Integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage

Abstract

The application discloses a kind of rural domestic sewage low carbon treatment and phosphorus recovery integrated equipment, including filter grit chamber, anaerobic tank, aerobic tank and several adsorption cylinders, and the inside of adsorption cylinder includes several adsorption modules, and La@D201 nanomaterial is filled in the inside of adsorption module, and water is flowed into from the top of the uppermost adsorption module after rising along the gap between each adsorption module and adsorption cylinder, and is flowed out from the lowermost one adsorption module.The application realizes the low carbon treatment of rural domestic sewage and the collaborative recovery of phosphorus resources by carrying adsorption cylinder assembly behind traditional filter grit chamber, anaerobic tank and aerobic tank.At the same time, based on the adsorption characteristics of La@D201 nanomaterial and the discharge characteristics of rural domestic sewage, a multi-layer superposition type adsorption module structure is designed, which is not only convenient for on-site replacement and desorption regeneration, but also has the advantages of simple operation and strong practicability, and has good application prospect, especially suitable for rural domestic sewage resource treatment scene.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an integrated device for low-carbon treatment and phosphorus recovery of rural domestic sewage. Background Technology

[0002] Rural domestic sewage is a major source of non-point source pollution in rural areas and a significant factor contributing to eutrophication of rivers and lakes. Currently, anaerobic digestion-aerobic oxidation combined processes are widely used in rural sewage treatment. While these processes are effective in removing organic pollutants, their ability to remove phosphorus from water bodies is limited, often resulting in excessive phosphorus concentrations in the effluent, making it difficult to meet discharge standards. Furthermore, phosphorus is a non-renewable resource with limited global reserves and extremely uneven distribution. Therefore, achieving efficient phosphorus recovery from rural domestic sewage not only helps improve effluent quality and reduce environmental risks but also holds significant strategic importance for alleviating dependence on natural phosphate rock resources, promoting resource recycling, and fostering sustainable agricultural development.

[0003] La@D201 nanomaterials are a highly efficient phosphorus adsorption composite material discovered in recent years. This material uses La(NO3)3 as a raw material, reacting it with NaOH to prepare well-dispersed large-sized La(OH)3 nanoparticles. After grinding and freeze-drying, these nanoparticles are immobilized and loaded onto a D201 resin support. This composite material utilizes the surface complexation reaction between La(OH)3 and phosphate ions in wastewater to generate stable and persistent LaPO4, thereby significantly accelerating phosphorus recovery and fixation efficiency. From the perspective of adsorption mechanism, La@D201 nanomaterials are a phosphorus recovery adsorbent with broad application prospects.

[0004] Currently, most phosphorus recovery devices on the market are biochar-based adsorption systems. For example, patent publication number CN211712680U discloses a nitrogen and phosphorus adsorption device for aquaculture wastewater based on MgCl2-modified biochar. This device includes a flow inlet system and three adsorption units arranged in series. Each unit is equipped with a biochar adsorption membrane, and the flow is achieved through a liquid level difference, resulting in good space utilization and adsorption effect. However, such devices cannot fully utilize the advantages of La@D201 nanomaterials in phosphorus adsorption and recovery. Therefore, there is an urgent need to develop a low-carbon integrated phosphorus recovery treatment device that combines the adsorption performance of La@D201 nanomaterials with the characteristics of rural domestic sewage discharge, in order to improve the resource utilization level and environmental governance effectiveness of rural sewage treatment systems. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an integrated device for low-carbon treatment and phosphorus recovery of rural domestic sewage.

[0006] The technical solution of this invention is: An integrated device for low-carbon treatment and phosphorus recovery of rural domestic sewage includes a filter grit chamber, an anaerobic tank, an aerobic tank, and several adsorption cylinders arranged in a circle. Each of the adsorption cylinders is fixedly connected to the others. An inlet pipe is provided on one side of the lower part of the adsorption cylinder. Each inlet pipe is interconnected. The adsorption cylinder contains several adsorption modules arranged vertically. Each adsorption module is detachable and filled with La@D201 nanomaterial. Each adsorption module is interconnected and sealed externally. Water from the end of the inlet pipe rises along the gap between each adsorption module and the adsorption cylinder and flows into the top of the uppermost adsorption module, and flows out from the outlet pipe provided on the side wall of the lowermost adsorption module.

[0007] Furthermore, each of the liquid inlet pipes is connected by an annular guide pipe, and the liquid inlet pipe is fixedly connected to the annular guide pipe. Each liquid inlet pipe is equipped with a valve, and the annular guide pipe is provided with several conduits at equal intervals.

[0008] Explanation: In view of the intermittent and concentrated discharge of rural domestic sewage, the design of the ring-shaped diversion pipe ensures that the water intake inside each adsorption tank is uniform, avoiding the phenomenon of excessive burden on a single adsorption tank, thereby improving the overall system's shock resistance.

[0009] Furthermore, the adsorption module is cylindrical and narrows at the bottom. An extension at the bottom of the adsorption module connects with an opening at the top of another adsorption module. Limiting slide rods are provided on both sides of the bottom of the adsorption module. The limiting slide rods are slidably connected to limiting grooves on both sides of the inner wall of the adsorption cylinder. A detachable plug is provided at the bottom of the limiting groove.

[0010] Note: In view of the dispersed nature of rural domestic sewage, the multiple adsorption modules can be disassembled and installed to facilitate replacement, and the continuous adsorption treatment of wastewater can be maintained during replacement. It also facilitates centralized desorption and regeneration after adsorption saturation.

[0011] Furthermore, the extension is equipped with a filter screen, and the filter screen is filled with the La@D201 nanomaterial. The particle size of the La@D201 nanomaterial is 100~800μm, and the surface of the La@D201 nanomaterial has nanoscale pores. The filter screen is a PTFE-coated polyester mesh with a pore size of 10~100μm.

[0012] Note: The filter screen is used to prevent the loss of La@D201 nanomaterials.

[0013] Furthermore, the liquid outlet pipe is connected to the liquid outlet provided on the side wall of the adsorption module. The liquid outlet pipe includes a front section pipe and a rear section pipe, which are threaded together. The rear section pipe is threaded to the liquid outlet. A rubber stopper is provided inside the liquid outlet. The rubber stopper has a gap in the middle for inserting the rear section pipe and keeping it sealed. Each front section pipe is connected to a main water outlet pipe.

[0014] Note: The liquid outlet tube allows for a detachable connection to the liquid outlet.

[0015] Furthermore, each of the adsorption cylinders is provided with a fixing ring at the top, and the fixing rings are fixedly connected to each other by a connecting rod. Each fixing ring is provided with a support rod at the rear, and the bottom of each support rod is fixed to the ground.

[0016] Note: The support rods are used to maintain the stability of the adsorption cylinder and adsorption module during operation.

[0017] Furthermore, each of the adsorption modules is connected to an annular collection tray below, the collection tray is fixedly set on the ground, the collection tray is provided with a collection groove, the collection groove is provided with several support columns, the top of the support columns is threaded with a sealing sleeve, the sealing sleeve is connected to the bottom of the extension, and the bottom of the collection tray is provided with several upright columns.

[0018] Explanation: The adsorption module is removed and placed in a collection tray. At the same time, eluent is injected into the collection tank to desorb the adsorption module. This is especially useful for rural domestic sewage, which is small in volume and relatively dispersed. After adsorption saturation, the module is desorbed in a concentrated manner to achieve continuous recycling.

[0019] Preferably, the bottom inner side of the extension is provided with a stepped surface, and the sealing sleeve abuts against the stepped surface.

[0020] Note: The sealing sleeve ensures that the bottom of the lowest adsorption module is sealed, allowing wastewater to flow out through the outlet.

[0021] Furthermore, the top of the adsorption cylinder is provided with a sealing cap.

[0022] Note: Keep the top of the adsorption cylinder sealed with the sealing cap to prevent wastewater from overflowing.

[0023] The beneficial effects of this invention are: (1) This invention achieves low-carbon treatment of rural domestic sewage and synergistic recovery of phosphorus resources by installing an adsorption cylinder assembly after the traditional filtration grit chamber, anaerobic tank and aerobic tank. It solves the problem of excessive phosphorus in traditional rural domestic sewage treatment processes. At the same time, after the wastewater is treated by the filtration grit chamber, anaerobic tank and aerobic tank process, organic pollutants in the wastewater can be deeply removed, which is conducive to improving the quality of phosphorus recovery.

[0024] (2) In view of the characteristics of intermittent centralized discharge, large seasonal variation and scattered distribution of rural domestic sewage, a multi-layer stacked detachable adsorption module was designed. This not only improves the system's impact resistance, but also facilitates on-site replacement and desorption regeneration. It has the advantages of simple operation and strong practicality, and has great application prospects. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an integrated low-carbon treatment and phosphorus recovery device for rural domestic sewage according to the present invention; Figure 2 This is a schematic diagram of the combined structure of several adsorption cylinders of the present invention; Figure 3 This is a front view of a combination of several adsorption cylinders of the present invention; Figure 4 This is a top view of a combination of several adsorption cylinders of the present invention; Figure 5 This is a schematic diagram of the adsorption cylinder and its internal adsorption module structure of the present invention; Figure 6 This is a schematic diagram of the internal structure of the adsorption module of the present invention; Figure 7 This is a schematic diagram of the rubber stopper structure of the present invention; Figure 8 This is a schematic diagram of the liquid outlet pipe structure of the present invention; Figure 9 This is a schematic diagram of the support column and sealing sleeve structure of the present invention.

[0026] Among them, 1-filtration and sedimentation tank, 2-anaerobic tank, 3-aerobic tank, 4-adsorption cylinder, 41-inlet pipe, 42-ring guide pipe, 43-valve, 44-conduit pipe, 45-limiting slide groove, 46-plug, 47-sealing cover, 5-adsorption module, 51-extension, 52-opening, 53-limiting slide rod, 54-filter screen, 55-outlet, 56-rubber plug, 57-step surface, 6-outlet pipe, 61-front section pipe, 62-rear section pipe, 63-main outlet pipe, 7-fixing ring, 71-connecting rod, 72-support rod, 8-collecting tray, 81-collecting trough, 82-support column, 83-sealing sleeve. Detailed Implementation

[0027] Example 1 like Figure 1 As shown, an integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage includes a grit chamber 1, an anaerobic tank 2, an aerobic tank 3, and six adsorption cylinders 4 arranged in a circle. The grit chamber 1, the anaerobic tank 2, and the aerobic tank 3 are all commercially available products. like Figure 2 and Figure 3As shown, each adsorption cylinder 4 is fixedly connected to the others. An inlet pipe 41 is provided on one side of the lower part of the adsorption cylinder 4. Each inlet pipe 41 is interconnected with the others. Each inlet pipe 41 is connected to the others through an annular guide pipe 42. The inlet pipe 41 and the annular guide pipe 42 are fixedly connected. Each inlet pipe 41 is provided with a valve 43. Three guide tubes 44 are provided at equal intervals on the annular guide pipe 42. like Figures 3-6 As shown, the adsorption cylinder 4 includes five adsorption modules 5 arranged vertically. The adsorption modules 5 are detachable and filled with La@D201 nanomaterials. The adsorption modules 5 are interconnected and sealed externally. Water from the end of the inlet pipe 41 rises through the gap between each adsorption module 5 and the adsorption cylinder 4 and flows into the top of the uppermost adsorption module 5. It then flows out from the outlet pipe 6 on the side wall of the lowermost adsorption module 5. The top of the adsorption cylinder 4 is provided with a sealing cap 47. like Figure 5 and Figure 6 As shown, the adsorption module 5 is cylindrical and narrows at the bottom. The extension 51 at the bottom of the adsorption module 5 is connected to the opening 52 at the top of another adsorption module 5. Limiting slide rods 53 are provided on both sides of the bottom of the adsorption module 5. The limiting slide rods 53 are slidably connected to the limiting slide grooves 45 on both sides of the inner wall of the adsorption cylinder 4. The bottom of the limiting slide grooves 45 is provided with a detachable plug 46. The extension 51 is provided with a filter screen 54. The filter screen 54 is filled with La@D201 nanomaterial. The particle size of the La@D201 nanomaterial is 200~700μm. The surface of the La@D201 nanomaterial has nanoscale pores. The filter screen 54 is a PTFE-coated polyester mesh with a pore size of 50μm. like Figure 7 and Figure 8 As shown, the liquid outlet pipe 6 is connected to the liquid outlet 55 provided on the side wall of the adsorption module 5. The liquid outlet pipe 6 includes a front section pipe 61 and a rear section pipe 62. The front section pipe 61 and the rear section pipe 62 are threaded together. The rear section pipe 62 is threaded to the liquid outlet 55. A rubber stopper 56 is provided inside the liquid outlet 55. The rubber stopper 56 has a gap in the middle for inserting the rear section pipe 62 and keeping it sealed. Each front section pipe 61 is connected to a main water outlet pipe 63. like Figures 2-4 , Figure 9As shown, each adsorption cylinder 4 has a fixing ring 7 on its upper part, and the fixing rings 7 are fixedly connected to each other by a connecting rod 71. Each fixing ring 7 has a support rod 72 at its rear, and the bottom of each support rod 72 is fixed to the ground. Each adsorption module 5 is connected to an annular collection tray 8 at its lower part. The collection tray 8 is fixedly set on the ground. The collection tray 8 has a collection groove 81 inside, and six support columns 82 inside the collection groove 81. The top of the support column 82 is threadedly connected to a sealing sleeve 83, which is connected to the bottom of the extension 51. The bottom of the collection tray 8 has three columns, and the inner side of the bottom of the extension 51 has a stepped surface 57. The sealing sleeve 83 and the stepped surface 57 abut against each other.

[0028] Example 2 The difference between this embodiment and Embodiment 1 is that: The grit chamber is equipped with a grit filtration assembly, which includes a pulse grit chamber pipe located inside the grit chamber and distributed horizontally, three cleaning valves at the bottom of the pulse grit chamber pipe, a material discharge cleaning box located inside the grit chamber and at the bottom of the pulse grit chamber pipe, and an opening and closing cover plate located on the side wall of the grit chamber. When sewage flows into the grit chamber through the collection pipe, it enters the pulse grit chamber pipe. The pulse grit chamber pipe extends the flow path of the sewage, providing more time for suspended solids to settle. This can improve the settling efficiency without significantly increasing the size of the grit chamber. The settled sediment falls into the material discharge cleaning box through the cleaning valves. When the material discharge cleaning box needs to be cleaned, the opening and closing cover plate is opened and the material discharge cleaning box is pulled out. This grit filtration assembly can effectively improve the grit settling effect in the sewage treatment process and is easy to clean, thereby improving the efficiency and environmental friendliness of the entire sewage treatment system. The cleaning valves and opening and closing cover plate adopt existing technologies. The pulse grit chamber consists of three grit sub-pipes connected in series, with cleaning valves corresponding to each grit sub-pipe and located at the lower end of each sub-pipe. A horizontal limiting frame is installed inside the grit chamber, with limiting ports on the outer wall of each grit sub-pipe. Compared to the overall structure, the pulse grit chamber is designed as several connected grit sub-pipes, which can be replaced or repaired individually, increasing the convenience of installation and disassembly. The limiting ports on the horizontal limiting frame restrict the outer wall of each grit sub-pipe, improving its installation stability. Adjacent grit sub-pipes can be connected by one of the following: flange connection, threaded connection, or clamp connection. An exhaust pipe is provided at the upper end of the anaerobic tank. A support frame is provided on the anaerobic tank and directly above the exhaust pipe. A rotating fan is connected to the center of the support frame via a non-destructive rotating shaft. The height between the upper end of the exhaust pipe and the upper end of the anaerobic tank is 2m. Both the non-destructive rotating shaft and the rotating fan adopt existing technologies. The aerobic tank is equipped with a first fixed packing frame. The packing material in the first fixed packing frame consists of: 10g of zirconium oxide, 25g of alumina, 5g of glass powder, 5g of sodium metasilicate, 3g of alginate, and 1g of polyethylene glycol. An air inlet pipe is provided at the top of the aerobic tank. The aeration pipeline assembly includes a U-shaped aeration pipe located in the aerobic tank and a horizontal aeration pipe used to connect one end of the air outlet pipe and the U-shaped aeration pipe. Both the horizontal aeration pipe and the U-shaped aeration pipe have 20 spray holes on their side walls. The bottom of the anaerobic tank is connected to the horizontal aeration pipe through a water pipe. For rural sewage, which is characterized by small sewage volume and intermittent inflow, the water in the water pipe and the horizontal aeration pipe is not usually full. In order to save pipes, the water path of the water pipe and the air path of the U-shaped aeration pipe are connected by the same pipe.

[0029] Example 3 The difference between this embodiment and Embodiment 1 is that: The adsorption cylinder 4 is arranged in a ring of 8, and the fixing ring 7 and the support column 82 are also arranged in a ring of 8.

[0030] Example 4 The difference between this embodiment and Embodiment 1 is that: The adsorption cylinder 4 contains 6 adsorption modules 5 arranged vertically.

[0031] Example 5 The difference between this embodiment and Embodiment 1 is that: The adsorption cylinder 4 contains 7 adsorption modules 5 arranged vertically.

[0032] Example 6 The difference between this embodiment and Embodiment 1 is that: The difference between this embodiment and Embodiment 1 is that: The adsorption cylinder 4 contains four adsorption modules 5 arranged vertically.

[0033] Example 7 The difference between this embodiment and Embodiment 1 is that: The particle size of La@D201 nanomaterials is 100~500μm. The surface of La@D201 nanomaterials has nanoscale pores. The filter screen 54 is a PTFE-coated polyester mesh with a pore size of 10μm.

[0034] Example 8 The difference between this embodiment and Embodiment 1 is that: The particle size of La@D201 nanomaterials is 400~800μm. The surface of La@D201 nanomaterials has nanoscale pores, and the filter screen 54 is a PTFE-coated polyester mesh with a pore size of 100μm.

[0035] Working principle The working principle of an integrated low-carbon treatment and phosphorus recovery device for rural domestic sewage according to the present invention will be briefly explained below.

[0036] Taking Example 2 as an example, the sewage produced by rural users is collected and flows into the filter grit chamber 1. At this time, the sewage enters the pulse grit chamber. The pulse grit chamber can extend the flow path of the sewage, providing more time for suspended solids to settle. The settled sediment falls into the discharge cleaning box through various cleaning valves. When the discharge cleaning box needs to be cleaned, the opening and closing cover is opened and the discharge cleaning box is pulled out. The treated water enters the anaerobic tank 2. Anaerobic treatment of water is carried out in anaerobic tank 2. When anaerobic treatment of sewage, the water flows from the pulse grit chamber into the distribution plate, and then flows into the first hollow cross ring on the left through the forward connecting pipe. The water flow impacts the floating packing balls in the hollow cross ring, and the anaerobic microorganisms in the floating packing balls carry out the first anaerobic treatment of the water. Then, under the impact of the water flow, it passes through each hollow cross ring in sequence to complete multiple anaerobic treatments. Finally, it flows out through the forward outlet pipe and falls onto the second fixed packing frame for the second anaerobic treatment. Finally, it overflows through the water pipe. When anaerobic treatment of sewage is carried out again, in order to balance the position of the porous packing balls and avoid them being overly concentrated in one place in the hollow cross ring, after the water flows into the distribution plate from the pulse grit chamber, the water flows through the reverse connecting pipe into the first hollow cross ring on the right, so that the water flow impacts and carries out anaerobic treatment in the opposite direction. After being treated in anaerobic tank 2, the water overflows into aerobic tank 3 through a section of the water pipe and horizontal aeration pipe for aerobic treatment. This process removes organic matter, nitrogen, phosphorus, and heavy metals from the water. After the aerobic treatment is completed, the water is discharged and collected. During the anaerobic treatment process, the biogas produced overflows from the bottom of the outlet pipe. Under the action of natural wind at the top of the outlet pipe, it drives the rotating fan to rotate. The rotation of the rotating fan generates negative pressure, creating negative pressure in the outlet pipe. At this time, external air enters the U-shaped aeration pipe through the air inlet pipe and is sprayed into the water body through the spray holes on the side wall of the U-shaped aeration pipe, thereby promoting aeration. Rural sewage is characterized by small sewage volume and intermittent inflow. Therefore, the water in the horizontal aeration pipe is basically not in a full pipe state. In order to save pipes, the water and air circuits share the horizontal aeration pipe. The residual air in the U-shaped aeration pipe flows out through the top of the horizontal aeration pipe and the outlet pipe. When the air force is weak, in order to improve the aeration effect, the external control is drawn into the U-shaped aeration pipe by the air compressor and sprayed into the water body through the spray holes on the side wall of the U-shaped aeration pipe, thereby promoting aeration. The residual air in the U-shaped aeration pipe flows out through the horizontal aeration pipe and the outlet pipe and enters each adsorption tank 4 for phosphorus removal. When using the adsorption cylinder 4, first open the sealing cover 47, and then insert a specified number of adsorption modules 5 into the adsorption cylinder 4 in sequence. The limiting slide rods 53 of the adsorption modules 5 slide down within the limiting slide grooves 45 on both sides inside the adsorption cylinder 4 until the bottom of the lowest adsorption module 5 aligns with the sealing sleeve 83, aligning the upper surface of the sealing sleeve 83 with the inner stepped surface 57 of the extension 51 and maintaining a seal. Then, by rotating the sealing sleeve 83, finely adjust its height relative to the support column 82 so that the limiting slide rod 53 of the second-to-last adsorption module 5 is positioned a distance above the bottom of the limiting slide groove 45. Finally, install the plug 46 at the bottom of the limiting slide groove 45 to maintain the overall seal of the bottom of the adsorption cylinder 4. Figure 5 As shown; After setting up each adsorption cylinder 4 in sequence, the liquid feeding begins. The wastewater to be dephosphorized enters the annular guide pipe 42 through the conduit 44. Opening each valve 43 allows the water to enter each inlet pipe 41. The water exiting the end of the inlet pipe 41 enters the interior of the adsorption cylinder 4, rises along the gap between each adsorption module 5 and the adsorption cylinder 4, and flows in through the top opening 52 of the uppermost adsorption module 5. After being adsorbed and dephosphorized by the La@D2O1 nanomaterials filled inside the adsorption module 5, the water is then discharged into the next adsorption module 5 through the filter screen 54 and the extension section 51. After being processed by each adsorption module 5 in sequence, the water flows out through the outlet pipe 6 on the side wall of the lowermost adsorption module 5. The rear section 62 of the outlet pipe 6 passes through the gap in the middle of the rubber stopper 56 and extends to the upper part of the adsorption module 5. Figure 6 As shown; After a period of time, the adsorption module 5 needs to be replaced and cleaned. At this time, the valve 43 on the corresponding adsorption cylinder 4 is closed. Then, the rear tube 62 is rotated a distance to move it into the front tube 61 so that it is separated from the rubber stopper 56 and the liquid outlet 55. Then, the sealing sleeve 83 is rotated to lower it a distance so that the bottom adsorption module 5 can be taken out. Then, the sealing cover 47 is opened and a new adsorption module 5 is inserted. The removed adsorption module 5 is placed in the collection tank 81 of the collection tray 8. After replacing the bottom adsorption module 5 of each adsorption cylinder 4 in sequence, a mixture of NaOH (15wt%) and NaCl (5wt%) is added into the collection tank 81, and the mixture is made to cover the opening 52 of the adsorption module 5, so that the mixture enters the adsorption module 5 and contacts the La@D201 nanomaterial. At the same time, an electric heater can be set at the bottom of the collection tray 8 to heat the collection tray 8 to 55~60℃ to promote the desorption of phosphorus on the La@D201 nanomaterial. After 24 hours, the mixture inside the collection tray 8 is poured out and rinsed several times with clean water to complete the cleaning and desorption of the adsorption module 5. At this time, when it is time to replace the adsorption module 5 again, the cleaned and desorbed adsorption module 5 is placed back on the top of the adsorption cylinder 4 to realize the cycle.

[0037] The mechanism for selecting La@D201 nanomaterials is as follows: La@D201 nanomaterials refer to La(OH)3 doped and loaded into the pores of D201 nanoresin. For details, please refer to the literature: Structural Evolution of Lanthanum Hydroxides during Long-Term Phosphate Mitigation: Effect of Nanoconfnement. First, P mainly binds to the La(OH)3 surface through ligand exchange to form bidentate mononuclear (EQ1) or bidentate binuclear (EQ2) structures without affecting the crystal structure of the La(OH)3 surface. This stage lasts for about 0.5 days. Subsequently, the increased adsorption of P promoted the transformation of the La(OH)3 surface from a complex state to hydrated lanthanum phosphate microcrystals (EQ3), a process that lasted 2 to 2.5 days. Finally, the hydrated lanthanum phosphate microcrystals slowly lose their water of crystallization and transform into anhydrous lanthanum phosphate (EQ4-5), which has stronger thermodynamic stability.

[0038]

Claims

1. An integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage, characterized in that, It includes a grit chamber (1), an anaerobic tank (2), an aerobic tank (3), and several adsorption cylinders (4) arranged in a circle. Each of the adsorption cylinders (4) is fixedly connected to each other. An inlet pipe (41) is provided on one side of the lower part of the adsorption cylinder (4). Each of the inlet pipes (41) is interconnected. The adsorption cylinder (4) includes several adsorption modules (5) arranged vertically. The adsorption modules (5) are detachable. The adsorption modules (5) are filled with La@D201 nanomaterials. Each adsorption module (5) is interconnected. The adsorption modules (5) are sealed externally. Water from the end of the inlet pipe (41) rises along the gap between each adsorption module (5) and the adsorption cylinder (4) and flows into the top of the uppermost adsorption module (5). It flows out from the outlet pipe (6) provided on the side wall of the lowermost adsorption module (5).

2. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 1, characterized in that, Each of the liquid inlet pipes (41) is connected by an annular guide pipe (42). The liquid inlet pipe (41) is fixedly connected to the annular guide pipe (42). Each liquid inlet pipe (41) is provided with a valve (43). Several guide tubes (44) are provided at equal intervals on the annular guide pipe (42).

3. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 1, characterized in that, The adsorption module (5) is cylindrical and narrows at the bottom. The extension (51) at the bottom of the adsorption module (5) is connected to the opening (52) at the top of another adsorption module (5). Limiting slide rods (53) are provided on both sides of the bottom of the adsorption module (5). The limiting slide rods (53) are slidably connected to the limiting slide grooves (45) provided on both sides of the inner wall of the adsorption cylinder (4). The bottom of the limiting slide grooves (45) is provided with a detachable plug (46).

4. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 3, characterized in that, The extension (51) is provided with a filter screen (54), and the filter screen (54) is filled with the La@D201 nanomaterial. The particle size of the La@D201 nanomaterial is 100~800μm, and the surface of the La@D201 nanomaterial has nanoscale pores. The filter screen (54) is a PTFE-coated polyester mesh with a pore size of 10~100μm.

5. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 1, characterized in that, The liquid outlet pipe (6) is connected to the liquid outlet (55) provided on the side wall of the adsorption module (5). The liquid outlet pipe (6) includes a front section pipe (61) and a rear section pipe (62). The front section pipe (61) and the rear section pipe (62) are threaded together. The rear section pipe (62) is threaded together with the liquid outlet (55). A rubber stopper (56) is provided inside the liquid outlet (55). The rubber stopper (56) has a gap in the middle for inserting the rear section pipe (62) and keeping it sealed. Each front section pipe (61) is connected to a main water outlet pipe (63).

6. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 1, characterized in that, Each of the adsorption cylinders (4) is provided with a fixing ring (7) on the upper part. Each of the fixing rings (7) is fixedly connected to each other by a connecting rod (71). Each fixing ring (7) is provided with a support rod (72) at the rear. The bottom of each support rod (72) is fixed to the ground.

7. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 3, characterized in that, Each of the adsorption modules (5) is connected to an annular collection tray (8) below. The collection tray (8) is fixedly set on the ground. The collection tray (8) is provided with a collection groove (81). The collection groove (81) is provided with several support columns (82). The top of the support column (82) is threadedly connected with a sealing sleeve (83). The sealing sleeve (83) is connected to the bottom of the extension (51). The bottom of the collection tray (8) is provided with several uprights.

8. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 7, characterized in that, The extension (51) has a stepped surface (57) on the inner side of its bottom, and the sealing sleeve (83) abuts against the stepped surface (57).

9. The integrated equipment for low-carbon treatment and phosphorus recovery of rural domestic sewage according to claim 1, characterized in that, The top of the adsorption cylinder (4) is provided with a sealing cap (47).

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