Farmland runoff ecological filter ditch water treatment system

Abstract

The utility model discloses an ecological filter ditch water treatment system for farmland runoff, and aims to solve the problem that the removal effect of nitrogen and phosphorus pollutants in the farmland runoff is poor. A water outlet of a buffer tank in the ecological filter ditch water treatment system is connected with a water inlet of a first sedimentation tank through a water pipe, effluent of the first sedimentation tank flows into an ecological filter ditch through an overflow weir, a matrix is laid at the bottom of the ecological filter ditch, aquatic plants are planted in the ecological filter ditch, and an adsorption section is arranged at the water flow tail end of the ecological filter ditch. A ceramsite filler is stacked in the adsorption section, and an anaerobic zone, a first anoxic zone, a first aerobic zone, a second anoxic zone and a second aerobic zone are sequentially arranged in the A / O biological treatment tank along the water flow direction in the A / O biological treatment tank. According to the farmland runoff ecological filter ditch water treatment system, the ecological filter ditch and the A / O biological treatment pond are combined, the removal rate of TN and TP in runoff sewage can reach 85%-95%, and the removal effect of nitrogen and phosphorus pollutants is excellent.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of water treatment, concretely relates to a water treatment system of farmland runoff. BACKGROUND

[0002] Non-point source pollution, also known as diffuse pollution or dispersed source pollution, refers to dissolved and solid pollutants from unspecified locations, which are washed by rainfall or snowmelt and then flow into receiving water bodies (including rivers, lakes, reservoirs and bays, etc.) through runoff processes, causing organic pollution, water eutrophication or other forms of pollution such as toxicity and harm.

[0003] In the process of crop growth, nitrogen fertilizer, phosphorus fertilizer or compound fertilizer is applied in farmland areas, and nitrogen and phosphorus in the fertilizer will remain in the soil and enter the runoff under the scouring action of rainwater, which will cause eutrophication pollution of water bodies. In the field of agriculture, in addition to drainage and irrigation, ditches can also prevent and drain waterlogging, lower groundwater level and improve soil physical and chemical properties to create good environmental conditions for the growth and development of crops. In addition, ditches provide habitats and shelters for various animals in the agricultural ecosystem, thus meeting the growth of aquatic plants and having the effect of purifying wastewater, i.e. the function of wetland ecosystems. Therefore, ditch wetland systems are widely used in non-point source pollution control. However, the effect of using ecological ditches to remove nitrogen and phosphorus pollutants in runoff is limited. SUMMARY

[0004] The utility model aims at solving the problem of poor removal effect of nitrogen and phosphorus pollutants in farmland runoff, and provides a farmland runoff ecological filter ditch water treatment system.

[0005] The farmland runoff ecological filter ditch water treatment system comprises a buffer tank, a first sedimentation tank, an ecological filter ditch, an A / O biological treatment tank and a second sedimentation tank. The outlet of the buffer tank is connected to the inlet of the first sedimentation tank through a water pipe. The outlet of the first sedimentation tank flows into the ecological filter ditch through an overflow weir. Pebbles or gravel are laid at the bottom of the ecological filter ditch. Aquatic plants are planted in the ecological filter ditch. An adsorption section is arranged at the end of the water flow in the ecological filter ditch. Ceramic filler is stacked in the adsorption section.

[0006] The tank body of the A / O biological treatment tank is divided into an anaerobic zone, an anoxic zone and an aerobic zone by a partition. The anaerobic zone, the first anoxic zone, the first aerobic zone, the second anoxic zone and the second aerobic zone are arranged in the tank body of the A / O biological treatment tank in sequence along the water flow direction. An aeration disc is arranged at the bottom of the first aerobic zone and the second aerobic zone. The first aerobic zone is connected to the first anoxic zone through a No. 1 reflux pipe. The second aerobic zone is connected to the second anoxic zone through a No. 2 reflux pipe.

[0007] The outlet of the A / O biological treatment tank is connected to the inlet of the second sedimentation tank through a water pipe.

[0008] The farmland runoff ecological filter ditch water treatment system mainly comprises a buffer pool, a first sedimentation pool, an ecological filter ditch, an A / O biological treatment pool and a second sedimentation pool, floating matters in farmland runoff sewage are intercepted by a grid arranged in the buffer pool, and then flow into the first sedimentation pool for sand setting treatment, and then flow into the ecological filter ditch, the root system of aquatic plants in the ecological filter ditch can absorb nitrogen and phosphorus pollutants, soluble organic matters can also be adsorbed by the biological membrane of the plant root system, and can be degraded and removed by anaerobic and aerobic biological metabolism, the biological membrane on the substrate can remove nitrogen by nitrification and denitrification, but the removal effect of the ecological filter ditch on heavy metal ions is limited, therefore, an adsorption section is arranged at the end of the water flow of the ecological filter ditch, the heavy metal can be adsorbed and removed by the ceramic filler, and the biodegradability of the farmland runoff sewage is improved. The A / O biological treatment pool strengthens denitrification and phosphorus removal, the anaerobic phosphorus release reaction is carried out in the anaerobic zone, the carbon source in the water is converted into organic particles PHB in the body, so that the aerobic phosphorus absorption is carried out in the subsequent aerobic zone. Two-stage anaerobic zones and aerobic zones are arranged, and nitrification and denitrification are carried out respectively to strengthen denitrification.

[0009] The farmland runoff ecological filter ditch water treatment system can remove 85% to 95% of TN and TP in farmland runoff sewage, and has excellent removal effect on nitrogen and phosphorus pollutants. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is a top view structural schematic view of the farmland runoff ecological filter ditch water treatment system.

[0011] Figure 2 It is an internal structure schematic view of the A / O biological treatment pool. DETAILED DESCRIPTION

[0012] Specific implementation manner one: the farmland runoff ecological filter ditch water treatment system comprises a buffer pool 1, a first sedimentation pool 2, an ecological filter ditch 3, an A / O biological treatment pool 4 and a second sedimentation pool 5, the water outlet of the buffer pool 1 is connected with the water inlet of the first sedimentation pool 2 through a water pipe, the water outlet of the first sedimentation pool 2 flows into the ecological filter ditch 3 through an overflow weir, the bottom of the ecological filter ditch 3 is paved with a substrate, the substrate is pebbles or gravel, aquatic plants 3-1 are planted in the ecological filter ditch 3, an adsorption section 3-2 is arranged at the end of the water flow of the ecological filter ditch 3, and ceramic filler is stacked in the adsorption section 3-2.

[0013] The A / O biological treatment tank 4 is divided into an anaerobic zone 4-1, an anoxic zone and an aerobic zone by a partition plate. The anaerobic zone 4-1, the first anoxic zone 4-2, the first aerobic zone 4-3, the second anoxic zone 4-4 and the second aerobic zone 4-5 are sequentially arranged in the tank body of the A / O biological treatment tank 4 along the water flow direction. The aeration plates are arranged at the bottom of the first aerobic zone 4-3 and the second aerobic zone 4-5. The first aerobic zone 4-3 is connected with the first anoxic zone 4-2 through the first reflux pipe 7-1. The second aerobic zone 4-5 is connected with the second anoxic zone 4-4 through the second reflux pipe 7-2.

[0014] The effluent of the A / O biological treatment tank 4 is connected with the water inlet of the second sedimentation tank 5 through a water pipe.

[0015] Specific embodiment two: The difference between the embodiment and the specific embodiment one is that the length of the adsorption section 3-2 in the ecological filter ditch 3 is 1-2 m.

[0016] Specific embodiment three: The difference between the embodiment and the specific embodiment one or two is that the total length of the ecological filter ditch 3 is 35-60 m.

[0017] Specific embodiment four: The difference between the embodiment and one of the specific embodiments one to three is that the aquatic plants in the ecological filter ditch 3 are acorus calamus, reed, canna or zantedeschia aethiopica.

[0018] Specific embodiment five: The difference between the embodiment and one of the specific embodiments one to four is that the sludge reflux port is opened at the bottom of the second sedimentation tank 5. One end of the sludge return pipe 6 is connected with the sludge reflux port, and the other end of the sludge return pipe 6 is connected with the anaerobic zone 4-1.

[0019] The embodiment makes the sludge in the second sedimentation tank 5 reflux into the anaerobic zone 4-1 through the sludge return pipe.

[0020] Specific embodiment six: The difference between the embodiment and one of the specific embodiments one to five is that the stirring devices are arranged in the anaerobic zone 4-1, the first anoxic zone 4-2 and the second anoxic zone 4-4 of the A / O biological treatment tank 4.

[0021] Example: The farmland runoff ecological filter ditch water treatment system includes a buffer tank 1, a first sedimentation tank 2, an ecological filter ditch 3, an A / O biological treatment tank 4 and a second sedimentation tank 5. The effluent of the buffer tank 1 is connected with the water inlet of the first sedimentation tank 2 through a water pipe. The effluent of the first sedimentation tank 2 flows into the ecological filter ditch 3 through an overflow weir. The substrate is laid at the bottom of the ecological filter ditch 3. The substrate is gravel. The aquatic plants 3-1 are planted in the ecological filter ditch 3. The aquatic plants 3-1 are acorus calamus. The adsorption section 3-2 is arranged at the water flow end of the ecological filter ditch 3. The ceramsite filler is stacked in the adsorption section 3-2. The length of the ecological filter ditch 3 is 37 m. The ecological filter ditch 3 is an S-shaped filter ditch.

[0022] The A / O biological treatment tank 4 is divided into an anaerobic zone 4-1, an anoxic zone and an aerobic zone by a partition plate. The anaerobic zone 4-1, a first anoxic zone 4-2, a first aerobic zone 4-3, a second anoxic zone 4-4 and a second aerobic zone 4-5 are sequentially arranged in the tank body of the A / O biological treatment tank 4 along the water flow direction. An aeration plate is arranged at the bottom of the first aerobic zone 4-3 and the second aerobic zone 4-5. The first aerobic zone 4-3 is connected with the first anoxic zone 4-2 through a first reflux pipe 7-1. The second aerobic zone 4-5 is connected with the second anoxic zone 4-4 through a second reflux pipe 7-2. Water pumps are arranged on the first reflux pipe 7-1 and the second reflux pipe 7-2, respectively.

[0023] The effluent of the A / O biological treatment tank 4 is connected with the water inlet of the second sedimentation tank 5 through a water pipe. A sludge reflux port is opened at the bottom of the second sedimentation tank 5. One end of a sludge return pipe 6 is connected with the sludge reflux port, and the other end of the sludge return pipe 6 is connected with the anaerobic zone 4-1.

[0024] The A / O biological treatment tank 4 of the embodiment can adopt two-point water inlet, and water is respectively introduced from the anaerobic zone 4-1 and the second anoxic zone 4-4. The A / O biological treatment tank 4 is inoculated with activated sludge. The hydraulic retention time of the A / O biological treatment tank is controlled to be 10 h.

[0025] In the farmland runoff wastewater of the embodiment, the COD is 105.2 mg / L, the TN is 36.3 mg / L, and the TP is 4.6 mg / L. The farmland runoff ecological filter ditch water treatment system is used for treatment. The COD of the effluent of the second sedimentation tank is 9.55 mg / L, the TN is 4.5 mg / L, and the TP is 0.28 mg / L.

Claims

1. The farmland runoff ecological filter ditch water treatment system is characterized by The farmland runoff ecological filter ditch water treatment system comprises a buffer tank (1), a first sedimentation tank (2), an ecological filter ditch (3), an A / O biological treatment tank (4) and a second sedimentation tank (5); the water outlet of the buffer tank (1) is connected to the water inlet of the first sedimentation tank (2) through a water pipe; the effluent of the first sedimentation tank (2) flows into the ecological filter ditch (3) through an overflow weir; a substrate is laid at the bottom of the ecological filter ditch (3), the substrate being pebbles or gravel; aquatic plants (3-1) are planted in the ecological filter ditch (3); an adsorption section (3-2) is provided at the water flow end of the ecological filter ditch (3); and ceramsite filler is stacked in the adsorption section (3-2); The A / O biological treatment tank (4) is divided into an anaerobic zone (4-1), an anoxic zone and an aerobic zone by a partition. The anaerobic zone (4-1), a first anoxic zone (4-2), a first aerobic zone (4-3), a second anoxic zone (4-4) and a second aerobic zone (4-5) are sequentially arranged in the tank body of the A / O biological treatment tank (4) along the direction of water flow. Aeration disks are arranged at the bottoms of the first aerobic zone (4-3) and the second aerobic zone (4-5). The first aerobic zone (4-3) is connected to the first anoxic zone (4-2) through a first return pipe (7-1), and the second aerobic zone (4-5) is connected to the second anoxic zone (4-4) through a second return pipe (7-2). The effluent from the A / O biological treatment tank (4) is connected to the water inlet of the second sedimentation tank (5) through a water pipe.

2. The farmland runoff ecological filter ditch water treatment system according to claim 1 is characterized in that The length of the adsorption section (3-2) in the ecological filter ditch (3) is 1 to 2 meters.

3. The farmland runoff ecological filter ditch water treatment system according to claim 1 is characterized in that The total length of the ecological filter ditch (3) is 35 to 60 m.

4. The farmland runoff ecological filter ditch water treatment system according to claim 1 is characterized in that The aquatic plants in the ecological filter ditch (3) are calamus, reed, canna or calla lily.

5. The farmland runoff ecological filter ditch water treatment system according to claim 1 is characterized in that A sludge return port is provided at the bottom of the second sedimentation tank (5), one end of a sludge return pipe (6) is connected to the sludge return port, and the other end of the sludge return pipe (6) is connected to the anaerobic zone (4-1).

6. The farmland runoff ecological filter ditch water treatment system according to claim 1 is characterized in that A stirring device is provided in the anaerobic zone (4-1), the first anoxic zone (4-2) and the second anoxic zone (4-4) of the A / O biological treatment tank (4).

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