Runway type seawater constructed wetland purification system and method

Abstract

The invention provides a runway type seawater constructed wetland purification system and method, and the system comprises a tail water collection module and a purification pool. The purification pond comprises a fish runway, a shellfish purification runway, an ecological floating bed runway, an oyster shell matrix wetland runway, a compound matrix wetland runway and a water purification area. When tail water is treated, residual feed is ingested by omnivorous fishes in the fish runway and enters the shellfish purification runway, organic debris is filtered and eaten by filter-feeding shellfishes and enters the ecological floating bed runway, suspended matter is filtered and adsorbed by floating bed plants, part of nutritive salt is absorbed and utilized, the suspended matter enters the oyster shell matrix wetland runway, and organic particulate matter is adsorbed by the artificial wetland; a part of nutritive salt is absorbed and utilized again and enters the composite substrate wetland runway, the organic particles are filtered and adsorbed by the artificial wetland, a part of nutritive salt is absorbed and utilized again and finally enters the water purification area, and effective purification of the mariculture tail water is achieved.

Description

[0001] This application is a divisional application of the patent application entitled "A runway-type seawater artificial wetland purification system and method". The application date of the original application is March 26, 2021, and the application number is 202110327689.9. Technical Field

[0002] The invention relates to a runway type seawater artificial wetland purification system and method. Background Art

[0003] my country's marine aquaculture has developed rapidly. In 2019, China's marine aquaculture area was 19,921,800 hectares and its output was 20,653,300 tons. Whether in terms of aquaculture area or output, China has become the largest country in marine aquaculture.

[0004] Residual bait, excrement from aquaculture animals, remains of aquatic organisms, etc. in the tail water of marine aquaculture cause excessive levels of organic debris, chemical oxygen demand, and nutrients such as nitrogen and phosphorus in the water, leading to environmental deterioration of aquaculture waters, frequent red tides, and restricting the green and healthy development of the aquaculture industry.

[0005] At present, the treatment of aquaculture tailwater in my country is in its infancy, and pilot projects for tailwater treatment are being carried out in some local areas. The main reason is that the treatment technology for marine aquaculture tailwater is not mature enough. Artificial wetland technology is a new water treatment process developed in the 1970s and 1980s. It is a complex composed of some floating or submerged plants, salt layers in a water-saturated state, and organisms. In the wetland ecosystem, there are a series of biological, physical, and chemical processes to purify sewage. It is a water treatment technology that has environmental, economic, and social benefits.

[0006] At present, artificial wetland treatment technology is widely used in freshwater systems, but progress in seawater systems is slow and urgently needs to be solved. Summary of the invention

[0007] In view of the background technology, the present invention aims to provide a system and method that can be applied to seawater tail water treatment.

[0008] In a first aspect, a runway-type artificial seawater wetland purification system is proposed, comprising a tailwater collection module and a purification pool.

[0009] The tailwater collection module transports the tailwater from the breeding pond to the purification pool. The tailwater collection module transports the tailwater from the breeding pond to the purification pool through the tailwater transport component; the tailwater transport component includes a tailwater lift pump and a transport pipeline; the area of ​​the tailwater treatment area (i.e., the purification pool) is 10-20% of the total breeding area.

[0010] The purification pool comprises a fish runway, a shellfish purification runway, an ecological floating bed runway, an oyster shell matrix wetland runway, a composite matrix wetland runway and a water purification area which are connected in series in a preset order.

[0011] Among them, the fish runway, shellfish purification runway, ecological floating bed runway and composite matrix wetland runway are horizontal flow.

[0012] The oyster shell matrix wetland runway is a subsurface flow.

[0013] When treating tail water, it enters the fish runway, with a horizontal flow. Most of the residual bait will be eaten by omnivorous fish. Then it enters the shellfish purification runway, with a horizontal flow. The residual organic debris is filtered by filter-feeding shellfish. Then it enters the ecological floating bed runway, with a horizontal flow. Most of the suspended matter is filtered and adsorbed by the floating bed plants, and some nutrients are absorbed and utilized. Then it enters the oyster shell matrix wetland runway, with a subsurface flow. Organic particles are adsorbed by the oyster shell matrix artificial wetland, and some nutrients are absorbed and utilized by the floating bed plants again. Then it enters the composite matrix wetland runway, with a horizontal flow. Organic particles are filtered and adsorbed by the composite matrix artificial wetland, and some nutrients are absorbed and utilized again. Finally, it enters the water purification area and becomes recyclable water or water that meets emission standards.

[0014] The fish runway, the shellfish purification runway, the ecological floating bed runway, the oyster shell matrix wetland runway, the composite matrix wetland runway and the water purification area are located in the same plane, and the fish runway, the shellfish purification runway, the ecological floating bed runway, the oyster shell matrix wetland runway, the composite matrix wetland runway and the water purification area are arranged in a circuitous manner. The circuitous arrangement can reduce the floor space of the purification pool and improve the utilization rate of the purification pool. At the same time, the circuitous arrangement can also slow down the water flow speed to ensure that each runway can fully treat the tail water.

[0015] The water surface of the ecological floating bed runway is arranged with a seahorse tooth ecological floating bed; wherein the seahorse teeth are used to filter and absorb suspended matter and nutrients.

[0016] The lower layer of the oyster shell matrix wetland runway is paved with an oyster shell layer, and seahorse teeth are planted on the oyster shell layer; oyster shells, coral stones and fine sand are laid from bottom to top in the composite matrix wetland runway.

[0017] Preferably, the fish runway and the shellfish purification runway are separated by a first guide plate.

[0018] The first guide plate is provided with a first guide hole on the upper part, and the water in the fish runway flows to the shellfish purification runway through the first guide hole. The first guide plate can clearly separate the fish runway from the shellfish purification runway and play a role in slowing down the water flow.

[0019] Preferably, the ecological floating bed runway and the oyster shell matrix wetland runway are separated by a second guide plate.

[0020] A second guide hole is provided at the lower part of the second guide plate, and the height of the second guide hole is lower than the height of the wetland in the oyster shell matrix wetland runway.

[0021] The second guide plate can clearly divide the ecological floating bed runway and the oyster shell matrix wetland runway, and through the second guide hole, the water of the ecological floating bed runway flows to the lower part of the oyster shell matrix wetland runway, and then flows to the upper part of the oyster shell matrix wetland runway, and the organic particles are adsorbed by the oyster shell matrix artificial wetland.

[0022] Preferably, a buffer zone is provided between the oyster shell matrix wetland runway and the composite matrix wetland runway to slow down the water flow velocity from the oyster shell matrix wetland runway to the composite matrix wetland runway.

[0023] Preferably, a third guide plate is provided between the oyster shell matrix wetland runway and the buffer zone. A third guide hole is provided in the middle of the third guide plate, and water from the oyster shell matrix wetland runway flows into the buffer zone through the third guide hole.

[0024] A fourth guide plate is provided between the buffer zone and the composite matrix wetland runway, and water in the buffer zone overflows into the composite matrix wetland runway through the fourth guide plate.

[0025] Preferably, the water purification zone is a submerged flow, so that the water in the composite matrix wetland runway flows from top to bottom, and the organic particles are first absorbed by the composite matrix wetland runway and then enter the water purification zone.

[0026] A fifth guide plate is provided between the composite matrix wetland runway and the water purification area. A fifth guide hole is provided at the lower part of the fifth guide plate, and the height of the fifth guide hole is lower than the wetland height of the composite matrix wetland runway.

[0027] Preferably, the lower layer of the ecological floating bed runway is paved with an oyster shell layer, and seahorses are planted on the oyster shell layer; and oyster shells, coral stones and fine sand are laid from bottom to top in the composite matrix wetland runway.

[0028] By utilizing seahorse teeth, the problems in existing seawater tail water treatment processes, such as the difficulty in selecting artificial wetland restoration plants suitable for treating marine aquaculture tail water and the immature technology for treating saline tail water, can be solved.

[0029] Preferably, the tailwater conveying assembly includes a tailwater lifting pump and a conveying pipeline, and the water outlet of the water purification area is connected to the water inlet of the breeding pond.

[0030] The water purification area is provided with an aeration pipe and an aerator, and the oxygen content of the water is increased by the aerator, making it more suitable for recycling.

[0031] In the second aspect, a runway-type artificial wetland purification method for seawater is proposed, and seahorse teeth are selected as artificial wetland restoration plants for seawater tailwater treatment, including setting up fish runways, shellfish purification runways, ecological floating bed runways, oyster shell matrix wetland runways, composite matrix wetland runways and water purification areas in sequence. Among them, the fish runway, shellfish purification runway and ecological floating bed runway use horizontal flow. The oyster shell matrix wetland runway is a subsurface flow.

[0032] The runway type artificial seawater wetland purification system proposed by the present invention has the following advantages:

[0033] 1. Various tailwater treatment tracks are set up in sequence, and different tracks have different corresponding water flow modes, which can effectively and specifically treat the residual bait, organic debris, suspended matter, organic particles, etc. in the tailwater;

[0034] 2. By arranging each runway in a circuitous manner, the utilization rate of the purification pool can be effectively improved, and the water flow of each runway can be effectively slowed down, thereby increasing the treatment time of tail water and improving the treatment effect;

[0035] 3. Select seahorse teeth as artificial wetland restoration plants for seawater tailwater treatment. Their roots can effectively filter and adsorb suspended matter and nutrients. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a simple schematic diagram of the tailwater collection module;

[0037] Figure 2 It is a simple schematic diagram of the purification tank;

[0038] Figure 3 is a schematic diagram of a first guide plate;

[0039] Figure 4 It is a schematic diagram of the oyster shell matrix wetland runway;

[0040] Figure 5 is a schematic diagram of the second guide plate;

[0041] Figure 6 is a schematic diagram of the third guide plate;

[0042] Figure 7 It is a schematic diagram of the composite matrix wetland runway;

[0043] Figure 8 is a schematic diagram of the fourth guide plate;

[0044] Fig. 9 is a schematic diagram of the fifth guide plate;

[0045] The markings in the accompanying drawings are: tail water collection module 11, purification tank 12, first guide plate 2, first guide hole 21, second guide plate 3, second guide hole 31, third guide plate 4, third guide hole 41, fourth guide plate 5, fifth guide plate 6, fifth guide hole 61. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] Embodiment 1:

[0048] See also Figures 1 to 9 , a runway-type seawater artificial wetland purification system comprises a tailwater collection module 11 and a purification pool 12.

[0049] The tailwater collection module 11 can collect tailwater from the breeding pond and transport the tailwater to the purification pool 12 through the tailwater transport assembly. The tailwater transport assembly includes a tailwater lift pump and a transport pipeline. The tailwater collection module 11 can transport the tailwater from the breeding pond to the fish runway of the purification pool 12 at one time, which is simpler and more convenient.

[0050] The tailwater treatment facilities should be designed in detail according to factors such as the breeding species, scale, design output, and hydraulic retention time of the drainage in the farm. The size of the purification tank 12 is appropriately adjusted according to factors such as the topography, scale, and water use characteristics of the farm. The area of ​​the tailwater treatment zone is 10-20% of the total breeding area. Compared with the prior art, the purification efficiency of the tailwater treatment of this application is higher, and the purification tank has a great advantage in terms of floor space, which saves floor space and significantly improves practicality. At the same time, in order to increase the hydraulic retention time, each treatment unit should adopt a rectangular structure.

[0051] In this embodiment, the purification pool 12 is 20% of the total breeding area, the pool is 1.5m high, and is divided into 6 runways, each runway is 3 meters wide and about 12 meters long. Guide plates made of PP are cross-set at both ends of the runway to control the water flow of two adjacent runways.

[0052] Specifically, the purification pool 12 includes a fish runway, a shellfish purification runway, an ecological floating bed runway, an oyster shell matrix wetland runway, a composite matrix ground runway and a water purification area connected in series. Figure 2 The fish runway, the shellfish purification runway, the ecological floating bed runway, the oyster shell matrix wetland runway, the composite matrix wetland runway and the water purification area are located on the same plane.

[0053] In this embodiment, the fish runway is designed with a water level of 1.2 meters, and omnivorous fish such as basket fish are placed at a density of 1-2 kg / m 3 , and a first guide plate 2 is arranged at the end, and a first guide hole is provided on the upper part of the first guide plate 2, and the water of the fish runway flows to the shellfish purification runway through the first guide hole.

[0054] See also Figure 3 The first guide plate 2 has a width of 1m and a height of 1.2m, and the first guide hole is opened at a position above 0.9m in height. The first guide plate 2 can clearly separate the fish runway and the shellfish purification runway, and play a role in slowing down the water flow.

[0055] The shellfish purification runway is designed with a water level of 1.2 meters and oyster longlines are deployed to cover an area of ​​30m 2 .

[0056] The ecological floating bed runway is designed to have a water level of 1.2 meters, and seahorse tooth ecological floating beds are laid on the water surface, covering an area of ​​30m 2 .

[0057] See also Figure 4 The oyster shell matrix wetland runway has a designed water level of 0.8 meters, an oyster shell layer height of 0.8 meters, and seahorses are planted on the top. A second guide plate 3 is arranged at the front end of the runway and a third guide plate 4 is arranged at the rear end. A second guide hole is arranged at the lower part of the second guide plate 3, and the height of the second guide hole is lower than the height of the wetland in the oyster shell matrix wetland runway. A third guide hole is arranged in the middle part of the third guide plate 4, and the third guide hole is higher than the height of the wetland in the oyster shell matrix wetland runway. The water flow is controlled by the second guide plate 3 and the third guide plate 4 as a submerged flow type. The oyster shell matrix is ​​0.8 meters high, and can be other heights in other embodiments. Seahorses are planted.

[0058] See also Figure 5 In this embodiment, the width of the second guide plate 3 is 3m, the height is 1.2m, and the second guide hole is opened at a position below 0.3m.

[0059] See also Figure 6 The width of the third guide plate 4 is 1 m, and the height is 1 m. The third guide hole is opened at a height of 0.5 m to 0.8 m.

[0060] See also Figure 7 The composite matrix runway is paved with sand, coral stone and oyster shell from top to bottom in sequence, wherein the sand particle size is 2 mm, the thickness is 0.1 m, the coral stone layer is 0.1 m high, and the oyster shell layer is 0.5 m high.

[0061] The front end of the composite matrix runway is provided with a fourth guide plate 5, and the rear end is provided with a fifth guide plate 6, which is a horizontal flow type and is planted with seahorse teeth.

[0062] A buffer zone is formed between the third guide plate 4 and the fourth guide plate 5 to slow down the water flow from the oyster shell matrix wetland runway to the composite matrix runway. Specifically, the water of the oyster shell matrix wetland runway flows into the buffer zone through the third guide hole. The water of the buffer zone overflows into the composite matrix runway through the fourth guide plate 5.

[0063] See also Figure 8 In this embodiment, the width of the four guide plates is 3m and the height is 0.5m.

[0064] See also Fig. 9 The width of the fifth guide plate 6 is 1 m, the height is 0.6 m, and the fifth guide hole is opened at a position below 0.3 m in height.

[0065] The water purification area is provided with existing facilities for increasing the dissolved oxygen content in the water body, such as aeration plates, aeration pipes, and aerators.

[0066] When treating tail water, it enters the fish runway, where the water flow is horizontal, and most of the residual bait will be eaten and utilized by omnivorous fish. Then it enters the shellfish purification runway, where the water flow is horizontal, and the residual organic debris is filtered and eaten by filter-feeding shellfish. Then it enters the ecological floating bed runway, where the water flow is horizontal, and most of the suspended matter is filtered and adsorbed by the floating bed plants, and some nutrients are absorbed and utilized. Then it enters the oyster shell matrix wetland runway, where the water flow is subsurface, and organic particles are adsorbed by the oyster shell matrix artificial wetland, and some nutrients are absorbed and utilized by the floating bed plants again. Then it enters the composite matrix ground runway, where the water flow is horizontal, and organic particles are filtered and adsorbed by the composite matrix artificial wetland, and some nutrients are absorbed and utilized again. Finally, it enters the water purification area and becomes recyclable water or water that meets emission standards.

[0067] Embodiment 2:

[0068] A raceway-type artificial wetland purification method for seawater, using the system proposed in Example 1, placing omnivorous fish in the fish raceway. In this embodiment, the omnivorous fish is basket fish, and the placement density is 1-2 kg / m 3 . The filter-feeding shellfish is an oyster. The salt-tolerant plant is a seahorse. Filter-feeding shellfish are placed in the shellfish purification runway. Salt-tolerant plants are planted on the ecological floating bed runway. An oyster shell layer is laid on the lower layer of the oyster shell matrix wetland runway, and salt-tolerant plants are planted on the oyster shell layer. Oyster shells, coral stones and fine sand are laid from bottom to top in the composite matrix wetland runway.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A runway-type artificial wetland purification system for seawater, characterized in that: The racetrack-type seawater artificial wetland purification system includes a tailwater collection module and a purification tank; The tail water collection module transports the tail water from the breeding pond to the purification pool; the tail water collection module transports the tail water from the breeding pond to the purification pool through the tail water transport component; the tail water transport component includes a tail water lifting pump and a transport pipeline; the area of ​​the purification pool is 10-20% of the total breeding area; The purification pool comprises a fish runway, a shellfish purification runway, an ecological floating bed runway, an oyster shell matrix wetland runway, a composite matrix wetland runway and a water purification area which are connected in series in a preset order; wherein the fish runway is used to utilize omnivorous fish to feed on residual bait in the tail water; the shellfish purification runway is used to utilize filter-feeding shellfish to filter residual organic debris; the ecological floating bed runway is used to utilize floating bed plants to filter and adsorb suspended matter and perform preliminary absorption and utilization of nutrient salts; the oyster shell matrix wetland runway is used to utilize oyster shells to adsorb organic particulate matter, and utilize floating bed plants to perform secondary absorption and utilization of nutrient salts; the composite matrix wetland runway is used to filter and adsorb organic particulate matter, and perform a third absorption and utilization of nutrient salts; The fish runway, shellfish purification runway, ecological floating bed runway and composite matrix wetland runway are advection-type water flows; The oyster shell matrix wetland runway is a subsurface flow; The fish runway, the shellfish purification runway, the ecological floating bed runway, the oyster shell matrix wetland runway, the composite matrix wetland runway and the water purification area are located in the same plane, and the fish runway, the shellfish purification runway, the ecological floating bed runway, the oyster shell matrix wetland runway, the composite matrix wetland runway and the water purification area are arranged in a circuitous manner; The water surface of the ecological floating bed runway is provided with a seahorse tooth ecological floating bed; wherein the seahorse teeth are used to filter and absorb suspended matter and nutrients; The lower layer of the oyster shell matrix wetland runway is paved with an oyster shell layer, and seahorse teeth are planted on the oyster shell layer; oyster shells, coral stones and fine sand are laid from bottom to top in the composite matrix wetland runway.

2. A racetrack-type artificial wetland seawater purification system according to claim 1, characterized in that: The fish runway and the shellfish purification runway are separated by a first guide plate; A first guide hole is provided on the upper portion of the first guide plate, and the water in the fish raceway flows to the shellfish purification raceway through the first guide hole.

3. A racetrack-type artificial wetland seawater purification system according to claim 1, characterized in that: The ecological floating bed runway and the oyster shell matrix wetland runway are separated by a second guide plate; A second guide hole is provided at the lower part of the second guide plate, and the height of the second guide hole is lower than the height of the wetland in the oyster shell matrix wetland runway; The water of the ecological floating bed runway flows underground to the lower part of the oyster shell matrix wetland runway through the second diversion holes.

4. The raceway type artificial wetland purification system for seawater according to claim 1, characterized in that: A buffer zone is provided between the oyster shell matrix wetland runway and the composite matrix wetland runway, and a third guide plate is provided between the oyster shell matrix wetland runway and the buffer zone; a third guide hole is provided in the middle of the third guide plate, and water from the oyster shell matrix wetland runway flows into the buffer zone through the third guide hole; A fourth guide plate is provided between the buffer zone and the composite matrix wetland runway, and water in the buffer zone overflows into the composite matrix wetland runway through the fourth guide plate.

5. The racetrack type artificial wetland purification system for seawater according to claim 1, characterized in that: The water purification area is a submerged flow; A fifth guide plate is provided between the composite matrix wetland runway and the water purification area; a fifth guide hole is provided at the lower part of the fifth guide plate, and the height of the fifth guide hole is lower than the wetland height of the composite matrix wetland runway.

6. The racetrack type artificial wetland purification system for seawater according to claim 1, characterized in that: The tail water collection module transports the tail water of the breeding pond to the purification tank through the tail water transport component; the tail water transport component includes a tail water lift pump and a transport pipeline, the water purification area is provided with an aeration pipe and an aerator, and the water outlet of the water purification area is connected to the water inlet of the breeding pond.

7. A racetrack-type artificial wetland method for purifying seawater, characterized in that: The runway-type artificial wetland purification system described in any one of claims 1 to 6 is adopted, omnivorous fish are placed in the fish runway, filter-feeding shellfish are placed in the shellfish purification runway, salt-tolerant plants are planted on the ecological floating bed runway, an oyster shell layer is laid on the lower layer of the oyster shell matrix wetland runway, salt-tolerant plants are planted on the oyster shell layer, and oyster shells, coral stones and fine sand are laid from bottom to top in the composite matrix wetland runway.

8. The raceway type artificial wetland method for purifying seawater according to claim 7, characterized in that: The omnivorous fish is a basket fish, and the stocking density is 1-2 kg / m 3 ; The filter-feeding shellfish is oyster; the salt-tolerant plant is seahorse.

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