A sewage treatment device

Abstract

The present invention relates to the technical field of sewage treatment, and specifically to a sewage treatment device, comprising a reaction channel unit, a sludge recovery unit and a light supply unit; the reaction channel unit is arranged to extend in a reciprocating manner from bottom to top, comprising a granulation channel and a sedimentation channel located above the granulation channel, the lower end of the granulation channel is a liquid inlet, the upper end of the granulation channel is connected with the lower end of the sedimentation channel, the upper end of the sedimentation channel is a liquid outlet, and the aperture of the sedimentation channel is larger than the aperture of the granulation channel; the sedimentation channel is provided with a gas collecting port near the liquid outlet, and the gas collecting port is connected with the granulation channel through a first branch pipe; the sludge recovery unit is connected to the granulation channel through a second branch pipe; the light supply unit provides light for the reaction channel unit; it is flexible in operation and simple in management, can occupy less space, consume less energy, and efficiently treat urban domestic sewage, and recover carbon, nitrogen and phosphorus resources in the sewage, thereby achieving zero emission of sewage and waste gas.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a sewage treatment device. Background Art

[0002] Currently, sewage treatment plants or integrated treatment facilities require a complex, multi-unit operation structure. Aeration and agitation are used to provide an aerobic environment for microorganisms, and gravity sedimentation tanks are used for solid-liquid separation to separate flocs from the sewage mixture. This occupies a large area, is costly to construct, and is complex to operate and manage. Furthermore, the sewage treatment process is often accompanied by the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide, which can easily cause secondary atmospheric pollution. Furthermore, the operation of sewage treatment plants or treatment facilities lacks flexibility, significantly reducing treatment efficiency when sewage quality and quantity fluctuate.

[0003] Currently, wastewater treatment plants or integrated treatment facilities often use visible flocculent microorganisms composed of various types of microorganisms, including bacteria, molds, actinomycetes, and yeasts, forming a relatively balanced ecosystem. Microorganisms oxidize and degrade organic matter in wastewater, partially breaking it down into water and carbon dioxide, while others synthesize new cellular material, forming flocs. Since the microorganisms used in wastewater treatment are primarily aerobic, aeration and agitation are required to create an aerobic environment, consuming significant amounts of electricity. Since wastewater purification requires the separation of flocs from the wastewater mixture, gravity sedimentation tanks are required for solid-liquid separation, increasing floor space and construction costs. Due to the limited adsorption and absorption capacity of bacteria for pollutants such as nitrogen and phosphorus, activated sludge generally has low nitrogen and phosphorus removal rates, leading to nutrient loss and ineffective recycling in wastewater, posing aquatic ecological risks such as eutrophication to the discharged water. The wastewater treatment process is often accompanied by the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide, which can easily cause secondary atmospheric pollution. In addition, the operation of sewage treatment plants or treatment devices lacks flexibility. When the quality and quantity of sewage fluctuate, the sewage treatment efficiency will be greatly reduced. Summary of the Invention

[0004] The purpose of the present invention is to provide a sewage treatment device with flexible operation, simple management, small footprint, low energy consumption, high efficiency in treating urban domestic sewage, and recovery of carbon, nitrogen and phosphorus resources in the sewage, achieving zero discharge of sewage and waste gas.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The present application provides a sewage treatment device, including a reaction channel unit, a sludge recovery unit and a light supply unit; the reaction channel unit is arranged to extend in a reciprocating manner from bottom to top, including a granulation channel and a sedimentation channel located above the granulation channel, the lower end of the granulation channel is a liquid inlet, the upper end of the granulation channel is connected to the lower end of the sedimentation channel, the upper end of the sedimentation channel is a liquid outlet, the aperture of the sedimentation channel is larger than the aperture of the granulation channel; the sedimentation channel is provided with an air collecting port near the liquid outlet, the air collecting port is connected to the granulation channel through a first branch pipe; the sludge recovery unit is connected to the granulation channel The granulation flow channel is connected through a second branch pipe; the light supply unit provides light for the reaction flow channel unit; the sewage to be treated and the preset microorganisms are transported to the granulation flow channel through the liquid inlet, and under the light induction of the light supply unit, the pollutants in the sewage to be treated are absorbed and degraded by the preset microorganisms to produce mixed-culture granular sludge; after the sewage to be treated flows through the sedimentation flow channel, the flow velocity decays, and the mixed-culture granular sludge is intercepted in the granulation flow channel and collected and processed by the sludge recovery unit; the waste gas generated in the treatment process is introduced into the granulation flow channel along the gas collecting port through the first branch pipe and is absorbed and degraded by the mixed-culture granular sludge.

[0007] In some embodiments, the sludge recovery unit includes a crushing component, a sorting component and an activation component; the crushing component is used to crush the collected mixed-culture granular sludge; the sorting component is used to sort the crushed mixed-culture granular sludge to obtain sludge that meets the preset particle size requirements; the activation component is used to activate the sludge after sorting.

[0008] In some embodiments, activated sludge is used as the predetermined microorganism donor.

[0009] In some embodiments, the sludge recovery unit is arranged in a recovery tank, the crushing component is an ultrasonic plate arranged on the side wall of the recovery tank, and the sorting component is an electromagnetic plate arranged on the bottom surface of the recovery tank.

[0010] In some embodiments, the reaction channel unit has a slope of 5-10% relative to the horizontal line.

[0011] In some embodiments, a photovoltaic power supply unit is further included to supply power to the sludge recovery unit and the light supply unit.

[0012] In some embodiments, the granulation channel includes several first straight tubes and first bent tubes connecting the several first straight tubes, and the several first straight tubes are arranged alternately and obliquely from bottom to top. The first bent tubes are used to connect the ends of adjacent first straight tubes. The lower end of the lowest first straight tube is the liquid inlet, and the upper end of the highest first straight tube is connected to the lower end of the sedimentation channel.

[0013] In some embodiments, the sedimentation channel includes a plurality of second straight tubes and second curved tubes connecting the plurality of second straight tubes, the plurality of second straight tubes are alternately arranged obliquely from bottom to top, the second curved tubes are used to connect the ends of adjacent second straight tubes, the lower end of the lowest second straight tube is connected to the upper end of the granulation channel, and the upper end of the highest second straight tube is the liquid outlet.

[0014] In some embodiments, the granulation channel and the sedimentation channel are connected by a reducing pipe.

[0015] In some embodiments, the preset microorganisms are autotrophic and heterotrophic symbiotic microorganisms, with heterotrophic bacteria such as Comamonas and Actinomycetes as the basic structure of the sludge, and autotrophic bacteria such as Spirulina and Chlorobacterium are coated on the surface.

[0016] Beneficial effects of the present invention:

[0017] 1. The present invention arranges a reaction channel by extending and bending back and forth from bottom to top, and the reaction channel includes a granulation channel and a sedimentation channel located above the granulation channel. The aperture of the sedimentation channel is larger than that of the granulation channel. Three purification functional zones, namely a granulation reaction zone, a variable speed separation zone, and a slow sedimentation zone, are formed in the same reaction channel, achieving functions such as sludge granulation, pollutant absorption, mud-water separation, and sludge sedimentation. Unlike horizontal or upward flow, sewage flows in a vertical upward and zigzag manner in the sewage treatment device described in the present invention. The sewage to be treated and the preset microorganisms are transported to the granulation channel through the liquid inlet. Under the light induction of the light supply unit, the pollutants in the sewage to be treated are absorbed and degraded by the preset microorganisms, producing mixed-breeding granular sludge. In addition, the setting of the bending position in the reaction channel causes the fluid flow rate to attenuate and form vortices. The vortex shears the surface of the mixed-culture granular sludge, causing it to shed any aged bacteria that have already absorbed and metabolized pollutants in the previous straight tube. This keeps the surface of the granular sludge in the reaction channel coated with rapidly growing new bacteria, maintaining the granular sludge's high degradation activity. The vortex shearing effect at the bend also maintains a uniform particle size in the reaction channel, facilitating full contact between the granular sludge and pollutants, enhancing the mass transfer process of degradation, and facilitating the separation and sedimentation of mud and water in the reaction channel. After the wastewater to be treated flows through the sedimentation channel, the flow rate decays, and the mixed-culture granular sludge is intercepted in the granulation channel and collected and processed by the sludge recovery unit. The device has a compact overall structure, a small footprint, low cost, and is easy to flexibly combine and operate.

[0018] 2. The sewage treatment device of the present invention, through the installation of a light supply unit, the vertical upward and zigzag flow of sewage along the reaction channel, and the addition of a preset activator, induces the production of a mixed-trophic granular sludge with autotrophic and heterotrophic symbiosis. This not only retains the organic matter removal of aerobic heterotrophic bacteria, but also enables the absorption and removal of nitrogen and phosphorus by autotrophic bacteria, thus resolving the low nitrogen and phosphorus removal rates of current sewage biochemical treatment technologies. Furthermore, the oxygen released by the growing autotrophic bacteria is provided to the growth of aerobic heterotrophic bacteria, eliminating the need for energy-consuming operations such as aeration, thereby reducing operating and maintenance costs.

[0019] 3. The sludge recovery unit of the sewage treatment device described herein utilizes electromagnetic plates on the bottom of the recovery tank and ultrasonic plates on the side to achieve a single-step dehydration and concentration of the recovered polyculture granular sludge, sludge extraction and thickening, and modification and activation of active substances, thereby reducing sludge treatment and disposal costs. Furthermore, the concentrated sludge solution, rich in organic matter, nitrogen, and phosphorus, can be directly used as fertilizer and feed. The sewage treatment device described herein achieves the multiple goals of sewage treatment, sludge disposal, and resource utilization.

[0020] 4. The sewage treatment device of the present invention sets a gas collecting port near the liquid outlet of the sedimentation channel. The gas collecting port is connected to the granulation channel through a first branch pipe, thereby completely introducing the greenhouse gases generated in the sewage treatment process into the mixed-culture granular sludge layer in the granulation channel, thereby strengthening the disturbance and mixing of the mixed-culture granular sludge layer, and promoting the autotrophic bacteria in the mixed-culture granular sludge to fully metabolize, absorb and utilize the gas, thereby achieving zero emission of greenhouse gases in the sewage treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of the sewage treatment device described in an embodiment of the present application;

[0022] Figure 2 This is a top view of the sewage treatment device described in an embodiment of the present application;

[0023] Figure 3 This is a schematic diagram of backwashing of the sewage treatment device described in the embodiment of the present application.

[0024] In the figure, 1 is a reaction channel unit, 11 is a granulation channel, 111 is a first straight pipe, 112 is a first curved pipe, 12 is a sedimentation channel, 121 is a second straight pipe, 122 is a second curved pipe, 13 is a liquid inlet, 14 is a liquid outlet, 15 is a reducing pipe, 2 is a sludge recovery unit, 3 is a light supply unit, 4 is a gas collecting port, 5 is a first branch pipe, 6 is a second branch pipe, 7 is a photoelectric energy supply unit, 8 is a reactor, 9 is a honeycomb cleaning cotton, 100 is a water distribution pipe, 200 is a water collecting pipe, and 300 is a sludge discharge pipe. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0026] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. The illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0027] See also Figure 1 As shown, an embodiment of the present application provides a sewage treatment device, including a reaction channel unit 1, a sludge recovery unit 2, and a light supply unit 3; the reaction channel unit 1 is arranged to extend in a reciprocating manner from bottom to top, including a granulation channel 11 and a sedimentation channel 12 located above the granulation channel 11, the lower end of the granulation channel 11 is a liquid inlet 13, the upper end of the granulation channel 11 is connected to the lower end of the sedimentation channel 12, the upper end of the sedimentation channel 12 is a liquid outlet 14, and the aperture of the sedimentation channel 12 is larger than that of the granulation channel 11. The sludge recovery unit 2 is connected to the granulation channel 11 through a second branch pipe 6. The light supply unit 3 provides light to the granulation channel 11.

[0028] During specific treatment, the sewage to be treated and the preset microorganisms are transported to the granulation channel 11 below the reaction channel unit 1 through the liquid inlet 13, and flow along the granulation channel 11 in a vertical upward and zigzag manner. Under the light induction of the light supply unit 3, the pollutants in the sewage to be treated will be absorbed and degraded by the preset microorganisms, producing mixed-culture granular sludge, achieving pollutant absorption and sludge granulation. As the sewage to be treated continues to flow in, it will flow from the granulation channel 11 into the sedimentation channel 12. Since the aperture of the sedimentation channel 12 is larger than the aperture of the granulation channel 11, the flow rate of the sewage to be treated will decay after flowing through the sedimentation channel 12, and the formed mixed-culture granular sludge will be intercepted in the granulation channel 11 and precipitated under the action of gravity to form a sludge layer. When the sludge layer reaches the preset thickness, the second branch pipe 6 is opened, and the mixed-culture granular sludge is passed into the sludge recovery unit 2 for recovery and treatment. After the sewage to be treated flows into the sedimentation channel 12, the flow rate is lower than that of the granulation channel 11. The organic matter, nitrogen, phosphorus and other pollutants in the sewage are fully degraded to form particulate precipitation. The particulate precipitation will sink into the granulation channel 11 under the action of gravity and mix with the mixed-breeding granular sludge.

[0029] Currently, the sewage treatment process is often accompanied by the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide, which can easily cause secondary pollution to the atmosphere. The sewage treatment device of the present invention provides a gas collecting port 4 near the liquid outlet 14 in the sedimentation channel 12. The gas collecting port 4 is connected to the granulation channel 11 through the first branch pipe 5, thereby completely introducing the greenhouse gases generated by the sewage treatment process into the mixed-culture granular sludge layer in the granulation channel 11. This strengthens the disturbance and mixing of the mixed-culture granular sludge layer, promotes the autotrophic bacteria in the mixed-culture granular sludge to fully metabolize, absorb and utilize the gases, and achieves zero greenhouse gas emissions during the sewage treatment process. It also effectively controls the internal air pressure of the reaction channel unit 1, reduces high-pressure shock, and ensures the stability of the treatment process.

[0030] In some embodiments, the sludge recovery unit 2 includes a crushing component, a sorting component and an activation component; the crushing component is used to crush the collected mixed-culture granular sludge; the sorting component is used to sort the crushed mixed-culture granular sludge to obtain sludge that meets the preset particle size requirements; the activation component is used to activate the sludge after sorting.

[0031] Activated sludge serves as the pre-determined microbial donor. For example, in the case of urban sewage, the sludge activator used in the activation process is cytochrome C and cobalt ferrite powder with a particle size of 30 nm. The mass ratio of cytochrome C to cobalt ferrite powder is set at 1:200, and the sludge activator is added at a rate of 0.15‰ of the sludge weight. Directly using activated sludge as the pre-determined microbial donor eliminates the need for a separate microbial donor, reducing treatment costs and achieving effective sludge recycling.

[0032] In some embodiments, the sludge recovery unit 2 is located within a recovery tank. The crushing components are ultrasonic plates located on the sidewalls of the recovery tank, and the sorting components are electromagnetic plates located on the bottom of the recovery tank. For example, the recovery tank dimensions are: 180 cm long, 40 cm wide, 25 cm high, with a total volume of 180 L. The recovery tank is constructed of stainless and acid-resistant steel that is resistant to corrosion from air, steam, and water, ensuring efficient crushing and sorting. A sludge activator is then added to activate the sludge for ultimate recycling.

[0033] Currently, sewage treatment plants or integrated treatment devices produce large amounts of sludge with high water content and low content of useful substances. The treatment and disposal process is complex and reuse is difficult. However, the present application uses the directional setting of the electromagnetic plate on the bottom of the recovery tank and the ultrasonic plate on the side to complete the dehydration and concentration of the recovered mixed-breeding granular sludge, sludge extraction and thickening, modification and stimulation of active substances in one step, thereby reducing the cost of sludge treatment and disposal. At the same time, the sludge concentrate is rich in organic matter, nitrogen, phosphorus and other substances, and can be directly used as fertilizer and feed. The sewage treatment device described in the present invention achieves the multiple purposes of sewage treatment, sludge disposal, and resource utilization.

[0034] In some embodiments, the reaction channel unit 1 has a slope of 5-10% relative to the horizontal. If the slope is set too small, the mixed-breeding granular sludge may be discharged from the reaction channel unit along with the water, and the sedimentation and collection function may not be achieved. If the slope is set too large, the pumping energy for the sewage to be treated will be increased, thereby increasing the treatment energy consumption.

[0035] Exemplarily, the reaction channel unit 1 has a slope of 6% with respect to the horizontal line and is along the vertical line of the ground.

[0036] In some embodiments, a photovoltaic power supply unit 7 is further included to power the sludge recovery unit 2 and the light supply unit 3. Exemplarily, the photovoltaic power supply unit 7 comprises a solar panel mounted on top of the reactor 8 and a battery connected to the panel. The panel absorbs solar energy and stores electricity, which is then used to power the sludge recovery unit 2 and the light supply unit 3, eliminating the need for an additional power source. Each set of solar panels has dimensions of 100 cm long, 70 cm wide, and a power output of 250 W.

[0037] In some embodiments, the granulation channel 11 includes a plurality of first straight tubes 111 and a first curved tube 112 connecting the plurality of first straight tubes 111. The plurality of first straight tubes 111 are alternately arranged obliquely from bottom to top. The first curved tube 112 is used to connect the ends of adjacent first straight tubes 111. The lower end of the lowest first straight tube 111 is the liquid inlet 13.

[0038] The sedimentation channel 12 includes a plurality of second straight pipes 121 and second curved pipes 122 connecting the plurality of second straight pipes 121. The plurality of second straight pipes 121 are arranged alternately and obliquely from bottom to top. The second curved pipes 122 are used to connect the ends of adjacent second straight pipes 121. The lower end of the lowest second straight pipe 121 is connected to the upper end of the top first straight pipe 111 of the granulation channel 11. The upper end of the top second straight pipe 121 is the liquid outlet 14.

[0039] For example, see Figure 1As shown, the reaction channel unit 1 has a five-layer structure, comprising four first straight tubes 111 and two second straight tubes 121. The four first straight tubes 111 are arranged alternately and diagonally. For example, one of the two adjacent first straight tubes 111 at the bottom extends toward the upper right, while the other extends toward the upper left. The left end of the top first straight tube 111 is connected to the right end of the bottom second straight tube 121 via a reducer 15, connecting the granulation channel 11 and the sedimentation channel 12 via the reducer 15. The reducer 15 is 0.2 m long. The first straight tube 111 of the granulation channel 11 has an outer diameter of 110 mm and an inner diameter of 100 mm. The three first straight tubes at the bottom are 5 m long, and the top first straight tube connected to the sedimentation channel 12 is 2.4 m long, with a capacity of 118 L. The second straight pipe in the sedimentation channel 12 has an outer diameter of 130 mm and an inner diameter of 120 mm. The upper second straight pipe is 5 m long, while the lower second straight pipe connecting to the granulation channel 11 is 2.4 m long, with a capacity of 105 L. The total volume of one reaction channel unit 1 is 223 L. Both the first elbow 112 and the second elbow 122 have an arc of 160°. The connection between the straight pipe and the elbow is made of high-temperature and corrosion-resistant PVC tubing approximately 10 mm thick, secured with a stainless steel clamp.

[0040] See also Figure 2 As shown, there are six reaction channel units 1, which are arranged in parallel in the reactor 8. The liquid inlets 13 of the six reaction channel units 1 are connected to the water distribution pipe 100, and the liquid outlets 14 of the six reaction channel units 1 are connected to the water collection pipe 200. The water distribution pipe is connected to the water inlet pump, which adopts a low-speed centrifugal pump combined with a frequency converter to control the water inlet flow rate to 0.4m / s and the water inlet flow rate to 10 m 3 / h. The flow rate in granulation channel 11 is consistent with that in liquid inlet 13. The wastewater passes through reducer 15, where the flow rate decays, resulting in a flow rate of approximately 0.25 m / s in sedimentation channel 12. By providing multiple parallel reaction channel units 1, the number of reaction channel units 1 in operation can be designed based on the actual water inflow, enabling flexible combined operation.

[0041] The light supply unit 3 is a lamp tube, and there are five lamp tubes arranged between adjacent straight tubes with the ends of the lamp tubes extending to the transition and bending positions of adjacent straight tubes. The light intensity of the lamp tube is 12000 lux, ensuring that the light can fully cover the reaction channel unit 1.

[0042] In the present application, the first straight tube 111 , the first curved tube 112 , the second straight tube 121 and the second curved tube 122 of the reaction channel unit 1 are all made of transparent PVC material with good light transmittance, and the lamp tube can be arranged outside the reaction channel unit 1 .

[0043] In some embodiments, the preset microorganisms are symbiotic heterotrophic actinomycetes and autotrophic spirulina. At present, sewage biochemical treatment uses aerobic heterotrophic bacteria to treat sewage, which has a good effect on removing organic matter in sewage, but has a low efficiency in removing pollutants such as nitrogen and phosphorus. The sewage treatment device of the present invention induces the production of autotrophic and heterotrophic symbiotic mixed-type granular sludge by means of the setting of a light supply unit, the vertical upward and zigzag flow of sewage along the reaction flow channel, the addition of a preset activator, etc., and uses the mixed-type granular sludge as the preset microbial donor, which not only retains the removal of organic matter by aerobic heterotrophic bacteria, but also realizes the absorption and removal of nitrogen and phosphorus by autotrophic bacteria, solving the problem of low removal rate of nitrogen, phosphorus and other pollutants in current sewage biochemical treatment technology. At the same time, the oxygen released by the growth of autotrophic bacteria can be provided to the growth of aerobic heterotrophic bacteria, without the need for energy-consuming operations such as aeration, thereby reducing operation and maintenance costs.

[0044] See also Figure 3 As shown, after the sewage treatment device has been in use for a period of time, the reaction channel unit 1 is backwashed using honeycomb cleaning cotton 9. The specific operation includes: stopping the water supply to the reactor 8, opening the second branch pipe 6, and discharging the mixed-culture granular sludge deposited in the granulation channel 11 into the sludge recovery unit 2 for recycling. Then, tap water and honeycomb cleaning cotton 9 are introduced through the liquid outlet 14. The water flow pushes the honeycomb cleaning cotton 9 to clean the inner wall of the pipe. Finally, the honeycomb cleaning cotton 9 is removed from the liquid inlet 13. The above steps are repeated three times to complete the reactor backwash operation.

[0045] The honeycomb cleaning sponge 9 is a polyurethane cylinder with a pore size of 0.1 cm to 0.5 cm and activated carbon adsorbed on its surface. Its diameter is 1.1 to 1.3 times the diameter of the granulation channel 11. For example, the honeycomb cleaning sponge 9 has the following dimensions: 12 cm in diameter, 50 cm in length, and a backwash flow rate of 0.9 m / s.

[0046] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A sewage treatment device, characterized in that: It comprises a reaction channel unit (1), a sludge recovery unit (2) and a light supply unit (3); The reaction channel unit (1) is arranged to extend in a reciprocating bend from bottom to top, and includes a granulation channel (11) and a sedimentation channel (12) located above the granulation channel (11); the lower end of the granulation channel (11) is a liquid inlet (13); the upper end of the granulation channel (11) is connected to the lower end of the sedimentation channel (12); the upper end of the sedimentation channel (12) is a liquid outlet (14); the pore size of the sedimentation channel (12) is larger than the pore size of the granulation channel (11); The reaction channel unit (1) has a slope of 5 to 10% relative to the horizontal line; The granulation flow channel (11) and the sedimentation flow channel (12) are connected via a reducing pipe (15); The sedimentation flow channel (12) is provided with a gas collecting port (4) near the liquid outlet (14), and the gas collecting port (4) is connected to the granulation flow channel (11) through the first branch pipe (5); The sludge recovery unit (2) is connected to the granulation flow channel (11) via a second branch pipe (6); The light supply unit (3) provides light to the reaction channel unit (1); The sewage to be treated and the preset microorganisms are transported to the granulation flow channel (11) through the liquid inlet (13). Under the light induction of the light supply unit (3), the pollutants in the sewage to be treated are absorbed and degraded by the preset microorganisms to produce mixed-culture granular sludge; After the sewage to be treated flows through the sedimentation flow channel (12), the flow velocity decays, and the mixed-culture granular sludge is intercepted in the granulation flow channel (11) and collected and treated by the sludge recovery unit; the waste gas generated during the treatment process is introduced into the granulation flow channel (11) along the gas collecting port (4) through the first branch pipe (5) and is absorbed and degraded by the mixed-culture granular sludge.

2. The sewage treatment device according to claim 1, characterized in that: The sludge recovery unit (2) comprises a crushing component, a sorting component and an activation component; The crushing component is used to crush the collected mixed-culture granular sludge; The separation component is used to separate the crushed mixed-culture granular sludge to obtain sludge that meets the preset particle size requirements; The activation component is used to activate the sludge after sorting.

3. The sewage treatment device according to claim 2, characterized in that: The activated sludge is used as the preset microbial donor.

4. The sewage treatment device according to claim 2, characterized in that: The sludge recovery unit (2) is arranged in a recovery tank, the crushing component is an ultrasonic plate arranged on the side wall of the recovery tank, and the sorting component is an electromagnetic plate arranged on the bottom surface of the recovery tank.

5. The sewage treatment device according to claim 1 or 2, characterized in that: It also includes a photoelectric energy supply unit (7) for supplying power to the sludge recovery unit (2) and the light supply unit (3).

6. The sewage treatment device according to claim 1 or 2, characterized in that: The granulation flow channel (11) comprises a plurality of first straight tubes (111) and first curved tubes (112) connecting the plurality of first straight tubes (111). The plurality of first straight tubes (111) are alternately arranged obliquely from bottom to top. The first curved tubes (112) are used to connect the ends of adjacent first straight tubes (111). The lower end of the lowest first straight tube (111) is a liquid inlet (13), and the upper end of the highest first straight tube (111) is connected to the lower end of the sedimentation flow channel (12).

7. The sewage treatment device according to claim 1 or 2, characterized in that: The sedimentation flow channel (12) comprises a plurality of second straight tubes (121) and second curved tubes (122) connecting the plurality of second straight tubes (121). The plurality of second straight tubes (121) are alternately arranged obliquely from bottom to top. The second curved tubes (122) are used to connect the ends of adjacent second straight tubes (121). The lower end of the lowest second straight tube (121) is connected to the upper end of the granulation flow channel (11), and the upper end of the highest second straight tube (121) is a liquid outlet (14).

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