Water return pollution interception system for farmland with high suspended matter content

Abstract

The utility model discloses a high-suspended-matter-content farmland return water pollution intercepting system. The system comprises a biological gravel bed section and an ecological ditch section which are sequentially arranged at intervals from front to back in the water flow direction. The biological gravel bed section is sequentially provided with a filler layer and a potting layer from bottom to top; the filler layer sequentially comprises a coarse-particle-size filler section, a medium-particle-size filler section and a fine-particle-size filler section from front to back in the water flow direction; partition walls are arranged at the two ends of each of the coarse-particle-size filler section, the medium-particle-size filler section and the fine-particle-size filler section. An ecological filler layer, a soil layer and a vegetation layer are sequentially arranged in the ecological ditch section from bottom to top. According to the utility model, the farmland runoff can be ensured to be discharged into a water body, and efficient interception and control of farmland non-point source suspended matters and pollutants can be realized by adopting a partitioned and segmented treatment strategy according to the discharge characteristics of the farmland runoff suspended matters and the pollutants, so that the farmland non-point source pollutants can be efficiently intercepted and controlled, and the long-acting maintenance of the ditch function is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of ecological environment engineering, in particular to a pollution interception system for farmland drainage with high suspended matter content. Background Art

[0002] In modern agricultural production, the treatment of farmland runoff is an important issue. Farmland runoff usually contains high suspended matter and various agricultural chemicals, such as fertilizers and pesticides. If these substances are discharged directly without treatment, they will have a serious impact on the environment, not only affecting the water quality of rivers and lakes, but also leading to a serious loss of biodiversity, posing a huge threat to the stability of the ecosystem and the overall health of the biosphere. Traditional methods of farmland runoff treatment mainly rely on natural sedimentation or simple filtration facilities, which are less efficient when treating water bodies with high suspended matter content. On the other hand, during farmland runoff, soil particles become suspended matter due to rainfall and are lost together with rainwater, while soil particles absorb a large amount of pollutants, such as COD, nitrogen and phosphorus. According to research, 60% of nitrogen elements, such as ammonia nitrogen, will be lost along with soil particles in farmland runoff, while more than 85% of phosphorus is adsorbed by the soil and lost in particulate form. This not only causes nutrient pollutants such as nitrogen and phosphorus, but also causes a large loss of nitrogen and phosphorus nutrients.

[0003] In recent years, ecological engineering technology has been widely used in the field of water pollution treatment. By simulating the structure and function of natural ecosystems and using natural materials such as plants, microorganisms and soil, suspended solids, organic matter and nutrients in water can be effectively removed. However, existing ecological treatment systems are often complex in design, occupy a large area, and the treatment effect of water bodies with high suspended solids content still needs to be improved. Utility Model Content

[0004] In order to solve the above problems, the purpose of the utility model is to provide a pollution interception system for farmland drainage with high suspended matter content, which is used to achieve efficient interception and removal of farmland non-point source pollution, improve the treatment capacity of water bodies with high suspended matter content, and at the same time take into account the economy and practicality of the system.

[0005] In order to achieve the above objectives, the technical solution adopted by the utility model is:

[0006] A pollution interception system for farmland runoff with high suspended solids content, including:

[0007] At least one biological gravel bed section with a height of 40 to 60 cm and at least one ecological ditch section with a height of 45 to 50 cm are arranged in sequence from front to back along the water flow direction;

[0008] The bio-gravel bed section is provided with a packing layer and a potted plant layer from bottom to top; the packing layer includes a coarse-grained packing section with a packing diameter of 100-150 mm, a medium-grained packing section with a packing diameter of 30-50 mm, and a fine-grained packing section with a packing diameter of 10-20 mm from front to back along the water flow direction; partition walls are provided at both ends of the coarse-grained packing section, the medium-grained packing section, and the fine-grained packing section; the filling material of the packing layer is at least one of crushed stone, pebbles, or volcanic rock;

[0009] The ecological ditch section is provided with an ecological filler layer, a soil layer and a vegetation layer from bottom to top in sequence; the ecological filler layer is filled with at least one of pebbles, volcanic rocks, functional materials and biochar particles.

[0010] In some preferred embodiments, the length ratio of the coarse particle size filler segment, the medium particle size filler segment and the fine particle size filler segment is 1:1:1.

[0011] In some preferred embodiments, the partition wall is any one of a perforated flower wall or a gravel partition wall with a particle size of 100-150 mm, and has a width of 15-25 cm.

[0012] In some preferred embodiments, the ecological filler layer is filled with pebbles or volcanic rocks, functional materials and biochar particles, and the filling ratio is calculated by weight: the pebbles or volcanic rocks are 20 to 40 parts, the functional materials are 20 to 60 parts, and the biochar particles are 10 to 20 parts; the initial porosity of the ecological filler layer is 35% to 50%.

[0013] In some preferred embodiments, the functional material is composed of a mixture of ceramsite and medical stone, and the mixing ratio is 10 to 30 parts by weight of ceramsite and 10 to 30 parts of medical stone.

[0014] In some preferred embodiments, the soil layer of the ecological ditch section is composed of a mixture of soil and at least one of gravel or volcanic rock, and the mixing ratio is 70 to 90 parts by weight of soil and 10 to 30 parts of gravel or volcanic rock; the initial porosity of the soil layer is 10% to 40%.

[0015] In some preferred embodiments, the biochar particles are prepared from wood chips and / or crop straw.

[0016] In some preferred embodiments, a connecting ditch section is provided between the biological gravel bed section and the ecological ditch section; and a partition wall is provided between the connecting ditch section and the ecological ditch section.

[0017] In some preferred embodiments, the vegetation layer of the ecological ditch section includes native economic crops suitable for the local climate planted on the soil layer.

[0018] Beneficial Effects

[0019] The utility model can ensure that farmland runoff is discharged into the water body, and at the same time, according to the emission characteristics of suspended matter and pollutants in farmland runoff, adopt a zoned and segmented treatment strategy to achieve efficient interception and control of farmland non-point source suspended matter and pollutants, thereby efficiently intercepting and controlling farmland non-point source pollutants, and is beneficial to the long-term maintenance and protection of ditch functions; at the same time, it also achieves the effective utilization of agricultural and forestry wastes, is suitable for the comprehensive ecological management projects of urban or rural rivers or lakes, and also has landscape functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a pollution interception system for farmland drainage with high suspended matter content in a preferred embodiment of the utility model;

[0021] Figure 2 It is a schematic diagram of the on-site layout of a pollution interception system for farmland drainage with high suspended solids content in a preferred embodiment of the utility model;

[0022] Figure 3 This is a schematic diagram of the structure of a pollution interception system for farmland drainage with high suspended matter content in another preferred embodiment of the utility model;

[0023] In the figure: 1, biological gravel bed section; 101, coarse-grained filler section; 102, medium-grained filler section; 103, fine-grained filler section; 104, potted layer; 105, partition wall; 2, ecological ditch section; 201, ecological filler layer; 202, soil layer; 203, vegetation layer; 3, connecting ditch section; DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described below in conjunction with the accompanying drawings. In the description of the utility model, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment provides a system for intercepting farmland drainage pollution with high suspended matter content, including:

[0027] At least one biological gravel bed section 1 with a height of 40 to 60 cm and at least one ecological ditch section 2 with a height of 45 to 50 cm are arranged in sequence from front to back along the direction of water flow. Among them, the biological gravel bed section 1 is used to intercept suspended matter and its attached pollutants in the runoff, and the ecological ditch section 2 is used to deeply purify soluble non-point source pollutants in the runoff, such as nitrogen, phosphorus and other nutrient pollutants. The lengths of the biological gravel bed section 1 and the ecological ditch section 2 are determined by technical personnel based on the actual situation on site. The preferred laying length is determined based on the total length of the ditch. The length ratio of the biological gravel bed section 1 to the ecological ditch section 2 is 2 to 4:8 to 6. In some preferred embodiments, Figure 2 As shown, the biological gravel bed section 1 and the ecological ditch section 2 can be arranged in sections and cross-sections according to the project topography and requirements, so as to obtain different hydraulic and biological conditions and further enhance the interception and reduction effect of non-point source pollutants.

[0028] The biological gravel bed section 1 is provided with a packing layer and a potting layer 104 from bottom to top; the packing layer includes a coarse-grained packing section 101 with a packing diameter of 100-150 mm, a medium-grained packing section 102 with a packing diameter of 30-50 mm, and a fine-grained packing section 103 with a packing diameter of 10-20 mm from front to back along the water flow direction; both ends of the coarse-grained packing section 101, the medium-grained packing section 102, and the fine-grained packing section 103 are provided with partition walls 105; the filling material of the packing layer is at least one of crushed stone, pebble gravel, or volcanic rock, preferably pebble gravel or volcanic rock. The partition wall 105 is used to ensure the segmentation of the three particle sizes of coarse, medium, and fine and the water flow penetration. Preferably, the partition wall 105 is any one of a perforated flower wall or a 100-150 mm particle size pebble gravel partition wall, with a width of 15-25 cm. The potting layer 104 is provided to enhance water flow resistance and provide landscape effects. Specifically, complete or broken flower pots can be placed and native plants can be planted therein. In some preferred embodiments, the length ratio of the coarse particle size filler segment 101, the medium particle size filler segment 102 and the fine particle size filler segment 103 is 1:1:1.

[0029] The ecological ditch section 2 is provided with an ecological filler layer 201, a soil layer 202 and a vegetation layer 203 from bottom to top; the ecological filler layer 201 is filled with at least one of pebbles, volcanic rocks, functional materials and biochar particles. In some preferred embodiments, a specific setting example of the ecological filler layer 201 is given, the ecological filler layer 201 is filled with pebbles or volcanic rocks with a particle size of 5-15mm, functional materials and biochar particles, and the filling ratio is calculated by weight, the pebbles or volcanic rocks are 20-40 parts, the functional materials are 20-60 parts, and the biochar particles are 10-20 parts; the initial porosity of the ecological filler layer 201 is 35% to 50%. Among them, the functional material is preferably composed of a mixture of ceramsite and medical stone, and the mixing ratio is calculated by weight, the ceramsite is 10-30 parts, and the medical stone is 10-30 parts. The biochar particles are prepared from sawdust and / or crop straw.

[0030] The soil layer 202 of the ecological ditch section 2 is composed of a mixture of soil and at least one of gravel or volcanic rock, with the mixing ratio being 70 to 90 parts by weight of soil and 10 to 30 parts of gravel or volcanic rock; the initial porosity of the soil layer 202 is 10% to 40%.

[0031] The vegetation layer 203 of the ecological ditch section 2 includes local economic crops suitable for the local climate planted on the soil layer 202. Preferably, it can be water spinach, water celery or wild rice stem, etc., or it can be the local plant variety most suitable for the local climate, so as to achieve rapid plant growth through harvesting and enhance the pollution interception effect. On the one hand, the nitrogen and phosphorus nutrient resources are recovered by plants, and the high-efficiency interception and control function of the ditch for nitrogen and phosphorus is restored or maintained, and on the other hand, a certain economic value is generated. The ecological revetment is at least one of mortar block stone, gabion, imitation wood pile and ecological concrete block.

[0032] Example 2

[0033] like Figure 2 As shown, this embodiment is developed on the basis of the above-mentioned embodiment 1, and this embodiment provides an improved system taking into account the water outlet mode of the biological gravel bed section 1.

[0034] Obviously, the water from the biological gravel bed section 1 is the water from the upper layer of the partition wall 105, preferably in the form of a waterfall, and then enters the ecological ditch section 2 from the bottom. To this end, in this embodiment, a connecting ditch section 3 is arranged between the biological gravel bed section 1 and the ecological ditch section 2; a partition wall 105 is arranged between the connecting ditch section 3 and the ecological ditch section 2. Among them, the connecting ditch section 3 is an ordinary ditch, in which no filler or plant is arranged, and its preferred width is 40 cm, and it is made of 100-150 mm gravel.

[0035] The utility model aims at the characteristics of the farmland non-point source runoff discharge process, firstly realizes the interception of farmland runoff with high suspended matter content to remove most of the suspended matter adsorbed pollutants, and then effectively intercepts and controls various non-point source pollutants through multiple ways of ecological ditch filling layer, and ensures that the farmland non-point source does not enter the water body due to the interception and control of the system as much as possible. The utility model is suitable for the comprehensive ecological management project of rural rivers or lakes and reservoirs mainly for the control of farmland non-point source pollution with high suspended matter content.

[0036] Experimental Example 1

[0037] (1) A biological gravel bed section 1 is provided, which has a thickness of 40 cm and is provided with a packing layer and a potting layer 104 from bottom to top; the packing layer includes a coarse-grained packing section 101 with a packing diameter of 100 mm, a medium-grained packing section 102 with a packing diameter of 30 mm, and a fine-grained packing section 103 with a packing diameter of 10 mm, which are all of the same length from front to back along the water flow direction; the potting layer 104 is provided with complete or broken flower pots, and native plants are planted in them; the filling material of the packing layer is gravel;

[0038] (2) An ecological ditch section 2 is provided, with a thickness of 45 cm, and an ecological filler layer 201, a soil layer 202 and a vegetation layer 203 are provided from bottom to top in sequence; the ecological filler layer 201 is filled with volcanic rocks, functional materials and biochar particles, and the filling ratio is calculated by weight: the volcanic rocks are 40 parts, the functional materials are 50 parts, and the biochar particles are 10 parts; the initial porosity of the ecological filler layer 201 is 50%. The functional material is composed of a mixture of ceramsite and medical stone, and the mixing ratio is calculated by weight: the ceramsite is 30 parts and the medical stone is 20 parts. The soil layer 202 is composed of a mixture of soil and volcanic rocks, and the mixing ratio is calculated by weight: the soil is 90 parts and the volcanic rocks are 10 parts; the initial porosity of the soil layer 202 is 40%. The vegetation layer 203 is planted with local economic crops suitable for the local climate.

[0039] Experimental Example 2

[0040] (1) A biological gravel bed section 1 is provided, which has a thickness of 40 cm and is provided with a packing layer and a potting layer 104 from bottom to top; the packing layer includes a coarse-grained packing section 101 with a packing diameter of 100 mm, a medium-grained packing section 102 with a packing diameter of 30 mm, and a fine-grained packing section 103 with a packing diameter of 10 mm, which are all of the same length from front to back along the water flow direction; the potting layer 104 is provided with complete or broken flower pots, and native plants are planted in them; the filling material of the packing layer is gravel;

[0041] (2) An ecological ditch section 2 is provided, with a thickness of 45 cm, and an ecological filler layer 201, a soil layer 202 and a vegetation layer 203 are provided from bottom to top in sequence; the ecological filler layer 201 is filled with volcanic rocks, functional materials and biochar particles, and the filling ratio is calculated by weight: the volcanic rocks are 30 parts, the functional materials are 60 parts, and the biochar particles are 10 parts; the initial porosity of the ecological filler layer 201 is 45%. The functional material is composed of a mixture of ceramsite and medical stone, and the mixing ratio is calculated by weight: the ceramsite is 30 parts and the medical stone is 30 parts. The soil layer 202 is composed of a mixture of soil and volcanic rocks, and the mixing ratio is calculated by weight: the soil is 90 parts and the volcanic rocks are 10 parts; the initial porosity of the soil layer 202 is 30%. The vegetation layer 203 is planted with local economic crops suitable for the local climate.

[0042] Experimental Example 3

[0043] (1) A bio-gravel bed section 1 is provided, which has a thickness of 50 cm and is provided with a packing layer and a potting layer 104 from bottom to top; the packing layer includes a coarse-grained packing section 101 with a packing diameter of 130 mm, a medium-grained packing section 102 with a packing diameter of 40 mm, and a fine-grained packing section 103 with a packing diameter of 15 mm, which are all of the same length from front to back along the water flow direction; the potting layer 104 is provided with complete or broken flower pots, and native plants are planted in them; the filling material of the packing layer is gravel;

[0044] (2) An ecological ditch section 2 is provided, with a thickness of 45 cm, and an ecological filler layer 201, a soil layer 202 and a vegetation layer 203 are provided in order from bottom to top; the ecological filler layer 201 is filled with pebbles, functional materials and biochar particles, and the filling ratio is calculated by weight: the pebbles are 40 parts, the functional materials are 40 parts, and the biochar particles are 20 parts; the initial porosity of the ecological filler layer 201 is 45%. The functional material is composed of a mixture of ceramsite and medical stone, and the mixing ratio is calculated by weight: the ceramsite is 20 parts and the medical stone is 20 parts. The soil layer 202 is composed of a mixture of soil and gravel, and the mixing ratio is calculated by weight: the soil is 80 parts and the gravel is 20 parts; the initial porosity of the soil layer 202 is 20%. The vegetation layer 203 is planted with local economic crops suitable for the local climate.

[0045] (3) A connecting ditch section 3 is set between the biological gravel bed section 1 and the ecological ditch section 2. No filler or plants are set inside the connecting ditch section 3. The connecting ditch section 3 is 40 cm wide and is made of 100-150 mm gravel.

[0046] Experimental Example 4

[0047] (1) A bio-gravel bed section 1 is provided, which has a thickness of 60 cm and is provided with a packing layer and a potting layer 104 from bottom to top; the packing layer includes a coarse-grained packing section 101 with a packing diameter of 150 mm, a medium-grained packing section 102 with a packing diameter of 50 mm, and a fine-grained packing section 103 with a packing diameter of 20 mm, which are all of the same length from front to back along the water flow direction; the potting layer 104 is provided with complete or broken flower pots, and native plants are planted in them; the filling material of the packing layer is volcanic rock;

[0048] (2) An ecological ditch section 2 is provided, with a thickness of 50 cm, and an ecological filler layer 201, a soil layer 202 and a vegetation layer 203 are provided from bottom to top in sequence; the ecological filler layer 201 is filled with pebbles, functional materials and biochar particles, and the filling ratio is calculated by weight, the pebbles are 20 parts, the functional materials are 60 parts, and the biochar particles are 20 parts; the initial porosity of the ecological filler layer 201 is 50%. The functional material is composed of a mixture of ceramsite and medical stone, and the mixing ratio is calculated by weight, the ceramsite is 30 parts, and the medical stone is 30 parts. The soil layer 202 is composed of a mixture of soil and gravel, and the mixing ratio is calculated by weight, the soil is 70 parts, and the gravel is 30 parts; the initial porosity of the soil layer 202 is 10%. The vegetation layer 203 is planted with local economic crops suitable for the local climate.

[0049] (3) A connecting ditch section 3 is set between the biological gravel bed section 1 and the ecological ditch section 2. No filler or plants are set inside the connecting ditch section 3. The connecting ditch section 3 is 40 cm wide and is made of 100-150 mm gravel.

[0050] Test results

[0051] The above experimental examples 1-4 were tested for nitrogen and phosphorus removal effects and drainage efficiency. When the ditch water flow velocity was 0.1-0.80 m / s, various non-point source pollutants in farmland runoff, such as suspended solids SS, total organic carbon TOC, ammonia nitrogen NH4-N, and total phosphorus TP, could be effectively removed. The results are shown in Table 1 below:

[0052] Table 1 Data table of interception and control of surface source pollutants in various experimental cases

[0053]

[0054] The data in the table are based on the interception rate as an indicator, which means that during the period when runoff is generated by rainfall in farmland, the runoff water sample at the entrance of the corresponding embodiment is taken as a control, and the runoff water sample flowing through the farmland drainage pollution interception system for high suspended matter content is taken to measure the value of each pollutant and calculate the interception rate.

[0055] From the above analysis, it can be seen that the utility model can achieve efficient removal of various non-point source pollutants, such as COD, ammonia nitrogen, total phosphorus and suspended solids SS, while ensuring the smooth discharge of surface runoff within the corresponding farmland area, thereby effectively intercepting and controlling various non-point source pollutants entering the water body through runoff, ensuring a good river and lake water environment and ecological functions; at the same time, it also realizes the effective utilization of agricultural and forestry wastes, is suitable for the comprehensive ecological management projects of rural rivers or lakes, and also has landscape functions.

[0056] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A pollution interception system for farmland drainage with high suspended solids content, characterized in that: include: At least one biological gravel bed section (1) with a height of 40 to 60 cm and at least one ecological ditch section (2) with a height of 45 to 50 cm are arranged in sequence from front to back along the water flow direction; The bio-gravel bed section (1) is provided with a packing layer and a potting layer (104) in sequence from bottom to top; the packing layer comprises, from front to back along the water flow direction, a coarse-grained packing section (101) with a packing diameter of 100-150 mm, a medium-grained packing section (102) with a packing diameter of 30-50 mm, and a fine-grained packing section (103) with a packing diameter of 10-20 mm; partition walls (105) are provided at both ends of the coarse-grained packing section (101), the medium-grained packing section (102), and the fine-grained packing section (103); the packing material of the packing layer is at least one of crushed stone, pebbles, or volcanic rock; The ecological ditch section (2) is provided with an ecological filler layer (201), a soil layer (202) and a vegetation layer (203) in order from bottom to top; the ecological filler layer (201) is filled with at least one of pebbles, volcanic rocks, functional materials and biochar particles; The functional material is composed of a mixture of ceramsite and medical stone.

2. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1, characterized in that: The length ratio of the coarse particle size filler section (101), the medium particle size filler section (102) and the fine particle size filler section (103) is 1:1:

1.

3. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1, characterized in that: The partition wall (105) is any one of a perforated flower wall and a gravel partition wall with a particle size of 100 to 150 mm, and has a width of 15 to 25 cm.

4. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1, characterized in that: The ecological filler layer (201) is filled with pebbles or volcanic rocks, functional materials and biochar particles, and the initial porosity of the ecological filler layer (201) is 35% to 50%.

5. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1, characterized in that: The soil layer (202) of the ecological ditch section (2) is composed of a mixture of soil and at least one of gravel or volcanic rock, and the initial porosity of the soil layer (202) is 10% to 40%.

6. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1 or 4, characterized in that: The biochar particles are prepared from wood chips and / or crop straws.

7. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1, characterized in that: A connecting ditch section (3) is provided between the biological gravel bed section (1) and the ecological ditch section (2); and a partition wall (105) is provided between the connecting ditch section (3) and the ecological ditch section (2).

8. The system for intercepting farmland drainage pollution with high suspended solids content as claimed in claim 1, characterized in that: The vegetation layer (203) of the ecological ditch section (2) includes local economic crops suitable for the local climate planted on the soil layer (202).

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