Reservoir in-situ sediment oxygen consumption rate measuring device and method

Abstract

The invention discloses a reservoir in-situ sediment oxygen consumption rate measuring device and method.The reservoir in-situ sediment oxygen consumption rate measuring device is characterized in that the reservoir in-situ sediment oxygen consumption rate measuring device comprises a sediment oxygen consumption rate measuring assembly, and the sediment oxygen consumption rate measuring assembly is used for measuring the reservoir in-situ sediment oxygen consumption rate; the sediment oxygen consumption rate measuring assembly comprises a cylinder, a circular ring transverse plate and a DO measuring probe, the cylinder comprises an upper half section cylinder and a lower half section cylinder, the upper half section cylinder is made of a PVC material, and the lower half section cylinder is made of a stainless steel material; a flange is fixedly installed on the periphery of the bottom end of the upper half section cylinder, a flange is fixedly installed on the periphery of the upper end of the lower half section cylinder, a headless screw is inserted between the two flanges in a penetrating mode, and the headless screw is sleeved with a plurality of nuts in a threaded mode. The device is compact in structure, simple and convenient to operate and capable of accurately reflecting oxygen consumption characteristics of reservoir sediments.

Description

Technical Field

[0001] The invention relates to the technical field of environmental monitoring, and in particular to a device for measuring the oxygen consumption rate of in-situ sediments in a reservoir. Background Art

[0002] As an important water resource storage and regulation facility, the water quality of a reservoir directly affects the production and life 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 a reservoir is of great significance for evaluating reservoir water quality, predicting water quality change trends, and formulating corresponding water quality management measures.

[0003] Traditional sediment oxygen consumption rate measurement methods mostly use laboratory simulation experiments. Although this method can simulate the oxygen consumption process of sediments in reservoirs, due to the difference between laboratory conditions and the actual reservoir environment, the measurement results are often difficult to accurately reflect the oxygen consumption rate of sediments in situ in the reservoir. In order to overcome this defect, it is necessary to develop a device and method for measuring sediment oxygen consumption rate directly in situ in the reservoir. Summary of the invention

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

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A reservoir in-situ sediment oxygen consumption rate measuring device, comprising a sediment oxygen consumption rate measuring component, the sediment oxygen consumption rate measuring component is used to measure the reservoir in-situ sediment oxygen consumption rate, and the sediment oxygen consumption rate measuring component comprises a cylindrical barrel, a circular ring horizontal plate and a DO measuring probe, wherein:

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

[0008] A flange is fixedly installed on the outer periphery of the bottom end of the upper half of the cylindrical tube, and a flange is fixedly installed on the outer periphery of the upper end of the lower half of the cylindrical tube. A headless screw is inserted between the two flanges, and a plurality of nuts are threadedly mounted on the headless screw. The headless screw is fixedly connected to the two flanges through nuts, and the circular cross plate is mounted on the headless screw, and the circular cross plate is located between the two flanges. The headless screw is fixedly connected to the circular cross plate through nuts, and two nuts are distributed on the upper and lower surfaces of the circular cross plate and the two flanges.

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

[0010] The DO measuring probe is arranged inside the upper part of the upper cylindrical barrel, and the DO measuring probe is connected to an external dissolved oxygen meter for real-time monitoring of the DO concentration of the water body inside the upper cylindrical barrel.

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

[0012] A bottom water pumping pipe is fixed to the upper half of the cylindrical tube in the experimental group by means of an iron wire, and 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 water inlet of a peristaltic pump and at the same time, the end of the circulating water inlet pipe 1 away from the upper half of the cylindrical tube is connected to the water outlet of a peristaltic pump 1, the peristaltic pump 1 is started to update the water inside the upper half of the cylindrical tube in the experimental group to the bottom water.

[0013] A circulating water inlet pipe 2 and a circulating water outlet pipe 2 which are connected to the interior are symmetrically arranged on the upper end side surface of the upper half cylindrical tube in the control group. When the end of the circulating water inlet pipe 2 away from the upper half cylindrical tube and the end of the circulating water outlet pipe 1 away from the upper half cylindrical tube are respectively connected to the water inlet and the water outlet of the peristaltic pump 2, the peristaltic pump 2 is started to pump the bottom layer water body updated inside the upper half cylindrical tube in the experimental group into the interior of the upper half cylindrical tube in the control group, so as to achieve the purpose of updating the water body inside the upper half cylindrical tube in the control group to the bottom layer water body. When the circulating water outlet pipe 2 discharges water at the end away from the upper half cylindrical tube, it indicates that the water body inside the upper half cylindrical tube in the control group has been completely updated.

[0014] After the water inside the upper half of the cylindrical tube in the control group is renewed, a circulating water inlet pipe 1 and a circulating water outlet pipe 1 connected to the interior of the upper half of the cylindrical tube in the experimental group are symmetrically provided on the upper end side surface of the upper half of the cylindrical tube; when the end of the circulating water outlet pipe 1 away from the upper half of the cylindrical tube and the end of the circulating water inlet pipe 1 away from the upper half of the cylindrical tube are respectively connected to the water outlet and the water inlet of the peristaltic pump 1, the peristaltic pump 1 is started to circulate and pump water to evenly mix the water inside the upper half of the cylindrical tube; when the end of the circulating water inlet pipe 2 away from the upper half of the cylindrical tube and the end of the circulating water outlet pipe 2 away from the upper half of the cylindrical tube in the control group are respectively connected to the water inlet and the water outlet of the peristaltic pump 2, the peristaltic pump is started to circulate and pump water to evenly mix the water inside the upper half of the cylindrical tube in the control group.

[0015] The above-mentioned reservoir in-situ sediment oxygen consumption rate measuring device, wherein: it also includes a float, the float is made of high molecular weight high density polyethylene material, and is arranged above the cylindrical tube. The peristaltic pump 1 and the peristaltic pump 2 are both fixedly installed inside the float. The float provides a restraining force for the cylindrical tube through the traction of the circulating outlet pipe 1, the circulating inlet pipe 1, the circulating inlet pipe 2 and the circulating outlet pipe 2, so that the bottom end of the lower half of the cylindrical tube is stably inserted into the bottom mud.

[0016] The above-mentioned reservoir in-situ sediment oxygen consumption rate measuring device, wherein: also includes a plumb bob, which is connected to the buoy through a plumb line, and the plumb bob is used to position the buoy to ensure that the buoy does not drift or move with the water flow so as to remain at the set measuring position.

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

[0018] The above-mentioned reservoir in-situ sediment oxygen consumption rate measuring device, wherein: an isolation baffle is also installed inside the lower half of the cylindrical tube in the control group, and the isolation baffle is made of stainless steel material, which 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 respiratory oxygen consumption rate of the water body separately.

[0019] The present invention also proposes a method for measuring the oxygen consumption rate of in-situ sediments in a reservoir, wherein: the in-situ sediment oxygen consumption rate of the reservoir is measured using the above-mentioned in-situ sediment oxygen consumption rate measuring device, specifically comprising the following steps:

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

[0021] At the experimental point, the cylinder is placed vertically on the bottom of the reservoir, ensuring that the bottom end of the lower half of the cylinder is inserted into the sediment, and the interior of the lower half of the cylinder is filled with sediment by adjusting the height of the circular cross plate;

[0022] S2: Design of experimental and control groups

[0023] Six cylinders were set up at each experimental point. Before the experiment, it was ensured that the experimental point had thick enough sediment. 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 cylinder could be filled with sediment. The bottom of the three lower half cylinders in the experimental group was unobstructed, and the 0.1 m cylinder of the lower half cylinder was filled with sediment to simulate the oxygen consumption of sediment and the total oxygen consumption of water. In addition, the three lower half cylinders in the control group were equipped with isolation baffles to isolate sediment from water, which only simulated the total oxygen consumption of water.

[0024] S3: Recording experimental data

[0025] A 24-hour oxygen consumption experiment was conducted, and the sediment oxygen consumption rate measurement component was placed at the bottom of the reservoir. Before the experiment began, the upper end of the bottom water pump was connected to the water inlet of the peristaltic pump 1 and the end of the circulating water inlet pipe 1 away from the upper half of the cylindrical tube was connected to the water outlet of the peristaltic pump 1. The peristaltic pump 1 was started to update the water inside the upper half of the cylindrical tube in the experimental group to the bottom water. At the same time, the end of the circulating water inlet pipe 2 away from the upper half of the cylindrical tube and the circulating water outlet were connected. When one end of the pipe 1 away from the upper half of the cylindrical tube is respectively connected to the water inlet and the water outlet of the peristaltic pump 2, the peristaltic pump 2 is started to pump the bottom water body updated inside the upper half of the cylindrical tube in the experimental group into the interior of the upper half of the cylindrical tube in the control group, and the water body inside the upper half of the cylindrical tube in the control group is updated to the bottom water body. When the end of the circulating water outlet pipe 2 away from the upper half of the cylindrical tube discharges water, it indicates that the water body inside the upper half of the cylindrical tube in the control group has been updated.

[0026] The test was started 5 minutes after the water was discharged from the end of the circulating water outlet pipe 2 away from the upper half of the cylindrical tube, and the DO concentration change was recorded once every hour during the experiment;

[0027] During the experiment, when the end of the circulating water outlet pipe 1 away from the upper half of the cylindrical barrel and the end of the circulating water inlet pipe 1 away from the upper half of the cylindrical barrel are connected to the water outlet and the water inlet of the peristaltic pump 1 respectively, the peristaltic pump 1 is started to circulate water so that the water inside the upper half of the cylindrical barrel is kept evenly mixed;

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

[0029] S4: Analyze experimental data

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

[0031] First, according to the change of DO concentration before and after the experiment, the DO consumption of the water body during the experiment was calculated;

[0032] Then, based on the volume of water and sediment area inside the upper half of the cylinder in 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 respiratory 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 a reservoir, wherein: it also includes S5: correcting the experimental results, according to the changes in the concentrations of BOD5 (biochemical oxygen demand in five days), ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in the in-situ experimental water body before and after, the degradation rate is calculated using the first-order reaction kinetic equation of pollutant degradation, as a supplement and correction to the above-mentioned calculation results.

[0035] The above-mentioned reservoir in-situ sediment oxygen consumption rate determination method, wherein: the calculation formula of the sediment oxygen consumption rate is as follows: (1) (2)

[0036] Where: is the oxygen production rate of the primary productivity of the water body (d -1 ); is the oxygen consumption rate of algae and other microorganisms in water (d -1 ); is the oxygen consumption rate of carbon-containing organic matter oxidation (d -1 ); is the oxygen consumption rate of nitrification (d -1 ) ; AOCR is the ratio of dissolved oxygen to carbon in respiration (2.67 g O2 / g C); The unit mass of ammonium ions required for nitration (4.33 g O2 / g N), see Wezernak (1968) for details; is the oxygen consumption rate of ammonia nitrogen oxidation (d -1 ); The unit mass of ammonia nitrogen oxidation required (g O2 / g N); is the oxygen consumption rate of nitrite nitrogen oxidation (d -1 ); Required for oxidation of unit mass of nitrite nitrogen (g O2 / g N); S is the sediment area at the bottom of the sediment test cylinder (m 2 ); V is the volume of water in the sediment test cylinder (m 3 ).

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

[0038] 1. Accurately reflect the oxygen consumption characteristics of sediments: The present 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 operation: The experimental device has a compact structure and is easy to operate, which reduces the difficulty and cost of the experiment.

[0040] 3. Comprehensive data: Combined with the changes in the concentration of water pollutants, the first-order reaction kinetic equation of pollutant degradation is used to supplement and correct the data, making the experimental results more comprehensive and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0042] Reference numerals:

[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 cross plate; 8. Plumb bob; 9. Upper half of cylindrical tube; 10. Lower half of cylindrical tube; 11. Headless screw; 12. Nut; 13. Bottom water pumping pipe. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Example 1

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

[0047] The diameter of the cylindrical tube is 0.2 m, and the cylindrical tube includes an upper cylindrical tube 9 and a lower cylindrical tube 10. The height of the upper cylindrical tube 9 is 0.2 m, and the upper cylindrical tube 9 is made of a light PVC material, and the height of the lower cylindrical tube 10 is 0.1 m. The lower cylindrical tube 10 is made of a heavy stainless steel material with a weight of 5 kg, and the bottom edge is sharp, so it can be smoothly inserted into the sediment under the action of its own weight;

[0048] In order to facilitate the adjustment of the height position of the circular ring horizontal plate 7, the following scheme is specifically 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. A plurality of nuts 12 are threadedly mounted on the headless screw 11. The headless screw 11 is fixedly connected to the two flanges through the nuts 12. The circular cross plate 7 is mounted on the headless screw 11, and the circular cross plate 7 is located between the two flanges. The headless screw 11 is fixedly connected to the circular cross plate 7 through the nuts 12. Two nuts 12 are distributed on the upper and lower surfaces of the circular cross plate 7 and the two flanges.

[0050] If the thickness of the sediment is insufficient, the circular cross plate 7 can also be fixed under the flange of the lower half cylindrical barrel by means of a headless screw and two nuts to ensure that the lower half cylindrical barrel 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 arranged inside the upper part of the upper cylindrical tube 9 , and the DO measuring probe is connected to an external dissolved oxygen meter for real-time monitoring of the DO concentration of the water body inside the upper cylindrical tube 9 .

[0053] Specifically, the reservoir in-situ sediment oxygen consumption rate measuring device is divided into an experimental group and a control group when measuring the reservoir in-situ sediment oxygen consumption rate, wherein:

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

[0055] A circulating water inlet pipe 2 5 and a circulating water outlet pipe 2 4 connected to the interior of the upper half cylindrical tube 9 in the control group are symmetrically arranged on the upper end side surface thereof. When the end of the circulating water inlet pipe 2 5 away from the upper half cylindrical tube 9 and the end of the circulating water outlet pipe 1 2 away from the upper half cylindrical tube 9 are respectively connected to the water inlet and the water outlet of the peristaltic pump 2, the peristaltic pump 2 is started to pump the bottom layer water body updated inside the upper half cylindrical tube 9 in the experimental group into the interior of the upper half cylindrical tube 9 in the control group, so as to achieve the purpose of updating the water body inside the upper half cylindrical tube 9 in the control group to the bottom layer water body. When the end of the circulating water outlet pipe 2 4 away from the upper half cylindrical tube 9 discharges water, it indicates that the water body inside the upper half cylindrical tube 9 in the control group has been completely updated.

[0056] After the water inside the upper half 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 of the upper half cylindrical tube 9 in the experimental group are symmetrically provided on the upper end side surface thereof, and when the end of the circulating water outlet pipe 2 away from the upper half cylindrical tube 9 and the end of the circulating water inlet pipe 3 away from the upper half cylindrical tube 9 are respectively connected to the water outlet and the water inlet of the peristaltic pump 1, the peristaltic pump 1 is started to circulate and pump water to evenly mix the water inside the upper half cylindrical tube 9;

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

[0058] An isolation baffle 6 is also installed inside the lower half of the cylindrical tube 10 in the control group. The isolation baffle 6 is made of stainless steel and is used to isolate the sediment inside the lower half of the cylindrical tube 10 from the water inside the upper half of the cylindrical tube 9 to separately measure the respiratory oxygen consumption rate of the water body to ensure that the sediment and the water body will not mix with each other during the experiment, thereby ensuring the accuracy of the test data. The height of the isolation baffle 6 can be adjusted, for example, bolts are installed around the bottom of the isolation baffle 6 near the edge, and the bolts are used to tighten against the inner wall of the lower half of the cylindrical tube 10.

[0059] Among them, the circular cross plate 7 is used to ensure that only the cylinder of 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, and the height of the isolation baffle 6 is adjusted at the same time to ensure that the sediment and water will not mix with each other during the experiment.

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

[0061] Specifically, in the present embodiment, a plumb bob 8 is also provided, which is connected to the buoy 1 through a plumb line. The plumb bob 8 is used to position the buoy 1 to ensure that the buoy 1 does not drift or move with the water flow so as to remain at the set measuring 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 the present embodiment, in order to ensure the service life of the circulating water outlet pipe 2, the circulating water inlet pipe 3, the circulating water inlet pipe 25, the circulating water outlet pipe 24 and the bottom water pumping pipe, the circulating water outlet pipe 2, the circulating water inlet pipe 3, the circulating water inlet pipe 25, the circulating water outlet pipe 24 and the bottom water pumping pipe are all made of corrosion-resistant, high-strength, good elasticity, not prone to air leakage and water leakage due to aging and hardening, low-cost and easily replaceable hoses, such as rubber hoses, thereby ensuring the long-term and reliable use of the circulating water outlet pipe 2, the circulating water inlet pipe 3, the circulating water inlet pipe 25, the circulating water outlet pipe 24 and the bottom water pumping pipe to ensure that they will not be damaged by water erosion 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 in-situ sediment oxygen consumption rate measuring device in Example 1 is used to measure the in-situ sediment oxygen consumption rate in a reservoir, specifically comprising the following steps:

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

[0066] At the experimental point, the cylinder is placed vertically on the bottom of the reservoir, ensuring that the bottom end of the lower half of the cylinder 10 is inserted into the sediment, and the interior of the lower half of the cylinder 10 is filled with sediment by adjusting the height of the circular cross plate 7;

[0067] S2: Design of experimental and control groups

[0068] Six cylindrical tubes were set up at each experimental point. Before the experiment, it was ensured that the experimental point had thick enough sediment. If the sediment thickness was insufficient, the height of the circular cross plate 7 and the isolation baffle 6 was adjusted to ensure that the interior of the lower half of the cylindrical tube 10 could be filled with sediment. The bottom of the three lower half cylindrical tubes 10 of the experimental group was unobstructed, and the 0.1 m cylinder of the lower half cylindrical tube 10 was filled with sediment to simulate the oxygen consumption of sediment and the total oxygen consumption of water. In addition, the isolation baffle 6 was set inside the three lower half cylindrical tubes 10 of the control group to isolate the sediment from the water, and only the total oxygen consumption of water was simulated.

[0069] S3: Recording experimental data

[0070] A 24-hour oxygen consumption experiment was conducted, and the sediment oxygen consumption rate determination component 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 water inlet of the peristaltic pump 1 and the end of the circulating water inlet pipe 13 away from the upper cylindrical tube 9 was connected to the water outlet of the peristaltic pump 1, and the peristaltic pump 1 was started to update the water body inside the upper cylindrical tube 9 in the experimental group to the bottom water body; at the same time, the end of the circulating water inlet pipe 2 5 away from the upper cylindrical tube 9 and the end of the circulating water outlet pipe 1 2 away from the upper cylindrical tube 9 were respectively connected to the water inlet and the water outlet of the peristaltic pump 2, and the peristaltic pump 2 was started to pump the bottom water body updated inside the upper cylindrical tube 9 in the experimental group into the interior of the upper cylindrical tube 9 in the control group, and the water body inside the upper cylindrical tube 9 in the control group was updated to the bottom water body. When the end of the circulating water outlet pipe 2 4 away from the upper cylindrical tube 9 discharges water, it indicates that the water body inside the upper cylindrical tube 9 in the control group has been completely updated;

[0071] The test was started 5 minutes after the water was discharged from the end of the circulating water outlet pipe 2 4 away from the upper half of the cylindrical tube 9. The DO concentration change was recorded every hour during the experiment.

[0072] During the experiment, 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 water outlet and water inlet of the peristaltic pump 1 respectively, and the peristaltic pump 1 is started to circulate and pump water every 1 minute to keep the water inside the upper cylindrical tube 9 evenly mixed, and then the DO concentration is measured;

[0073] At the same time, one end of the circulating water inlet pipe 2 5 away from the upper half of the cylindrical tube 9 and one end of the circulating water outlet pipe 2 4 away from the upper half of the cylindrical tube 9 are connected to the water inlet and the water outlet of the peristaltic pump 2 respectively, and the peristaltic pump is started every 1 minute to circulate and pump water so that the water inside the upper half of the cylindrical tube 9 in the control group is evenly mixed, and then the DO concentration is measured;

[0074] The water inside the upper cylindrical tube 9 is updated to the bottom water body, and water is pumped out every 1 minute to keep the water inside the upper cylindrical tube 9 evenly 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 the reservoir.

[0075] S4: Analyze experimental data

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

[0077] First, according to the change of DO concentration before and after the experiment, the DO consumption of the water body during the experiment was calculated;

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

[0079] Finally, based on the experimental data of the control group, the respiratory 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: Correct the experimental results. According to the changes in the concentrations of BOD5 (biochemical oxygen demand in five days), ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in the water body before and after the in-situ experiment, the degradation rate is calculated using the first-order reaction kinetic equation of pollutant degradation as a supplement and correction to the above calculation results.

[0081] In the above-mentioned reservoir in-situ sediment oxygen consumption rate determination method, the calculation formula of the sediment oxygen consumption rate is as follows:

[0082] (1)

[0083] (2)

[0084] Where: is the oxygen production rate of the primary productivity of the water body (d -1 ); is the oxygen consumption rate of algae and other microorganisms in water (d -1 ); is the oxygen consumption rate of carbon-containing organic matter oxidation (d -1 ); is the oxygen consumption rate of nitrification (d-1 ) ; AOCR is the ratio of dissolved oxygen to carbon in respiration (2.67 g O2 / g C); The unit mass of ammonium ions required for nitration (4.33 g O2 / g N), see Wezernak (1968) for details; is the oxygen consumption rate of ammonia nitrogen oxidation (d -1 ); The unit mass of ammonia nitrogen oxidation required (g O2 / g N); is the oxygen consumption rate of nitrite nitrogen oxidation (d -1 ); Required for oxidation of unit mass of nitrite nitrogen (g O2 / g N); S is the sediment area at the bottom of the sediment test cylinder (m 2 ); V is the volume of water in the sediment test cylinder (m 3 ).

[0085] In summary, the reservoir in-situ sediment oxygen consumption rate determination device and method provided in this embodiment mainly have the following beneficial effects:

[0086] 1. Accurately reflect the oxygen consumption characteristics of sediments: The present 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 operation: The experimental device has a compact structure and is easy to operate, which reduces the difficulty and cost of the experiment.

[0088] 3. Comprehensive data: Combined with the changes in the concentration of water pollutants, the first-order reaction kinetic equation of pollutant degradation is used to supplement and correct the data, making the experimental results more comprehensive and accurate.

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

Claims

1. A reservoir in-situ sediment oxygen consumption rate measuring device, characterized in that: The invention comprises a sediment oxygen consumption rate measuring component, which is used to measure the in-situ sediment oxygen consumption rate of a reservoir, and the sediment oxygen consumption rate measuring component comprises a cylindrical barrel, a circular ring cross plate (7) and a DO measuring probe, wherein: The cylindrical tube comprises an upper cylindrical tube (9) and a lower cylindrical tube (10), wherein the upper cylindrical tube (9) is made of PVC material, and the lower cylindrical tube (10) is made of stainless steel material; A flange is fixedly installed on the outer periphery of the bottom end of the upper half cylindrical tube (9), and a flange is fixedly installed on the outer periphery of the upper end of the lower half cylindrical tube (10). A headless screw (11) is inserted between the two flanges. A plurality of nuts (12) are threadedly sleeved on the headless screw (11). The headless screw (11) is fixedly connected to the two flanges respectively through the nuts (12). The circular cross plate (7) is sleeved on the headless screw (11), and the circular cross plate (7) is located between the two flanges. The headless screw (11) is fixedly connected to the circular cross plate (7) through the nuts (12). Two nuts (12) are distributed on the upper and lower surfaces of the circular cross plate (7) and the two flanges. The circular ring cross plate (7) is used to ensure that only the cylinder of the lower half of the cylindrical barrel (10) is filled with sediment, and when the sediment thickness is insufficient, the height of the circular ring 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 DO measuring probe is arranged inside the upper part of the upper cylindrical barrel (9), and the DO measuring probe is connected to an external dissolved oxygen meter for real-time monitoring of the DO concentration of the water body inside the upper cylindrical barrel (9).

2. The device for measuring the oxygen consumption rate of in-situ sediment in a reservoir according to claim 1, characterized in that: The reservoir in-situ sediment oxygen consumption rate measuring device is divided into an experimental group and a control group when measuring the reservoir in-situ sediment oxygen consumption rate, wherein: A bottom water pumping pipe (13) is fixed to the upper half cylindrical tube (9) in the experimental group by means of an iron wire, and the bottom end of the bottom water pumping pipe (13) is located above the circular cross plate (7). When the upper end of the bottom water pumping pipe (13) is connected to the water inlet of a peristaltic pump and at the same time the end of the circulating water inlet pipe (3) away from the upper half cylindrical tube (9) is connected to the water outlet of a peristaltic pump, the peristaltic pump is started to update the water inside the upper half cylindrical tube (9) in the experimental group to the bottom water. A circulating water inlet pipe 2 (5) and a circulating water outlet pipe 2 (4) which are connected to the interior of the upper half cylindrical tube (9) are symmetrically arranged on the upper end side surface of the upper half cylindrical tube (9) in the control group. When the end of the circulating water inlet pipe 2 (5) away from the upper half cylindrical tube (9) and the end of the circulating water outlet pipe 1 (2) away from the upper half cylindrical tube (9) are respectively connected to the water inlet and the water outlet of the peristaltic pump 2, the peristaltic pump 2 is started to pump the bottom layer water body updated inside the upper half cylindrical tube (9) in the experimental group into the interior of the upper half cylindrical tube (9) in the control group, so as to achieve the purpose of updating the water body inside the upper half cylindrical tube (9) in the control group to the bottom layer water body. When the end of the circulating water outlet pipe 2 (4) away from the upper half cylindrical tube (9) discharges water, it indicates that the water body inside the upper half cylindrical tube (9) in the control group has been updated. After the water inside the upper half cylindrical tube (9) in the control group is renewed, a circulating water inlet pipe (3) and a circulating water outlet pipe (2) are symmetrically provided on the upper end side surface of the upper half cylindrical tube (9) in the experimental group and are connected to the interior thereof. When the end of the circulating water outlet pipe (2) away from the upper half cylindrical tube (9) and the end of the circulating water inlet pipe (3) away from the upper half cylindrical tube (9) are respectively connected to the water outlet and the water inlet of the peristaltic pump (1), the peristaltic pump (1) is started to circulate and pump water so as to evenly mix the water inside the upper half cylindrical tube (9); In the control group, when the end of the second circulating water inlet pipe (5) away from the upper half cylindrical tube (9) and the end of the second circulating water outlet pipe (4) away from the upper half cylindrical tube (9) are respectively connected to the water inlet and the water outlet of the second peristaltic pump, the peristaltic pump is started to circulate and pump water so as to evenly mix the water inside the upper half cylindrical tube (9) in the control group.

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

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

5. The device for measuring the oxygen consumption rate of in-situ sediment in a reservoir according to claim 4, 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, flexible hoses with good elasticity, which are not prone to air or water leakage due to aging and hardening, and are low in cost and easy to replace, so as to ensure that they will not be damaged by water scouring during the experiment.

6. The device for measuring the oxygen consumption rate of in-situ sediment in a reservoir according to claim 5, characterized in that: An isolation baffle (6) is also installed inside the lower half cylindrical tube (10) in the control group. The isolation baffle (6) is made of stainless steel and is used to isolate the sediment inside the lower half cylindrical tube (10) from the water inside the upper half cylindrical tube (9) so as to measure the respiratory oxygen consumption rate of the water body separately.

7. A method for measuring the oxygen consumption rate of in-situ sediments in a reservoir, characterized in that: The reservoir in-situ sediment oxygen consumption rate measuring device according to claim 6 is used to measure the reservoir in-situ sediment oxygen consumption rate, which specifically includes the following steps: S1: Set up sediment oxygen consumption rate measurement components At the experimental point, the cylinder is placed vertically on the bottom layer of the reservoir, ensuring that the bottom end of the lower half of the cylinder (10) is inserted into the sediment, and the interior of the lower half of the cylinder (10) is filled with sediment by adjusting the height of the circular cross plate (7); S2: Design of experimental and control groups Six cylindrical tubes were set up at each experimental point. Before the experiment, it was ensured that the experimental point had a sufficiently thick sediment. If the sediment thickness was insufficient, the height of the circular cross plate (7) was adjusted to ensure that the interior of the lower half cylindrical tube (10) was filled with sediment. The bottoms of the three lower half cylindrical tubes (10) of the experimental group were not blocked, and the cylinders of the lower half cylindrical tubes (10) were filled with sediment to simulate the oxygen consumption of sediment and the total oxygen consumption of the water body. In addition, the interiors of the three lower half cylindrical tubes (10) of the control group were set with an isolation baffle (6) to isolate the sediment from the water body, only simulating the total oxygen consumption of the water body. S3: Recording experimental data A 24-hour oxygen consumption experiment was conducted, and the sediment oxygen consumption rate measurement component was placed at the bottom of the reservoir. Before the experiment begins, the upper end of the bottom water pumping pipe (13) is connected to the water 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 water outlet of the peristaltic pump 1. The peristaltic pump 1 is started to update the water inside the upper cylindrical tube (9) in the experimental group to the bottom water. At the same time, the end of the circulating water inlet pipe 2 (5) away from the upper cylindrical tube (9) and the end of the circulating water outlet pipe 1 (2) away from the upper cylindrical tube (9) are connected to the water inlet of the peristaltic pump 1. When the ends of the second circulating water outlet pipe (4) are respectively connected to the water inlet and the water outlet of the second peristaltic pump, the second peristaltic pump is started to pump the bottom water body updated inside the upper half cylindrical tube (9) in the experimental group into the interior of the upper half cylindrical tube (9) in the control group, so that the water body inside the upper half cylindrical tube (9) in the control group is updated to the bottom water body. When the second circulating water outlet pipe (4) discharges water from the end away from the upper half cylindrical tube (9), it indicates that the water body inside the upper half cylindrical tube (9) in the control group has been updated. The test was started 5 minutes after the water was discharged from the end of the circulating water outlet pipe 2 (4) away from the upper cylindrical tube (9), and the DO concentration change was recorded once every hour during the experiment; During the experiment, 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 water outlet and water inlet of the peristaltic pump, and the peristaltic pump is started to circulate water so that the water inside the upper cylindrical tube (9) is kept uniformly mixed; At the same time, when the end of the second circulating water inlet pipe (5) away from the upper half cylindrical tube (9) and the end of the second circulating water outlet pipe (4) away from the upper half cylindrical tube (9) are respectively connected to the water inlet and the water outlet of the second peristaltic pump, the peristaltic pump is started to circulate water so that the water inside the upper half cylindrical tube (9) in the control group is kept uniformly mixed; S4: Analyze experimental data According to the DO concentration data recorded during the experiment, the sediment oxygen consumption rate was calculated. The specific calculation method is as follows: First, according to the change of DO concentration before and after the experiment, the DO consumption of the water body during the experiment was calculated; Then, the oxygen consumption rate per unit area of ​​sediment is calculated based on the volume of water and the sediment area inside the upper half of the cylindrical tube (9) in the experimental group; Finally, based on the experimental data of the control group, the respiratory 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.

8. The method for measuring the oxygen consumption rate of in-situ sediments in a reservoir according to claim 7, characterized in that: It also includes S5: Correction of experimental results. According to the changes in the concentrations of BOD5, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in the water body before and after the in-situ experiment, the degradation rate is calculated using the first-order reaction kinetic equation of pollutant degradation as a supplement and correction to the above calculation results.

9. A reservoir in-situ sediment oxygen consumption rate determination method according to claim 8, characterized in that: The calculation formula of the oxygen consumption rate of the sediment is as follows: Where: K P is the oxygen production rate of water body primary productivity (d -1 );K B is the oxygen consumption rate of algae microorganisms in water (d -1 );K C is the oxygen consumption rate of carbon-containing organic matter oxidation (d -1 );K N is the oxygen consumption rate of nitrification (d -1 ) ; AOCR is the ratio of dissolved oxygen to carbon in respiration (2.67 g O2 / g C); AONT is the DO required for nitrification of unit mass of ammonium ions (4.33 g O2 / g N); K NA is the oxygen consumption rate of ammonia nitrogen oxidation (d -1 );AONT A is the DO required for oxidation of unit mass of ammoniacal nitrogen (g O2 / g N); K NN is the oxygen consumption rate of nitrite nitrogen oxidation (d -1 );AONT N is the DO required for oxidation of unit mass of nitrite nitrogen (g O2 / g N); S is the sediment area at the bottom of the sediment test cylinder (m 2 ); V is the volume of water in the sediment test cylinder (m 3 ).

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