thickness is insufficient, the circular cross plate 7 can be fixed to the lower half of the cylindrical flange with headless screws and two nuts to ensure that the lower half of the cylindrical tube is filled with sediment.

[0051] The upper end of the upper cylindrical tube 9 is sealed with PVC material to seal the upper end of the upper cylindrical tube 9 and prevent external water from entering the interior of the upper cylindrical tube 9 through the upper end of the upper cylindrical tube 9.

[0052] The DO measuring probe is located inside the upper part of the upper cylindrical tube 9 and is connected to an external dissolved oxygen meter to monitor the DO concentration in the water inside the upper cylindrical tube 9 in real time.

[0053] Specifically, the in-situ sediment oxygen consumption rate measuring device for reservoirs is divided into an experimental group and a control group when measuring the oxygen consumption rate of in-situ sediments in reservoirs.

[0054] A bottom water pumping pipe 13 is fixed to the upper cylindrical tube 9 in the experimental group by wire. The bottom end of the bottom water pumping pipe 13 is located above the circular horizontal plate 7. When the upper end of the bottom water pumping pipe 13 is connected to the inlet of the peristaltic pump 1 and the end of the circulating water inlet pipe 1 3 away from the upper cylindrical tube 9 is connected to the outlet of the peristaltic pump 1, the peristaltic pump 1 is started to replace the water inside the upper cylindrical tube 9 in the experimental group with the bottom water.

[0055] In the control group, the upper half of the cylindrical tube 9 is symmetrically provided with a second circulating water inlet pipe 5 and a second circulating water outlet pipe 4 connected to its interior. When the end of the second circulating water inlet pipe 5 away from the upper half of the cylindrical tube 9 and the end of the second circulating water outlet pipe 2 away from the upper half of the cylindrical tube 9 are respectively connected to the inlet and outlet of the second peristaltic pump, the second peristaltic pump is started to pump the renewed bottom water in the upper half of the cylindrical tube 9 in the experimental group into the upper half of the cylindrical tube 9 in the control group, so as to renew the water in the upper half of the cylindrical tube 9 in the control group as bottom water. When water comes out from the end of the second circulating water outlet pipe 4 away from the upper half of the cylindrical tube 9, it indicates that the water in the upper half of the cylindrical tube 9 in the control group has been renewed.

[0056] After the water inside the upper cylindrical tube 9 in the control group is renewed, a circulating water inlet pipe 3 and a circulating water outlet pipe 2 are symmetrically arranged on the upper side of the upper cylindrical tube 9 in the experimental group and are connected to its interior. When the end of the circulating water outlet pipe 2 away from the upper cylindrical tube 9 and the end of the circulating water inlet pipe 3 away from the upper cylindrical tube 9 are respectively connected to the outlet and inlet of the peristaltic pump, the peristaltic pump is started to circulate and pump water to make the water inside the upper cylindrical tube 9 evenly mixed.

[0057] In the control group, when the end of the circulating water inlet pipe 2 5 away from the upper cylindrical section 9 and the end of the circulating water outlet pipe 2 4 away from the upper cylindrical section 9 are respectively connected to the inlet and outlet of the peristaltic pump 2, the peristaltic pump is started to circulate and pump water to make the water inside the upper cylindrical section 9 in the control group evenly mixed.

[0058] In the control group, an isolation baffle 6 is installed inside the lower cylindrical tube 10. The isolation baffle 6 is made of stainless steel and is used to isolate the sediment inside the lower cylindrical tube 10 from the water inside the upper cylindrical tube 9 so as to measure the oxygen consumption rate of the water separately. This ensures that the sediment and water do not mix during the experiment, thereby ensuring the accuracy of the experimental data. The height of the isolation baffle 6 can be adjusted. For example, bolts can be installed around the bottom edge of the isolation baffle 6 to secure it to the inner wall of the lower cylindrical tube 10.

[0059] The circular horizontal plate 7 is designed to ensure that only the lower half of the cylindrical tube 10 is filled with sediment. When the sediment thickness is insufficient, the height of the circular horizontal plate 7 is adjusted downwards, and the height of the isolation baffle 6 is also adjusted to ensure that the sediment and water do not mix during the experiment.

[0060] In this embodiment, the reservoir in-situ sediment oxygen consumption rate measuring device uses a float 1 made of high molecular weight high-density polyethylene material, which is positioned above the cylindrical tube. Peristaltic pump one and peristaltic pump two are fixedly installed inside the float 1. The float 1 provides constraint force to the cylindrical tube through the traction of the circulating water outlet pipe one 2, circulating water inlet pipe one 3, circulating water inlet pipe two 5, circulating water outlet pipe two 4, and bottom pumping pipe 13, so that the bottom end of the lower half of the cylindrical tube 10 is stably inserted into the bottom sediment. The dissolved oxygen meter can be installed inside the float 1. Specifically, the dissolved oxygen meter can be a YSI 5500 model dissolved oxygen meter, which has the characteristics of high precision, stability, and ease of operation, and can accurately monitor changes in dissolved oxygen in the water.

[0061] Specifically, in this embodiment, a plumb bob 8 is also provided. The plumb bob 8 is connected to the float 1 by a plumb line. The plumb bob 8 is used to position the float 1 to ensure that the float 1 will not drift or move with the water flow, so as to keep it at the set measurement position. The relatively fixed position can reduce the interference of external factors on the experimental results and improve the accuracy and reliability of the experimental data.

[0062] Specifically, in this embodiment, to ensure the service life of the circulating water outlet pipe 2, circulating water inlet pipe 3, circulating water inlet pipe 5, circulating water outlet pipe 4, and bottom pumping pipe, the circulating water outlet pipe 2, circulating water inlet pipe 3, circulating water inlet pipe 5, circulating water outlet pipe 4, and bottom pumping pipe are all made of corrosion-resistant, high-strength, elastic, and low-cost flexible hoses, such as rubber hoses, which are not prone to air or water leakage due to aging and hardening. This ensures the long-term reliable use of the circulating water outlet pipe 2, circulating water inlet pipe 3, circulating water inlet pipe 5, circulating water outlet pipe 4, and bottom pumping pipe, and ensures that they will not be damaged by water flow during the experiment.

[0063] Example 2

[0064] This embodiment provides a method for measuring the oxygen consumption rate of in-situ sediments in a reservoir, wherein: the oxygen consumption rate of in-situ sediments in a reservoir is measured using the oxygen consumption rate measuring device in Embodiment 1, specifically including the following steps:

[0065] S1: Set up sediment oxygen consumption rate measurement component

[0066] At the experimental site, the cylindrical tube was placed vertically at the bottom of the reservoir, ensuring that the bottom of the lower half of the cylindrical tube 10 was inserted into the sediment. By adjusting the height of the circular cross plate 7, the interior of the lower half of the cylindrical tube 10 was filled with sediment.

[0067] S2: Design the experimental group and the control group

[0068] Six cylindrical tubes were set up at each experimental site. Before the experiment, it was ensured that there was a sufficiently thick sediment at the experimental site. If the sediment thickness was insufficient, the height of the circular horizontal plate 7 and the isolation baffle 6 were adjusted to ensure that the interior of the lower cylindrical tube 10 was filled with sediment. In the experimental group, the bottom of the lower cylindrical tube 10 was unobstructed, and the 0.1 m cylinder of the lower cylindrical tube 10 was filled with sediment to simulate the oxygen consumption of sediment and the total oxygen consumption of water. In the control group, the lower cylindrical tube 10 was equipped with isolation baffle 6 to isolate sediment from water, and only simulated the total oxygen consumption of water.

[0069] S3: Record experimental data

[0070] A 24-hour oxygen consumption experiment was conducted. The sediment oxygen consumption rate measuring device was placed at the bottom of the reservoir. Before the experiment began, the upper end of the bottom water pumping pipe 13 was connected to the inlet of peristaltic pump 1, and the end of the circulating water inlet pipe 13 away from the upper cylindrical section 9 was connected to the outlet of peristaltic pump 1. Peristaltic pump 1 was started to replace the water inside the upper cylindrical section 9 in the experimental group with bottom water. At the same time, the end of the circulating water inlet pipe 2 5 away from the upper cylindrical section 9 and the end of the circulating water outlet pipe 1 2 away from the upper cylindrical section 9 were connected to the inlet and outlet of peristaltic pump 2, respectively. Peristaltic pump 2 was started to pump the renewed bottom water inside the upper cylindrical section 9 in the experimental group into the upper cylindrical section 9 in the control group, replacing the water inside the upper cylindrical section 9 in the control group with bottom water. When water came out from the end of the circulating water outlet pipe 2 4 away from the upper cylindrical section 9, it indicated that the water inside the upper cylindrical section 9 in the control group had been renewed.

[0071] The experiment was started 5 minutes after water was discharged from the end of the circulating water outlet pipe 4 away from the upper cylindrical section 9. The DO concentration change was recorded once every hour during the experiment.

[0072] During the experiment, when the end of the circulating water outlet pipe 2 away from the upper cylindrical tube 9 and the end of the circulating water inlet pipe 3 away from the upper cylindrical tube 9 are connected to the outlet and inlet of the peristaltic pump 1 respectively, the peristaltic pump 1 is started every 1 minute to circulate and pump water to keep the water inside the upper cylindrical tube 9 uniformly mixed, and then the DO concentration is measured.

[0073] At the same time, when the end of the circulating water inlet pipe 2 5 away from the upper cylindrical section 9 and the end of the circulating water outlet pipe 2 4 away from the upper cylindrical section 9 are connected to the inlet and outlet of the peristaltic pump 2 respectively, the peristaltic pump is started every 1 minute to circulate and pump water to keep the water inside the upper cylindrical section 9 in the control group uniformly mixed, and then the DO concentration is measured.

[0074] The water inside the upper cylindrical tube 9 is replaced with bottom water. At the same time, water is pumped in every 1 minute to keep the water inside the upper cylindrical tube 9 uniformly mixed, which more realistically simulates the actual situation of natural water bodies and can improve the accuracy of the results of measuring the oxygen consumption rate of in-situ sediments in reservoirs.

[0075] S4: Analyze experimental data

[0076] Based on the DO concentration data recorded during the experiment, the sediment oxygen consumption rate was calculated. The specific calculation method is as follows:

[0077] First, based on the change in DO concentration before and after the experiment, the amount of DO consumed in the water during the experiment was calculated.

[0078] Then, based on the volume of water and the area of ​​sediment inside the upper cylindrical tube 9 in the experimental group, the oxygen consumption rate per unit area of ​​sediment was calculated.

[0079] Finally, based on the experimental data of the control group, the oxygen consumption rate of the water body was calculated and subtracted from the oxygen consumption rate of the experimental group to obtain the oxygen consumption rate of the sediment itself.

[0080] S5: Correcting experimental results. Based on the changes in the concentrations of BOD5 (five-day biochemical oxygen demand), ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen in the in-situ experimental water, the degradation rate is calculated using the first-order reaction kinetic equation for pollutant degradation, which serves as a supplement and correction to the above calculation results.

[0081] The above-mentioned method for determining the oxygen consumption rate of in-situ sediments in reservoirs includes the following formula for calculating the oxygen consumption rate of sediments:

[0082] (1)

[0083] (2)

[0084] In the formula: Oxygen production rate (d) of primary productivity in water bodies -1 ); The oxygen consumption rate of aquatic algae and other microorganisms during respiration (d) -1 ); The rate of oxygen consumption for the oxidation of carbon-containing organic matter (d) -1 ); The oxygen consumption rate of nitrification (d-1 ); AOCR is the ratio of dissolved oxygen to carbon during respiration (2.67 g O2 / g C); The amount required for nitration of ammonium ions per unit mass (4.33 g O2 / g N), see Wezernak (1968) for details; The oxygen consumption rate of ammonia nitrogen oxidation (d -1 ); The amount required for oxidation of ammonia nitrogen per unit mass (g O2 / g N); The oxygen consumption rate of nitrite oxidation (d) -1 ); The amount required for oxidation of nitrite per unit mass (g O2 / g N); S is the sediment area at the bottom of the sediment experimental cylinder (m²). 2 V is the volume of water inside the sediment experiment cylinder (m³). 3 ).

[0085] In summary, the apparatus and method for measuring the oxygen consumption rate of in-situ sediments in reservoirs provided in this embodiment have the following beneficial effects:

[0086] 1. Accurately reflects the oxygen consumption characteristics of sediments: This invention can accurately simulate the oxygen consumption process of reservoir sediments through in-situ experiments, thereby improving the accuracy and reliability of experimental results.

[0087] 2. Easy to operate: The experimental apparatus has a compact structure and is easy to operate, which reduces the difficulty and cost of the experiment.

[0088] 3. Comprehensive data: By combining the changes in pollutant concentration in the water body, the experimental results are supplemented and corrected using the first-order reaction kinetic equation of pollutant degradation, making the experimental results more comprehensive and accurate.

[0089] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for measuring the oxygen consumption rate of in-situ sediments in a reservoir, characterized in that: The system includes a sediment oxygen consumption rate measuring component, which is used to measure the oxygen consumption rate of in-situ sediments in a reservoir. The sediment oxygen consumption rate measuring component includes a cylindrical tube, a circular transverse plate (7), and a DO measuring probe, wherein: The cylindrical tube includes an upper cylindrical tube (9) and a lower cylindrical tube (10). The upper cylindrical tube (9) is made of PVC material, and the lower cylindrical tube (10) is made of stainless steel material. The DO measuring probe is set inside the upper part of the upper cylindrical tube (9) and is connected to an external dissolved oxygen meter to monitor the DO concentration of the water inside the upper cylindrical tube (9) in real time. A flange is fixedly installed on the outer periphery of the bottom end of the upper cylindrical tube (9), and a flange is fixedly installed on the outer periphery of the upper end of the lower cylindrical tube (10). A headless screw (11) is inserted between the two flanges. Several nuts (12) are threaded on the headless screw (11). The headless screw (11) is fixedly connected to the two flanges respectively through the nuts (12). A circular horizontal plate (7) is fitted on the headless screw (11) and the circular horizontal plate (7) is located between the two flanges. The headless screw (11) is fixedly connected to the circular horizontal plate (7) through the nuts (12). Two nuts (12) are distributed on the upper and lower surfaces of the circular horizontal plate (7) and the two flanges. The circular cross plate (7) is used to ensure that only the lower half of the cylindrical tube (10) is filled with sediment. When the sediment thickness is insufficient, the height of the circular cross plate (7) is adjusted downward. The upper end of the upper cylindrical tube (9) is sealed with PVC material to seal the upper end of the upper cylindrical tube (9) and prevent external water from entering the interior of the upper cylindrical tube (9) through the upper end of the upper cylindrical tube (9). The in-situ sediment oxygen consumption rate measuring device for reservoirs is divided into an experimental group and a control group when measuring the in-situ sediment oxygen consumption rate of the reservoir, wherein: A bottom water pumping pipe (13) is fixed to the upper cylindrical tube (9) in the experimental group by wire. The bottom end of the bottom water pumping pipe (13) is located above the circular horizontal plate (7). When the upper end of the bottom water pumping pipe (13) is connected to the inlet of the peristaltic pump and the end of the circulating water inlet pipe (3) away from the upper cylindrical tube (9) is connected to the outlet of the peristaltic pump, the peristaltic pump is started to renew the water inside the upper cylindrical tube (9) in the experimental group into bottom water. In the control group, the upper half of the cylindrical tube (9) is symmetrically provided with a second circulating water inlet pipe (5) and a second circulating water outlet pipe (4) connected to its interior. When the end of the second circulating water inlet pipe (5) away from the upper half of the cylindrical tube (9) and the end of the first circulating water outlet pipe (2) away from the upper half of the cylindrical tube (9) are respectively connected to the inlet and outlet of the second peristaltic pump, the second peristaltic pump is started to pump the renewed bottom water in the upper half of the cylindrical tube (9) in the experimental group into the upper half of the cylindrical tube (9) in the control group, so as to renew the water in the upper half of the cylindrical tube (9) in the control group into the bottom water. When the end of the second circulating water outlet pipe (4) away from the upper half of the cylindrical tube (9) is exposed, it indicates that the water in the upper half of the cylindrical tube (9) in the control group has been renewed. After the water inside the upper cylindrical tube (9) in the control group is renewed, a circulating water inlet pipe (3) and a circulating water outlet pipe (2) connected to the inside are symmetrically arranged on the upper side of the upper cylindrical tube (9) in the experimental group. When the end of the circulating water outlet pipe (2) away from the upper cylindrical tube (9) and the end of the circulating water inlet pipe (3) away from the upper cylindrical tube (9) are respectively connected to the outlet and inlet of the peristaltic pump, the peristaltic pump is started to circulate and pump water to make the water inside the upper cylindrical tube (9) evenly mixed. In the control group, when the end of the circulating water inlet pipe 2 (5) away from the upper cylindrical section (9) and the end of the circulating water outlet pipe 2 (4) away from the upper cylindrical section (9) are respectively connected to the inlet and outlet of the peristaltic pump 2, the peristaltic pump 2 is started to circulate and pump water to make the water inside the upper cylindrical section (9) in the control group evenly mixed.

2. The device for measuring the oxygen consumption rate of in-situ sediments in a reservoir according to claim 1, characterized in that: It also includes a float (1), which is made of high molecular weight high density polyethylene material and is set above the cylindrical tube. The first peristaltic pump and the second peristaltic pump are fixedly installed inside the float (1). The float (1) provides a constraint force to the cylindrical tube through the traction of the first circulating water outlet pipe (2), the first circulating water inlet pipe (3), the second circulating water inlet pipe (5) and the second circulating water outlet pipe (4), so that the bottom end of the lower half of the cylindrical tube (10) is stably inserted into the bottom mud.

3. The device for measuring the oxygen consumption rate of in-situ sediments in a reservoir according to claim 2, characterized in that: It also includes a plumb bob (8), which is connected to the float (1) by a plumb line. The plumb bob (8) is used to position the float (1) to ensure that the float (1) does not drift or move with the water flow, so as to keep it at the set measurement position.

4. The device for measuring the oxygen consumption rate of in-situ sediments in a reservoir according to claim 3, characterized in that: The circulating water outlet pipe 1 (2), the circulating water inlet pipe 1 (3), the circulating water inlet pipe 2 (5), the circulating water outlet pipe 2 (4), and the bottom water pumping pipe (13) are all made of corrosion-resistant, high-strength, elastic, and low-cost flexible hoses that are not prone to air or water leakage due to aging and hardening. This ensures that they will not be damaged by water flow during the experiment.

5. The device for measuring the oxygen consumption rate of in-situ sediments in a reservoir according to claim 4, characterized in that: In the control group, the lower cylindrical section (10) is also equipped with an isolation baffle (6), which is made of stainless steel and is used to isolate the sediment inside the lower cylindrical section (10) from the water inside the upper cylindrical section (9) so as to measure the oxygen consumption rate of the water separately.

6. A method for determining the oxygen consumption rate of in-situ sediments in a reservoir, characterized in that: The method for measuring the oxygen consumption rate of in-situ sediments in a reservoir using the apparatus described in claim 5 specifically includes the following steps: S1: Set up sediment oxygen consumption rate measurement component At the experimental site, the cylindrical tube was placed vertically at the bottom of the reservoir, ensuring that the bottom of the lower half of the cylindrical tube (10) was inserted into the sediment. By adjusting the height of the circular cross plate (7), the interior of the lower half of the cylindrical tube (10) was filled with sediment. S2: Design the experimental group and the control group Six cylindrical tubes were set up at each experimental site. Before the experiment, it was ensured that there was a sufficient thickness of sediment at the experimental site. If the sediment thickness was insufficient, the height of the circular horizontal plate (7) was adjusted to ensure that the interior of the lower cylindrical tube (10) was filled with sediment. The bottom of the three lower cylindrical tubes (10) in the experimental group was unobstructed, and the cylinder of the lower cylindrical tube (10) was filled with sediment to simulate the oxygen consumption of sediment and the total oxygen consumption of water. In addition, the three lower cylindrical tubes (10) in the control group were equipped with isolation baffles (6) to isolate sediment from water, and only simulated the total oxygen consumption of water. S3: Record experimental data A 24-hour oxygen consumption experiment was conducted by placing the sediment oxygen consumption rate measuring device at the bottom of the reservoir. Before the experiment begins, the upper end of the bottom water inlet pipe (13) is connected to the inlet of the peristaltic pump, and the end of the circulating water inlet pipe (3) away from the upper cylindrical section (9) is connected to the outlet of the peristaltic pump. The peristaltic pump is then activated to replace the water inside the upper cylindrical section (9) in the experimental group with the bottom water. Simultaneously, the end of the circulating water inlet pipe (2) away from the upper cylindrical section (9) and the end of the circulating water outlet pipe (2) away from the upper cylindrical section (9) are connected. When the end is connected to the inlet and outlet of the peristaltic pump two, the peristaltic pump two is started to pump the bottom water that is renewed inside the upper half of the cylindrical tube (9) in the experimental group into the upper half of the cylindrical tube (9) in the control group, and the water inside the upper half of the cylindrical tube (9) in the control group is renewed as bottom water. When water comes out from the end of the circulating water outlet pipe two (4) away from the upper half of the cylindrical tube (9), it indicates that the water inside the upper half of the cylindrical tube (9) in the control group has been renewed. The experiment was started 5 minutes after water was discharged from the end of the circulating water outlet pipe 2 (4) away from the upper cylindrical section (9). The DO concentration change was recorded once every hour during the experiment. During the experiment, when the end of the circulating water outlet pipe (2) away from the upper cylindrical section (9) and the end of the circulating water inlet pipe (3) away from the upper cylindrical section (9) are respectively connected to the outlet and inlet of the peristaltic pump, the peristaltic pump is started to circulate and pump water so that the water inside the upper cylindrical section (9) is kept uniformly mixed. At the same time, when the end of the second circulating water inlet pipe (5) away from the upper cylindrical section (9) and the end of the second circulating water outlet pipe (4) away from the upper cylindrical section (9) are respectively connected to the inlet and outlet of the second peristaltic pump, the second peristaltic pump is started to circulate and pump water so that the water inside the upper cylindrical section (9) in the control group is kept uniformly mixed. S4: Analyze experimental data Based on the DO concentration data recorded during the experiment, the sediment oxygen consumption rate was calculated. The specific calculation method is as follows: First, based on the change in DO concentration before and after the experiment, the amount of DO consumed in the water during the experiment was calculated. Then, based on the volume of water and the area of ​​sediment inside the upper cylindrical tube (9) in the experimental group, the oxygen consumption rate per unit area of ​​sediment was calculated. Finally, based on the experimental data of the control group, the oxygen consumption rate of the water body was calculated and subtracted from the oxygen consumption rate of the experimental group to obtain the oxygen consumption rate of the sediment itself.

7. The method for determining the oxygen consumption rate of in-situ sediments in a reservoir according to claim 6, characterized in that: It also includes S5: Correction of experimental results. Based on the changes in the concentrations of biochemical oxygen demand, ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen in the in-situ experimental water body over five days, the degradation rate is calculated using the first-order reaction kinetic equation for pollutant degradation, which serves as a supplement and correction to the above calculation results.

8. The method for determining the oxygen consumption rate of in-situ sediments in a reservoir according to claim 7, characterized in that: The formula for calculating the oxygen consumption rate of the sediment is as follows: (1) (2) Where: The oxygen consumption rate of aquatic algae microorganisms during respiration, d -1 ; d represents the rate at which carbon-containing organic matter is oxidized and requires oxygen. -1 ; The oxygen consumption rate of nitrification, d -1 ;AOCR is the ratio of dissolved oxygen to carbon during respiration, 2.67 g O2 / g C; The amount required for nitration of ammonium ions per unit mass 4.33 gO2 / gN; S is the sediment area at the bottom of the sedimentary cylinder in the sediment experiment, m². 2 V represents the volume of water inside the sediment experiment cylinder, in meters. 3 .

Images