Farmland type saturated buffer wetland system for treating non-point source pollution and working method thereof

Abstract

This invention discloses a farmland-type saturated buffer wetland system and its operating method for controlling non-point source pollution. The invention relates to the technical field of non-point source pollution control. It includes a saturated buffer field located on one side of an ecological ditch, with protective embankments and water-blocking dams on both the front and rear sides of the buffer field. The buffer field comprises a soil improvement layer 30-100cm below the surface and a cultivated layer above the soil improvement layer. Multiple homogeneous water distribution pipes are laid at intervals within the soil improvement layer. Multiple saturated buffer stop valves, corresponding to the homogeneous water distribution pipes, are fixed at the bottom of the ecological ditch. Each saturated buffer stop valve includes a sealed housing with an inlet on the front side and an outlet on the right side wall. The beneficial effects of this invention are: automatic control of non-point source pollution and improved control effectiveness.

Description

Technical Field

[0001] This invention relates to the technical field of non-point source pollution control, and in particular to a farmland-type saturated buffer wetland system and its operating method for controlling non-point source pollution. Background Technology

[0002] With governments at all levels placing greater emphasis on ecological and environmental protection, the nation has recently set forth ecological governance goals, shifting from simply meeting environmental standards to gradually aiming for ecological improvement. Rivers and waterways are a key area for ecological and environmental governance. Addressing shortcomings in rural domestic sewage treatment, an incomplete integrated farming system, and insufficient promotion of green aquaculture, key tasks include strengthening rural domestic sewage treatment, steadily improving pollution prevention and control in crop farming, constructing a pollution prevention and utilization system for aquaculture, and conducting supervision and guidance on agricultural non-point source pollution.

[0003] The topsoil, used for planting crops, contains high levels of nitrogen, phosphorus, COD, and organic matter during crop growth. These are known as non-point source pollution, which significantly impacts crop growth. To address non-point source pollution in the topsoil, farmers apply chemical agents to reduce the levels of nitrogen, phosphorus, COD, and organic matter, thus resolving the problem.

[0004] While the above methods for controlling non-point source pollution in the topsoil can ensure normal crop growth, they still have the following technical shortcomings: I. The need for manual, timed application of chemical agents to the topsoil undoubtedly increases the workload of non-point source pollution control and also adds to the cost of purchasing chemical agents. II. The distribution of chemical agents applied to the topsoil is uneven; in some localized areas, non-point source pollutants are not effectively weakened, resulting in poor effectiveness in controlling non-point source pollution. Therefore, there is an urgent need for a wet-bottom system and operating method that can automatically control non-point source pollution and improve its effectiveness. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a farmland-type saturated buffer wetland system and its working method for controlling non-point source pollution, which realizes automatic control of non-point source pollution and improves the control effect of non-point source pollution.

[0006] The objective of this invention is achieved through the following technical solution: a farmland-type saturated buffer wetland system for treating non-point source pollution, comprising a saturated buffer field set on one side of an ecological ditch, with protective dikes and water-blocking dams set on both the front and rear sides of the saturated buffer field, the saturated buffer field comprising a modified soil layer located 30-100cm below the ground surface and a cultivated soil layer set above the modified soil layer, on which crops are planted, and multiple homogeneous water distribution pipes are laid at intervals in the modified soil layer, each homogeneous water distribution pipe being horizontally set, and each homogeneous water distribution pipe having multiple small holes distributed on its cylindrical surface;

[0007] The ecological ditch is equipped with multiple saturated buffer stop valves, each corresponding to a homogeneous water distribution pipe, fixed at its bottom. Each saturated buffer stop valve includes a sealed box with an inlet on the front face and an outlet on the right side wall. The outlet is located below the inlet, and both the inlet and outlet are connected to the sealed cavity of the box. The inlet is flush with the surface of the ecological water in the ecological ditch, and the outlet is connected to the left end of the homogeneous water distribution pipe.

[0008] The homogeneous water distribution pipe is a rigid PE or PVC pipe, and the spacing between the small holes on the homogeneous water distribution pipe is 30~50cm, and the diameter of the small holes is 10~40mm.

[0009] The slope of the ecological ditch is 0.05~0.5°, and the bottom of the ecological ditch is planted with potted aquatic and terrestrial plants with a planting density of 5~15 plants / ㎡.

[0010] The aforementioned aquatic and terrestrial plants that stop flowing water are Thalia dealbata and Acorus calamus.

[0011] The spacing between any two adjacent saturated buffer stop valves is equal.

[0012] The aforementioned embankment and water-blocking dam is made of permeable concrete or permeable structural components.

[0013] A method for operating a farmland-type saturated buffer wetland system for controlling non-point source pollution includes the following steps:

[0014] Ecological water in the ecological ditch overflows into the sealed cavity through the inlet of the saturated buffer stop valve. Then, the ecological water flows out from the outlet and into the homogeneous water distribution pipe. Subsequently, the ecological water flows into the improved soil layer through small holes in the homogeneous water distribution pipe. Finally, the ecological water permeates into the topsoil layer through the improved soil layer. The microorganisms in the ecological water undergo nitrification and denitrification to reduce the nitrogen, phosphorus, and COD content in the topsoil layer. At the same time, they consume the organic matter in the topsoil layer as energy for the reproduction, growth, and metabolism of crops in the topsoil layer, thereby reducing the organic matter content and ultimately achieving the goal of controlling source pollution in the topsoil layer.

[0015] The present invention has the following advantages: the present invention realizes automatic control of non-point source pollution and improves the effect of non-point source pollution control. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of a saturated buffer stop valve;

[0018] In the diagram, 1-ecological ditch, 2-saturated buffer field, 3-embankment and water-blocking dam, 4-homogeneous water distribution pipe, 5-saturated buffer water stop valve, 6-box body, 7-inlet, 8-outlet. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. The scope of protection of the present invention is not limited to the following description:

[0020] like Figures 1-2 As shown, a farmland-type saturated buffer wetland system for treating non-point source pollution includes a saturated buffer field 2 located on one side of an ecological ditch 1. Protective dikes and water-retaining dams 3 are installed on both the front and rear sides of the saturated buffer field 2. The protective dikes and water-retaining dams 3 are made of permeable concrete or permeable structural components. The saturated buffer field 2 includes a modified soil layer 30-100cm below the surface and a cultivated soil layer above the modified soil layer. Crops are planted on the cultivated soil layer. Multiple homogeneous water distribution pipes 4 are laid at intervals within the modified soil layer. Each homogeneous water distribution pipe 4 is horizontally positioned, and multiple small holes are distributed on the cylindrical surface of each homogeneous water distribution pipe 4. The homogeneous water distribution pipe 4 is made of rigid PE or PVC pipe, and the spacing between the small holes on the homogeneous water distribution pipe 4 is 30-50cm, with a diameter of 10-40mm. The soil improvement process involves using mechanical equipment to rotary tillage and pulverize the soil layer 30-100cm below the surface, then mixing it with green sand in a ratio of 3:1 to 10:1. After soil improvement, the soil permeability coefficient is maintained at 0.05-0.5.

[0021] Multiple saturated buffer stop valves 5, each corresponding to a homogeneous water distribution pipe 4, are fixedly installed at the bottom of the ecological ditch 1. The spacing between any two adjacent saturated buffer stop valves 5 is equal. Each saturated buffer stop valve 5 includes a sealed box 6. An inlet 7 is provided on the front face of the box 6, and an outlet 8 is provided on the right side wall of the box 6. The outlet 8 is located below the inlet 7. Both the outlet 8 and the inlet 7 are connected to the sealed cavity of the box 6. The inlet 7 is flush with the surface of the ecological water in the ecological ditch 1, and the outlet 8 is connected to the left end of the homogeneous water distribution pipe 4.

[0022] The slope of the ecological ditch 1 is 0.05~0.5°. The bottom of the ecological ditch 1 is planted with potted aquatic and terrestrial water-stopping plants at a planting density of 5~15 plants / ㎡. The aquatic and terrestrial water-stopping plants are Thalia dealbata and Acorus calamus. The bottom surface of the ecological ditch 1 is covered with a 15~35cm thick filter filler.

[0023] A method for operating a farmland-type saturated buffer wetland system for controlling non-point source pollution includes the following steps:

[0024] Ecological water in ecological ditch 1 overflows into the sealed cavity through inlet 7 on saturated buffer stop valve 5, and then flows out from outlet 8. The outflowing ecological water flows into homogeneous water distribution pipe 4, and then flows into the improved soil layer through small holes on the homogeneous water distribution pipe 4. Finally, the ecological water permeates into the topsoil layer through the improved soil layer. Microorganisms in the ecological water undergo nitrification and denitrification to reduce the content of nitrogen, phosphorus and COD in the topsoil layer. At the same time, they consume the organic matter in the topsoil layer as energy for the reproduction, growth and metabolism of crops in the topsoil layer, thereby reducing the content of organic matter and ultimately achieving the purpose of controlling source pollution in the topsoil layer.

[0025] Therefore, this buffer wetland system first introduces ecological water from the ecological ditch 1 into the saturated buffer stop valve 5, then introduces the ecological water into the homogeneous water distribution pipe 4 through the saturated buffer stop valve 5, and finally automatically distributes the ecological water into the topsoil. Through microbial nitrification and denitrification, the levels of nitrogen, phosphorus, and COD in the topsoil are reduced, as is the content of organic matter, thus achieving automatic treatment. Therefore, this buffer wetland system can treat non-point source pollution without the need for manual application of chemical agents to the topsoil at regular intervals, greatly reducing the workload of non-point source pollution control and eliminating the need to purchase chemical agents, thereby saving treatment costs.

[0026] In addition, this buffer wetland system automatically increases the soil moisture content of the topsoil layer without the need for artificial irrigation; the entire buffer wetland system has low renovation costs and simple construction: the construction conditions are not limited by pipeline installation conditions, and the existing ditches can be used on-site to treat non-point source pollution, which has the characteristics of low management costs and convenient maintenance.

[0027] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A farmland-type saturated buffer wetland system for controlling non-point source pollution, characterized in that: It includes a saturated buffer field (2) set on one side of an ecological ditch (1), and a water-blocking dam (3) is set on both the front and back sides of the saturated buffer field (2). The saturated buffer field (2) includes a soil improvement layer 30-100cm below the ground surface and a land cultivation layer set above the soil improvement layer. Crops are planted on the land cultivation layer. Multiple homogeneous water distribution pipes (4) are laid in the soil improvement layer at intervals. Each homogeneous water distribution pipe (4) is set horizontally, and multiple small holes are distributed on the cylindrical surface of each homogeneous water distribution pipe (4). The ecological ditch (1) is equipped with multiple saturated buffer stop valves (5) at its bottom, each corresponding to a homogeneous water distribution pipe (4). Each saturated buffer stop valve (5) includes a sealed box (6). An inlet (7) is provided on the front end of the box (6), and an outlet (8) is provided on the right side wall of the box (6). The outlet (8) is located below the inlet (7). Both the outlet (8) and the inlet (7) are connected to the sealed cavity of the box (6). The inlet (7) is connected to the ecological ditch (1). The surface of the ecological water in the ditch (1) is level, and the outlet (8) is connected to the left end of the homogeneous water distribution pipe (4); the homogeneous water distribution pipe (4) is a rigid PE or PVC pipe, the spacing between the small holes on the homogeneous water distribution pipe (4) is 30~50cm, and the diameter of the small holes is 10~40mm; the slope of the ecological ditch (1) is 0.05~0.5°, and the bottom of the ecological ditch (1) is planted with potted emergent aquatic plants, with a planting density of 5~15 plants / ㎡; It includes the following steps: The working method for farmland-type saturated buffer wetland systems used to control non-point source pollution is as follows: Ecological water in the ecological ditch (1) overflows into the sealed cavity through the inlet (7) of the saturated buffer stop valve (5). Then, the ecological water flows out from the outlet (8) and flows into the homogeneous water distribution pipe (4). Then, the ecological water flows into the improved land layer through the small hole on the homogeneous water distribution pipe (4). Finally, the ecological water permeates into the cultivated layer through the improved land layer. The microorganisms in the ecological water undergo nitrification and denitrification to reduce the content of nitrogen, phosphorus and COD in the cultivated layer. At the same time, they consume the organic matter in the cultivated layer as energy for the reproduction, growth and metabolism of crops in the cultivated layer, thereby reducing the content of organic matter and ultimately achieving the purpose of controlling source pollution in the cultivated layer.

2. The farmland-type saturated buffer wetland system for controlling non-point source pollution according to claim 1, characterized in that: The aforementioned emergent aquatic plants are Thalia dealbata and Acorus calamus.

3. The farmland-type saturated buffer wetland system for controlling non-point source pollution according to claim 2, characterized in that: The spacing between any two adjacent saturated buffer stop valves (5) is equal.

4. The farmland-type saturated buffer wetland system for controlling non-point source pollution according to claim 3, characterized in that: The aforementioned embankment and water-blocking dam (3) is made of permeable concrete or permeable structural components.

Images