Multifunctional ecological purification system for large-scale circulation breeding water

[0038] Example

[0039] A multifunctional ecological purification system of large-scale circulating aquaculture water, such as figure 1 , figure 2 As shown, the system includes a high-efficiency sedimentation filtration zone, an ecological breeding purification zone, and an artificial wetland purification zone. At the same time, it is equipped with an automatic water quality monitoring and control device. At the same time, the aquatic animals and plants and sediments produced in the purification system can be recycled and utilized.

[0040] Such as figure 2 As shown, pond 1 is connected to primary sedimentation pond 2 through a PVC pipe. At the beginning of the purification, the tail water discharged from the pond 1 containing aquaculture excrement and residual bait enters the primary sedimentation tank 2 for pretreatment through the action of a pump. During routine purification, the pre-treated tail water enters the underflow dam 3, the filter-feeding fish breeding area 4, the crab breeding area 5, the benthic animal breeding area 6, the horizontal underflow artificial wetland 7, the emergent plants in turn from the primary sedimentation tank 2 Constructed wetland 8, floating plant artificial wetland 9, submerged plant artificial wetland 10. Finally, the purified water enters the sump 11 at the end of the submerged plant artificial wetland 10 through a lift pump. After the water quality monitor detects, the water that meets the standard will be input into the corresponding pond 1 to complete the water exchange and purification of the pond. The sump 11 is connected with the inlet and outlet pump stations 13 at the same time. If the water in the collection tank 11 fails the test, it will be re-input to the primary sedimentation tank to continue purification. The water collection tank 11 and the primary sedimentation tank 2 are realized by a water delivery hose and a pump. When the water quality deteriorates abnormally and the conventional purification fails to meet the standard, the water in the primary sedimentation tank 2 is pumped into the water quality adjustment tank 12 for neutralization or biological treatment.

[0041] The purification system is equipped with automatic water quality monitoring and control devices, including controllers, aeration devices, water quality online detectors, control valves and pumps. The water quality online monitor has the ability to monitor the pH, nitrite nitrogen, ammonia nitrogen, dissolved oxygen and temperature of the water quality. The monitoring results of the water quality online monitor will be fed back to the controller, and the controller will judge according to the preset water quality qualification indicators. Once the water quality indicators Failure to meet the preset indicators will automatically trigger related facility valves and pumps to exchange and purify pond 1 and sump 11. The online water quality detector is set in each pond 1 and collection basin 11. The water inlet valve and water inlet pump of the primary sedimentation tank 2, the water quality adjustment tank 12, the drainage pump and the water inlet and outlet valves of the collection tank 11, and the aeration device of the pond 1 are automatically controlled by the controller.

[0042] The purification system has a resource recovery function, including a composting area 14 and a plant cultivation area 15. During the purification process, pond 1, primary sedimentation pond 2, filter-feeding fish breeding area 4, crab breeding area 5, benthic animal breeding area 6, horizontal subsurface flow artificial wetland 7, emergent plant artificial wetland 8, floating water plant artificial wetland 9, The bottom sludge produced by the submerged plant artificial wetland 10 will enter the composting area 14 through the action of the sludge pipe 27 and the sludge pump, and provide fertilizer for the plant cultivation area 15 after composting. figure 2 Middle 16 represents the sediment collection process, and the plants harvested in the ecological breeding purification zone and constructed wetland purifier can be cultivated in the plant cultivation zone 15 to provide plants for the purification system, and excess plants can also be sold on the market. figure 2 Middle 17 represents the plant harvesting process. In addition, the aquatic animals and plants produced in the water purification system, such as silver carp, mussels, snails, crabs, and water lilies, can be sold externally to increase economic benefits. At the same time, some plants can also be used as plant materials for constructed wetlands.

[0043] The functions and structural features of each component of the above system are as follows:

[0044] Pond 1: The length-to-width ratio of the culture pond is 2:1, and the area of ​​a single pond is within 5-10 mu, and the depth of the pond is 2.5m.

[0045] Primary sedimentation tank 2: The aspect ratio is 3:2, and the tank depth is 3m.

[0046] Undercurrent dam 3: The dam height is 1.5m. Including the underflow pipe, the permeable walls on both sides of the inlet and outlet, and the filter material layer. Permeable walls are set on both sides of the water inlet and outlet, and a 90cm thick gravel layer, an underflow tube and a 60cm thick soil cover layer are set up between the walls from bottom to top. Among them, ryegrass, coronaria, boxwood and heather are planted on the soil cover to form a vegetation system, and the particle size of gravel is gradually reduced from 8cm at the water inlet to about 2cm at the water outlet.

[0047] Filter-feeding fish breeding area 4: The main water depth is about 1.5m. Mainly stock filter-feeding fish such as silver carp, bighead carp, etc., and plant water hyacinth.

[0048] Crab breeding area 5: The characteristic is that the main water depth is 0.5-1.5m. Crabs are mainly stocked and aquatic plants such as Hydrilla verticillata and Elodea are planted.

[0049] Benthic animal breeding area 6: It is characterized by that the main water depth is about 1m, and the benthic animals such as mussels and snails are mainly stocked and water lilies are planted.

[0050] Such as image 3 As shown, the water quality adjustment tank 12 is provided with a neutralization filter 18 and a biological purification tank 21 according to the direction of water flow. The neutralization filter 18 is provided with a water inlet and a water outlet, as well as a water retaining structure. The bottom end of the water retaining structure It is a perforated plate bottom 19, and above the water retaining structure is a water collection tank 20. The water to be treated enters the water collection tank 20 from the lower end of the perforated plate bottom 19, and then enters the biological purification tank 21 through the water outlet. 21 is a biological feeding tank with a vertical agitator 22 inside, and a water pump 23 at the outlet end through which the treated liquid is discharged.

[0051] Horizontal subsurface flow constructed wetland 7: such as Figure 4 As shown, the filler height is set to 0.7m. Gravel is selected as the filler 24 of the horizontal subsurface flow constructed wetland. The matrix adopts a grade 3 gravel gradation, the thickness of the matrix is ​​70cm, and the bottom is laid with 0.5mm HDPE plastic cloth as the impermeable layer 25. The substrate is divided into three layers: the bottom layer is a 30cm-thick gravel layer with a particle size of 50-80mm, the middle layer is a 30cm-thick gravel layer with a particle size of 20-50mm, and the upper layer is a 10cm-thick gravel layer with a particle size of 10-20mm, on which emergent plants are planted. 26. The bottom layer is provided with a mud pipe 27 with a diameter of 300mm.

[0052] Such as Figure 5 As shown, emergent plant artificial wetland 8: control the water depth to 0.5m, mainly plant 26 emergent plants, choose reeds, yellow calamus, Zaili flower, and cattail, and control the planting density at 5 plants/m 2 about. Floating plant artificial wetland 9: Control the water depth to 0.5m, mainly plant floating plants 29, choose water lilies, water hyacinth and other aquatic plants, and control the planting density at 5 plants/m 2 about. Submerged plant artificial wetland 10: Control the water depth to 0.5m. The submerged plants 30 are mainly planted, and the submerged plants of Hydrilla verticillata and Elodea are selected to form the constructed wetland, and the ratio of planting area to wetland area is 1:2. An overflow dam 28 is set between each wetland.

[0053] The qualified water quality index values ​​set by the above-mentioned automatic water quality monitoring and control device are as follows:

[0054] Table 1 Water quality monitoring items and standards

[0055]

[0056] The water quality of the pond must meet the standards for aquaculture water. When the pond water level is lower than the specified water level, start the pump for water intake, and open the pump for drainage when the water level is higher than the dangerous water level. Start the aeration device when the pond dissolved oxygen index fails. When the water quality indicators of the sump are qualified, if any of the pH, ammonia nitrogen, and nitrite nitrogen in the pond are not qualified, the pump and valve are activated to change the water of the pond.

[0057] The sump must meet the water source water standard. The collection basin is connected with the natural water body, and water can be supplemented and drained according to the water level of the collection basin. The following measures shall be taken when any of the indicators of pH, ammonia nitrogen, and nitrite nitrogen in the collection tank are unqualified:

[0058] 1. Start the lift pump, drain the water in the sump into the primary sedimentation tank to achieve multiple cycles of purification, and adjust the hydraulic retention time according to the water quality of the sump.

[0059] 2. When the above measures fail to meet the standards and the water quality of the sump meets the aquaculture wastewater discharge standard, the water in the sump can be discharged into a natural water body and supplemented from the natural water body.

[0060] 3. When the water quality of the sump cannot meet the aquaculture wastewater discharge standard, the water in the primary sedimentation tank is passed through the lift pump into the water quality adjustment tank for treatment. When the pH is not up to the standard, the neutralization reaction is carried out. When the ammonia nitrogen and nitrite nitrogen are not up to the standard, the microbial agent is added and mixed to purify the water quality through microorganisms.