Device and method for measuring oxygen consumption rate of water body sediment

Abstract

The invention provides a device and a method for measuring the oxygen consumption rate of water sediment, the device comprises a stirring mechanism, a dissolved oxygen concentration detection mechanism and a culture tank, the stirring mechanism comprises a magnetic stirrer and a stirrer, and the magnetic stirrer is provided with a heating element and a temperature controller; the culture tank is arranged on a magnetic stirrer, the magnetic stirrer drives the stirrer to rotate in the culture tank through a magnetic force effect, and sediments and a water sample in the culture tank are uniformly mixed; the dissolved oxygen concentration detection mechanism is connected with the culture tank; the culture tank is used for loading sediments and a water sample and isolating air through a methyl silicone oil liquid seal. By controlling the suspension amount of the sediment in the oxygen consumption culture tank, the oxygen consumption characteristics of the sediment in the actual environmental water body under different hydrodynamic conditions are simulated; by effectively isolating air, the interference of aeration and air reoxygenation processes caused by stirring is prevented, so that the reliability and the accuracy of dissolved oxygen concentration change data are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of water ecological environment technology, and in particular to a device and method for measuring the oxygen consumption rate of water body sediments. Background Art

[0002] Sediment refers to particulate matter deposited at the bottom of a water body. It contains rich microbial populations and a variety of compounds, and is an important component of the material cycle and energy flow of water bodies. Biochemical reactions such as the degradation of organic matter in sediments and the oxidation of sulfides consume a large amount of oxygen, directly affecting the living environment of benthic organisms and the material exchange process at the water-sediment interface. Studies have shown that sediment oxygen consumption can account for about 90% of the total oxygen consumption of water bodies. Therefore, measuring the sediment oxygen consumption rate can not only reflect the intensity of organic matter degradation and biological metabolism in sediments, but also provide a scientific basis for evaluating the health of aquatic ecosystems and guiding water management, which is of great significance.

[0003] Traditional methods for measuring sediment oxygen consumption mainly include laboratory simulation and in-situ measurement. Laboratory simulation experiments require sediment samples to be brought to the laboratory, which can easily affect the composition of the sediment during sample transportation and processing, thereby affecting the measurement results of oxygen consumption. Secondly, there is a large difference between the laboratory environment and the in-situ conditions of the sediment, and the actual state of the sediment in the natural environment cannot be completely restored during the experiment. Although the in-situ measurement method avoids laboratory interference, it is difficult to simulate the flow of real water bodies due to the stillness of the water flow or the low flow rate, resulting in the inability to accurately reflect the actual process of sediment oxygen consumption. Summary of the invention

[0004] The purpose of the present invention is to provide a water sediment aerobic rate detection scheme which can simulate different water flow rates and avoid the influence of external factors.

[0005] To achieve the above object, the present invention provides a device for measuring the oxygen consumption rate of water sediments, comprising a stirring mechanism, a dissolved oxygen concentration detection mechanism and a culture tank:

[0006] The stirring mechanism includes a magnetic stirrer and a stirrer. The magnetic stirrer is provided with a heating element and a temperature controller, which can simultaneously realize stirring and mixing and heating and temperature control functions. The heating element and the temperature controller are used to stabilize the temperature of the culture tank body to meet the requirements of laboratory simulation environment conditions.

[0007] The culture tank is placed on the magnetic stirrer, and the magnetic stirrer drives the stirrer to rotate in the culture tank through the magnetic effect, so as to evenly mix the sediment and the water sample in the culture tank;

[0008] The dissolved oxygen concentration detection mechanism is connected to the culture tank; the culture tank is used to load sediment and water samples and is isolated from the air by a methyl silicone oil liquid seal.

[0009] Furthermore, the dissolved oxygen concentration detection mechanism includes a dissolved oxygen electrode and a dissolved oxygen concentration display screen. One end of the dissolved oxygen electrode is inserted into the culture tank through a stand to detect the dissolved oxygen concentration in the water sample; the other end is connected to the dissolved oxygen concentration display screen signal through a data line, and the data line transmits the detection result to the display screen, which dynamically displays and records the current dissolved oxygen concentration value. When the concentration of dissolved oxygen is lower than 2 mg / L, the dissolved oxygen may be exhausted in too short a time, resulting in the inability to effectively evaluate the oxygen consumption rate of the sediment. In this case, it is necessary to stop the measurement or use an oxygen-containing water pump for aeration until the dissolved oxygen concentration recovers and stabilizes at a sufficiently high level before re-measuring.

[0010] Furthermore, the ratio of the water sample volume (in liters) to the bottom area of ​​the tank (in square meters) in the culture tank is in the range of 100-400. This ratio design can effectively ensure sufficient stirring and uniform mixing of the water sample in the container while providing appropriate surface area for contact with the water body.

[0011] Furthermore, the culture tank is made of borosilicate glass, the tank mouth is a screw mouth, and 10-50mL of methyl silicone oil is used to isolate the air.

[0012] Based on the above-mentioned device for measuring the oxygen consumption rate of water sediments, the present invention also proposes a method for measuring the oxygen consumption rate of water sediments, comprising the following steps:

[0013] S1: Weigh the sediment sample and place it in a culture tank, and slowly inject water with a known volume and dissolved oxygen concentration along the tank wall to avoid the generation of bubbles;

[0014] S2: Add methyl silicone oil to the culture tank until the bottle mouth forms a liquid seal, insert the dissolved oxygen electrode, and ensure that the methyl silicone oil overflows slightly to completely isolate the interference of external air;

[0015] S3: Start the stirring mechanism and adjust the stirring intensity to make the sediment and water evenly mixed, while ensuring that the methyl silicone oil liquid level remains stable without obvious fluctuations, and heating the culture tank to keep the temperature constant;

[0016] S4: Collect data through the dissolved oxygen concentration detection mechanism and calculate the sediment oxygen consumption and oxygen consumption rate.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] 1. The present invention adjusts the amount of sediment added and the stirring intensity through the stirring mechanism so that the sediment is in a completely suspended state, thereby simulating the effect of different water flow velocities in the water body on the sediment oxygen consumption rate. The present invention can truly reproduce the oxygen consumption characteristics of sediments under different water flow velocities, thereby studying the effect of water body disturbance on the sediment oxygen consumption rate.

[0019] 2. The present invention adopts methyl silicone oil liquid seal to ensure that the experimental system is completely isolated from the outside air, effectively prevent the aeration of liquid and air, and avoid the interference of external oxygen diffusion on the dissolved oxygen concentration measurement results, thereby improving the reliability and accuracy of the dissolved oxygen concentration change data.

[0020] 3. The device of the present invention is simple in design, the method is easy to operate, and can provide high-precision data support, providing a measurement tool for water environment management and ecological restoration research. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic plan view of the overall structure of a device for measuring oxygen consumption rate of water sediments according to an embodiment of the present invention.

[0022] 1-Dissolved oxygen concentration display screen; 2-Dissolved oxygen electrode; 3-Data line; 4-Magnetic stirrer; 5-Magnetic stirring bar; 6-Iron stand; 7-Screw-mouth glass bottle. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described below.

[0024] This embodiment provides a device for measuring the oxygen consumption rate of water sediments, such as Figure 1 As shown, the device includes a stirring mechanism, a dissolved oxygen concentration detection mechanism and a culture tank 7:

[0025] Among them, the culture tank 7 is used to load sediment and water, and is isolated from the air by a methyl silicone oil liquid seal; the stirring mechanism includes a magnetic stirrer 4 and a magnetic stirrer 5, the magnetic stirrer 5 is placed in the culture tank 7, and the culture tank 7 is placed on the magnetic stirrer 4, so that the magnetic stirrer 4 drives the magnetic stirrer 5 to rotate in the culture tank 7 through the magnetic effect, thereby evenly mixing the sediment and water sample in the culture tank 7.

[0026] In this embodiment, the magnetic stirrer 4 is also provided with a heating element and a temperature controller, which can simultaneously realize the stirring and mixing function and the heating and temperature control function. The heating element and the temperature controller are used to stabilize the temperature of the culture tank 7, thereby meeting the requirements of the laboratory simulation environment conditions.

[0027] In addition, the culture tank 7 is also connected to a dissolved oxygen concentration detection mechanism, which includes a dissolved oxygen electrode 2 and a dissolved oxygen concentration display screen 1. The dissolved oxygen electrode 2 and the dissolved oxygen concentration display screen 1 are connected by a data line 3. Figure 1 As shown, the data line 3 is fixed on the iron frame 6, so that one end of the dissolved oxygen electrode 2 is suspended and inserted into the culture tank 7 to detect the dissolved oxygen concentration in the water sample; the other end of the dissolved oxygen electrode 2 is connected to the dissolved oxygen concentration display screen 1 through the data line 3, and the detected dissolved oxygen concentration result is transmitted to the display screen 1, and the current dissolved oxygen concentration value is dynamically displayed and recorded on the display screen 1. When the concentration of dissolved oxygen is lower than 2 mg / L, the dissolved oxygen may be exhausted in too short a time, resulting in the inability to effectively evaluate the oxygen consumption rate of the sediment. In this case, it is necessary to stop the measurement or use an oxygen-containing water pump for aeration until the dissolved oxygen concentration recovers and stabilizes at a sufficiently high level before re-measuring.

[0028] In this embodiment, the culture tank 7 is a borosilicate glass tank with a screw mouth. 10-50mL of methyl silicone oil is used to isolate the air. The ratio of the volume of the water sample in the tank (in liters) to the bottom area of ​​the tank (in square meters) is in the range of 100-400. This ratio design can effectively ensure that the water sample is fully stirred and evenly mixed in the container, while providing an appropriate surface area for contact with the water body.

[0029] The oxygen consumption rate of water sediments is measured by the above-mentioned device for measuring the oxygen consumption rate of water sediments, and the method steps are as follows:

[0030] S1: Weigh a sediment sample of known weight and put it into the culture tank 7, and slowly inject water of known volume and dissolved oxygen concentration along the wall of the culture tank 7 to avoid the generation of bubbles;

[0031] S2: Add methyl silicone oil to the culture tank 7 until the bottle mouth forms a liquid seal, insert the dissolved oxygen electrode 2, and ensure that the methyl silicone oil slightly overflows to completely isolate the interference of external air;

[0032] S3: adding a magnetic stirrer 5, starting the magnetic stirrer 4, adjusting the stirring intensity so that the sediment and the water are evenly mixed, while ensuring that the liquid level of the methyl silicone oil remains stable without obvious fluctuations, and turning on the heating function of the magnetic stirrer to heat the culture tank 7 and keep the temperature in the culture tank 7 constant;

[0033] S4: Record the reading of the dissolved oxygen concentration meter every 30 minutes, collect and analyze the concentration change data, and stop the experiment when the dissolved oxygen concentration remains unchanged for a long time or drops to 2 mg / L. By analyzing the experimental data of this experiment, calculate the sediment oxygen consumption and oxygen consumption rate.

[0034] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A device for measuring oxygen consumption rate of water sediment, characterized in that: Including stirring mechanism, dissolved oxygen concentration detection mechanism and culture tank: The stirring mechanism comprises a magnetic stirrer and a stirrer, and the magnetic stirrer is provided with a heating element and a temperature controller; The culture tank is placed on the magnetic stirrer, and the magnetic stirrer drives the stirrer to rotate in the culture tank through magnetic effect; The dissolved oxygen concentration detection mechanism is connected to the culture tank; the culture tank is used to load sediment and water samples and is isolated from the air by a methyl silicone oil liquid seal.

2. The device for measuring oxygen consumption rate of water sediment according to claim 1, characterized in that: The dissolved oxygen concentration detection mechanism comprises a dissolved oxygen electrode and a dissolved oxygen concentration display screen. One end of the dissolved oxygen electrode is inserted into the culture tank through a stand, and the other end is connected to the dissolved oxygen concentration display screen signal through a data line.

3. The device for measuring oxygen consumption rate of water sediment according to claim 1, characterized in that: The ratio of the water sample volume of the culture tank to the bottom area of ​​the tank body is in the range of 100-400.

4. The device for measuring oxygen consumption rate of water sediment according to claim 1, characterized in that: The culture tank is made of borosilicate glass, has a screw mouth, and uses 10-50 mL of methyl silicone oil to isolate the air.

5. A method for measuring the oxygen consumption rate of water sediments, based on the device for measuring the oxygen consumption rate of water sediments as claimed in any one of claims 1 to 4, characterized in that: The steps include: S1: Weigh the sediment sample and place it in a culture tank, and inject water with known volume and dissolved oxygen concentration along the tank wall; S2: Add methyl silicone oil to the culture tank until the bottle mouth forms a liquid seal, and insert the dissolved oxygen electrode; S3: Start the stirring mechanism to mix the sediment and water evenly, and heat the culture tank to keep the temperature constant; S4: Collect data through the dissolved oxygen concentration detection mechanism and calculate the sediment oxygen consumption and oxygen consumption rate.

Images