A device and method for biological phosphorus removal by using a bacteria-algae symbiotic complete autotrophic organism

Abstract

The present application relates to the technical field of sewage treatment, and particularly relates to a bacteria-algae symbiosis full-process autotrophic biological phosphorus removal device and method; the device and method can reduce operation cost, reduce system energy consumption, avoid secondary pollution, and further improve phosphorus removal effect; the device comprises a photosynthetic reactor main body, a bacteria-algae biofilm filler assembly, an aeration mechanism, an LED light source, a wall cleaning mechanism and a water inlet pump; the photosynthetic reactor main body is a light-transmitting cylindrical body; the bacteria-algae biofilm filler assembly is built-in the photosynthetic reactor main body; the bacteria-algae biofilm filler assembly is used for bacteria-algae biofilm formation; the LED light source is uniformly distributed on the outer part of the photosynthetic reactor main body; the LED light source provides light to promote oxygen production and assimilation phosphorus removal of algae photosynthesis; the wall cleaning mechanism is used for cleaning the inner wall of the photosynthetic reactor main body; one side of the middle part of the photosynthetic reactor main body is provided with a discharge pipe; the discharge pipe is provided with a first switch valve; one side of the bottom of the photosynthetic reactor main body is provided with a blow-off pipe; the blow-off pipe is provided with a second switch valve.

Description

Technical Field

[0001] This invention relates to the technical field of wastewater treatment, and in particular to a fully autotrophic biological phosphorus removal device and method based on algae-bacteria symbiosis. Background Technology

[0002] With the development of industries such as petroleum, chemicals, food, and pharmaceuticals, and the continuous improvement of people's living standards, the levels of ammonia nitrogen and phosphorus in various industrial wastewater and urban sewage are rising. Excessive nitrogen and phosphorus levels in water bodies can lead to eutrophication and a series of other ecological and environmental problems, disrupting the balance of ecosystems and even endangering human health. Therefore, the issue of efficient nitrogen and phosphorus removal from wastewater should be given serious attention.

[0003] The fully autotrophic process has significant advantages in treating high ammonia nitrogen wastewater. Compared to traditional biological denitrification, which requires a certain amount of carbon source to support complete biological denitrification and excessive phosphorus uptake in the aerobic stage, the fully autotrophic process utilizes the synergistic effect of ammonia-oxidizing bacteria and anaerobic ammonia-oxidizing bacteria to achieve highly efficient biological denitrification. It can save approximately 60% of aeration volume and 100% of carbon source, while minimizing infrastructure investment, making it a highly favored process in wastewater denitrification. However, the fully autotrophic process does not require a carbon source, which prevents polyphosphate-accumulating bacteria from accumulating within the reaction system. The slow proliferation of these functional microorganisms leads to low sludge production, and phosphorus cannot be removed with the sludge discharged from the system. Therefore, the fully autotrophic process does not possess good phosphorus removal performance.

[0004] To achieve efficient nitrogen and phosphorus removal, it is possible to add an external carbon source or phosphorus removal agent to the fully autotrophic system, or couple it with other phosphorus removal processes. Adding an external carbon source often increases operating costs and negatively impacts the growth of anaerobic ammonia-oxidizing bacteria, thus reducing nitrogen removal efficiency; adding an external phosphorus removal agent also increases system energy consumption and poses a secondary pollution problem. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] Based on the fact that traditional anaerobic ammonia oxidation or fully autotrophic processes are not effective in removing phosphorus when treating high ammonia nitrogen wastewater, this invention provides a fully autotrophic biological phosphorus removal device and method based on algae-bacteria symbiosis, which reduces operating costs, lowers system energy consumption, avoids secondary pollution, and further improves phosphorus removal efficiency.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: a fully autotrophic biological phosphorus removal device based on algae-bacteria symbiosis, comprising a photosynthetic reactor body, an algae-bacteria biofilm packing assembly, an aeration mechanism, an LED light source, a wall cleaning mechanism, and an inlet pump. The photosynthetic reactor body is a translucent cylindrical shape. The algae-bacteria biofilm packing assembly is built inside the photosynthetic reactor body and is used for algae and bacteria to attach to the biofilm. The LED light source is circumferentially distributed on the outside of the photosynthetic reactor body, providing illumination to promote algal photosynthesis for oxygen production and phosphorus assimilation. The wall cleaning mechanism is used for cleaning the inner wall of the photosynthetic reactor body. A discharge pipe is provided on one side of the middle of the photosynthetic reactor body, and a first switching valve is installed at the discharge pipe. The output end of the inlet pump extends into the photosynthetic reactor body. At the bottom of the reactor body, a drain pipe is provided on one side of the bottom of the photosynthetic reactor body, and a second switch valve is installed on the drain pipe; furthermore, the drain pipe is used for the discharge of treated wastewater from the photosynthetic reactor body, and the drain pipe is used for the discharge of sludge / algae; the LED light source is externally placed on the photosynthetic reactor body to reduce the incidence of leakage accidents, and at the same time to prevent sludge, bacteria and algae from adhering to the LED light source, ensuring smooth contact between the photosynthetic reactor body and the light source; the LED light source, aeration mechanism and wall cleaning mechanism are all automatically controlled by an external PLC system, and the PLC system can use a commercially available PLC control cabinet, which will not be further described here; wastewater is supplied to the photosynthetic reactor body through an inlet pump; the photosynthetic reactor body is preferably made of transparent acrylic material, but other materials such as transparent glass can also be used.

[0009] Preferably, the wall cleaning mechanism includes two electromagnets, a permanent magnet core that slides vertically within the main body of the photosynthetic reactor, an impeller that rotates on the permanent magnet core, and brushes evenly distributed circumferentially on the impeller; the two electromagnets are respectively installed at the upper and lower parts of the main body of the photosynthetic reactor, wherein a set of electromagnets at the bottom of the main body of the photosynthetic reactor has the same magnetic pole as the bottom of the permanent magnet core, and a set of electromagnets at the top of the main body of the photosynthetic reactor has the opposite magnetic pole to the top of the permanent magnet core, the outer diameter of the permanent magnet core matches the inner diameter of the main body of the photosynthetic reactor, and a through-hole is provided in the middle of the permanent magnet core.

[0010] Preferably, the upper part of the permanent magnet core is provided with a conical groove and multiple through-holes running vertically through it.

[0011] Preferably, the aeration mechanism includes an aeration pump and a probe-type dissolved oxygen monitor. The output end of the aeration pump extends into the bottom of the photosynthetic reactor body, and the detection end of the probe-type dissolved oxygen monitor extends into the wastewater inside the photosynthetic reactor body. Furthermore, an aeration assembly is installed at the bottom of the photosynthetic reactor body, and the output end of the aeration pump is connected to the aeration assembly. The aeration assembly includes an aeration pipe and an aeration head installed on the aeration pipe.

[0012] Preferably, the algae and bacteria biofilm packing assembly includes a bracket built into the middle of the photosynthetic reactor body and a sponge packing suspended on the bracket; the bracket is rotatably installed at the bottom of the photosynthetic reactor body; further, the bracket is made of stainless steel and the sponge packing is made of cubic sponge blocks.

[0013] A fully autotrophic biological phosphorus removal method based on algae-bacteria symbiosis, employing the aforementioned fully autotrophic biological phosphorus removal device to treat wastewater, includes the following steps:

[0014] S1. During the main start-up stage of the photosynthetic reactor, 3-10 g / L of fully autotrophic sludge and 0.2-1.0 g / L of Chlorella in the logarithmic growth phase are inoculated to acclimate the bacteria and algae to the surface and pores of the sponge packing to form a symbiotic biofilm.

[0015] S2. Wastewater is pumped into the main body of the photosynthetic reactor using an influent pump. A sequential batch reactor process is adopted, which includes influent, aeration, sedimentation, and drainage. The influent and aeration processes are the illumination stage, in which the LED light source is turned on, the light intensity is controlled, and the dissolved oxygen concentration of the system is adjusted. The sedimentation and drainage processes are the darkness stage, in which the light / dark time ratio is controlled to be 12h:12h, 10h:2h, or 6h:2h, depending on the phosphorus removal effect.

[0016] S3. The treated wastewater is discharged through the discharge pipe in the middle of the main body of the photosynthetic reactor.

[0017] S4. Repeat S1-S3 to continuously treat the wastewater.

[0018] Preferably, the intensity of the LED light source is 2000-5000 lux;

[0019] Preferably, the dissolved oxygen concentration is controlled at 1-3 mg / L;

[0020] Preferably, the inner wall of the photosynthetic reactor is cleaned once every 10 days for 5 minutes each time, and the brush on the impeller rotates at a speed of 10-30 revolutions per minute.

[0021] (III) Beneficial Effects

[0022] Compared with the prior art, the present invention provides a fully autotrophic biological phosphorus removal device and method based on algae-bacteria symbiosis, which has the following beneficial effects:

[0023] 1. Highly efficient nitrogen and phosphorus removal: By inoculating Chlorella into the autotrophic reaction system to form a symbiotic biofilm of bacteria and algae, the biofilm has good stability and can effectively exert the synergistic effect of bacteria and microalgae, resulting in excellent nitrogen and phosphorus removal performance, especially in phosphorus removal rate.

[0024] 2. Reduced energy consumption: In the reaction system, microalgae can use the carbon dioxide produced by bacteria for photosynthesis, while the oxygen produced by microalgae supplies the growth needs of bacteria. Therefore, the system further reduces mechanical aeration and effectively saves energy consumption.

[0025] 3. It conforms to the low-carbon concept; the reaction system can achieve energy self-sufficiency through the nutrient exchange mechanism of microalgae and bacteria, so the system does not require an external carbon source, which conforms to the low-carbon and energy-saving concept. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0027] Figure 2 This is a schematic diagram of the front planar structure of the present invention;

[0028] Figure 3 This is the invention Figure 2 Schematic diagram of the cross-sectional structure at point AA;

[0029] Figure 4 This is a three-dimensional structural diagram illustrating the connection relationship between the permanent magnet core and the impeller of the present invention;

[0030] Figure 5 This is the invention Figure 1 A magnified view of the structure at point A in the middle;

[0031] Figure 6 This is the invention Figure 1 A magnified schematic diagram of the structure at point B in the middle;

[0032] Figure 7 This is the invention Figure 3 A magnified schematic diagram of the structure at point C in the middle;

[0033] The attached diagram is labeled as follows: 1. Main body of the photosynthetic reactor; 2. LED light source; 3. Inlet pump; 4. Discharge pipe; 5. First switch valve; 6. Electromagnet; 7. Permanent magnet core; 8. Impeller; 9. Brush; 10. Through port; 11. Conical groove; 12. Outlet; 13. Aeration pump; 14. Probe-type dissolved oxygen monitor; 15. Hanging frame; 16. Sponge packing; 17. Sewage pipe; 18. Second switch valve. Detailed Implementation

[0034] To enable those skilled in the art to better understand the invention, the technical solutions in the embodiments of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the invention.

[0035] As described in the background section, the autotrophic process does not require a carbon source, which prevents polyphosphate-accumulating bacteria from accumulating within the reaction system. The slow proliferation of functional microorganisms results in low sludge production, and phosphorus cannot be removed with the sludge discharged from the system. Therefore, the autotrophic process does not have good phosphorus removal performance. Adding an external carbon source often increases operating costs and negatively impacts the growth of anaerobic ammonia-oxidizing bacteria, thereby reducing denitrification efficiency. Adding phosphorus removal agents also increases system energy consumption and poses secondary pollution problems.

[0036] To address this technical problem, the present invention provides a fully autotrophic biological phosphorus removal device and method based on algae-bacteria symbiosis, which is applied to wastewater treatment.

[0037] It should be noted that, without conflict, the embodiments and features and technical solutions in the invention can be combined with each other.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] Example 1

[0040] For details, please refer to Figure 1-3 The fully autotrophic biological phosphorus removal device based on algae-bacteria symbiosis specifically includes: a photosynthetic reactor body 1, an algae-bacteria biofilm packing assembly, an aeration mechanism, an LED light source 2, a wall cleaning mechanism, and an inlet pump 3. The photosynthetic reactor body 1 is a translucent cylindrical shape. The algae-bacteria biofilm packing assembly is built into the photosynthetic reactor body 1 and is used for algae and bacteria to form a biofilm. The LED light source 2 is evenly distributed around the outside of the photosynthetic reactor body 1, providing illumination to promote algal photosynthesis, oxygen production, and phosphorus assimilation. The wall cleaning mechanism is used to clean the inner wall of the photosynthetic reactor body 1. A discharge pipe 4 is provided on one side of the middle of the photosynthetic reactor body 1, and a first switching valve 5 is installed at the discharge pipe 4. The output end of the inlet pump 3 extends into the bottom of the photosynthetic reactor body 1. A drain pipe 17 is provided on the side, and a second switch valve 18 is installed on the drain pipe 17; furthermore, the discharge pipe 4 is used for the discharge of treated wastewater inside the photosynthetic reactor body 1, and the drain pipe 17 is used for the discharge of sludge / algae; the LED light source 2 is externally placed on the photosynthetic reactor body 1 to reduce the incidence of leakage accidents, and at the same time to prevent sludge, bacteria and algae from adhering to the LED light source 2, ensuring smooth contact between the photosynthetic reactor body 1 and the light source; the LED light source 2, the aeration mechanism and the wall cleaning mechanism are all automatically controlled by an external PLC system. The PLC system can use a commercially available PLC control cabinet, which will not be described further here; wastewater is supplied to the photosynthetic reactor body 1 through the inlet pump 3; the photosynthetic reactor body 1 is preferably made of transparent acrylic material, but other materials such as transparent glass can also be used.

[0041] Please refer to Figure 3-4 The wall cleaning mechanism includes two electromagnets 6, a permanent magnet core 7 that is slidably installed inside the photosynthetic reactor body 1, an impeller 8 that is rotatably installed on the permanent magnet core 7, and a brush 9 that is evenly distributed around the impeller 8. The two electromagnets 6 are respectively installed at the upper and lower parts of the photosynthetic reactor body 1. The set of electromagnets 6 at the bottom of the photosynthetic reactor body 1 has the same magnetic pole as the bottom of the permanent magnet core 7, and the set of electromagnets 6 at the top of the photosynthetic reactor body 1 has the opposite magnetic pole to the top of the permanent magnet core 7. The outer diameter of the permanent magnet core 7 matches the inner diameter of the photosynthetic reactor body 1, and a through-hole 10 is provided in the middle of the permanent magnet core 7.

[0042] Please refer to Figure 5 The upper part of the permanent magnet core 7 is provided with a conical groove 11 and multiple through-holes 12.

[0043] The fully autotrophic biological phosphorus removal device with bacterial-algae symbiosis provided in this embodiment will accumulate a lot of sludge and algae on the inner wall of the photosynthetic reactor body 1 after a period of use, thus affecting light transmittance and impacting the normal growth of bacteria and algae on the bacterial-algae biofilm packing assembly. While traditional rotating cleaning components can clean the inner wall of the photosynthetic reactor body 1, they often cover a large area of ​​the reactor body 1 to achieve the cleaning purpose, affecting the amount of light entering the reactor. Therefore, the wall cleaning mechanism in this embodiment activates two electromagnets 6 when cleaning the inner wall of the photosynthetic reactor body 1 is required. The set of electromagnets 6 at the bottom of the photosynthetic reactor body 1 generates a repulsive force on the permanent magnet core 7, while the set of electromagnets 6 at the top of the reactor body 1 generates an attractive force on the permanent magnet core 7. The resultant force of the repulsive and attractive forces is greater than the weight of the permanent magnet core 7, causing the permanent magnet core 7 to move upward along the inner wall of the photosynthetic reactor body 1. At this time, the wastewater comes into contact with the impeller 8. The impeller 8 then rotates, which in turn drives the brush 9 to rotate. The brush 9 performs a circumferential scrubbing of the inner wall of the photosynthetic reactor body 1 from top to bottom. During the rotation of the impeller 8, the wastewater inside the photosynthetic reactor body 1 forms a swirling flow. Under the action of the swirling flow, the scraped sludge and algae settle downwards, while the conical groove 11 can reduce the accumulation of sludge and algae on the upper part of the permanent magnet core 7. The wastewater passes through the through-hole 10 and acts on the impeller 8 to make the impeller 8 rotate. When the permanent magnet core 7 moves to the top of the photosynthetic reactor body 1, the electromagnet 6 is turned off. Under the action of its own weight, the permanent magnet core 7 automatically falls back to the bottom of the photosynthetic reactor body 1. This can achieve a comprehensive cleaning of the inner wall of the photosynthetic reactor body 1. In the non-use state, the permanent magnet core 7 is located at the bottom of the photosynthetic reactor body 1, which avoids blocking the light source and can improve the settling rate of sludge and algae in the wastewater, thereby improving the sewage discharge efficiency and reducing the wastewater replacement volume.

[0044] Example 2

[0045] The fully autotrophic biological phosphorus removal device with symbiotic bacteria and algae provided in Example 1 has been further optimized, specifically, as follows: Figure 1-3as well as Figure 7 As shown, the algal biofilm packing assembly includes a bracket 15 built into the middle of the photosynthetic reactor body 1 and a sponge packing 16 suspended on the bracket 15; the bracket 15 is rotatably installed at the bottom of the photosynthetic reactor body 1; furthermore, the bracket 15 is made of stainless steel, and the sponge packing 16 is made of cubic sponge block; the bracket 15 penetrates through the sponge packing 16; the sponge packing 16 is porous and has strong water absorption, which is conducive to the growth of algae and bacteria.

[0046] The fully autotrophic biological phosphorus removal device with symbiotic bacteria and algae provided in this embodiment has the following characteristics: During the wall cleaning operation inside the main body 1 of the photosynthetic reactor, the swirling flow generated by the wastewater will impact the bacteria and algae on the sponge packing 16. The hanging bracket 15 can rotate synchronously with the swirling flow in the wastewater, thereby reducing the impact of the swirling flow on the bacteria and algae on the sponge packing 16 and reducing the amount of bacteria and algae detaching from the sponge packing 16. At the same time, after the hanging bracket 15 rotates, it can randomly adjust the orientation of the sponge to improve the contact balance between the bacteria and algae and the LED light source 2.

[0047] Specifically, the aeration mechanism includes an aeration pump 13 and a probe-type dissolved oxygen monitor 14. The output end of the aeration pump 13 extends into the bottom of the photosynthetic reactor body 1, and the detection end of the probe-type dissolved oxygen monitor 14 extends into the wastewater inside the photosynthetic reactor body 1. Furthermore, an aeration assembly is installed at the bottom of the photosynthetic reactor body 1, and the output end of the aeration pump 13 is connected to the aeration assembly. The aeration assembly includes an aeration pipe and an aeration head installed on the aeration pipe. Fresh air is blown into the wastewater inside the photosynthetic reactor body 1 through the aeration pump 13 and the aeration assembly to increase the dissolved oxygen content in the wastewater. The dissolved oxygen content can be monitored in real time by the probe-type dissolved oxygen monitor 14.

[0048] A fully autotrophic biological phosphorus removal method based on algae-bacteria symbiosis, employing the aforementioned fully autotrophic biological phosphorus removal device to treat wastewater, includes the following steps:

[0049] S1, the start-up stage of the main body 1 of the photosynthetic reactor, inoculate 3-10 g / L of fully autotrophic sludge and 0.2-1.0 g / L of Chlorella in the logarithmic growth phase, and acclimate it to form a bacterial-algae symbiotic biofilm on the surface and pores of the sponge packing 16;

[0050] S2. Wastewater is pumped into the main body of the photosynthetic reactor 1 via the inlet pump 3. A sequential batch process is adopted, including inlet, aeration, sedimentation and drainage. The inlet and aeration processes are the light stage, in which the LED light source 2 is turned on, the light intensity is controlled, and the dissolved oxygen concentration of the system is adjusted. The sedimentation and drainage processes are the dark stage, in which the light / dark time ratio is controlled to be 12h:12h, 10h:2h or 6h:2h, depending on the phosphorus removal effect.

[0051] S3. The treated wastewater is discharged through the discharge pipe 4 in the middle of the main body 1 of the photosynthetic reactor.

[0052] S4. Repeat S1-S3 to continuously treat the wastewater.

[0053] Specifically, the intensity of LED light source 2 is 2000-5000 lux;

[0054] Specifically, the dissolved oxygen concentration should be controlled at 1-3 mg / L;

[0055] Specifically, the inner wall of the main body 1 of the photosynthetic reactor is cleaned once every 10 days for 5 minutes each time, and the brush 9 on the impeller 8 rotates at a speed of 10-30 revolutions per minute.

[0056] The experiment used artificially simulated high ammonia nitrogen wastewater as the raw water. The relevant water quality characteristics were: ammonia nitrogen 200±10mg / L, phosphorus 3.0±0.2mg / L. Sodium bicarbonate was added to control the pH of the influent of the main body of the photosynthetic reactor 1 to be around 7.5.

[0057] More specifically, the experiment was conducted in two groups: the experimental group was carried out in a fully autotrophic biological phosphorus removal device with a symbiotic microbial culture. The main body 1 of the photosynthetic reactor was made of a translucent cylindrical material with an effective volume of 4.5L. The main body 1 of the photosynthetic reactor contained a microbial biofilm packing assembly for microbial biofilm formation. The entire microbial biofilm packing assembly was located below the water level, with a filling rate of 20%. Illumination was provided by an LED light source 2. The control group was carried out in a fully autotrophic device without microalgae inoculation. The main body 1 of the fully autotrophic photosynthetic reactor was made of a translucent cylindrical material with an effective volume of 4.5L. The main body 1 of the photosynthetic reactor contained a microbial biofilm packing assembly for fully autotrophic microbial biofilm formation. The entire microbial biofilm packing assembly was located below the water level, with a filling rate of 20%.

[0058] Both groups of photosynthetic reactors 1 were inoculated with 5 g / L of fully autotrophic sludge, while the experimental group was simultaneously inoculated with 0.5 g / L of Chlorella vulgaris in its logarithmic growth phase. A sequencing batch reactor (SBR) process was employed, with the main body of the photosynthetic reactor 1 operating for one cycle per day, comprising four stages: influent (10 min), aeration (7-10 min), settling (7-10 min), and drainage (10 min). In the experimental group, LED light sources 2 were added during the influent and aeration stages to control the light intensity at 3000 lux, thereby promoting algal photosynthesis for oxygen production and phosphorus assimilation. The settling and drainage stages constituted the dark phase for the experimental group, with a light / dark time ratio of 12 h:12 h.

[0059] Wastewater enters the two groups of photosynthetic reactor bodies 1 through inlet pump 3, contacting the fully autotrophic microorganisms formed on the algal biofilm packing components. Under suitable dissolved oxygen concentration, the experimental group utilizes the synergistic effect of bacteria and microalgae, mainly the assimilation effect of microalgae, to absorb phosphorus from the inlet water of the photosynthetic reactor body 1 to achieve phosphorus removal. The control group utilizes microbial metabolism for phosphorus removal. The treated wastewater in the two groups of photosynthetic reactor bodies 1 is discharged through the discharge pipe 4 in the middle of the photosynthetic reactor body 1, with a volume exchange ratio of 50%. The photosynthetic reactor body 1 of the experimental group is equipped with a wall cleaning mechanism, in which the brush 9 on the impeller 8 rotates at a speed of 10-30 rpm, cleaning the wall once every 10 days for 5 minutes each time, and the mud / algae is discharged through the drain pipe 18 at the bottom of the photosynthetic reactor body 1.

[0060] Repeat the above steps to continuously treat the wastewater.

[0061] Table 1. Comparison of treatment effects between the two experimental setups (average of 5 sets of data).

[0062]

[0063] Experimental results show that after 30 days of system operation, the effluent quality stabilizes. Compared with the control group, the nitrogen and phosphorus removal effect of the wastewater treatment device with bacteria and algae symbiosis is significantly improved, with the total nitrogen removal rate reaching over 99% and the total phosphorus removal rate reaching 87.1%.

[0064] In this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

Claims

1. A fully autotrophic biological phosphorus removal device based on algae-bacteria symbiosis, characterized in that, The reactor includes a photosynthetic reactor body (1), a bacterial and algal biofilm packing assembly, an aeration mechanism, an LED light source (2), a wall cleaning mechanism, and an inlet pump (3). The photosynthetic reactor body (1) is a transparent cylindrical shape. The bacterial and algal biofilm packing assembly is built inside the photosynthetic reactor body (1) and is used for bacterial and algal biofilm formation. The LED light source (2) is evenly distributed around the outside of the photosynthetic reactor body (1) and provides illumination to promote oxygen production and phosphorus assimilation by algae. The wall cleaning mechanism is used to clean the inner wall of the photosynthetic reactor body (1). A discharge pipe (4) is provided on one side of the middle of the photosynthetic reactor body (1), and a first switch valve (5) is installed at the discharge pipe (4). The output end of the inlet pump (3) extends into the bottom of the photosynthetic reactor body (1). A sewage pipe (17) is provided on one side of the bottom of the photosynthetic reactor body (1), and a second switch valve (18) is installed on the sewage pipe (17). The cleaning mechanism includes two electromagnets (6), a permanent magnet core (7) that is slidably installed inside the photosynthetic reactor body (1), an impeller (8) that is rotatably installed on the permanent magnet core (7), and a brush (9) that is evenly distributed on the impeller (8) in the circumferential direction. The two electromagnets (6) are respectively installed on the upper and lower parts of the photosynthetic reactor body (1). The set of electromagnets (6) at the bottom of the photosynthetic reactor body (1) has the same magnetic pole as the bottom of the permanent magnet core (7), and the set of electromagnets (6) at the top of the photosynthetic reactor body (1) has the opposite magnetic pole to the top of the permanent magnet core (7). The outer diameter of the permanent magnet core (7) matches the inner diameter of the photosynthetic reactor body (1), and the permanent magnet core (7) has a through-hole (10) in the middle. The algal biofilm packing assembly includes a bracket (15) built into the middle of the photosynthetic reactor body (1) and a sponge packing (16) suspended on the bracket (15); the bracket (15) is rotatably installed at the bottom of the photosynthetic reactor body (1).

2. The fully autotrophic biological phosphorus removal device based on algae-bacteria symbiosis according to claim 1, characterized in that, The permanent magnet core (7) has a tapered groove (11) and multiple through-holes (12) on its upper part.

3. The fully autotrophic biological phosphorus removal device based on algae-bacteria symbiosis according to claim 1, characterized in that, The aeration mechanism includes an aeration pump (13) and a probe-type dissolved oxygen monitor (14). The output end of the aeration pump (13) extends into the bottom of the photosynthetic reactor body (1), and the detection end of the probe-type dissolved oxygen monitor (14) extends into the wastewater inside the photosynthetic reactor body (1).

4. A fully autotrophic biological phosphorus removal method based on algae-bacteria symbiosis, characterized in that, The wastewater treatment using any one of the algae-bacterial symbiotic autotrophic biological phosphorus removal devices according to claims 1-3 includes the following steps: S1, the main body of the photosynthetic reactor (1) is in the start-up stage, inoculated with 3-10 g / L of autotrophic sludge and 0.2-1.0 g / L of Chlorella in the logarithmic growth phase, and acclimated to form a bacterial-algae symbiotic biofilm on the surface and pores of the sponge packing (16); S2. Wastewater is pumped into the main body (1) of the photosynthetic reactor by the inlet pump (3). The sequential batch operation process is adopted, including water intake, aeration, sedimentation and drainage. The water intake and aeration process is the light stage. The LED light source (2) is turned on, the light intensity is controlled and the dissolved oxygen concentration of the system is adjusted. The sedimentation and drainage process is the dark stage. According to the phosphorus removal effect, the light / dark time ratio is controlled to be 12h:12h or 10h:2h or 6h:2h. S3. The treated wastewater is discharged through the discharge pipe (4) in the middle of the main body (1) of the photosynthetic reactor. S4. Repeat S1-S3 to continuously treat the wastewater.

5. The fully autotrophic biological phosphorus removal method based on algae-bacteria symbiosis according to claim 4, characterized in that, The intensity of the LED light source (2) is 2000-5000 lux.

6. The fully autotrophic biological phosphorus removal method based on algae-bacteria symbiosis according to claim 5, characterized in that, The dissolved oxygen concentration is controlled at 1-3 mg / L.

7. The fully autotrophic biological phosphorus removal method based on algae-bacteria symbiosis according to claim 6, characterized in that, The cleaning frequency of the inner wall of the main body (1) of the photosynthetic reactor is once every 10 days, for 5 minutes each time, and the rotation speed of the brush (9) on the impeller (8) is 10-30 revolutions per minute.

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