Subsurface flow constructed wetland sewage treatment system

Abstract

The utility model discloses a sewage treatment system for a subsurface flow constructed wetland. The sewage treatment system comprises a water distribution channel, a wetland unit and a water outlet channel which are connected in sequence, the water distribution channel is connected with a wetland water inlet pipe through a first conical filter, the water distribution channel is further connected with a connecting pipe used for being connected with the front water treatment unit, and an emptying opening is formed in the bottom of the water distribution channel; a bottom porous filter plate is arranged between the wetland unit and the water distribution channel, the wetland unit comprises a traditional filler area, wetland plants are planted in the traditional filler area, a porous filter column is further arranged in the traditional filler area, and a functional filler is arranged in the porous filter column; the water outlet channel is connected with a wetland water outlet pipe through a water outlet flow distribution valve, the water outlet flow distribution valve is further connected with a backflow pipe through a second conical filter, and the backflow pipe is used for being connected with the front water treatment unit. According to the utility model, the sewage can directly or indirectly pass through the constructed wetland to realize deep purification of water quality, so that the emission standard is reached, and the economical efficiency and the adaptability are excellent.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a subsurface flow constructed wetland wastewater treatment system. Background Technology

[0002] With rapid urbanization and continuous population growth, the total discharge of domestic sewage is increasing, leading to eutrophication of water bodies and frequent algal blooms. Under the low-carbon concept, efficient treatment technologies are urgently needed. Currently, mainstream domestic sewage treatment technologies, whether traditional processes like activated sludge and biofilm processes or emerging technologies like membrane bioreactors, all suffer from varying degrees of instability and high energy consumption when dealing with fluctuations in water volume and quality in small and medium-sized sewage treatment processes. In terms of stability, the traditional activated sludge process has poor tolerance to fluctuations in water quality and quantity. Once the influent water quality changes significantly, the activated sludge on which the microorganisms depend for survival will experience problems such as expansion and disintegration, resulting in poor treatment effects and difficulty in consistently meeting effluent standards. Although the biofilm process has slightly better shock resistance, under extreme conditions such as low temperature and high load, the biofilm will also detach, seriously affecting treatment efficiency. Regarding energy consumption, the aeration system of the activated sludge process operates at high power for extended periods to meet the aerobic needs of microorganisms, consuming a large amount of energy. In the membrane filtration stage, membrane bioreactors require pumps to maintain flux, and energy consumption increases even more after membrane fouling, which contradicts the concept of green development. Therefore, it is particularly urgent and necessary to develop and promote new domestic wastewater treatment technology systems that are stable, efficient, and low-consumption, in order to enhance the removal capacity of nutrients such as nitrogen and phosphorus from receiving water bodies and reduce the risk of eutrophication. Utility Model Content

[0003] This utility model aims to solve the problems existing in the prior art and provides a subsurface flow constructed wetland sewage treatment system, which enables sewage to pass directly or indirectly through the constructed wetland to achieve deep water purification, thereby meeting discharge standards. It has excellent economic efficiency and adaptability.

[0004] The technical solution of this utility model is: a subsurface flow constructed wetland wastewater treatment system, comprising a distribution channel, a wetland unit, and an outlet channel connected in sequence; the distribution channel is connected to a wetland inlet pipe through a first conical filter, and a connecting pipe for connecting to a pre-treatment unit is also connected to the distribution channel, with an outlet at the bottom of the distribution channel; a bottom porous filter plate is provided between the wetland unit and the distribution channel, the wetland unit includes a traditional packing area planted with wetland plants, and a porous filter column containing functional packing material is also provided in the traditional packing area; the outlet channel is connected to a wetland outlet pipe through an outlet flow distribution valve, and the outlet flow distribution valve is also connected to a return pipe through a second conical filter, the return pipe being used to connect to the pre-treatment unit.

[0005] Furthermore, in this invention, multiple porous filter columns are arranged at intervals along the direction of water inlet flow, and the distance between two adjacent porous filter columns is 35-40% of the total length of the wetland unit.

[0006] Furthermore, in this invention, the porous filter column is vertically arranged in the conventional packing area, and the diameter of the porous filter column is 20-25% of the total width of the wetland unit.

[0007] Furthermore, the porous filter column of this invention has several round holes with a diameter of 6 to 8 mm on its surface, and the distance between two adjacent round holes is 8 to 10 mm. The round holes are evenly distributed on the surface of the porous filter column.

[0008] Furthermore, in this utility model, the traditional filler zone consists of a pebble layer, a gravel layer, and a fine sand layer from bottom to top.

[0009] Furthermore, in this invention, several wetland plants are planted at equal intervals in the traditional filler area, and the roots of the wetland plants are fixed at a depth of 20-30mm in the fine sand layer.

[0010] This utility model has the following advantages compared with the prior art:

[0011] 1) The subsurface flow constructed wetland of this utility model can be used in conjunction with a pre-treatment water unit to treat sewage. Some sewage can directly enter the subsurface flow constructed wetland without going through the pre-treatment water unit. The wetland’s strong shock resistance reduces the load on the pre-treatment water unit. At the same time, the sewage treated by the pre-treatment water unit can also enter the subsurface flow constructed wetland to achieve deep water purification, thereby meeting the discharge standards. It has excellent economy and adaptability.

[0012] 2) This utility model uses a recirculation assembly consisting of a second conical filter and a recirculation pipe to achieve recirculation, which can cope with the load impact caused by fluctuations in water quality and quantity; in the low-temperature season, the recirculation assembly reduces heat loss through water circulation and improves the system's resilience.

[0013] 3) In this utility model, the substrate and vegetation in the subsurface flow constructed wetland have a loose and porous surface structure and a well-developed root system, which can play a physical buffering role in the treatment of sewage; at the same time, the complex ecosystem composed of microorganisms, plants and substrate in the wetland has high biodiversity and a certain self-regulation and repair capacity, which can treat sewage through multiple physical, chemical and biological processes, and greatly improve the system's shock resistance and treatment effect. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model (where the arrows indicate the direction of water flow);

[0015] Figure 2 This is a schematic diagram showing the specific layout of the water distribution channel, the wetland unit, and the outlet channel in this utility model.

[0016] The components include: 1. Wetland inlet pipe; 2. First cone filter; 3. Connecting pipe; 4. Water distribution channel; 5. Drain outlet; 6. Bottom porous filter plate; 7. Traditional packing area; 8. Wetland plants; 9. Porous filter column; 10. Functional packing material; 11. Outlet channel; 12. Outlet flow distribution valve; 13. Wetland outlet pipe; 14. Second cone filter; 15. Return pipe. Detailed Implementation

[0017] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0018] Example:

[0019] The accompanying drawings illustrate a specific implementation of a subsurface flow constructed wetland wastewater treatment system of this utility model. It mainly includes a water distribution channel 4, a wetland unit, and an outlet channel 11 connected in sequence. The water distribution channel 4 is connected to a wetland inlet pipe 1 through a first conical filter 2. The water distribution channel 4 is also connected to a connecting pipe 3 for connecting to a pre-treatment water unit. The bottom of the water distribution channel 4 is provided with an outlet 5.

[0020] A bottom porous filter plate 6 is installed between the wetland unit and the water distribution channel 4. The wetland unit includes a traditional filler area 7, which consists of a pebble layer, a gravel layer, and a fine sand layer from bottom to top. Wetland plants 8 are planted in the traditional filler area 7. Several wetland plants 8 are planted at equal intervals in the traditional filler area 7. The roots of the wetland plants 8 are fixed at a depth of 20-30 mm in the fine sand layer.

[0021] The traditional packing zone 7 is also equipped with porous filter columns 9. Multiple porous filter columns 9 are arranged at intervals along the direction of water inlet flow. The distance between two adjacent porous filter columns 9 is 35-40% of the total length of the wetland unit. The porous filter columns 9 are vertically arranged in the traditional packing zone 7. The diameter of the porous filter columns 9 is 20-25% of the total width of the wetland unit. The surface of the porous filter columns 9 is provided with several round holes with a diameter of 6-8 mm. The distance between two adjacent round holes is 8-10 mm. The round holes are evenly distributed on the surface of the porous filter columns 9.

[0022] Each porous filter column 9 is equipped with functional packing material 10. The functional packing material 10 is flexibly configured with various self-developed functional packing materials such as calamus-based composite solid carbon source packing material, calamus-based biochar composite solid antibiotic adsorption packing material, and modified steel slag-based composite functional packing material according to the characteristics of water quality, so as to deeply remove nitrogen, phosphorus, antibiotics and other components in the water. The packing material can be replaced regularly according to the performance of various packing materials.

[0023] The outlet channel 11 is connected to the wetland outlet pipe 13 through the outlet flow distribution valve 12. The outlet flow distribution valve 12 is also connected to the return pipe 15 through the second cone filter 14. The return pipe 15 is used to connect to the pre-treatment water unit.

[0024] In this embodiment, the subsurface flow constructed wetland works in conjunction with a pre-treatment unit to treat wastewater. The pre-treatment unit can be a membrane aeration biofilm reactor. Part of the wastewater enters the subsurface flow constructed wetland directly, bypassing the pre-treatment unit. This portion of wastewater enters the distribution channel 4 after being filtered by the first conical filter 2 through the wetland inlet pipe 1. Another portion of the wastewater is treated by the pre-treatment unit before entering the subsurface flow constructed wetland, and this portion is discharged into the distribution channel 4 through the connecting pipe 3. The distribution channel 4 collects water from the pre-treatment unit and raw water that directly enters the subsurface flow constructed wetland. The water in the distribution channel 4 first enters the wetland unit through the bottom porous filter plate 6. During operation, the substrate, plants, and microorganisms remove pollutants from the water through a combination of physical, chemical, and biological degradation. The effluent overflows into the effluent channel 11 and is then discharged from the wetland outlet pipe 13. When the water quality fluctuates significantly, adjust the outlet flow distribution valve 12 and set the reflux ratio to 0-60%. The reflux liquid is filtered by the second conical filter 14 and then returned to the pre-treatment water unit through the reflux pipe 15 for wastewater recycling treatment.

[0025] Of course, the above embodiments are only for illustrating the technical concept and features of this utility model, and their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All modifications made in accordance with the spirit and essence of the main technical solution of this utility model should be covered within the protection scope of this utility model.

Claims

1. A subsurface constructed wetland wastewater treatment system characterized by: The application relates to a water treatment device, which comprises a water distribution channel (4), a wetland unit and a water outlet channel (11) connected in sequence; the water distribution channel (4) is connected with a wetland water inlet pipe (1) through a first conical filter (2), and a connecting pipe (3) for connecting a front water treatment unit is further connected to the water distribution channel (4); a bottom emptying port (5) is arranged at the bottom of the water distribution channel (4); a bottom porous filter plate (6) is arranged between the wetland unit and the water distribution channel (4); the wetland unit comprises a traditional filler area (7), wetland plants (8) are planted in the traditional filler area (7), and a porous filter column (9) is further arranged in the traditional filler area (7); the porous filter column (9) is arranged with functional filler (10); the water outlet channel (11) is connected with a wetland water outlet pipe (13) through a water outlet flow distribution valve (12), the water outlet flow distribution valve (12) is further connected with a backflow pipe (15) through a second conical filter (14), and the backflow pipe (15) is used for connecting the front water treatment unit.

2. The subsurface constructed wetland wastewater treatment system of claim 1, wherein: A plurality of porous filter columns (9) are arranged along the water inflow direction, and the interval between two adjacent porous filter columns (9) is 35-40% of the total length of the wetland unit.

3. The subsurface constructed wetland wastewater treatment system of claim 1, wherein: The porous filter column (9) is vertically arranged in the traditional filler area (7), and the diameter of the porous filter column (9) is 20-25% of the total width of the wetland unit.

4. The subsurface constructed wetland wastewater treatment system of claim 1, wherein: The surface of the porous filter column (9) is provided with a plurality of circular holes with a diameter of 6-8 mm, the interval between two adjacent circular holes in the upper and lower positions or in the left and right positions is 8-10 mm, and the plurality of circular holes are uniformly distributed on the surface of the porous filter column (9).

5. The subsurface constructed wetland wastewater treatment system of claim 1, wherein: The traditional filler area (7) comprises, from bottom to top, a cobblestone layer, a gravel layer and a fine sand layer.

6. The subsurface constructed wetland wastewater treatment system of claim 5, wherein: A plurality of wetland plants (8) are planted in the traditional filler area (7) at equal intervals, and the root system of the wetland plant (8) is fixed in the fine sand layer at a depth of 20-30 mm.

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