A device and method for simulating nitrogen and phosphorus conversion in river sediments

Abstract

The present invention provides a device and method for simulating nitrogen and phosphorus conversion in river sediments, belonging to the field of migration and transformation of nutrients. The device for simulating nitrogen and phosphorus conversion in river sediments includes: a water supply system, a simulation system, a sampling system, and a measurement system; the water supply system is used to provide water rich in nitrogen and phosphorus nutrients to the simulation system; the simulation system is used to simulate the migration and transformation process of nitrogen and phosphorus pollutants in soil; the sampling system is used to collect water samples from the simulation system; and the measurement system is used to measure the amount of water flowing out of the simulation system. The present invention can be used to simulate well the process of nitrogen and phosphorus nutrients in river water migrating and transforming in sediments and gradually infiltrating into groundwater indoors.

Description

Technical Field

[0001] The invention belongs to the field of migration and transformation of nutrient salts, and specifically relates to a device and method for simulating nitrogen and phosphorus transformation in river sediments. Background Art

[0002] Due to economic development, a large amount of sewage is discharged into rivers, and nitrogen and phosphorus nutrients in river water gradually accumulate, causing eutrophication of river water. Excessive nitrogen and phosphorus in river water will be enriched in sediments and gradually infiltrate into groundwater. Due to research needs, it is necessary to design an indoor experimental device to study this migration and transformation process for physical simulation. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and to provide a device and method for simulating the transformation of nitrogen and phosphorus in river sediments to simulate the migration and transformation process of nitrogen and phosphorus pollutants in soil.

[0004] The present invention is achieved through the following technical solutions:

[0005] The first aspect of the present invention provides a device for simulating nitrogen and phosphorus conversion in river sediments, the device comprising: a water supply system, a simulation system, a sampling system, and a measurement system;

[0006] The water supply system is used to provide water rich in nitrogen and phosphorus nutrients to the simulation system;

[0007] The simulation system is used to simulate the migration and transformation process of nitrogen and phosphorus pollutants in soil;

[0008] The sampling system is used to collect water samples from the simulation system;

[0009] The measuring system is used to measure the amount of water flowing out of the simulation system.

[0010] A further improvement of the present invention is that the water supply system comprises a water bucket, a water pump, and a water pipe;

[0011] The water pump is arranged in the water bucket;

[0012] The water delivery pipe is connected to a water pump;

[0013] An automatic flow regulating device is arranged on the water delivery pipe.

[0014] A further improvement of the present invention is that the simulation system includes a simulation tank;

[0015] The simulation tank is filled with coarse sand and soil;

[0016] A plurality of water injection and measuring components are arranged in the simulation tank; the plurality of water injection and measuring components are evenly distributed along the length direction of the simulation tank; each water injection and measuring component comprises a groundwater injection pipe and a groundwater level measuring pipe; the height of each groundwater injection pipe and groundwater level measuring pipe is greater than the height of the simulation tank, and the lower end of each groundwater injection pipe and each groundwater level measuring pipe is directly in contact with the bottom surface of the simulation tank;

[0017] A group of soil moisture collectors is arranged beside each group of water injection and measurement components; each group of soil moisture collectors includes a plurality of measuring heads, and the installation depth of each measuring head is different.

[0018] A further improvement of the present invention is that a plurality of groups of water outlet holes are opened at the lower part of each groundwater injection pipe, and each group of water outlet holes includes a plurality of water outlet holes located at the same horizontal height and evenly distributed on the circumference;

[0019] A plurality of groups of measuring holes are opened on each groundwater level measuring pipe, and each group of measuring holes includes a plurality of measuring holes located at the same horizontal height and evenly distributed on the circumference;

[0020] A groundwater level sensor is installed in the inner cavity of the groundwater level measuring tube.

[0021] A further improvement of the present invention is that a triangular weir of surface outflow is provided at the upper end of one side wall of the simulation tank;

[0022] At least one drain hole is also provided at the lower part of the side wall with the surface outflow triangular weir, and each drain hole is respectively connected with a drain valve.

[0023] A further improvement of the present invention is that the sampling system comprises: a sampling catheter, a sampling bottle;

[0024] The sampling bottle is located outside the simulation tank;

[0025] One end of each of the sampling tubes is connected to a probe in the soil moisture collector, and the other end is connected to a sampling bottle;

[0026] A stopper is arranged at the open end of the sampling bottle, and two connecting ports are opened on the stopper, one connecting port is connected to the sampling catheter, and the other connecting port is connected to the airway tube.

[0027] A further improvement of the present invention is that the measuring system adopts a tipping bucket measuring device, which is arranged below the drain valve;

[0028] The tipping bucket measuring device comprises a housing in the shape of a rectangular parallelepiped;

[0029] A water receiver is provided at the upper part of the inner cavity of the shell, and the water receiver is in the shape of a polygonal funnel, and its outlet is a water receiver hole;

[0030] A buffer is arranged directly below the water receiver, and the buffer is a polygonal funnel with an outlet at the bottom;

[0031] A tipping bucket is arranged below the buffer;

[0032] Adjusting ejectors are respectively arranged on both sides below the tipping bucket.

[0033] A further improvement of the present invention is that the tipping bucket comprises a bottom plate, a partition plate and a side plate;

[0034] The bottom plate is a rectangular plate-shaped structure, the partition plate is parallel to the width direction of the bottom plate and is located on the symmetry axis plane of the bottom plate; the partition plate is perpendicular to the bottom plate and the lower end is fixedly connected to the bottom plate, and the partition plate divides the tipping bucket into two identical water receiving buckets;

[0035] Side plates are respectively arranged on the two long sides of the bottom plate, the two side plates are perpendicular to the bottom plate, and the lower ends of the two side plates are fixedly connected to the bottom plate;

[0036] The side panels on each side are in the shape of an isosceles triangle, and the two sides of the partition panel are connected to the heights on the bottom edges of the two side panels respectively;

[0037] The outlet of the buffer is located directly above the partition plate;

[0038] A rotating shaft is provided below the bottom plate at a position corresponding to the partition plate;

[0039] An adjusting ejector pin is arranged below each water receiving bucket, a threaded hole is opened on the bottom surface of the shell, and the adjusting ejector pin adopts a threaded rod, and the lower end of the threaded rod is connected in the threaded hole.

[0040] A further improvement of the present invention is that a dump bucket bracket is also provided in the inner cavity of the shell;

[0041] The dump bucket bracket includes two support plates, which are perpendicular to the bottom surface of the shell and parallel to the front side wall and the rear side wall of the shell;

[0042] A hole is opened on each support plate, the central axes of the two holes are located on the same horizontal line, and the two ends of the rotating shaft are respectively installed in the holes of the two support plates.

[0043] A second aspect of the present invention provides a method for simulating nitrogen and phosphorus transformation in river sediments, the method comprising:

[0044] (1) Prepare water containing nitrogen and phosphorus nutrients in a bucket;

[0045] (2) Fill the simulation tank with the first coarse sand layer, the second coarse sand layer and the experimental soil sample layer from bottom to top;

[0046] (3) Use a water pump to extract the water of nitrogen and phosphorus nutrients in the bucket, and supply water to the groundwater injection pipe and the soil surface through the water pipe; while supplying water, open the water release valve; after the water sample reacts in the soil, part of the water sample flows out through the water release valve, and part of the water sample flows out through the surface outflow triangular weir, calculate the flow rate of the surface outflow triangular weir, and measure the water volume of the water release valve through the tipping bucket meter;

[0047] (4) Regularly use sampling bottles to extract water samples from the soil, and collect water samples from the drain valve, the surface outflow triangular weir, the water in the water injection pipe and the water in the soil surface. Test the water samples to determine the content of ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total nitrogen, orthophosphate and total phosphorus.

[0048] Compared with the prior art, the beneficial effect of the present invention is that the present invention can well simulate the process of nitrogen and phosphorus nutrients in river water migrating and transforming in sediments and gradually infiltrating into groundwater indoors. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram of the structure of a device for simulating nitrogen and phosphorus conversion in river sediments of the present invention;

[0050] Figure 2 A schematic diagram of the buried method of the soil water collection pipe of a certain section in the nitrogen and phosphorus conversion simulation device in the river sediment of the present invention;

[0051] Figure 3 A schematic diagram of the structure of an underground water injection pipe and a measuring pipe in the device for simulating nitrogen and phosphorus conversion in river sediments of the present invention;

[0052] Figure 4 A schematic structural diagram of a tipping bucket measuring device in a device for simulating nitrogen and phosphorus conversion in river sediments of the present invention.

[0053] Figure 5 A diagram showing the position of the bucket of the bucket measuring device in the nitrogen and phosphorus conversion simulation device in the river sediment of the present invention, in the initial state, where the outlet of the buffer corresponds to the bucket. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0055] The present invention provides a device for simulating the transformation of nitrogen and phosphorus in river sediments, the device comprising: a water supply system, a simulation system, a sampling system, and a measuring system. The water supply system is used to provide water rich in nitrogen and phosphorus nutrients to the simulation system; the simulation system is used to simulate the physical and chemical reactions that occur during the migration of water bodies containing nitrogen and phosphorus pollutants after surface or groundwater enters the soil, that is, to simulate the migration and transformation process of nitrogen and phosphorus pollutants in the soil. The sampling system is used to collect water samples from the simulation system; the measuring system is used to measure the amount of water flowing out of the simulation system.

[0056] Embodiments of the present invention are as follows:

[0057] [Example 1]

[0058] The water supply system includes a water bucket 11, a water pump 12, an automatic flow regulating device 13, and a water pipe 14. The water pump 12 is arranged in the water bucket 11, the water pipe 14 is connected to the water pump 12, and the automatic flow regulating device 13 is arranged on the water pipe 14. The volume of the water bucket 11 can be designed according to actual needs, and the volume of the water bucket in this embodiment is 1 cubic meter.

[0059] A prepared nitrogen and phosphorus nutrient salt solution of a certain concentration is placed in the water bucket 11. The type and concentration of the solution can be designed according to experimental needs. In this embodiment, a nitrate solution (the concentration used in this embodiment is: 30 mg / L in terms of nitrogen) or a phosphate solution (the concentration used in this embodiment is: 1 mg / L in terms of phosphorus) is used.

[0060] The nitrogen and phosphorus nutrient solution is extracted by a water pump 12 in the water bucket 11, and water is supplied to the simulation system through a water pipe 14. The water supply is adjusted by an automatic flow regulating device 13, and the flow rate in this embodiment is 125 L / h. The automatic flow regulating device 13 can be an existing automatic flow regulating device, which will not be described in detail here.

[0061] [Example 2]

[0062] The simulation system includes a simulation tank 21, a groundwater injection pipe 22, a groundwater level measuring pipe 23, a reinforcement component 24, a water release valve 26, and a surface outflow triangular weir 27.

[0063] The size of the simulation tank 21 can be designed according to actual needs. The size of the simulation tank 21 in this embodiment is: 6 meters long, 1 meter wide, and 1.2 meters high, and the material is stainless steel. Since the volume of the simulation tank 1 is relatively large, in order to reinforce the simulation tank 21, preferably, a reinforcement component 24 is provided on the outside thereof, and the reinforcement component 24 can be a steel frame, which can be sleeved on the outside of the simulation tank 21.

[0064] The simulation tank 21 is filled with coarse sand and soil. Specifically, a layer of coarse sand with a particle size of 10 mm is filled at the bottom of the simulation tank 21 to form a first coarse sand layer. The height of the first coarse sand layer is h4. In this embodiment, h4 is 5 cm. A layer of coarse sand with a particle size of 5 mm is filled above the first coarse sand layer to form a second coarse sand layer. The height of the second coarse sand layer is h3. In this embodiment, h3 is 5 cm. A layer of experimental soil sample is filled above the second coarse sand layer to form an experimental soil sample layer. The height of the experimental soil sample layer is h2. In this embodiment, h2 is 1 m.

[0065] Multiple groups of water injection and measurement components are arranged in the simulation tank 21. Preferably, the multiple groups of water injection and measurement components are evenly distributed along the length direction of the simulation tank 21 and are located on the center line of the length direction of the simulation tank 21. In this embodiment, the length of the simulation tank is 6 meters, so a group of water injection and measurement components is respectively arranged at 1.5 meters, 3 meters and 4.5 meters along its length direction. Each group of water injection and measurement components includes a groundwater injection pipe 22 and a groundwater level measuring pipe 23. The groundwater injection pipe 22 and the groundwater level measuring pipe 23 in each group can be 10-15 cm apart.

[0066] The height of each groundwater injection pipe 22 and groundwater level measuring pipe 23 is greater than the height of the simulation tank 21, and the lower end of each groundwater injection pipe 22 and groundwater level measuring pipe 23 directly contacts the bottom surface of the simulation tank 21. In this embodiment, the height of each groundwater injection pipe 22 and groundwater level measuring pipe 23 is 1.5 meters.

[0067] like Figure 3 As shown, multiple groups of water outlet holes are opened at the bottom of each underground water injection pipe 22, and the diameter of each water outlet hole in this embodiment is 3mm. Preferably, the range of the water outlet holes opened in the underground water injection pipe 22 is from the bottom end of the underground water injection pipe to a height of 10cm from the bottom end of the underground water injection pipe. A group of water outlet holes includes multiple water outlet holes evenly distributed on the circumference at the same horizontal height. In this embodiment, a group of water outlet holes includes 4 water outlet holes, that is, a hole is drilled every 90 degrees at the same height, and a total of 4 holes are drilled. The vertical spacing of each group of water outlet holes is 2cm, that is, the height between two adjacent groups of water outlet holes is 2cm. In this way, the solution entering from the upper end of the underground water injection pipe 22 can enter the bottom of the simulation tank from each water outlet hole.

[0068] Multiple groups of measuring holes are opened on each groundwater level measuring tube 23. In this embodiment, the diameter of each measuring hole is 3 mm. Preferably, the range of the measuring holes is from the bottom end of the groundwater level measuring tube 23 to a height of 100 cm from the bottom end of the groundwater level measuring tube 23. A group of measuring holes includes multiple measuring holes evenly distributed on the circumference at the same horizontal height. In this embodiment, a group of measuring holes includes 4 measuring holes, that is, a hole is drilled every 90 degrees at the same height, and a total of 4 holes are drilled. The vertical spacing of each group of measuring holes is 10 cm, that is, the height distance between two adjacent groups of measuring holes is 10 cm.

[0069] A groundwater level sensor 28 is installed in the inner cavity of the groundwater level measuring tube 23, so that water in the soil can enter the groundwater level measuring tube 23 from each measuring hole, and the groundwater level in the experimental soil sample can be measured by the groundwater level sensor 28. The groundwater level sensor 28 can be an existing water level sensor, which will not be described in detail here.

[0070] A plurality of groups of soil moisture collectors are arranged in the simulation tank 21. Preferably, the plurality of groups of soil moisture collectors are evenly distributed along the length direction of the simulation tank 21. In this embodiment, the length of the simulation tank is 6 meters, so a group of soil moisture collectors are respectively installed at the three sections of 1.5 meters, 3 meters, and 4.5 meters along the length direction, that is, a group of soil moisture collectors is arranged next to each group of water injection and measurement components.

[0071] Specifically, Figure 2 As shown, each group of soil moisture collectors includes 5 probes, and the installation depths of the 5 probes are 10, 20, 30, 50, and 70 cm respectively. The plane where the central axes of the 5 probes in each group are located is parallel to the width direction of the simulation tank. Each group of soil moisture collectors can use an existing soil moisture collector, for example, the soil moisture collector disclosed in patent 200520110649.5 can be used, which will not be repeated here.

[0072] A surface outflow triangular weir 27 is provided at the upper end of one side wall of the simulation tank 21. Specifically, a triangular groove is provided at the upper edge of one side wall of the simulation tank 21 as the surface outflow triangular weir 27. The bottom edge of the triangular groove is located at the upper edge of the side wall. The vertex of the triangular groove opposite to the bottom edge is located below the upper edge of the side wall. The angle θ at the vertex is 15 degrees. Figure 2 shown.

[0073] At the same time, two drain holes are opened at the lower part of the side wall of the simulation tank 21 provided with the surface outflow triangular weir 27. In this embodiment, the diameter of the drain hole is 75 mm. Preferably, the two drain holes are symmetrically distributed along the vertical central axis of the side wall. A drain valve 26 is connected to each drain hole, and the flow rate of the drain can be adjusted by opening and closing the drain valve 26.

[0074] Figure 1 In the present invention, the water supply to the simulation system by using the water pipe 14 can be carried out in the following three ways:

[0075] 1. Only the other end of the water pipe 14 is placed on the experimental soil sample layer (i.e., the soil surface) in the simulation tank 21, and the solution is directly input into the soil surface, i.e., water is supplied to the soil surface, so as to simulate the process of surface water replenishing groundwater;

[0076] 2. Only the other end of the water pipe 14 is connected to the groundwater injection pipe 22. The solution enters the groundwater injection pipe 22 through the water pipe 14 and then enters the bottom of the simulation tank 21 through the groundwater injection pipe 22. This can simulate the process of groundwater replenishing surface water.

[0077] 3. The other end of the water pipe 14 is divided into two branches, one branch is directly placed on the experimental soil sample layer in the simulation tank 21, and the other branch is connected to the groundwater injection pipe 22, so as to simulate the process of mutual replenishment of surface water and groundwater.

[0078] [Example 3]

[0079] The sampling system includes: a sampling conduit 31 and a sampling bottle 32. The sampling bottle 32 is located outside the simulation tank 21. One end of each sampling conduit 31 is connected to a probe in the soil moisture collector, and the other end is connected to the sampling bottle 32. Figure 1 Only the sampling bottles connected to a set of soil moisture collectors are shown.

[0080] Specifically, a stopper is provided at the open end of the sampling bottle 32, and two connection ports are opened on the stopper, one of which is connected to the sampling catheter 31, and the other is connected to the air guide tube 33. When not pumping air, the connection port connected to the air guide tube 33 is blocked with an aluminum rivet, and the diameter of the aluminum rivet in this embodiment is 5 mm. The air guide tube 33 is a silicone tube, which can be connected to the air pump.

[0081] When water needs to be collected, pull out the aluminum rivet, connect the air guide tube to the vacuum pump, and remove the air in the sampling bottle 32 to reduce the pressure in the sampling bottle to -75Kpa. After the vacuum is drawn, use the aluminum rivet to block the connection port. In this way, under the action of vacuum, the moisture in the experimental soil sample layer will enter the sampling bottle 32 through the probe and the sampling conduit 31 in turn.

[0082] [Example 4]

[0083] The measuring system adopts a tipping bucket measuring device 41, which is arranged below the drain valve 26. Figure 4As shown, the tipping bucket measuring device 41 includes a rectangular parallelepiped shell, and a water receiver 42, a buffer 44, a tipping bucket 45, a tipping bucket bracket 46, and an adjusting ejector pin 47 are arranged in the inner cavity of the shell.

[0084] Specifically, a water receiver 42 is provided at the upper part of the inner cavity of the shell, and the water receiver 42 is a polygonal funnel shape. The water receiver 42 in this embodiment includes two inclined surfaces inclined from top to bottom, the top edge of one inclined surface is connected to the upper edge of the left side wall of the shell, and the top edge of the other inclined surface is connected to the upper edge of the right side wall of the shell, and the two side edges of each inclined surface are respectively connected to the front side wall and the rear side wall of the shell, and the bottom edges of the two inclined surfaces are connected by a horizontal plate, which is parallel to the horizontal plane, and a water receiver hole 43 is opened on the horizontal plate.

[0085] A buffer 44 is provided below the water receiver 42 . The buffer 44 is a polygonal funnel with an outlet at its lower portion. The water receiver hole 43 is located directly above the buffer 44 .

[0086] A tipping bucket 45 is disposed below the buffer 44 , and adjusting ejector pins 47 are respectively disposed on both sides below the tipping bucket 45 .

[0087] Specifically, the tipping bucket 45 includes a bottom plate, a partition plate and a side plate. The bottom plate is a rectangular plate structure. The partition plate is parallel to the width direction of the bottom plate and is located on the symmetry axis plane of the bottom plate. The partition plate divides the bottom plate into two equal parts on the left and right. The partition plate is perpendicular to the bottom plate and the lower end is fixedly connected to the bottom plate. In this way, the tipping bucket 45 is divided into two identical water receiving buckets by the partition plate.

[0088] Side panels are respectively arranged on the two long sides of the bottom plate, and the two side panels are perpendicular to the bottom plate, and the lower ends are fixedly connected to the bottom plate. The two sides of the partition plate are respectively fixedly connected to the middle of the side panels on both sides, and the upper edges of the side panels on both sides are inclined from the highest point of the partition plate to the short sides on both sides of the bottom plate, that is, the shape of the side panels on each side is an isosceles triangle, and the two sides of the partition plate are respectively connected to the height on the bottom edges of the two side panels. Preferably, the angles of the two base angles of the isosceles triangle of each side plate are both 30 degrees. The outlet of the buffer is located directly above the partition plate.

[0089] A rotation axis is arranged below the bottom plate at a position corresponding to the partition plate, that is, the rotation axis is parallel to the width direction of the bottom plate, and the central axis of the rotation axis is located on the symmetry axis plane of the bottom plate.

[0090] An adjusting pin 47 is provided under each water receiving bucket. When the water receiving bucket is tilted downward, the adjusting pin 47 can contact the lower surface of the bottom plate to support the water receiving bucket. The height of the adjusting pin 47 is adjustable. Specifically, a threaded hole is provided on the bottom surface of the shell. The adjusting pin 47 adopts a threaded rod. The lower end of the threaded rod is connected to the threaded hole. The height of the adjusting pin 47 can be adjusted by rotating the threaded rod.

[0091] The height of the adjusting ejector pin 47 needs to meet the following requirements: when the adjusting ejector pin 47 on one side is adjusted to the minimum height, that is, when the adjusting ejector pin on one side is the shortest, when the water receiving bucket on this side is supported by the adjusting ejector pin 47, it can ensure that the upper edge of the side plate of the water receiving bucket on the other side is parallel to the horizontal plane. When the adjusting ejector pin 47 on one side is adjusted to the maximum height, that is, when the adjusting ejector pin on one side is the highest, when the water receiving bucket on this side is supported by the adjusting ejector pin 47, it can ensure that the upper edge of the side plate of the water receiving bucket on the other side is at an angle of 15 degrees to the horizontal plane. In this way, by adjusting the height of the ejector pin 47, the volume V2 of water received by the water receiving bucket each time can be adjusted (it can be calculated using geometric knowledge according to the bottom plate area, the inclination angle and the area of ​​the side plate, and it will not be repeated here that it is 35-45ml in this embodiment), that is, when the adjusting ejector pin 47 is higher, the volume of water received is small, and when the adjusting ejector pin 47 is shorter, the volume of water received is large.

[0092] When in use, first calculate the height of the adjustment pin 47 according to the experimental requirements, and adjust the adjustment pins 47 on both sides to the same height. In the initial state, the bottom plate of the water receiving bucket on the right side is in contact with the adjustment pin on that side, that is, the water receiving bucket on the right side is tilted downward, and the water receiving bucket on the left side is tilted upward. At this time, the partition plate is also tilted to the right. When water flows into the water receiver 42, the water will flow downward along the two inclined surfaces to the horizontal plate, and flow into the buffer 44 through the water receiver hole 43 on the horizontal plate, and flow to the tipping bucket 45 through the outlet of the buffer 44. Since the outlet of the buffer is located directly above the partition plate, when the partition plate is tilted, the outlet of the buffer is aligned with the position 48 of the water receiving bucket on the left side close to the partition plate (such as Figure 5 As shown in the figure, water flows from the buffer 44 into the water receiving bucket on the left. As the bottom plate tilts to the right, water will gather at the middle partition. When more and more water reaches the edge of the water receiving bucket on this side, the left water receiving bucket will tilt downward, and water will flow down from the left water receiving bucket to the bottom surface of the shell. At the same time, the right water receiving bucket tilts upward. At this time, the partition tilts to the left, and the outlet of the buffer is aligned with the position of the water receiving bucket on the right side close to the partition. Water flows into the water receiving bucket on the right. When more and more water reaches the edge of the water receiving bucket on the right side, the right water receiving bucket tilts downward, and the left water receiving bucket tilts upward. In this way, as long as there is liquid flowing down from the buffer 44, the process will be repeated. In the initial state, the right water receiving bucket can also be tilted upward first. The working process is the same as the above process and will not be repeated here.

[0093] The volume of each water receiving bucket is V2. By calculating the number of times the bucket flips per unit time, the water flow rate at the drain valve 26 can be calculated using the following formula:

[0094] F=V2*n

[0095] The dump bucket bracket includes two support plates, which are perpendicular to the bottom surface of the shell and parallel to the front side wall and the rear side wall of the shell. A hole is opened on each support plate, and the central axes of the two holes are located on the same horizontal line. The two ends of the rotating shaft are respectively installed in the holes of the two support plates.

[0096] The two sides of the buffer 44 are respectively installed on the front side wall and the rear side wall of the shell. Furthermore, the upper end of a support plate can be extended to the bottom of the buffer 44, and a buffer mounting plate is set at the upper end of the support plate. The lower end of the buffer is fixed on the buffer mounting plate, and a hole is also opened on the buffer mounting plate. The hole is aligned with and connected to the outlet of the buffer, so that the buffer is well supported by the buffer mounting plate.

[0097] An example of a method for simulating nitrogen and phosphorus conversion in river sediments using the above device is as follows:

[0098] [Example 5]

[0099] The method comprises:

[0100] 1. Prepare a certain concentration of nitrate solution (30 mg / L in nitrogen) or phosphate solution (1 mg / L in phosphorus) in a bucket;

[0101] 2. Fill the coarse sand and soil. Fill the coarse sand with a particle size of 10 mm at a height of h4 (5 cm) at the bottom of the simulation tank, fill the coarse sand with a particle size of 5 mm at a height of h3 (5 cm) upwards, and fill the experimental soil sample at a height of h2 (1 m) upwards. The distance from the surface of the experimental soil sample layer to the upper end surface of the simulation tank is h1. Figure 2 shown.

[0102] 3. Use a water pump to extract water containing nitrogen and phosphorus nutrients, and supply water to the groundwater injection pipe 22 and the soil surface at the same time. The water supply is adjusted by the automatic flow regulating device 13, and the flow rate in this embodiment is 125L / h. While supplying water, open the water release valve 26, and water is continuously poured into the simulation tank. After the supplied water sample is full of reactions in the soil (the flow rate of the water supply is large, the valve is opened small, and the water surface is kept at a depth of 5cm on the soil surface, so that the water can react in the soil), part of the water sample flows out through the valve 26, and part of the water sample flows out through the triangular weir 27. The flow rate of the triangular weir is calculated by the triangular weir formula (weir slot flow measurement specification (water conservancy industry standard SL24-91 of the People's Republic of China)), and the water volume of the water release valve is measured by the tipping bucket measuring device 41.

[0103] 4. Regularly (for example, every day) extract water samples from the soil using a sampling bottle 32, and collect water samples from the drain valve, triangular weir, water samples in the water injection pipe and water samples from the soil surface (wherein, the water samples from the valve and triangular weir are water samples directly received at the valve and triangular weir, and the water samples in the soil are extracted through a sampling bottle, and the water samples from the water injection pipe and the water samples from the soil surface are directly collected in the water injection pipe and the soil surface.), and test the ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total nitrogen, orthophosphate and total phosphorus in the water in the laboratory. The migration and transformation process of nitrogen and phosphorus in the soil can be analyzed through these data and the flow rate of the triangular weir and the flow rate of the drain valve. The specific analysis process can be achieved using existing technology and will not be repeated here. The present invention aims to protect the device and method for obtaining these data.

[0104] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0105] In the description of the present invention, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0106] Finally, it should be noted that the above technical solution is only one implementation method of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the application methods and principles disclosed in the present invention, and it is not limited to the method described in the above specific implementation method of the present invention. Therefore, the method described above is only preferred and does not have a restrictive meaning.

Claims

1. A device for simulating nitrogen and phosphorus conversion in river sediments, characterized in that: The device comprises: a water supply system, a simulation system, a sampling system, and a measurement system; The water supply system is used to provide water rich in nitrogen and phosphorus nutrients to the simulation system; The simulation system is used to simulate the migration and transformation process of nitrogen and phosphorus pollutants in soil; The sampling system is used to collect water samples from the simulation system; The measuring system is used to measure the amount of water flowing out of the simulation system; The water supply system includes a water bucket, a water pump, and a water pipe; The water pump is arranged in the water bucket; The water delivery pipe is connected to a water pump; An automatic flow regulating device is provided on the water delivery pipe; The simulation system includes a simulation tank; The simulation tank is filled with coarse sand and soil; A plurality of water injection and measuring components are arranged in the simulation tank; the plurality of water injection and measuring components are evenly distributed along the length direction of the simulation tank; each water injection and measuring component comprises a groundwater injection pipe and a groundwater level measuring pipe; the height of each groundwater injection pipe and groundwater level measuring pipe is greater than the height of the simulation tank, and the lower end of each groundwater injection pipe and each groundwater level measuring pipe is directly in contact with the bottom surface of the simulation tank; A set of soil moisture collectors is arranged beside each set of water injection and measurement components; each set of soil moisture collectors includes a plurality of probes, and each probe is installed at a different depth; A plurality of groups of water outlet holes are opened at the lower part of each groundwater injection pipe, and each group of water outlet holes includes a plurality of water outlet holes located at the same horizontal height and evenly distributed on the circumference; A plurality of groups of measuring holes are opened on each groundwater level measuring pipe, and each group of measuring holes includes a plurality of measuring holes located at the same horizontal height and evenly distributed on the circumference; A groundwater level sensor is installed in the inner cavity of the groundwater level measuring tube; A triangular weir for surface outflow is provided at the upper end of one side wall of the simulation tank; At least one drain hole is also formed at the lower part of the side wall with the surface outflow triangular weir, and each drain hole is connected to a drain valve; The sampling system comprises: a sampling catheter and a sampling bottle; The sampling bottle is located outside the simulation tank; One end of each of the sampling tubes is connected to a probe in the soil moisture collector, and the other end is connected to a sampling bottle; A stopper is provided at the open end of the sampling bottle, and the stopper has two connecting ports, one connecting port is connected to the sampling catheter, and the other connecting port is connected to the airway tube; The measuring system adopts a tipping bucket measuring device, which is arranged below the drain valve; The tipping bucket measuring device comprises a housing in the shape of a rectangular parallelepiped; A water receiver is provided at the upper part of the inner cavity of the shell, and the water receiver is in the shape of a polygonal funnel, and its outlet is a water receiver hole; A buffer is arranged directly below the water receiver, and the buffer is a polygonal funnel with an outlet at the bottom; A tipping bucket is arranged below the buffer; Adjusting ejectors are respectively arranged on both sides below the tipping bucket.

2. The device for simulating nitrogen and phosphorus conversion in river sediments according to claim 1, characterized in that: The tipping bucket comprises a bottom plate, a partition plate and side plates; The bottom plate is a rectangular plate-shaped structure, the partition plate is parallel to the width direction of the bottom plate and is located on the symmetry axis plane of the bottom plate; the partition plate is perpendicular to the bottom plate and the lower end is fixedly connected to the bottom plate, and the partition plate divides the tipping bucket into two identical water receiving buckets; Side plates are respectively arranged on the two long sides of the bottom plate, the two side plates are perpendicular to the bottom plate, and the lower ends of the two side plates are fixedly connected to the bottom plate; The side panels on each side are in the shape of an isosceles triangle, and the two sides of the partition panel are connected to the heights on the bottom edges of the two side panels respectively; The outlet of the buffer is located directly above the partition plate; A rotating shaft is provided below the bottom plate at a position corresponding to the partition plate; An adjusting ejector pin is arranged below each water receiving bucket; a threaded hole is opened on the bottom surface of the shell body, and the adjusting ejector pin adopts a threaded rod, and the lower end of the threaded rod is connected in the threaded hole.

3. The device for simulating nitrogen and phosphorus conversion in river sediments according to claim 2, characterized in that: A dump bucket bracket is also provided in the inner cavity of the shell; The dump bucket bracket includes two support plates, which are perpendicular to the bottom surface of the shell and parallel to the front side wall and the rear side wall of the shell; A hole is opened on each support plate, the central axes of the two holes are located on the same horizontal line, and the two ends of the rotating shaft are respectively installed in the holes of the two support plates.

4. A method for simulating nitrogen and phosphorus conversion in river sediments, applied to the device for simulating nitrogen and phosphorus conversion in river sediments as claimed in claim 1, characterized in that: The method comprises: (1) Prepare water containing nitrogen and phosphorus nutrients in a bucket; (2) Fill the simulation tank with the first coarse sand layer, the second coarse sand layer and the experimental soil sample layer from bottom to top; (3) Use a water pump to extract the water containing nitrogen and phosphorus nutrients in the bucket, and supply water to the groundwater injection pipe and the soil surface through the water pipe. While supplying water, open the water release valve. After the water sample reacts in the soil, part of the water sample flows out through the water release valve, and part of the water sample flows out through the surface outflow triangular weir. The flow rate of the surface outflow triangular weir is calculated, and the water volume of the water release valve is measured by the tipping bucket meter. (4) Regularly use sampling bottles to extract water samples from the soil, and collect water samples from the drain valve, the surface outflow triangular weir, the water in the water injection pipe and the water in the soil surface. Test the water samples to determine the content of ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total nitrogen, orthophosphate and total phosphorus.

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