A pond bypass circulating water purification system

Abstract

The present invention discloses a pond bypass circulating water purification system, which comprises: a breeding pond; an ecological ditch connected to the water outlet of the breeding pond, used to purify the breeding pond wastewater through plants in the ecological ditch; an artificial wetland connected to the water outlet of the ecological ditch, used to absorb pollutants in the breeding pond wastewater; an ecological pond connected to the water outlet of the artificial wetland, used to further purify the breeding pond wastewater. The plant roots planted in the ecological ditch of the present invention can absorb pollutants such as organic matter in the breeding wastewater, thereby purifying the water quality. The ecological ditch, artificial wetland and ecological pond cooperate to fully purify the breeding wastewater.

Description

Technical Field

[0001] The invention belongs to the technical field of pond water purification, and in particular relates to a pond bypass circulation water purification system. Background Art

[0002] Pond aquaculture is currently the main freshwater fishery aquaculture method in my country. According to statistics, in 2019, the freshwater pond aquaculture area was 2.6447 million hectares, and the aquaculture output was 22.3 million tons, accounting for 74% of the total freshwater aquaculture output (China Fisheries Statistical Yearbook 2020). During the aquaculture process, due to the residue of bait and the accumulation of excrement of aquaculture objects, the water quality of aquaculture water often deteriorates, which has many adverse effects on aquaculture. First, the decomposition of organic matter leads to an increase in the content of free ammonia nitrogen and nitrite nitrogen, which has a serious toxic effect on aquaculture objects; secondly, the increase in biochemical oxygen demand and chemical oxygen demand will cause aquaculture objects to be hypoxic, and even die in large numbers; thirdly, the eutrophication of water quality will cause the excessive reproduction of harmful microorganisms in the water, making aquaculture objects susceptible to disease and death. The monitoring results of the aquatic environment in northern China in recent years have shown that aquaculture water bodies have different degrees of aquaculture water pollution problems, and large-scale fish deaths due to deterioration of water quality conditions have occurred from time to time. Water exchange is an effective means to solve the deterioration of water quality in high-density pond aquaculture, but the discharge of aquaculture wastewater will cause pollution to the surrounding environment and waste a lot of water resources. It is not suitable for areas with severe water shortages such as the northern region, nor does it conform to the development direction of low-carbon, healthy and environmentally friendly aquaculture. Using chemical agents to react with pollutants to oxidize, reduce, precipitate, polymerize, etc., so that pollutants are separated from the aquaculture environment or degraded into non-toxic and harmless chemical forms, although it is effective quickly, the cost of treatment is high and it is easy to cause secondary pollution, which is also not suitable for pond aquaculture in the northern region. Summary of the invention

[0003] In view of the shortcomings and defects of the prior art, the object of the present invention is to provide a pond bypass circulating water purification system.

[0004] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0005] A pond bypass circulating water purification system comprises: a breeding pond;

[0006] An ecological ditch connected to the water outlet of the breeding pond and used to purify the wastewater from the breeding pond through plants in the ecological ditch;

[0007] An artificial wetland connected to the water outlet of the ecological ditch and used to absorb pollutants in the wastewater of the breeding pond;

[0008] The ecological pond is connected to the outlet of the artificial wetland and is used to further purify the wastewater from the breeding pond.

[0009] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the pond bypass circulating water purification system also includes a sedimentation tank arranged between the breeding pond and the ecological ditch, the water inlet of the sedimentation tank is connected to the water outlet of the breeding pond, and the water outlet of the sedimentation tank is connected to the water inlet of the ecological ditch, and the sedimentation tank is used to perform preliminary sedimentation of the breeding pond wastewater to remove particulate matter in the breeding pond wastewater.

[0010] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the pond bypass circulating water purification system also includes a high-position intensive breeding pond, which is used to breed high-quality fish with high water quality requirements. The high-position intensive breeding pond is connected to the water outlet of the ecological pond, and the wastewater purified by the ecological pond enters the high-position intensive breeding pond and is used as the water source of the high-position intensive breeding pond; preferably, the high-position intensive breeding pond is arranged above the ground for easy observation.

[0011] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the plants in the ecological ditch are perennial plants with strong adsorption capacity and high ornamental value.

[0012] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the ecological ditch includes a primary ecological ditch, a secondary ecological ditch and a tertiary ecological ditch in sequence, and the heights of plants in the primary ecological ditch, the secondary ecological ditch and the tertiary ecological ditch increase successively, so that the ecological ditch has high ornamental value.

[0013] In the above-mentioned pond bypass circulating water purification system, as a preferred implementation mode, the primary ecological ditch is connected to the outlet of the sedimentation tank, and the plants in the primary ecological ditch are lotus. Preferably, the variety of lotus is at least one of Lianyun Peony, Friendship Peony, Hongzhan Touzhu and Weishan Lake Red Lotus.

[0014] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the secondary ecological ditch is connected to the outlet of the primary ecological ditch. Preferably, the secondary ecological ditch includes water lily and Victoria regia area, lotus area, sedge grass area and lily of the valley area.

[0015] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the tertiary ecological ditch is connected to the outlet of the secondary ecological ditch. Preferably, the plants in the tertiary ecological ditch are at least one of Iris flavescentis and Lythrum salicaria.

[0016] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the artificial wetland includes a surface flow artificial wetland and a subsurface flow artificial wetland.

[0017] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the surface flow artificial wetland is connected to the outlet of the ecological ditch, and the plants in the surface flow artificial wetland are ornamental plants, preferably water lilies.

[0018] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, the subsurface flow artificial wetland is connected to the outlet of the surface flow artificial wetland, and the subsurface flow artificial wetland includes a substance with adsorption function, and the substance with adsorption function is preferably gravel, volcanic rock or sand.

[0019] In the above-mentioned pond bypass circulating water purification system, as a preferred embodiment, aquatic plants are planted in the ecological pond and / or microbial carriers are placed to treat organic matter, N, and P pollutants in aquaculture wastewater; preferably, the microbial carrier is an elastic filler.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) This patent forms a pond bypass circulating water purification system that is particularly suitable for northern regions through plant screening and the design and construction of ecological ditches, artificial wetlands, and ecological ponds.

[0022] (2) The plant roots planted in the ecological ditch of the present invention can absorb organic matter and other pollutants in the aquaculture wastewater, thereby purifying the water quality. The ecological ditch, artificial wetland and ecological pond cooperate to fully purify the aquaculture wastewater.

[0023] (3) The lotus and other plants planted in the ecological ditch and artificial wetland of the present invention have the ability to purify aquaculture water and can also achieve a high ornamental effect, while plants such as Lythrum salicaria can achieve high efficiency in purifying water and have high economic value.

[0024] (4) The plants in the system of the present invention grow better, the plant root system is more stable, and the water purification efficiency is greatly improved. The removal rates of ammonia nitrogen and nitrite nitrogen are both above 60%, the removal rates of total nitrogen, total phosphorus and COD are all above 40%, and the removal rate of chlorophyll (algae) is an average of more than 50%.

[0025] (5) During the operation of the system of the present invention, no sewage is discharged to the outside during the entire pond aquaculture, achieving the goal of zero drainage. Compared with the average drainage of ordinary aquaculture ponds, water saving is achieved by more than 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure is a structural diagram of a pond bypass circulating water purification system.

[0027] Among them, 1 is a breeding pond, 2 is a first-level ecological ditch, 3 is a second-level ecological ditch, 4 is a third-level ecological ditch, 5 is an artificial wetland, 6 is an ecological pond, 7 is a high-level intensive breeding pond, and 8 is a sedimentation pond. DETAILED DESCRIPTION

[0028] In order to highlight the purpose, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with embodiments, which are described by way of explanation of the present invention but not limiting the present invention. The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any combination of the specific implementation methods.

[0029] The present invention provides a pond bypass circulating water purification system, which comprises a breeding pond, an ecological ditch, an artificial wetland and an ecological purification pond; the pond bypass circulating water purification system also comprises a sedimentation tank and a high-level intensive breeding pond; Figure 1 The various components of the system of the present invention are described.

[0030] A breeding pond 1 is used for breeding aquatic products, such as fish, especially freshwater fish. The number of the breeding ponds 1 can be multiple, such as 3, 4, etc.;

[0031] Sedimentation tank 8, which is connected to the outlet of the aquaculture pond 1. The aquaculture wastewater first enters the sedimentation tank 8 from the aquaculture pond 1 for preliminary sedimentation, and the particulate matter such as fish feces and leftover bait is removed by bottom suction;

[0032] Ecological ditches, which mainly absorb nutrients in the water through the action of plant roots, mainly include the first-level ecological ditch 2, the second-level ecological ditch 3 and the third-level ecological ditch 4 which can be connected in sequence; the heights of the plants planted in the first-level ecological ditch 1, the second-level ecological ditch 2 and the third-level ecological ditch 3 are successively increased, which can not only increase the benefits of farmers but also make the ecological ditch as a whole highly ornamental;

[0033] Specifically, the primary ecological ditch 2 is connected to the outlet of the sedimentation tank 8, and the aquaculture wastewater of the sedimentation tank 8 enters the primary ecological ditch 2 and is purified by the plants planted in the primary ecological ditch 2, wherein the specification of the primary ecological ditch 2 is preferably 80 meters long and 1.5 meters wide, and the plants planted in the primary ecological ditch 1 are preferably lotus, and the lotus varieties may include lotus peony, friendship peony, red lantern and Weishan Lake red lotus;

[0034] The secondary ecological ditch 3 is connected to the outlet of the primary ecological ditch 2. The aquaculture wastewater treated by the primary ecological ditch 2 enters the secondary ecological ditch 3 and is further purified by the plants planted in the secondary ecological ditch 3. The secondary ecological ditch 3 is preferably 250 meters long and 3 meters wide. The plants planted in the secondary ecological ditch 3 are preferably Euryale ferox and Victoria amazonica area, multi-color lotus area, Pikespur area and Zygophyllum area.

[0035] The tertiary ecological ditch 4 is connected to the outlet of the secondary ecological ditch 3. The aquaculture wastewater treated by the secondary ecological ditch 3 enters the tertiary ecological ditch 4 and is further purified by the plants planted in the tertiary ecological ditch 4. The specifications of the tertiary ecological ditch 4 are preferably 120 meters long and 1.5 meters wide. The plants planted in the tertiary ecological ditch 4 are preferably yellow iris and loosestrife. The plants such as loosestrife of the present invention can achieve the effect of purifying water quality and have high economic value.

[0036] Artificial wetland 5, the artificial wetland includes a surface flow artificial wetland and a subsurface flow artificial wetland, the surface flow artificial wetland is connected to the outlet of the third-level ecological ditch 4, the surface flow artificial wetland is preferably 15 meters long and 3.5 meters wide, and mainly plants water lilies of various varieties and colors to make it more ornamental; the subsurface flow artificial wetland is connected to the outlet of the surface flow artificial wetland, and the aquaculture wastewater enters the subsurface flow artificial wetland through the surface flow artificial wetland. The subsurface flow artificial wetland includes gravel, volcanic rock or sandy soil and other materials with strong adsorption function. The materials with strong adsorption function adsorb pollutants in the aquaculture wastewater, and then the aquaculture wastewater enters the ecological purification pond;

[0037] The ecological pond 6 is connected to the outlet of the artificial wetland. Through artificial planting of aquatic plants and placement of microbial carriers, organic matter, N, P and other pollutants in the aquaculture wastewater are efficiently degraded, adsorbed and absorbed, so that the aquaculture wastewater is further purified.

[0038] The aquaculture wastewater treated by the ecological pond 6 can obtain purified water, and the purified water can be discharged or passed into the high-level intensive breeding pond 7 for reuse, wherein the high-level intensive breeding pond 7 is used for breeding high-quality fish with high water quality requirements. The aquaculture wastewater treated by the ecological pond 6 has good water quality, which can meet the water requirements of high-quality fish with high water quality requirements, and achieve the recycling of aquaculture wastewater; preferably, the high-level intensive breeding pond 7 is adjacent to the primary ecological ditch 2, so that the lotus in the primary ecological ditch 2 and the precious fish in the high-level intensive breeding pond 7 together constitute a highly ornamental scenery.

[0039] In the present invention, the selection of aquatic plants can follow certain principles. The first principle is to select aquatic plants with developed root systems, thick and dense roots that can penetrate deep into the matrix, which is conducive to absorbing more nutrients in the water. Secondly, it depends on the type of pollutants that need to be removed in the water body, so as to consider which plants to choose. For example, when the water body is rich in BOD, plants with strong root systems and strong oxygen transfer capabilities should be selected; and when plants are required to quickly absorb nitrogen, phosphorus and other elements in the water, species with good absorption capacity and rapid growth should be selected. Water hyacinth and big floating have developed root systems, fast growth rates, and can enrich a variety of heavy metals; reeds, cattails, etc. can secrete algae-killing substances and quickly absorb BOD and nitrogen. Secondly, different plants should be configured according to different water depths. If the water depth is more than one meter all year round and the transparency is high, submerged plants can be planted, and then equipped with ecological floating islands. In areas with a water depth of 0.3-1 meters, lotus, water lily, etc. can be used as the main ones, and submerged plants can be configured; if the water depth is less than 0.5 meters all year round, emergent plants are mainly selected. When the substrate is gravel or sand, some perennial emergent plants are often selected. Only they can expand to the exposed gravel substrate with the help of developed rhizomes and root systems, and gradually form sediments through their siltation-promoting effect. If it is a subsurface artificial wetland, the water level of the wetland should be considered, and species suitable for water level changes should be selected, such as irises, loosestrife and cannas. Finally, according to different water conditions, emergent plants, floating leaf plants and submerged plants can be optimized and matched; perennial species can also be matched with annual species; plants of different heights and flowering periods can also be matched. In short, choosing a variety of different types of plants can increase the diversity and stability of the ecosystem.

[0040] Example 1

[0041] A pond bypass circulating water purification system includes three breeding ponds 1;

[0042] A sedimentation tank 8, which is connected to the water outlet of the breeding pond 1;

[0043] Ecological ditches, the ecological ditches include the primary ecological ditch 2, the secondary ecological ditch 3 and the tertiary ecological ditch 4; specifically, the primary ecological ditch 2 is connected to the outlet of the sedimentation tank 8; wherein, the primary ecological ditch 2 is 80 meters long and 1.5 meters wide, and the four types of lotus, namely, Lotus Rhyme Peony, Friendship Peony, Red Lantern Pearl and Weishan Lake Red Lotus, are planted in the primary ecological ditch 2, and the ratio of the four types of lotus, namely, Lotus Rhyme Peony, Friendship Peony, Red Lantern Pearl and Weishan Lake Red Lotus, is 1:1:1:1; The first-level ecological ditch 3 is connected to the outlet of the first-level ecological ditch 2; among them, the second-level ecological ditch 3 is 250 meters long and 3 meters wide. The second-level ecological ditch 3 is planted with water chestnuts and Victoria regia areas, multi-color lotus areas, pickerel grass areas and lily of the valley areas; the ratio of water chestnuts and Victoria regia areas (the ratio of water chestnuts and Victoria regia is 1:1), multi-color lotus areas, pickerel grass areas and lily of the valley areas is 1:1:1:1; the third-level ecological ditch 4 is connected to the outlet of the second-level ecological ditch 3; the third-level ecological ditch 4 is 120 meters long and 1.5 meters wide. The third-level ecological ditch 4 is planted with yellow iris and loosestrife, and the ratio of yellow iris and loosestrife is 1:1;

[0044] Artificial wetland 5, the artificial wetland includes a surface flow artificial wetland and a subsurface flow artificial wetland. The surface flow artificial wetland is connected to the outlet of the third-level ecological ditch 4. The surface flow artificial wetland has a specification of 15 meters in length and 3.5 meters in width, and is planted with water lilies of various colors. The subsurface flow artificial wetland is connected to the outlet of the surface flow artificial wetland. The subsurface flow artificial wetland has a specification of 15 meters in length and 3.5 meters in width, and the adsorption function materials included in the subsurface flow artificial wetland are gravel, volcanic rock or sand from the bottom to the top;

[0045] Ecological purification pond 6, in which aquatic plants such as water hyacinth, iris, loosestrife and canna are planted, and microbial carriers with elastic fillers are placed. The elastic fillers are used to enrich the microorganisms in the water, and the aquatic plants are used to further efficiently degrade, adsorb and absorb organic matter, N, P and other pollutants in the aquaculture wastewater

[0046] The above pond bypass circulating water purification system is used to purify total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH4 + -N), nitrite nitrogen (NO2 - -N), chlorophyll a (Chla) and chemical oxygen demand (COD) removal effects were evaluated. The water quality of the aquaculture pond water, ecological ditch effluent, artificial wetland effluent and ecological purification pond effluent was measured every month from May to October. The specific results are as follows:

[0047] (1) Total nitrogen (TN)

[0048] TN values ​​in the pond bypass circulation water purification system in the breeding ponds, ecological ditches, artificial wetlands and ecological purification ponds from May to October. The average removal rate of TN in the ecological ditch was 23.24%, of which the purification effect was the best in September, with a TN removal rate of 44.83%; the average removal rate of TN in the artificial wetland was 29.19%, of which the purification effect was the best in August, with a TN removal rate of 38.71%; the average removal rate of TN in the ecological purification pond was 50.38%, of which the purification effect was the best in July and September, with TN removal rates of 63.16% and 63.64% respectively. The total removal rate of TN in the entire water purification system was 73.03%;

[0049] (2) Total phosphorus (TP)

[0050] TP values ​​in the pond bypass circulation water purification system in the breeding pond, ecological ditch, artificial wetland and ecological purification pond in each month from May to October. The average removal rate of TP in the ecological ditch was 21.43%, among which the purification effect was the best in July, with a TP removal rate of 35%; the average removal rate of TP in the artificial wetland was 23.64%, among which the purification effect was the best in July, with a TP removal rate of 46.15%; the average removal rate of TP in the ecological purification pond was 40.48%, among which the purification effect was the best in July, with a TP removal rate of 64.29%. The total removal rate of TP in the entire water purification system was 64.29%.

[0051] (3) Ammonia nitrogen (NH4 + -N)

[0052] NH4 in aquaculture ponds, ecological ditches, artificial wetlands and ecological purification ponds in the pond bypass circulating water purification system from May to October + -N value. Ecological ditch to NH4 + The average removal rate of -N was 29.67%, among which the purification effect was the best in August, and NH4 + -N removal rate reached 45.4%; artificial wetland for NH4 + The average removal rate of -N was 28.61%, with the best purification effect in September, NH4 + -N removal rate reached 56.92%; the ecological purification pond for NH4 + The average removal rate of -N was 48.76%, among which the purification effect was the best in June, and NH4 + -N removal rate reached 92.11%. The entire water purification system + The total removal rate of -N was 74.27%.

[0053] (4) Nitrite nitrogen (NO2 - -N)

[0054] NO2 in aquaculture ponds, ecological ditches, artificial wetlands and ecological purification ponds in the pond bypass circulating water purification system from May to October - -N value. Ecological ditch to NO2 - The average removal rate of -N was 62.16%, with the best purification effect in September, NO2 - -N removal rate reached 83.33%; artificial wetland for NO2 - The average removal rate of NO2-N was 48.81%, with the best purification effect in June and July. - -N removal rate reached 60%; the ecological purification pond for NO2 - The average removal rate of -N was 58.14%, with the best purification effect in October, and NO2 - -N removal rate reached 93.33%. The entire water purification system has a NO2 - The total removal rate of -N was 91.89%.

[0055] (5) Chlorophyll a (Chla)

[0056] Chla values ​​in the pond bypass circulation water purification system in the breeding pond, ecological ditch, artificial wetland and ecological purification pond in each month from May to October. The average removal rate of Chla in the ecological ditch was 27.88%, among which the purification effect was the best in July, with a Chla removal rate of 46.48%; the average removal rate of Chla in the artificial wetland was 40.37%, among which the purification effect was the best in June, with a Chla removal rate of 46.21%; the average removal rate of Chla in the ecological purification pond was 56.69%, among which the purification effect was the best in October, with a Chla removal rate of 83.02%. The total removal rate of Chla in the entire water purification system was 81.37%.

[0057] (6) Chemical oxygen demand (COD)

[0058] COD values ​​in the pond bypass circulation water purification system in the breeding pond, ecological ditch, artificial wetland and ecological purification pond in each month from May to October. The average COD removal rate of the ecological ditch was 15.59%, of which the purification effect was the best in August, with a COD removal rate of 30.43%; the average COD removal rate of the artificial wetland was 23.42%, of which the purification effect was the best in June, with a COD removal rate of 32.65%; the average COD removal rate of the ecological purification pond was 37.65%, of which the purification effect was the best in October, with a COD removal rate of 57.89%. The total COD removal rate of the entire water purification system was 59.69%.

[0059] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A pond bypass circulating water purification system, characterized in that: include: Breeding ponds; Sedimentation tank: The sedimentation tank is connected to the outlet of the breeding pond. The breeding wastewater first enters the sedimentation tank from the breeding pond for preliminary sedimentation, and the fish feces and residual bait particles are removed by bottom suction; The ecological ditch absorbs nutrients in the water through the action of plant roots, including a first-level ecological ditch, a second-level ecological ditch and a third-level ecological ditch connected in sequence, and the first-level ecological ditch is connected to the outlet of the sedimentation tank; the plants in the ecological ditch are perennial plants with strong adsorption capacity and high ornamental value, and the heights of the plants planted in the first-level ecological ditch, the second-level ecological ditch and the third-level ecological ditch are successively increased, the plants planted in the first-level ecological ditch are lotus, the plants planted in the second-level ecological ditch are Euryale ferox and Victoria amazonica area, multi-color lotus area, fish grass area and lily flower area, and the plants planted in the third-level ecological ditch are yellow iris and Lythrum salicaria; The artificial wetland includes a surface flow artificial wetland and a subsurface flow artificial wetland. The surface flow artificial wetland is connected to the outlet of the third-level ecological ditch. The plants in the surface flow artificial wetland are ornamental plants. The subsurface flow artificial wetland is connected to the outlet of the surface flow artificial wetland. The subsurface flow artificial wetland includes gravel, volcanic rock or sand, and is used to absorb pollutants in the wastewater of the breeding pond. The ecological pond is connected to the outlet of the artificial wetland, and the wastewater from the breeding pond is further purified by artificially planting aquatic plants and placing microbial carriers; The pond bypass circulating water purification system also includes a high-position intensive breeding pond, which is used to breed high-quality fish with high water quality requirements. The high-position intensive breeding pond is connected to the water outlet of the ecological pond, and the wastewater purified by the ecological pond enters the high-position intensive breeding pond and is used as the water source of the high-position intensive breeding pond.

2. The pond bypass circulating water purification system according to claim 1, characterized in that: The high-position intensive breeding pool is arranged above the ground for easy observation.

3. The pond bypass circulating water purification system according to claim 1, characterized in that: The variety of lotus is at least one of the lotus peony, friendship peony, red lotus and Weishan Lake red lotus.

4. The pond bypass circulating water purification system according to claim 1, characterized in that: The plants in the surface flow artificial wetland are water lilies.

5. The pond bypass circulating water purification system according to claim 1, characterized in that: The microorganism carrier is an elastic filler.

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