Rural domestic sewage treatment system based on physical-biochemical-ecological technology

Abstract

The application discloses a rural domestic sewage treatment system based on physical-biochemical-ecological technology, which comprises a pretreatment unit, an artificial wetland treatment unit, a liquid level control unit and a deep treatment unit, wherein the treatment units are sequentially communicated; and a valve well is arranged between the pretreatment unit and the artificial wetland treatment unit. The rural domestic sewage treatment system based on physical-biochemical-ecological technology has low operation energy consumption, good treatment effect, simple maintenance, can improve the surrounding ecological environment and can realize unattended operation.

Description

Technical Field

[0001] This invention relates to the field of domestic sewage treatment technology, specifically to a rural domestic sewage treatment system based on physical-biochemical-ecological technologies. Background Technology

[0002] With the accelerating pace of urban-rural integration in my country, the rural economy has developed rapidly in recent years. While people's quality of life has improved, new problems have also emerged, with sewage treatment being one of the most critical. Constructed wetlands utilize substrates, plants, and microorganisms to treat sewage through a synergistic combination of physical, chemical, and biological processes. This technology is currently widely used in rural sewage treatment, requiring relatively low investment and yielding significant results, playing a vital role in improving the quality of the rural environment.

[0003] In the treatment of rural domestic sewage using constructed wetlands, vertical subsurface flow constructed wetlands are widely used due to their small footprint and strong decontamination capacity. However, the denitrification capacity of existing vertical subsurface flow constructed wetlands is generally weak. Ammonia nitrogen removal mainly relies on adsorption, plant absorption, and transformation by nitrifying / denitrifying bacteria. The substrate in constructed wetlands easily reaches adsorption saturation, and plant absorption efficiency is low. Therefore, microbial transformation plays a crucial role, and the wetland environment should be able to support the survival of nitrifying and denitrifying bacteria. In addition, phosphorus removal in wetlands mainly depends on substrate adsorption and plant absorption, but plant absorption is limited. To extend the service life of wetlands, the selection of phosphorus removal substrates with strong adsorption capacity and large capacity becomes particularly important. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a rural domestic sewage treatment system based on physical-biochemical-ecological technology, which has the characteristics of low energy consumption, good treatment effect and simple operation and maintenance.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A rural domestic sewage treatment system based on physical-biochemical-ecological technologies is disclosed. The sewage treatment system includes a pretreatment unit, an constructed wetland treatment unit, a liquid level control unit, and an advanced treatment unit, with each treatment unit connected in sequence. A valve well is also provided between the pretreatment unit and the constructed wetland treatment unit.

[0007] The pretreatment unit includes a bar screen, an oil separator, a sedimentation tank, and a biological filter.

[0008] The biofilter is equipped with bioelastic packing material and a water pump for conveying the effluent from the biofilter to the valve well.

[0009] The constructed wetland treatment unit includes a water distribution pipe, a packing unit, and an effluent unit; wetland plants are planted on the upper layer of the packing unit.

[0010] The deep treatment unit includes a stepped structure, which is filled with deep treatment filler. Water-loving plants are planted on the upper layer of the stepped structure. Water from the stepped structure flows into a landscape pond from the outlet at the bottom of the stepped structure. Slope plants are planted on the slope opposite the stepped structure to the landscape pond.

[0011] Furthermore, the packing unit of the constructed wetland treatment unit consists of, from top to bottom, an insulation layer, a functional packing layer, and a phosphorus removal packing layer.

[0012] Furthermore, the functional filler layer is composed of one or more of zeolite, coarse sand, volcanic rock, anthracite, and bentonite mixed in a certain proportion.

[0013] Furthermore, the phosphorus removal filler layer is composed of one or more of gravel, magnetite, sponge iron, and calcite mixed in a certain proportion.

[0014] Furthermore, the water distribution pipe is located in the insulation layer, and holes are drilled evenly every 50-100cm on the water distribution pipe.

[0015] Furthermore, a water distribution valve is installed on the pipeline between the valve well and the constructed wetland treatment unit.

[0016] Furthermore, the valve well is equipped with a first and a second water supply pipe. The first water supply pipe is equipped with a first check valve, and the second water supply pipe is equipped with a second check valve. An ejector is provided after the second check valve, and a return pipe is provided after the ejector for returning part of the wastewater after simple aeration to the biological elastic packing material. A third check valve is provided on the return pipe, and a water distributor is provided at the end of the return pipe.

[0017] Furthermore, the deep-treatment filler is a mixture of limestone and quartz sand of a certain particle size in a certain proportion.

[0018] Furthermore, a baffle is installed 10-30cm to the left of the outlet of the sedimentation tank.

[0019] Furthermore, the wetland plants are one or more of cattails, sweet flag, and reeds;

[0020] The water-loving plants are pickerelweed or iris;

[0021] The slope vegetation consists of annual or perennial herbaceous plants and shrubs.

[0022] The beneficial effects of this invention are as follows:

[0023] The rural domestic sewage treatment system provided by this invention has low energy consumption, good treatment effect, simple maintenance, and improves the surrounding ecological environment. It can achieve unattended operation and provides a technically feasible, economical and ecological rural sewage treatment method for the country to promote ecological civilization construction and rural living environment improvement. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the wastewater treatment system in Embodiment 1 of the present invention;

[0025] Figure 2 This is a design diagram of the deep treatment unit of the sewage treatment system in Embodiment 1 of the present invention;

[0026] Figure 3 This is a schematic diagram of the valve well structure in Embodiment 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of the jet ejector structure used in Embodiment 1 of the present invention;

[0028] Figure 5 This is a graph showing the pollutant removal rate of the wastewater treatment system in Embodiment 1 of the present invention.

[0029] In the diagram: 1-Grit chamber; 2-Oil separator; 3-Sedimentation tank; 3.1-Baffle; 4-Biological filter; 4.1-Biological elastic packing material; 4.2-Water distributor; 4.3-Water pump; 5-Valve well; 5.1-First check valve; 5.2-Ejector; 5.3-Second check valve; 5.4-Third check valve; 5.2.1-Ejector inlet; 5.2.2-Air inlet; 5.2.3-Vacuum chamber; 5.2.4-Nozzle; 5.2.5-Expansion chamber; 5.2.6-Outlet 6-Water inlet; 7-Electrical distribution box; 8-Water distribution valve; 9-Artificial wetland treatment unit; 10-Water distribution pipe; 11-Wetland plants; 12-Insulation layer; 13-Functional filler layer; 14-Phosphorus removal filler layer; 15-Outlet pipe; 16-Level control unit; 17-Deep treatment unit; 18-Stepped structure; 19-Deep treatment filter media; 10-Hydrophilic plants; 10-Landscape pond; 10-Stepped structure outlet; 10-Slope plants. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0031] Example 1:

[0032] like Figure 1As shown, a rural domestic sewage deep treatment system based on physical-biochemical-ecological technology is disclosed. The system includes a pretreatment unit, an artificial wetland treatment unit, a liquid level control unit, and a deep treatment unit, with each treatment unit connected in sequence. A valve well 5 is also provided between the pretreatment unit and the artificial wetland treatment unit.

[0033] The pretreatment unit includes a bar screen 1, an oil separator 2, a sedimentation tank 3, and a biological filter 4;

[0034] The bar screen 1 consists of an inlet, a bar screen, an overflow outlet, and an outlet. A medium-coarse bar screen with a pore size of 10mm is selected.

[0035] A baffle is installed 20cm to the left of the outlet of sedimentation tank 3 to further prevent floating debris from entering the next stage of treatment facilities.

[0036] The pretreatment unit is added to the biological filter 4, and biological elastic packing material 4.1 is added to the biological filter 4. The packing material is suspended and fixed at the top and bottom to prevent floating, with each bundle spaced 10cm apart. A 25m³ / h flow rate filter is installed on the right side of the biological filter 4. 3 / d water pump 4.3, sewage enters valve well 5 through water pump 4.3.

[0037] like Figure 3 , Figure 4 As shown, valve well 5 is equipped with a first and a second water supply pipe. The first water supply pipe is equipped with a first check valve 5.1, and the second water supply pipe is equipped with a second check valve 5.3. A jet injector 5.2 is located downstream of the second check valve, and a return pipe is located downstream of the jet injector 5.2 for returning a portion of the wastewater after simple aeration to the biological elastic packing material. A third check valve 5.4 is located on the return pipe, and a water distributor 4.2 is located at the end of the return pipe. The jet injector 5.2 is equipped with a jet injector inlet 5.2.1, an air inlet 5.2.2, a vacuum chamber 5.2.3, a nozzle 5.2.4, an expansion chamber 5.2.5, and an outlet 5.2.6.

[0038] Opening the first one-way valve 5.1 and closing the second and third one-way valves 5.3 and 5.4 allows the pretreated wastewater to directly enter the wetland after being acted upon by microorganisms in an anoxic environment on the surface of the packing material. Opening the second and third one-way valves 5.3 and closing the first one-way valve 5.1 allows the pretreated wastewater to undergo simple aeration via an ejector, with some entering the wetland and some flowing back to the biological elastic packing material, achieving micro-oxygen treatment. This design allows for intermittent wastewater treatment under both anoxic and micro-oxygen environments.

[0039] The constructed wetland treatment unit includes a water distribution pipe 8.1, an insulation layer 8.3, a functional filler layer 8.4, a phosphorus removal filler layer 8.5, and wetland plants 8.2. The functional filler layer is composed of coarse sand, zeolite, anthracite, and volcanic rock in a volume ratio of 80:10:2:8, with a particle size between 0.25 and 6 mm and a layer thickness of 80 cm. The phosphorus removal filler layer is composed of gravel, magnetite, and calcite in a volume ratio of 5:3:2, with magnetite and calcite particle sizes between 1 and 4 mm, and gravel particle sizes between 8 and 32 mm, and a layer thickness of 20 cm. The wetland plant is cattail. The water distribution pipe 8.1 is located in the insulation layer above the functional filler layer. Every 50 cm, a hole with a diameter of, for example, 8 mm is drilled on each side of the pipe to ensure uniform water replenishment.

[0040] The effluent from the constructed wetland treatment unit is controlled by a liquid level control unit 9. For example, the height of the effluent pipe can be adjusted to 60cm to use the medium liquid level mode.

[0041] The effluent from the constructed wetland treatment unit enters the advanced treatment unit 10. The advanced treatment unit includes a stepped structure 10.1, which is filled with advanced treatment filter media 10.2. Hydrophilic plants 10.3 are planted on the upper layer of the stepped structure. The effluent from the constructed wetland treatment unit enters the advanced treatment unit 10 from the top. An outlet 10.5 is located at the lower end of the stepped structure 10.1. The effluent, after multi-stage treatment, enters the landscape pond 10.4. Slope vegetation 10.5 is planted on the slope opposite the stepped structure and around the landscape pond, while wetland plants are planted around it. The advanced treatment filter media 10.2 is a mixture of limestone and quartz sand of a certain particle size in different proportions. The wetland plants include yellow iris, the hydrophilic plants include pickerelweed, and the slope vegetation includes coreopsis, cosmos, and calendula, to enhance the landscape effect.

[0042] After being collected, domestic sewage is filtered by a screen and then enters an oil separator and sedimentation tank for physical treatment. It then enters a biological filter. After passing through the surface microorganisms of the biological elastic packing material in the biological filter, the sewage enters the wetland. At the same time, the biological filter also has a regulating function. After further treatment in the wetland, the effluent flows through a trapezoidal plant bed and finally enters the landscape pond.

[0043] After tracking and statistical analysis, the actual wastewater treatment effect of the entire system after stable operation is as follows: Figure 5 As shown, the wastewater treatment system achieved an average removal rate of 86.3% for COD, 97.7% for ammonia nitrogen, and 95.9% for total phosphorus.

[0044] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention is also intended to include these modifications and variations.

Claims

1. A rural domestic sewage treatment system based on physical-biochemical-ecological technologies, characterized in that, The wastewater treatment system includes: a pretreatment unit, an artificial wetland treatment unit, a liquid level control unit, and an advanced treatment unit, with each treatment unit connected in sequence; a valve well is also provided between the pretreatment unit and the artificial wetland treatment unit; The pretreatment unit includes a bar screen, an oil separator, a sedimentation tank, and a biological filter. The biofilter is equipped with bioelastic packing material and a water pump for conveying the effluent from the biofilter to the valve well. The valve well is equipped with a first and a second water supply pipe. The first water supply pipe is equipped with a first check valve, and the second water supply pipe is equipped with a second check valve. An ejector is installed after the second check valve, and a return pipe is installed after the ejector to return part of the wastewater after simple aeration to the biological elastic packing material. A third check valve is installed on the return pipe. A water distributor is installed at the end of the return pipe. The constructed wetland treatment unit includes a water distribution pipe, a packing unit, and an effluent unit; wetland plants are planted on the upper layer of the packing unit; the packing unit of the constructed wetland treatment unit consists of, from top to bottom, an insulation layer, a functional packing layer, and a phosphorus removal packing layer; the water distribution pipe is located in the insulation layer; the functional packing layer is composed of one or more of zeolite, coarse sand, volcanic rock, anthracite, and bentonite mixed in a certain proportion; the phosphorus removal packing layer is composed of one or more of gravel, magnetite, sponge iron, and calcite mixed in a certain proportion. The deep treatment unit includes a stepped structure, which is filled with deep treatment filler material, which is a mixture of limestone and quartz sand of a certain particle size in a certain proportion. Water-loving plants are planted on the upper layer of the stepped structure, and the water from the stepped structure flows into the landscape pond from the outlet at the lower part of the stepped structure. Slope plants are planted on the slope opposite the landscape pond and the stepped structure.

2. A rural domestic sewage treatment system based on physical-biochemical-ecological technologies as described in claim 1, characterized in that, Holes are drilled evenly every 50-100cm on the water distribution pipe.

3. A rural domestic sewage treatment system based on physical-biochemical-ecological technologies as described in claim 1, characterized in that, A water distribution valve is installed on the pipeline between the valve well and the constructed wetland treatment unit.

4. A rural domestic sewage treatment system based on physical-biochemical-ecological technologies as described in claim 1, characterized in that, A baffle is installed 10-30cm to the left of the outlet of the sedimentation tank.

5. A rural domestic sewage treatment system based on physical-biochemical-ecological technologies as described in claim 1, characterized in that, The wetland plants are one or more of the following: cattail, sweet flag, and reed. The water-loving plants are pickerelweed or iris; The slope vegetation consists of annual or perennial herbaceous plants and shrubs.

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