Device and method for realizing efficient recovery of phosphorus and PHAs by fermenting aerobic phosphorus removal granular sludge

Abstract

The invention discloses a device and a method for realizing efficient recovery of phosphorus and PHAs by fermenting aerobic phosphorus removal granular sludge, and belongs to the technical field of biological sewage treatment. The device comprises a non-biodegradable carbon source, an ammonia nitrogen and phosphate water inlet tank, a granular sludge reactor, a PHAs recycling tank, a phosphorus and ammonia nitrogen water outlet tank, a pH value regulator water inlet tank, a magnesium solution water inlet tank, a struvite reactor, a phosphorus recycling tank, a water outlet tank and an online monitoring system. The method comprises the following steps: in an anaerobic stage, converting a non-biodegradable carbon source into an easily biodegradable carbon source, storing the easily biodegradable carbon source as PHAs and releasing phosphorus, discharging supernatant and granular sludge in the anaerobic stage to realize phosphorus and PHAs recovery, and meanwhile, promoting sludge granulation by regulating and controlling water feeding without stirring and precipitation time; and in the aerobic stage, excessive phosphorus uptake is carried out. The method creatively solves the technical problems that the aerobic phosphorus removal bacteria cannot utilize a nonbiodegradable carbon source to realize synchronous recovery of phosphorus and PHAs, and the formation of struvite needs additional ammonia nitrogen to be matched with phosphate.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage biological treatment. Specifically, it particularly relates to a device and method for efficiently recovering phosphorus and PHAs by fermented aerobic phosphorus-removing granular sludge. Background Art

[0002] Phosphorus is an indispensable fertilizer for agricultural production. With the growth of the population and the increase in food demand, the demand for phosphorus shows a significant upward trend.

[0003] In the prior art, aerobic phosphorus-removing technology can achieve the recovery of phosphorus resources by discharging flocculent sludge at the end of the aerobic stage. However, aerobic phosphorus-removing technology requires a large amount of oxygen and carbon sources, and cannot simultaneously achieve the synchronous recovery of PHAs. Moreover, the flocculent sludge used in aerobic phosphorus-removing technology has the characteristics of low biomass and poor sedimentation performance, which will limit its phosphorus recovery load.

[0004] At the same time, aerobic phosphorus-removing technology can currently only utilize the easily biodegradable carbon sources in sewage. However, easily biodegradable carbon sources are often scarce in sewage, and more than 50% of the recalcitrant carbon sources in sewage cannot be utilized. Therefore, in order to achieve efficient phosphorus removal, aerobic phosphorus-removing technology usually needs to additionally add easily biodegradable carbon sources, which will significantly increase the cost of phosphorus recovery.

[0005] Currently, the recovery of phosphorus resources in the prior art is usually achieved by the way of struvite crystallization method. Struvite (NH4MgPO4•6H2O) is composed of ammonia nitrogen, phosphate and magnesium salt, and is more likely to form when the pH value is greater than 8.0. Since additional ammonia nitrogen usually needs to be added to match phosphate during the formation of struvite, it will not only increase the operation complexity, but also increase the cost of phosphorus recovery.

[0006] Based on the above prior art, the applicant believes that it is necessary to explore a device and method that can efficiently recover phosphorus and PHAs while making full use of the recalcitrant carbon sources in sewage, and no additional ammonia nitrogen is required during the recovery process of struvite. Summary of the Invention

[0007] The purpose of the present invention is to provide a device and method for efficiently recovering phosphorus and PHAs by fermented aerobic phosphorus-removing granular sludge. It can efficiently recover phosphorus and PHAs based on the anaerobic effluent rich in phosphorus supernatant and granular sludge while making full use of the recalcitrant carbon sources, and can also make no additional ammonia nitrogen required during the struvite recovery process by regulating the phosphorus and ammonia nitrogen concentrations in real time.

[0008] To achieve the above technical purpose, the present application is realized by the following technical solutions: An apparatus for efficiently recovering phosphorus and PHAs using fermented aerobic phosphorus-removing granular sludge, comprising a refractory biodegradable carbon source, an ammonia nitrogen and a phosphate inlet water tank connected in sequence, a granular sludge reactor, a PHAs recovery tank, a phosphorus and ammonia nitrogen outlet water tank, a pH value regulator inlet water tank, a magnesium solution inlet water tank, a struvite reactor, a phosphorus recovery tank, an outlet water tank, and an on-line monitoring and control system; wherein the refractory biodegradable carbon source, ammonia nitrogen and phosphate inlet water tank are connected to the granular sludge reactor through a first inlet water pump; the PHAs recovery tank is connected to the granular sludge reactor through a first sludge discharge pump; the phosphorus and ammonia nitrogen outlet water tank is connected to the granular sludge reactor through a first drainage pump; the phosphorus and ammonia nitrogen outlet water tank is connected to the struvite reactor through a second inlet water pump; the pH value regulator inlet water tank is connected to the struvite reactor through a third inlet water pump; the magnesium solution inlet water tank is connected to the struvite reactor through a fourth inlet water pump; the phosphorus recovery tank is connected to the struvite reactor through a second sludge discharge pump; the outlet water tank is connected to the struvite reactor through a second drainage pump; the granular sludge reactor is connected to the on-line monitoring and control system through a first phosphate concentration sensor, a dissolved oxygen concentration sensor and an ammonia nitrogen concentration sensor; the struvite reactor is connected to the on-line monitoring and control system through a pH value sensor and a second phosphate concentration sensor; Wherein the refractory biodegradable carbon source, ammonia nitrogen and phosphate inlet water tank are provided with a first overflow pipe and a first vent valve; The granular sludge reactor is provided with a first stirrer, an aeration pump, a flowmeter, a first inlet water pump, a first sludge discharge pump, a first drainage pump, a first phosphate concentration sensor, a dissolved oxygen concentration sensor and an ammonia nitrogen concentration sensor; The PHAs recovery tank is provided with a second overflow pipe and a second vent valve; The phosphorus and ammonia nitrogen outlet water tank is provided with a third overflow pipe and a third vent valve; The pH value regulator inlet water tank is provided with a fourth overflow pipe and a fourth vent valve; The magnesium solution inlet water tank is provided with a fifth overflow pipe and a fifth vent valve; The struvite reactor is provided with a second inlet water pump, a third inlet water pump, a fourth inlet water pump, a second stirrer, a third stirrer, a pH value sensor, a second phosphate concentration sensor, a second sludge discharge pump and a second drainage pump; The phosphorus recovery tank is provided with a sixth overflow pipe and a sixth vent valve; the outlet water tank is provided with a seventh overflow pipe and a seventh vent valve; The on-line monitoring and control system is built-in with an aeration pump relay, a first influent pump relay, a first agitator relay, a dissolved oxygen concentration sensor relay, an ammonia nitrogen concentration sensor relay, a first phosphate concentration sensor relay, a first sludge discharge pump relay, a first drainage pump relay, a second influent pump relay, a second agitator relay, a third agitator relay, a pH value sensor relay, a second phosphate concentration sensor relay, a second sludge discharge pump relay, a fourth influent pump relay, a second drainage pump relay, a third influent pump relay, a signal adapter A / D conversion interface, a signal adapter D / A conversion interface and a computer; Among them, the aeration pump relay of the on-line monitoring and control system is connected to the aeration pump; the first influent pump relay is connected to the first influent pump; the first agitator relay is connected to the first agitator; the dissolved oxygen concentration sensor relay is connected to the dissolved oxygen concentration sensor; the ammonia nitrogen concentration sensor relay is connected to the ammonia nitrogen concentration sensor; the first phosphate concentration sensor relay is connected to the first phosphate concentration sensor; the first sludge discharge pump relay is connected to the first sludge discharge pump; the first drainage pump relay is connected to the first drainage pump; the second influent pump relay is connected to the second influent pump; the second agitator relay is connected to the second agitator; the third agitator relay is connected to the third agitator; the pH value sensor relay is connected to the pH value sensor; the second phosphate concentration sensor relay is connected to the second phosphate concentration sensor; the second sludge discharge pump relay is connected to the second sludge discharge pump; the fourth influent pump relay is connected to the fourth influent pump; the second drainage pump relay is connected to the second drainage pump; the third influent pump relay is connected to the third influent pump; the on-line monitoring and control system converts analog signals into digital signals through the signal adapter A / D conversion interface and a cable and transmits them to the computer; the computer transmits digital instructions to the on-line monitoring and control system through a cable and the signal adapter D / A conversion interface.

[0009] A device for efficiently recovering phosphorus and PHAs by implementing aerobic phosphorus-removing granular sludge using the above-mentioned fermented aerobic phosphorus-removing granular sludge, and a method for efficiently recovering phosphorus and PHAs by implementing aerobic phosphorus-removing granular sludge, comprising the following steps: I. Cultivation of fermented aerobic phosphorus-removing granular sludge: 1) Add the activated sludge from the sewage treatment plant to the granular sludge reactor, and control the sludge concentration at 2000 mg / L - 8000 mg / L; 2) Start the first influent pump, and pump the influent of the hardly biodegradable carbon source, ammonia nitrogen and phosphate with a volume of V1 into the granular sludge reactor, and control V1 to be 40% - 80% of the effective volume V of the reactor; 3) Control the static time to be greater than 1 h, start the first drainage pump, and pump the supernatant containing phosphate and ammonia nitrogen with a volume of V2 into the phosphorus and ammonia nitrogen outlet water tank, and control V2 to be 30% - 90% of V1; 4) Start the first stirrer and stop stirring when the sewage and sludge are thoroughly mixed; 5) Control the sedimentation time to be less than 20 min, start the first sludge discharge pump, and discharge the fermented aerobic phosphorus-removing granular sludge with a volume of V3 into the PHAs recovery tank, where V3 is the difference between V1 and V2; 6) Start the first stirrer and the aeration pump, adjust the flowmeter to control the dissolved oxygen concentration to be greater than 0.5 mg / L, and turn off the first stirrer and the aeration pump when the phosphate concentration drops to 0 mg / L; 7) Repeat steps 2 - 6 until the proportion of granular sludge with a particle size greater than 200 μm in the mixed sludge is greater than 30%, and control the sedimentation time in step 5 to be less than 10 min; 8) Repeat steps 2 - 6 until the proportion of granular sludge with a particle size greater than 200 μm in the mixed sludge is greater than 50%, and the molar ratio of phosphate to ammonia nitrogen in the anaerobic end granular sludge reactor is greater than 1.0, indicating that the cultivation of fermented aerobic phosphorus-removing granular sludge is finally achieved; II. Struvite recovery: 1) Start the second water inlet pump and pump the water with a volume of V2 into the struvite reactor; 2) Start the second stirrer and the third stirrer for stirring; 3) Start the third water inlet pump and pump the pH regulator into the struvite reactor, controlling the pH value to be greater than 8.0; 4) Start the fourth water inlet pump and pump the magnesium solution into the struvite reactor, controlling the molar ratio of magnesium ions to phosphate ions to be 1.0; 5) Stop stirring when the phosphate concentration drops to 0 mg / L; 6) Control the sedimentation time to be greater than 10 min, start the second water discharge pump, and discharge the effluent into the outlet water tank; 7) Start the second sludge discharge pump, discharge the struvite precipitate into the phosphorus recovery tank, and finally achieve the recovery of phosphorus resources in the form of struvite.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1) Compared with the aerobic phosphorus-removing technology, the fermented aerobic phosphorus-removing granular sludge cultivated by the present invention can make full use of the recalcitrant biodegradable carbon source.

[0011] 2) Compared with the aerobic phosphorus-removing technology, the present invention adopts the method of recovering phosphorus-rich supernatant and granular sludge at the anaerobic end, solving the technical problem of the difficult synchronous recovery of phosphorus and PHAs.

[0012] 3) Compared with the aerobic phosphorus-removing technology, the granular sludge adopted by the present invention can significantly improve the biomass per unit volume and the sedimentation performance in the reactor, thus significantly improving the recovery load of phosphorus and PHAs.

[0013] 4) The present invention provides a method for granulation of fermented aerobic phosphorus-removing sludge, which promotes the formation of granular sludge by not stirring the anaerobic influent, strengthening the storage of internal carbon sources through fermentation, and regulating the sedimentation time.

[0014] 5) The present invention provides an economical and efficient method for recovering struvite, which effectively reduces the cost of phosphorus recovery by regulating the phosphorus concentration in real time so that no additional ammonia nitrogen needs to be added during the struvite recovery process. Brief Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of the device for realizing the efficient recovery of phosphorus and PHAs by the fermented aerobic phosphorus-removing granular sludge described in the present invention.

[0016] In the figure: 1 is the inlet water tank for recalcitrant carbon source, ammonia nitrogen and phosphate, 2 is the granular sludge reactor, 3 is the PHA recovery tank, 4 is the outlet water tank for phosphorus and ammonia nitrogen, 5 is the inlet water tank for pH regulator, 6 is the inlet water tank for magnesium solution, 7 is the struvite reactor, 8 is the phosphorus recovery tank, 9 is the outlet water tank, 10 is the on-line monitoring and control system; 1.1 is the first overflow pipe, 1.2 is the first emptying valve; 2.1 is the first stirrer, 2.2 is the aeration pump, 2.3 is the flowmeter, 2.4 is the first water inlet pump, 2.5 is the first sludge discharge pump, 2.6 is the first drainage pump, 2.7 is the first phosphate concentration sensor, 2.8 is the dissolved oxygen concentration sensor, 2.9 is the ammonia nitrogen concentration sensor; 3.1 is the second overflow pipe, 3.2 is the second emptying valve; 4.1 is the third overflow pipe, 4.2 is the third emptying valve; 5.1 is the fourth overflow pipe, 5.2 is the fourth emptying valve; 6.1 is the fifth overflow pipe, 6.2 is the fifth emptying valve; 7.1 is the second water inlet pump, 7.2 is the third water inlet pump, 7.3 is the fourth water inlet pump, 7.4 is the second stirrer, 7.5 is the third stirrer, 7.6 is the pH sensor, 7.7 is the second phosphate concentration sensor, 7.8 is the second sludge discharge pump, 7.9 is the second drainage pump; 8.1 is the sixth overflow pipe, 8.2 is the sixth emptying valve; 9.1 is the seventh overflow pipe, 9.2 is the seventh emptying valve; 10.1 is the aeration pump relay, 10.2 is the first water inlet pump relay, 10.3 is the first stirrer relay, 10.4 is the dissolved oxygen concentration sensor relay, 10.5 is the ammonia nitrogen concentration sensor relay, 10.6 is the first phosphate concentration sensor relay, 10.7 is the first sludge discharge pump relay, 10.8 is the first drainage pump relay, 10.9 is the second water inlet pump relay, 10.10 is the second stirrer relay, 10.11 is the third stirrer relay, 10.12 is the pH sensor relay, 10.13 is the second phosphate concentration sensor relay, 10.14 is the second sludge discharge pump relay, 10.15 is the fourth water inlet pump relay, 10.16 is the second drainage pump relay, 10.17 is the third water inlet pump relay, 10.18 is the signal adapter A / D conversion interface, 10.19 is the signal adapter D / A conversion interface, 10.20 is the computer. Detailed implementation mode

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] The technical principle of the present invention is as follows: Using the activated sludge from a sewage treatment plant as the seed sludge, during anaerobic influent, the recalcitrant carbon source is fermented and transformed into an easily biodegradable carbon source, while being stored as intracellular PHAs and releasing phosphorus; at the end of the anaerobic stage, the supernatant and granular sludge are respectively discharged to achieve efficient recovery of phosphorus and PHAs. During this process, through anaerobic non-stirring, fermentation enhancement, and screening of sedimentation time control, the formation of dense fermentative aerobic phosphorus-removing granular sludge is promoted. In the aerobic stage, the remaining granular sludge uses intracellular PHAs to absorb phosphorus. The present invention can efficiently achieve the synchronous recovery of phosphorus and PHAs on the basis of fully utilizing the recalcitrant carbon source, and at the same time solve the technical problem of adding ammonia nitrogen during the struvite recovery process.

[0019] Example 1: As Figure 1 shown, a device for efficiently recovering phosphorus and PHAs by fermentative aerobic phosphorus-removing granular sludge includes a recalcitrant carbon source, an ammonia nitrogen and a phosphate inlet water tank 1 connected in sequence, a granular sludge reactor 2, a PHAs recovery tank 3, a phosphorus and ammonia nitrogen outlet water tank 4, a pH value regulator inlet water tank 5, a magnesium solution inlet water tank 6, a struvite reactor 7, a phosphorus recovery tank 8, an outlet water tank 9, and an on-line monitoring and control system 10; wherein the recalcitrant carbon source, ammonia nitrogen and phosphate inlet water tank 1 is connected to the granular sludge reactor 2 through a first inlet water pump 2.4; the PHAs recovery tank 3 is connected to the granular sludge reactor 2 through a first sludge discharge pump 2.5; the phosphorus and ammonia nitrogen outlet water tank 4 is connected to the granular sludge reactor 2 through a first drainage pump 2.6; the phosphorus and ammonia nitrogen outlet water tank 4 is connected to the struvite reactor 7 through a second inlet water pump 7.1; the pH value regulator inlet water tank 5 is connected to the struvite reactor 7 through a third inlet water pump 7.2; the magnesium solution inlet water tank 6 is connected to the struvite reactor 7 through a fourth inlet water pump 7.3; the phosphorus recovery tank 8 is connected to the struvite reactor 7 through a second sludge discharge pump 7.8; the outlet water tank 9 is connected to the struvite reactor 7 through a second drainage pump 7.9; the granular sludge reactor 2 is connected to the on-line monitoring and control system 10 through a first phosphate concentration sensor 2.7, a dissolved oxygen concentration sensor 2.8, and an ammonia nitrogen concentration sensor 2.9; the struvite reactor 7 is connected to the on-line monitoring and control system 10 through a pH value sensor 7.6 and a second phosphate concentration sensor 7.7.

[0020] The recalcitrant carbon source, ammonia nitrogen and phosphate inlet water tank 1 is provided with a first overflow pipe 1.1 and a first emptying valve 1.2; The granular sludge reactor 2 is provided with a first stirrer 2.1, an aeration pump 2.2, a flow meter 2.3, a first inlet water pump 2.4, a first sludge discharge pump 2.5, a first drainage pump 2.6, a first phosphate concentration sensor 2.7, a dissolved oxygen concentration sensor 2.8, and an ammonia nitrogen concentration sensor 2.9; The PHAs recovery tank 3 is provided with a second overflow pipe 3.1 and a second emptying valve 3.2; The phosphorus and ammonia nitrogen outlet water tank 4 is equipped with a third overflow pipe 4.1 and a third drain valve 4.2; The pH value regulator inlet water tank 5 is equipped with a fourth overflow pipe 5.1 and a fourth drain valve 5.2; The magnesium solution inlet water tank 6 is equipped with a fifth overflow pipe 6.1 and a fifth drain valve 6.2; The struvite reactor 7 is equipped with a second inlet water pump 7.1, a third inlet water pump 7.2, a fourth inlet water pump 7.3, a second stirrer 7.4, a third stirrer 7.5, a pH value sensor 7.6, a second phosphate concentration sensor 7.7, a second sludge discharge pump 7.8 and a second drain pump 7.9; The phosphorus recovery tank 8 is equipped with a sixth overflow pipe 8.1 and a sixth drain valve 8.2; The outlet water tank 9 is equipped with a seventh overflow pipe 9.1 and a seventh drain valve 9.2; The on-line monitoring and control system 10 is internally provided with an aeration pump relay 10.1, a first inlet water pump relay 10.2, a first stirrer relay 10.3, a dissolved oxygen concentration sensor relay 10.4, an ammonia nitrogen concentration sensor relay 10.5, a first phosphate concentration sensor relay 10.6, a first sludge discharge pump relay 10.7, a first drain pump relay 10.8, a second inlet water pump relay 10.9, a second stirrer relay 10.10, a third stirrer relay 10.11, a pH value sensor relay 10.12, a second phosphate concentration sensor relay 10.13, a second sludge discharge pump relay 10.14, a fourth inlet water pump relay 10.15, a second drain pump relay 10.16, a third inlet water pump relay 10.17, a signal adapter A / D conversion interface 10.18, a signal adapter D / A conversion interface 10.19 and a computer 10.20.

[0021] The aeration pump relay 10.1 of the on-line monitoring and control system 10 is connected to the aeration pump 2.2; the first influent pump relay 10.2 is connected to the first influent pump 2.4; the first agitator relay 10.3 is connected to the first agitator 2.1; the dissolved oxygen concentration sensor relay 10.4 is connected to the dissolved oxygen concentration sensor 2.8; the ammonia nitrogen concentration sensor relay 10.5 is connected to the ammonia nitrogen concentration sensor 2.9; the first phosphate concentration sensor relay 10.6 is connected to the first phosphate concentration sensor 2.7; the first sludge discharge pump relay 10.7 is connected to the first sludge discharge pump 2.5; the first drainage pump relay 10.8 is connected to the first drainage pump 2.6; the second influent pump relay 10.9 is connected to the second influent pump 7.1; the second agitator relay 10.10 is connected to the second agitator 7.4; the third agitator relay 10.11 is connected to the third agitator 7.5; the pH value sensor relay 10.12 is connected to the pH value sensor 7.6; the second phosphate concentration sensor relay 10.13 is connected to the second phosphate concentration sensor 7.7; the second sludge discharge pump relay 10.14 is connected to the second sludge discharge pump 7.8; the fourth influent pump relay 10.15 is connected to the fourth influent pump 7.3; the second drainage pump relay 10.16 is connected to the second drainage pump 7.9; the third influent pump relay 10.17 is connected to the third influent pump 7.2; the on-line monitoring and control system 10 converts analog signals into digital signals through the signal adapter A / D conversion interface 10.18 and a cable and transmits them to the computer 10.20; the computer 10.20 transmits digital instructions to the on-line monitoring and control system 10 through a cable and the signal adapter D / A conversion interface 10.19.

[0022] During the test, starch, ammonium chloride, dipotassium hydrogen phosphate, tap water and 0.3 ml / L nutrient solution were used to simulate the influent of recalcitrant carbon source, ammonia nitrogen and phosphate. The concentrations of recalcitrant carbon source, ammonia nitrogen and phosphate were 800 mg COD / L, 50 mg N / L and 6 mg P / L respectively; sodium hydroxide and tap water were used to simulate the influent of pH regulator, with a concentration of 2000 mg / L; magnesium chloride hexahydrate and tap water were used to simulate the influent of magnesium solution, with a magnesium ion concentration of 500 mg / L. The nutrient solution components included: 5 g / L EDTA, 5 g / L FeSO4, 15 g / L EDTA, 0.014 g / L H3BO3, 0.25 g / L CuSO4·5H2O, 0.22 g / L NaMoO4·2H2O, 0.99 g / L MnCl2·4H2O, 0.43 ZnSO4·7H2O, 0.19 g / L NiCl2·6H2O.

[0023] The test reactor is as Figure 1As shown, the volumes of the granular sludge reactor 3 and the struvite reactor 7 are 10 L and 9 L respectively.

[0024] The specific operation is as follows: I. Cultivation of fermentative aerobic phosphorus-removing granular sludge: 1) Add the activated sludge from the sewage treatment plant to the granular sludge reactor 2, and control the sludge concentration at 5000 mg / L. 2) Start the first inlet pump 2.4 and pump 6 L of influent containing recalcitrant carbon source, ammonia nitrogen and phosphate into the granular sludge reactor 2. 3) Control the static time at 2 h, start the first drainage pump 2.6, and pump 5 L of supernatant containing phosphate and ammonia nitrogen into the phosphorus and ammonia nitrogen outlet water tank 4. 4) Start the first stirrer 2.1 and stop stirring when the sewage and sludge are fully mixed. 5) Control the sedimentation time at 15 min, start the first sludge discharge pump 2.5, and discharge 1 L of fermentative aerobic phosphorus-removing granular sludge into the PHAs recovery tank 3. 6) Start the first stirrer 2.1 and the aeration pump 2.2, adjust the flowmeter 2.3 to control the dissolved oxygen concentration at 2 mg / L, and turn off the first stirrer 2.1 and the aeration pump 2.2 when the phosphate concentration drops to 0 mg / L. 7) Repeat steps 2 - 6 until the proportion of granular sludge with a particle size greater than 200 μm in the mixed sludge is 40%, and control the sedimentation time in step 5 at 5 min. 8) Repeat steps 2 - 6 until the proportion of granular sludge with a particle size greater than 200 μm in the mixed sludge is 60%, and the molar ratio of phosphate to ammonia nitrogen in the granular sludge reactor 2 at the end of anaerobic stage is 1.2, indicating that the cultivation of fermentative aerobic phosphorus-removing granular sludge is finally achieved.

[0025] II. Struvite recovery: 1) Start the second inlet pump 7.1 and pump 5 L of influent into the struvite reactor 7. 2) Start the second stirrer 7.4 and the third stirrer 7.5 for stirring. 3) Start the third inlet pump 7.2 and pump the pH regulator into the struvite reactor 7, and control the pH value at 8.3. 4) Start the fourth inlet pump 7.3 and pump the magnesium solution into the struvite reactor 7, and control the molar ratio of magnesium ions to phosphate ions at 1.0. 5) Stop stirring when the phosphate concentration drops to 0 mg / L. 6) Control the sedimentation time at 30 min, start the second drainage pump 7.9, and discharge the effluent into the outlet water tank 9. 7) Start the second sludge pump 7.8 to discharge the struvite precipitate into the phosphorus recovery tank 8, and finally realize the recovery of phosphorus resources in the form of struvite.

[0026] The test results show that: in the fermented aerobic phosphorus-removing granular sludge, the proportion of particles with a particle size greater than 200 μm is 60%. Under the condition that the starch utilization rate reaches 63%, the PHAs content can reach 0.20 g / g of sludge, and the phosphorus recovery rate is 94%. Among them, phosphorus is recovered in the form of struvite, and the average particle size of the struvite particles is 0.55 mm, and the purity is 85%.

[0027] Finally, although this specification is described according to the implementation manners, not each implementation manner only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation manners that can be understood by those skilled in the art.

Claims

1. An apparatus for efficiently recovering phosphorus and PHAs by fermented aerobic phosphorus-removing granular sludge, characterized in that It includes a refractory biodegradable carbon source, ammonia nitrogen, and phosphate inlet water tank (1) connected in sequence, a granular sludge reactor (2), a PHAs recovery tank (3), a phosphorus and ammonia nitrogen outlet water tank (4), a pH value regulator inlet water tank (5), a magnesium solution inlet water tank (6), a struvite reactor (7), a phosphorus recovery tank (8), an outlet water tank (9), and an on-line monitoring and control system (10); wherein the refractory biodegradable carbon source, ammonia nitrogen, and phosphate inlet water tank (1) is connected to the granular sludge reactor (2) through a first inlet water pump (2.4); the PHAs recovery tank (3) is connected to the granular sludge reactor (2) through a first sludge discharge pump (2.5); the phosphorus and ammonia nitrogen outlet water tank (4) is connected to the granular sludge reactor (2) through a first drainage pump (2.6); the phosphorus and ammonia nitrogen outlet water tank (4) is connected to the struvite reactor (7) through a second inlet water pump (7.1); the pH value regulator inlet water tank (5) is connected to the struvite reactor (7) through a third inlet water pump (7.2); the magnesium solution inlet water tank (6) is connected to the struvite reactor (7) through a fourth inlet water pump (7.3); the phosphorus recovery tank (8) is connected to the struvite reactor (7) through a second sludge discharge pump (7.8); the outlet water tank (9) is connected to the struvite reactor (7) through a second drainage pump (7.9); the granular sludge reactor (2) is connected to the on-line monitoring and control system (10) through a first phosphate concentration sensor (2.7), a dissolved oxygen concentration sensor (2.8), and an ammonia nitrogen concentration sensor (2.9); the struvite reactor (7) is connected to the on-line monitoring and control system (10) through a pH value sensor (7.6) and a second phosphate concentration sensor (7.7); Wherein the refractory biodegradable carbon source, ammonia nitrogen, and phosphate inlet water tank (1) is equipped with a first overflow pipe (1.1) and a first emptying valve (1.2); The granular sludge reactor (2) is equipped with a first stirrer (2.1), an aeration pump (2.2), a flowmeter (2.3), a first inlet water pump (2.4), a first sludge discharge pump (2.5), a first drainage pump (2.6), a first phosphate concentration sensor (2.7), a dissolved oxygen concentration sensor (2.8), and an ammonia nitrogen concentration sensor (2.9); The PHAs recovery tank (3) is equipped with a second overflow pipe (3.1) and a second emptying valve (3.2); The phosphorus and ammonia nitrogen outlet water tank (4) is equipped with a third overflow pipe (4.1) and a third emptying valve (4.2); The pH value regulator inlet water tank (5) is equipped with a fourth overflow pipe (5.1) and a fourth emptying valve (5.2); The magnesium solution inlet water tank (6) is equipped with a fifth overflow pipe (6.1) and a fifth emptying valve (6.2); The struvite reactor (7) is equipped with a second inlet water pump (7.1), a third inlet water pump (7.2), a fourth inlet water pump (7.3), a second stirrer (7.4), a third stirrer (7.5), a pH value sensor (7.6), a second phosphate concentration sensor (7.7), a second sludge discharge pump (7.8), and a second drainage pump (7.9); The phosphorus recovery tank (8) is configured with a sixth overflow pipe (8.1) and a sixth vent valve (8.2); The water outlet tank (9) is configured with a seventh overflow pipe (9.1) and a seventh vent valve (9.2); The on-line monitoring and control system (10) is internally provided with an aeration pump relay (10.1), a first water inlet pump relay (10.2), a first stirrer relay (10.3), a dissolved oxygen concentration sensor relay (10.4), an ammonia nitrogen concentration sensor relay (10.5), a first phosphate concentration sensor relay (10.6), a first sludge discharge pump relay (10.7), a first drainage pump relay (10.8), a second water inlet pump relay (10.9), a second stirrer relay (10.10), a third stirrer relay (10.11), a pH value sensor relay (10.12), a second phosphate concentration sensor relay (10.13), a second sludge discharge pump relay (10.14), a fourth water inlet pump relay (10.15), a second drainage pump relay (10.16), a third water inlet pump relay (10.17), a signal adapter A / D conversion interface (10.18), a signal adapter D / A conversion interface (10.19) and a computer (10.20); Among them, the aeration pump relay (10.1) of the on-line monitoring and control system (10) is connected to the aeration pump (2.2); the first influent pump relay (10.2) is connected to the first influent pump (2.4); the first agitator relay (10.3) is connected to the first agitator (2.1); the dissolved oxygen concentration sensor relay (10.4) is connected to the dissolved oxygen concentration sensor (2.8); the ammonia nitrogen concentration sensor relay (10.5) is connected to the ammonia nitrogen concentration sensor (2.9); the first phosphate concentration sensor relay (10.6) is connected to the first phosphate concentration sensor (2.7); the first sludge discharge pump relay (10.7) is connected to the first sludge discharge pump (2.5); the first drainage pump relay (10.8) is connected to the first drainage pump (2.6); the second influent pump relay (10.9) is connected to the second influent pump (7.1); the second agitator relay (10.10) is connected to the second agitator (7.4); the third agitator relay (10.11) is connected to the third agitator (7.5); the pH value sensor relay (10.12) is connected to the pH value sensor (7.6); the second phosphate concentration sensor relay (10.13) is connected to the second phosphate concentration sensor (7.7); the second sludge discharge pump relay (10.14) is connected to the second sludge discharge pump (7.8); the fourth influent pump relay (10.15) is connected to the fourth influent pump (7.3); the second drainage pump relay (10.16) is connected to the second drainage pump (7.9); the third influent pump relay (10.17) is connected to the third influent pump (7.2); the on-line monitoring and control system (10) converts the analog signal into a digital signal through the signal adapter A / D conversion interface (10.18) and the cable and transmits it to the computer (10.20); the computer (10.20) transmits the digital instruction to the on-line monitoring and control system (10) through the cable and the signal adapter D / A conversion interface (10.19).

2. An apparatus for efficiently recovering phosphorus and PHAs by using the fermented aerobic phosphorus-removing granular sludge according to claim 1 implements a method for efficiently recovering phosphorus and PHAs by using the fermented aerobic phosphorus-removing granular sludge, which is characterized by comprising the following steps: I. Cultivation of fermented aerobic phosphorus-removing granular sludge: 1) Add the activated sludge from the sewage treatment plant to the granular sludge reactor (2), and control the sludge concentration at 2000 mg / L - 8000 mg / L; 2) Start the first influent pump (2.4), and pump the influent of the hardly biodegradable carbon source, ammonia nitrogen and phosphate with a volume of V1 into the granular sludge reactor (2), and control V1 to be 40% - 80% of the effective volume V of the reactor; 3) Control the static time to be greater than 1 h, start the first drainage pump (2.6), and pump the supernatant containing phosphate and ammonia nitrogen with a volume of V2 into the phosphorus and ammonia nitrogen outlet water tank (4), and control V2 to be 30% - 90% of V1; 4) Start the first agitator (2.1), and stop stirring when the sewage and the sludge are fully mixed; 5) Control the precipitation time to be less than 20 min, start the first sludge discharge pump (2.5), and discharge the fermented aerobic phosphorus-removing granular sludge with a volume of V3 into the PHA recovery tank (3), where V3 is the difference between V1 and V2; 6) Start the first stirrer (2.1) and the aeration pump (2.2), adjust the flowmeter (2.3) to control the dissolved oxygen concentration to be greater than 0.5 mg / L, and turn off the first stirrer ( 2.1) and the aeration pump (2.2) when the phosphate concentration drops to 0 mg / L; 7) Repeat steps 2 - 6 until the proportion of granular sludge with a particle size greater than 200 μm in the mixed sludge is greater than 30%, and control the precipitation time in step 5 to be less than 10 min; 8) Repeat steps 2 - 6 until the proportion of granular sludge with a particle size greater than 200 μm in the mixed sludge is greater than 50%, and the molar ratio of phosphate to ammonia nitrogen in the anaerobic end granular sludge reactor (2) is greater than 1.0, indicating that the cultivation of fermented aerobic phosphorus-removing granular sludge is finally achieved; II. Struvite recovery: 1) Start the second water inlet pump (7.1) and pump water with a volume of V2 into the struvite reactor (7); 2) Start the second stirrer (7.4) and the third stirrer (7.5) for stirring; 3) Start the third water inlet pump (7.2) and pump the pH regulator into the struvite reactor (7) to control the pH value to be greater than 8.0; 4) Start the fourth water inlet pump (7.3) and pump the magnesium solution into the struvite reactor (7) to control the molar ratio of magnesium ions to phosphate ions to be 1.0; 5) Stop stirring when the phosphate concentration drops to 0 mg / L; 6) Control the precipitation time to be greater than 10 min, start the second drain pump (7.9), and discharge the effluent into the outlet water tank (9); 7) Start the second sludge discharge pump (7.8) and discharge the struvite precipitate into the phosphorus recovery tank (8), finally achieving the recovery of phosphorus resources in the form of struvite.

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