CN115078237A

CN115078237A - Tidal simulation system for researching material circulation

Info

Publication number: CN115078237A
Application number: CN202210664726.XA
Authority: CN
Inventors: 郗敏; 张俊龙; 王鑫娟; 于纪民; 于政达
Original assignee: Qingdao University
Current assignee: Qingdao University
Priority date: 2022-06-14
Filing date: 2022-06-14
Publication date: 2022-09-20

Abstract

The invention provides a tide simulation system for researching material circulation, which is characterized in that a sandbox is connected with a water storage tank through a water suction pump, and the water suction pump and a water outlet are utilized to simulate rising tide and falling tide. The system utilizes the tide circulating pump to realize the circulating flow of water flow in the sand box, simulates the horizontal migration process of seawater, realizes the function of simulating tide in the coastal wetland substance circulation research, and provides a new way for researching the dynamic change of nutrient salt of the tide to the estuary wetland environment.

Description

Tide simulation system for researching material circulation

Technical Field

The invention relates to the field of coastal wetlands, in particular to the practical application in the aspect of material circulation research. Compared with the traditional tidal circulation device, the tidal simulation device has the advantages of simple and convenient operation, good hydraulic circulation, adjustable flow velocity and the like, and is suitable for the simulation research of the coastal wetland material circulation tide.

Background

The river mouth is located at the junction of the river and the ocean and is an area with strong material circulation, and surface sediments of the river mouth are rich in soluble nitrogen elements and soluble phosphorus elements. Under the tidal action, pollutants enter the overlying water due to physical and chemical actions such as particulate resuspension, ion exchange, oxidation reduction and the like, so that the problems of eutrophication and the like in river estuaries are caused. Under the condition that exogenous pollutants are controlled, nutrient salts released by sediments become one of pollution sources of offshore eutrophication. The eutrophication mechanism caused by the release of nitrogen, phosphorus and other nutrient substances from the sediment in the estuary area is more complex than that in the upstream of the estuary, so that a tide simulation system for researching the dynamic mechanism of the release of nutrient salts in the sediment in the estuary by the tide is urgently needed to be developed.

At present, researchers apply a tidal simulation system to multiple aspects of reproducing tidal environment, power generation application, coastal environment simulation and the like, and certain achievements are obtained in the fields of coastal engineering, beach runoff and the like. For example, in an automatic test device for simulating a sea water level change area, the patent with the application number of CN2013100079786, factors such as controlling water inlet and outlet time and the like are adopted to simulate a sea tidal environment and a wave splashing environment. In a test system and a method for simulating bearing capacity of coral reef sand in a tidal environment with the application number of CN202011509821.X, air pressure in a water storage tank is adjusted and controlled by an air pump, so that water entering a model box can be changed, and simulation of the tidal environment is realized. The simulation of the coastal wetland environment also needs to change the flow velocity and the water depth of the artificial seawater in the sandbox, so as to realize the change of the fluctuation tide level in the environment, thereby obtaining the nutrient release rule of the sediment in different tide cycles. However, in the field of coastal wetlands, tidal circulation is realized by utilizing the continuous change of water level, and a simulation system for researching the release of nutrients in sediments by tides is still lacked, so that the existing devices and systems cannot meet the requirements.

The tidal simulation system for researching substance circulation is constructed by combining the structures such as the sand box, the tidal circulation pump, the water storage tank, the water suction pump and the like, can change the flow velocity and the depth of water, simulate the hydrodynamic force and the tidal level of artificial seawater under the influence of different tides, realize the high reduction of the tidal environment of the coastal wetland, and is used for researching the influence of the tides on the dynamic release of nutritive salts in estuary sediments.

Disclosure of Invention

The invention aims to provide a tidal simulation system for researching material circulation, aiming at researching the influence of the tidal process of a coastal wetland on the dynamic release of nutrients in estuary sediments.

According to the characteristics of tidal water scouring of the coastal wetland, the release mechanism of nutrients under tidal circulation is explained by utilizing the short-term release rule and release amount of the tidal water to nitrogen and phosphorus in sediments through the built-in tidal circulation pump and the external water suction pump. The specific scheme is as follows: a tidal simulation system for researching substance circulation comprises a sand box, an upper water cover, a tidal circulating pump, a water inlet pipe, a water outlet, a water storage tank and a water suction pump.

The sandbox is made of organic glass, the length, the width and the height of the sandbox are respectively 70 cm, 40 cm and 45 cm, and sediment samples are paved at the bottom of the sandbox for 10 cm.

The upper water is artificial seawater (with salinity of 35 per mill) prepared from seawater crystal.

The tide circulating pump (c) is arranged at the right end of the inner wall of the sand box and is 5 cm away from sediment, and the tide circulating pump (c) is provided with a plurality of gears, can adjust different water flow rates and is used for simulating a tide circulating disturbance process.

The water inlet pipe (IV) and the water outlet (V) are respectively positioned at the upper end of the sandbox by 45 cm and at the position which is 10 cm away from the bottom of the right end of the external side of the sandbox, and the diameter of the water outlet (V) is 3 cm.

The water pump is arranged in a water storage tank at the lower end of the sand box and used for pumping water in the water tank into the sand box to realize rising and ebbing tide.

Drawings

Figure 1 is a diagram of a tidal cycle system.

FIG. 2 shows NH under tidal cycle and static Release cycle ₄ ⁺ -comparative plot of N release.

FIG. 3 is NH under tidal cycle of varying intensity ₄ ⁺ -N release profile.

FIG. 4 is a graph comparing the amount of TP released under tidal and static release cycles.

Figure 5 is a graph of TP release under different intensity tidal cycles.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

The invention provides a novel simulated tidal circulation system, which comprises the following steps: (1) and constructing a tidal circulation system unit, connecting the sand box with the water storage tank through a water suction pump, and placing the tidal circulation pump on the side wall of the sand box. (2) Sufficient overlying water and sediment samples are prepared respectively, the sediment is dried in the sun, and the overlying water is prepared in advance by using seawater crystal. (3) Filling sediment into a sand box, laying a layer of gauze above the sediment when covering water to reduce the suspension and disturbance of the sediment, and then placing the covering water into the sand box and a water storage tank. (4) Starting a tidal circulating pump to enable water flow in the sand box to circularly flow; two days of pre-cycling. (5) Preferably, different depths of overburden water are set and the effect of static release cycling on nutrient release in the sediment is observed. (6) Preferably, different depths of overburden and different water flow rates will be set and the effect of the tidal disturbed circulation on the release of nutrients from the sediment observed. (7) And (5) formally running.

The present invention will be described in detail with reference to specific examples.

The first embodiment is as follows: two water outlets with the diameter of 3 cm are arranged at the position 10 cm away from the bottom of the sandbox. A simulated tidal circulation pump is placed approximately 5 cm above the sediment in the sandbox, wherein the tidal pump has a plurality of gears and can adjust different water flow rates for simulating the tidal circulation disturbance process. The water storage tank is connected to the outside of the sandbox, water in the water storage tank can enter the sandbox through the water suction pump when tide rising is simulated, and water can flow into the water storage tank through the water outlet under the action of gravity when tide falling is simulated.

Example two: uniformly spreading sediment sample in each experimental device at a height of 10 cm, slowly injecting artificial seawater (with water content of 35 ‰) prepared from seawater crystal into the experimental device, spreading a layer of gauze above the sediment to minimize the suspension and disturbance of the sediment. The tide groups T1, T2, T3 and T4 respectively simulate the tide disturbance with the strength from small to large influenced by the tide, the overlying water depths are respectively 5 cm, 10 cm, 15 cm and 20 cm, and the water pumping speeds of the tide pumps are respectively 0.06 m/s, 0.12 m/s, 0.2 m/s and 0.56 m/s. Meanwhile, the overlying water heights of the control static release groups C1, C2, C3 and C4 are respectively 5 cm, 10 cm, 15 cm and 20 cm, no tidal disturbance is caused, and the research on NH in sediments caused by tidal cycles of different strengths is carried out ₄ ⁺ Influence of the amount of N released (FIG. 2, FIG. 3).

Example three: uniformly paving sediment samples in each experimental device, wherein the paving height of the sediment samples is 10 cm, slowly injecting artificial seawater (with water covering, the salinity of 35 per mill) prepared by seawater crystal into the experimental device, and paving a layer of gauze above the bottom sediment when water covering is carried out, so that the suspension and disturbance of the bottom sediment are reduced as much as possible. The tide groups T1, T2, T3 and T4 respectively simulate the tide disturbance with the strength from small to large influenced by the tide, the overlying water depths are respectively 5 cm, 10 cm, 15 cm and 20 cm, and the water pumping speeds of the tide pumps are respectively 0.06 m/s, 0.12 m/s, 0.2 m/s and 0.56 m/s. The control static release groups C1, C2, C3 and C4 were also set to have overburden heights of 5 cm, 10 cm, 15 cm and 20 cm respectively, and the effect of tidal cycles of different intensities on the amount of TP released from the sediment was investigated without tidal disturbance (FIG. 4, FIG. 5).

It should be understood that while the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein, and any combination of the various embodiments may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims

1. A tidal simulation system for studying material circulation, comprising: the device comprises a sand box, seawater, a tide circulating pump, a water inlet pipe, a water outlet, a water storage tank, a water suction pump and a water suction pump, wherein the water suction pump sucks the seawater in the water storage tank into the sand box.

2. The tidal simulation system of claim 1, wherein: the sandbox is made of organic glass materials, and soil or sediments are paved at the bottom end of the sandbox.

3. The tidal simulation system of claim 1, wherein: the seawater is placed in the sandbox, the tide circulating pump is placed on the right side inside the sandbox and used for pushing the seawater to circulate, and the tide circulating pump is provided with a plurality of gears and can adjust the flow velocity of water flow (0.06 m/s, 0.12 m/s, 0.2 m/s and 0.56 m/s).

4. The tidal simulation system of claim 1, wherein: the water inlet pipe (IV) is arranged at the top end of the sand box (IV), the water outlet (V) is arranged at the right side of the sand box (IV), and the caliber is 3 cm.

5. The tidal simulation system of claim 1, wherein: the water storage tank is arranged right below the water outlet fifthly, provides a water source for tidal circulation and receives circulating incoming water.

6. The tidal simulation system of claim 1, wherein: the water pump is arranged at the bottom of the water storage tank, and the joint of the water pump and the water inlet pipe is sealed by a sealant.

7. The tidal simulation system of claim 1, wherein: the structures are connected in the above way, and a tide simulation system for researching material circulation is obtained.