A device and method for realizing efficient recovery of phosphorus and PHAs by using a fermentation aerobic phosphorus removal granular sludge

Abstract

The application discloses a device and method for realizing high-efficiency recovery of phosphorus and PHAs by fermenting aerobic phosphorus-removing granular sludge, and belongs to the technical field of sewage biological treatment. The device comprises a difficult-biodegradable carbon source, an ammonia nitrogen and phosphate influent tank, a granular sludge reactor, a PHAs recovery tank, a phosphorus and ammonia nitrogen effluent tank, a pH regulator influent tank, a magnesium solution influent tank, a struvite reactor, a phosphorus recovery tank, an effluent tank and an online monitoring system. The method comprises the following steps: in an anaerobic stage, the difficult-biodegradable carbon source is converted into easily-biodegradable carbon source and stored as PHAs and phosphorus release; supernatant and granular sludge are discharged at the end of the anaerobic stage to realize recovery of phosphorus and PHAs, and meanwhile, sludge granulation is promoted by regulating non-stirring and sedimentation time of influent; and in an aerobic stage, excess phosphorus is absorbed. The application creatively solves the technical problems that the phosphorus-removing aerobic bacteria cannot utilize the difficult-biodegradable carbon source to realize simultaneous recovery of phosphorus and PHAs, and that external ammonia nitrogen needs to be added to match the phosphate for struvite formation.

Description

Technical Field

[0001] This invention belongs to the field of wastewater biological treatment technology, and more specifically, it relates to an apparatus and method for achieving efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge. Background Technology

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

[0003] In existing technologies, aerobic phosphorus removal technology can recover phosphorus resources by discharging flocculent sludge at the end of the aerobic stage. However, aerobic phosphorus removal technology requires a large amount of oxygen and carbon source, and cannot simultaneously recover PHAs. Moreover, the flocculent sludge used in aerobic phosphorus removal technology has the characteristics of low biomass and poor settling properties, which limits its phosphorus recovery load.

[0004] Meanwhile, aerobic phosphorus removal technology can currently only utilize readily biodegradable carbon sources in wastewater. However, readily biodegradable carbon sources are often scarce in wastewater, and more than 50% of the recalcitrant carbon sources present in wastewater cannot be utilized. Therefore, in order to achieve efficient phosphorus removal, aerobic phosphorus removal technology usually requires the addition of readily biodegradable carbon sources, which significantly increases phosphorus recovery costs.

[0005] Currently, the recovery of phosphorus resources in existing technologies is usually achieved through struvite crystallization. Struvite (NH4MgPO4•6H2O) is composed of ammonia nitrogen, phosphate, and magnesium salts, and it forms more readily at a pH greater than 8.0. Since the formation of struvite typically requires the addition of additional ammonia nitrogen to match the phosphate, this not only increases operational complexity but also raises the cost of phosphorus recovery.

[0006] Based on the aforementioned existing technologies, the applicant believes it is necessary to explore a method and apparatus that can achieve efficient recovery of phosphorus and PHAs while making full use of the recalcitrant carbon sources in wastewater, and that eliminates the need for additional ammonia nitrogen in the struvite recovery process. Summary of the Invention

[0007] The purpose of this invention is to provide an apparatus and method for efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge. It can achieve efficient recovery of phosphorus and PHAs by making full use of the recalcitrant carbon source and by using anaerobic end-discharge phosphorus-rich supernatant and granular sludge. Furthermore, it can eliminate the need for additional ammonia nitrogen addition during struvite recovery by real-time control of phosphorus and ammonia nitrogen concentrations.

[0008] To achieve the above technical objectives, this application employs the following technical solution:

[0009] A device for efficient recovery of phosphorus and PHAs from fermented aerobic granular sludge for phosphorus removal includes, in sequence, inlet tanks for a recalcitrant carbon source, ammonia nitrogen, and phosphate; a granular sludge reactor; a PHAs recovery tank; an outlet tank for phosphorus and ammonia nitrogen; an inlet tank for a pH adjuster; an inlet tank for a magnesium solution; a struvite reactor; a phosphorus recovery tank; an outlet tank; and an online monitoring and control system. The inlet tanks for the recalcitrant carbon source, ammonia nitrogen, and phosphate are connected to the granular sludge reactor via a first inlet pump; the PHAs recovery tank is connected to the granular sludge reactor via a first sludge discharge pump; and the outlet tank for phosphorus and ammonia nitrogen is connected to the granular sludge reactor via a first outlet pump. The following connections are made: Phosphorus and ammonia nitrogen effluent tanks are connected to the struvite reactor via a second influent pump; pH adjuster influent tanks are connected to the struvite reactor via a third influent pump; magnesium solution influent tanks are connected to the struvite reactor via a fourth influent pump; phosphorus recovery tanks are connected to the struvite reactor via a second sludge discharge pump; effluent tanks are connected to the struvite reactor via a second drainage pump; granular sludge reactors are connected to the online monitoring and control system via a first phosphate concentration sensor, a dissolved oxygen concentration sensor, and an ammonia nitrogen concentration sensor; the struvite reactors are connected to the online monitoring and control system via a pH sensor and a second phosphate concentration sensor.

[0010] The inlet tanks for the recalcitrant carbon source, ammonia nitrogen, and phosphate are equipped with a first overflow pipe and a first vent valve.

[0011] The granular sludge reactor is equipped with a first agitator, an aeration pump, a flow meter, a first influent pump, a first sludge discharge pump, a first drain pump, a first phosphate concentration sensor, a dissolved oxygen concentration sensor, and an ammonia nitrogen concentration sensor.

[0012] The PHAs recycling bin is equipped with a second overflow pipe and a second vent valve.

[0013] The phosphorus and ammonia nitrogen outlet tanks are equipped with a third overflow pipe and a third vent valve;

[0014] The pH adjuster inlet tank is equipped with a fourth overflow pipe and a fourth vent valve;

[0015] The magnesium solution inlet tank is equipped with a fifth overflow pipe and a fifth vent valve;

[0016] The struvite reactor is equipped with a second inlet pump, a third inlet pump, a fourth inlet pump, a second agitator, a third agitator, a pH sensor, a second phosphate concentration sensor, a second sludge discharge pump, and a second drain pump.

[0017] The phosphorus recovery tank is equipped with a sixth overflow pipe and a sixth vent valve; the outlet tank is equipped with a seventh overflow pipe and a seventh vent valve.

[0018] The online monitoring and control system includes relays for aeration pump, first inlet pump, first agitator, dissolved oxygen concentration sensor, ammonia nitrogen concentration sensor, first phosphate concentration sensor, first sludge discharge pump, first drainage pump, second inlet pump, second agitator, third agitator, pH sensor, second phosphate concentration sensor, second sludge discharge pump, fourth inlet pump, second drainage pump, third inlet pump, A / D converter, D / A converter, and a computer.

[0019] The online monitoring and control system includes: an aeration pump relay connected to the aeration pump; a first inlet pump relay connected to the first inlet pump; a first agitator relay connected to the first agitator; a dissolved oxygen concentration sensor relay connected to the dissolved oxygen concentration sensor; an ammonia nitrogen concentration sensor relay connected to the ammonia nitrogen concentration sensor; a first phosphate concentration sensor relay connected to the first phosphate concentration sensor; a first sludge discharge pump relay connected to the first sludge discharge pump; a first drainage pump relay connected to the first drainage pump; a second inlet pump relay connected to the second inlet pump; a second agitator relay connected to the second agitator; and a third agitator relay connected to the second agitator. The relay for the agitator is connected to the third agitator; the relay for the pH sensor is connected to the pH sensor; the relay for the second phosphate concentration sensor is connected to the second phosphate concentration sensor; the relay for the second sludge pump is connected to the second sludge pump; the relay for the fourth inlet pump is connected to the fourth inlet pump; the relay for the second drain pump is connected to the second drain pump; the relay for the third inlet pump is connected to the third inlet pump; the online monitoring and control system converts analog signals into digital signals and transmits them to the computer through an A / D converter and cable; the computer transmits digital commands to the online monitoring and control system through a cable and a D / A converter.

[0020] A method for achieving efficient recovery of phosphorus and PHAs using the aforementioned aerobic phosphorus removal granular sludge from fermentation includes the following steps:

[0021] I. Cultivation of fermented aerobic phosphorus removal granular sludge:

[0022] 1) Add activated sludge from the wastewater treatment plant to the granular sludge reactor, and control the sludge concentration at 2000 mg / L-8000 mg / L;

[0023] 2) Start the first influent pump to pump a volume of V1 of recalcitrant carbon source, ammonia nitrogen, and phosphate into the granular sludge reactor, controlling V1 to be 40%-80% of the effective volume V of the reactor;

[0024] 3) Control the settling time to be greater than 1 hour, 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 tank, controlling V2 to be 30%-90% of V1;

[0025] 4) Start the first mixer, and stop mixing when the sewage and sludge are fully mixed;

[0026] 5) Control the sedimentation time to be less than 20 minutes, start the first sludge discharge pump, and discharge the fermented aerobic phosphorus removal granular sludge with a volume of V3 into the PHAs recovery tank. V3 is the difference between V1 and V2.

[0027] 6) Start the first agitator and aeration pump, adjust the flow meter to control the dissolved oxygen concentration to be greater than 0.5 mg / L, and turn off the first agitator and aeration pump when the phosphate concentration drops to 0 mg / L;

[0028] 7) Repeat steps 2-6 until the proportion of granular sludge with a particle size greater than 200μm in the mixed sludge is greater than 30%, and control the settling time in step 5 to less than 10min.

[0029] 8) Repeat steps 2-6 until the proportion of granular sludge with a particle size greater than 200 μm is greater than 50% of the mixed sludge, and the molar ratio of phosphate to ammonia nitrogen in the anaerobic granular sludge reactor is greater than 1.0, indicating that the cultivation of fermented aerobic phosphorus removal granular sludge has finally been achieved.

[0030] II. Bird guano recycling:

[0031] 1) Start the second inlet pump to pump inlet water of volume V2 into the struvite reactor;

[0032] 2) Start the second and third mixers to mix;

[0033] 3) Start the third inlet pump to pump the pH adjuster into the struvite reactor and control the pH value to be greater than 8.0;

[0034] 4) Start the fourth inlet pump to pump the magnesium solution into the struvite reactor, and control the molar ratio of magnesium ions to phosphate ions to be 1.0.

[0035] 5) Stop stirring when the phosphate concentration drops to 0 mg / L;

[0036] 6) Control the sedimentation time to be greater than 10 minutes, then start the second drainage pump to discharge the effluent into the effluent tank;

[0037] 7) Start the second sludge pump to discharge the struvite sediment into the phosphorus recovery tank, thus realizing the recovery of phosphorus resources in the form of struvite.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1) Compared with aerobic phosphorus removal technology, the fermented aerobic phosphorus removal granular sludge cultivated in this invention can make full use of recalcitrant carbon sources.

[0040] 2) Compared with aerobic phosphorus removal technology, this invention uses anaerobic end recovery of phosphorus-rich supernatant and granular sludge, which solves the technical problem of simultaneous recovery of phosphorus and PHAs.

[0041] 3) Compared with aerobic phosphorus removal technology, the granular sludge used in this invention can significantly increase the biomass per unit volume and settling performance in the reactor, thereby significantly increasing the recovery load of phosphorus and PHAs.

[0042] 4) This invention provides a method for granulation of fermented aerobic phosphorus removal sludge, which promotes the formation of granular sludge by anaerobic influent without stirring, enhanced internal carbon source storage during fermentation, and regulation of sedimentation time.

[0043] 5) This invention provides an economical and efficient method for struvite recovery. By adjusting the phosphorus concentration in real time, the additional addition of ammonia nitrogen is no longer required during the struvite recovery process, effectively reducing the cost of phosphorus recovery. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the device for achieving efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge according to the present invention.

[0045] In the diagram: 1 is the inlet tank for recalcitrant carbon source, ammonia nitrogen, and phosphate; 2 is the granular sludge reactor; 3 is the PHAs recovery tank; 4 is the effluent tank for phosphorus and ammonia nitrogen; 5 is the inlet tank for pH adjuster; 6 is the inlet tank for magnesium solution; 7 is the struvite reactor; 8 is the phosphorus recovery tank; 9 is the effluent tank; 10 is the online monitoring and control system; 1.1 is the first overflow pipe; 1.2 is the first vent valve; 2.1 is the first agitator; 2.2 is the aeration pump; 2.3 is the flow meter. 2.4 is the first inlet pump, 2.5 is the first sludge pump, 2.6 is the first drain pump, 2.7 is the first phosphate concentration sensor, 2.8 is the dissolved oxygen concentration sensor, and 2.9 is the ammonia nitrogen concentration sensor; 3.1 is the second overflow pipe, and 3.2 is the second vent valve; 4.1 is the third overflow pipe, and 4.2 is the third vent valve; 5.1 is the fourth overflow pipe, and 5.2 is the fourth vent valve; 6.1 is the fifth overflow pipe, and 6.2 is the fifth vent valve; 7.1 is the... 7.2 is the second inlet pump, 7.3 is the third inlet pump, 7.4 is the second agitator, 7.5 is the third agitator, 7.6 is the pH sensor, 7.7 is the second phosphate concentration sensor, 7.8 is the second sludge discharge pump, and 7.9 is the second drainage pump; 8.1 is the sixth overflow pipe, 8.2 is the sixth vent valve; 9.1 is the seventh overflow pipe, 9.2 is the seventh vent valve; 10.1 is the aeration pump relay, 10.2 is the first inlet pump relay, 10.3 is the first agitator 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 inlet pump relay, 10.10 is the second agitator relay, 10.11 is the third agitator relay, and 10.12 is the pH sensor relay. 10.13 is the relay for the second phosphate concentration sensor, 10.14 is the relay for the second sludge pump, 10.15 is the relay for the fourth inlet pump, 10.16 is the relay for the second drain pump, 10.17 is the relay for the third inlet pump, 10.18 is the A / D converter interface, 10.19 is the D / A converter interface, and 10.20 is the computer. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] The technical principle of this invention is as follows: Using activated sludge from a wastewater treatment plant as seed sludge, during anaerobic influent, the recalcitrant carbon source is fermented and converted into a readily biodegradable carbon source, while simultaneously being stored as intracellular PHAs and releasing phosphorus. At the end of the anaerobic process, the supernatant and granular sludge are discharged separately to achieve efficient recovery of phosphorus and PHAs. During this process, the formation of dense, fermented, aerobic, phosphorus-removing granular sludge is promoted through anaerobic non-stirring, fermentation enhancement, and controlled sedimentation time screening. In the aerobic stage, the remaining granular sludge utilizes intracellular PHAs to absorb phosphorus. This invention can efficiently achieve simultaneous recovery of phosphorus and PHAs while fully utilizing the recalcitrant carbon source, and simultaneously solves the technical problem of requiring the addition of ammonia nitrogen during struvite recovery.

[0048] Example 1: As Figure 1 As shown, an apparatus for efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge includes, in sequence, a recalcitrant carbon source, ammonia nitrogen, and phosphate inlet tank 1; a granular sludge reactor 2; a PHAs recovery tank 3; a phosphorus and ammonia nitrogen outlet tank 4; a pH adjuster inlet tank 5; a magnesium solution inlet tank 6; a struvite reactor 7; a phosphorus recovery tank 8; an outlet tank 9; and an online monitoring and control system 10. The recalcitrant carbon source, ammonia nitrogen, and phosphate inlet tank 1 is connected to the granular sludge reactor 2 via a first inlet pump 2.4; the PHAs recovery tank 3 is connected to the granular sludge reactor 2 via a first sludge discharge pump 2.5; the phosphorus and ammonia nitrogen outlet tank 4 is connected to the granular sludge reactor 2 via a first drain pump 2.6; and the phosphorus and ammonia nitrogen outlet tank 9... 4 is connected to the struvite reactor 7 via the second inlet pump 7.1; the pH adjuster inlet tank 5 is connected to the struvite reactor 7 via the third inlet pump 7.2; the magnesium solution inlet tank 6 is connected to the struvite reactor 7 via the fourth inlet pump 7.3; the phosphorus recovery tank 8 is connected to the struvite reactor 7 via the second sludge discharge pump 7.8; the effluent tank 9 is connected to the struvite reactor 7 via the second drainage pump 7.9; the granular sludge reactor 2 is connected to the online monitoring and control system 10 via the first phosphate concentration sensor 2.7, the dissolved oxygen concentration sensor 2.8, and the ammonia nitrogen concentration sensor 2.9; the struvite reactor 7 is connected to the online monitoring and control system 10 via the pH sensor 7.6 and the second phosphate concentration sensor 7.7.

[0049] The inlet tank 1 for the recalcitrant carbon source, ammonia nitrogen, and phosphate is equipped with a first overflow pipe 1.1 and a first vent valve 1.2;

[0050] The granular sludge reactor 2 is equipped with a first agitator 2.1, an aeration pump 2.2, a flow meter 2.3, a first inlet 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.

[0051] The PHAs recycling bin 3 is equipped with a second overflow pipe 3.1 and a second vent valve 3.2;

[0052] The phosphorus and ammonia nitrogen outlet tank 4 is equipped with a third overflow pipe 4.1 and a third vent valve 4.2;

[0053] The pH adjuster inlet tank 5 is equipped with a fourth overflow pipe 5.1 and a fourth vent valve 5.2;

[0054] The magnesium solution inlet tank 6 is equipped with a fifth overflow pipe 6.1 and a fifth vent valve 6.2;

[0055] The struvite reactor 7 is equipped with a second inlet pump 7.1, a third inlet pump 7.2, a fourth inlet pump 7.3, a second agitator 7.4, a third agitator 7.5, a pH sensor 7.6, a second phosphate concentration sensor 7.7, a second sludge discharge pump 7.8, and a second drainage pump 7.9.

[0056] The phosphorus recovery tank 8 is equipped with a sixth overflow pipe 8.1 and a sixth vent valve 8.2;

[0057] The water outlet tank 9 is equipped with a seventh overflow pipe 9.1 and a seventh vent valve 9.2;

[0058] The online monitoring and control system 10 includes the following relays: aeration pump relay 10.1, first inlet pump relay 10.2, first agitator relay 10.3, dissolved oxygen concentration sensor relay 10.4, ammonia nitrogen concentration sensor relay 10.5, first phosphate concentration sensor relay 10.6, first sludge discharge pump relay 10.7, first drainage pump relay 10.8, second inlet pump relay 10.9, second agitator relay 10.10, third agitator relay 10.11, pH sensor relay 10.12, second phosphate concentration sensor relay 10.13, second sludge discharge pump relay 10.14, fourth inlet pump relay 10.15, second drainage pump relay 10.16, third inlet pump relay 10.17, A / D converter 10.18, D / A converter 10.19, and computer 10.20.

[0059] The online monitoring and control system 10 includes the following connections: aeration pump relay 10.1 connected to aeration pump 2.2; first inlet pump relay 10.2 connected to first inlet pump 2.4; first agitator relay 10.3 connected to first agitator 2.1; dissolved oxygen concentration sensor relay 10.4 connected to dissolved oxygen concentration sensor 2.8; ammonia nitrogen concentration sensor relay 10.5 connected to ammonia nitrogen concentration sensor 2.9; first phosphate concentration sensor relay 10.6 connected to first phosphate concentration sensor 2.7; first sludge discharge pump relay 10.7 connected to first sludge discharge pump 2.5; first drainage pump relay 10.8 connected to first drainage pump 2.6; second inlet pump relay 10.9 connected to second inlet pump 7.1; second agitator relay 10.10 connected to second agitator 7.4; and third agitator relay... 10.11 is connected to the third stirrer 7.5; pH sensor relay 10.12 is connected to pH sensor 7.6; second phosphate concentration sensor relay 10.13 is connected to second phosphate concentration sensor 7.7; second sludge pump relay 10.14 is connected to second sludge pump 7.8; fourth water inlet pump relay 10.15 is connected to fourth water inlet pump 7.3; second drainage pump relay 10.16 is connected to second drainage pump 7.9; third water inlet pump relay 10.17 is connected to third water inlet pump 7.2; the online monitoring and control system 10 converts analog signals into digital signals and transmits them to computer 10.20 through signal converter A / D converter interface 10.18 and cable; computer 10.20 transmits digital commands to online monitoring and control system 10 through cable and signal converter D / A converter interface 10.19.

[0060] During the experiment, starch, ammonium chloride, dipotassium hydrogen phosphate, tap water, and 0.3 ml / L nutrient solution were used to simulate the influent of recalcitrant carbon sources, ammonia nitrogen, and phosphate. The concentrations of recalcitrant carbon sources, 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 adjuster at a concentration of 2000 mg / L. Magnesium chloride hexahydrate and tap water were used to simulate the influent of magnesium solution at a magnesium ion concentration of 500 mg / L. The nutrient solution contains: 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 LnCl2·4H2O, 0.43 g / L ZnSO4·7H2O, and 0.19 g / L NiCl2·6H2O.

[0061] Test reactor such as Figure 1As shown, the granular sludge reactor 3 and the struvite reactor 7 have volumes of 10L and 9L, respectively.

[0062] The specific operation steps are as follows:

[0063] I. Cultivation of fermented aerobic phosphorus removal granular sludge:

[0064] 1) Add activated sludge from the wastewater treatment plant to granular sludge reactor 2, and control the sludge concentration at 5000 mg / L;

[0065] 2) Start the first influent pump 2.4 to pump 6L of recalcitrant carbon source, ammonia nitrogen and phosphate into the granular sludge reactor 2;

[0066] 3) Control the settling time to 2 hours, start the first drainage pump 2.6, and pump the supernatant containing phosphate and ammonia nitrogen with a volume of 5L into the phosphorus and ammonia nitrogen outlet tank 4;

[0067] 4) Start the first agitator 2.1, and stop agitating when the sewage and sludge are fully mixed;

[0068] 5) Control the sedimentation time to 15 minutes, start the first sludge discharge pump 2.5, and discharge 1L of fermented aerobic phosphorus removal granular sludge into the PHAs recovery tank 3.

[0069] 6) Start the first agitator 2.1 and aeration pump 2.2, adjust the flow meter 2.3 to control the dissolved oxygen concentration to 2 mg / L, and turn off the first agitator 2.1 and aeration pump 2.2 when the phosphate concentration drops to 0 mg / L;

[0070] 7) Repeat steps 2-6 until the proportion of granular sludge with a particle size greater than 200μm in the mixed sludge is 40%, and control the settling time in step 5 to 5min.

[0071] 8) Repeat steps 2-6 until the proportion of granular sludge with a particle size greater than 200 μm is 60% of the mixed sludge, and the molar ratio of phosphate to ammonia nitrogen in the anaerobic granular sludge reactor 2 is 1.2, indicating that the cultivation of fermented aerobic phosphorus removal granular sludge has finally been achieved.

[0072] II. Bird guano recycling:

[0073] 1) Start the second inlet pump 7.1 to pump 5L of inlet water into the struvite reactor 7;

[0074] 2) Start the second mixer 7.4 and the third mixer 7.5 to mix;

[0075] 3) Start the third inlet pump 7.2 to pump the pH adjuster into the struvite reactor 7 and control the pH value to 8.3;

[0076] 4) Start the fourth inlet pump 7.3 to pump the magnesium solution into the struvite reactor 7, and control the molar ratio of magnesium ions to phosphate ions to be 1.0;

[0077] 5) Stop stirring when the phosphate concentration drops to 0 mg / L;

[0078] 6) Control the sedimentation time to 30 minutes, start the second drainage pump 7.9, and discharge the effluent into the effluent tank 9;

[0079] 7) Start the second sludge pump 7.8 to discharge the struvite sediment into the phosphorus recovery tank 8, and finally realize the recovery of phosphorus resources in the form of struvite.

[0080] The experimental results showed that in the fermented aerobic phosphorus removal granular sludge, particles with a diameter greater than 200 μm accounted for 60%. Under the condition that the starch utilization rate reached 63%, the PHA content could reach 0.20 g / g sludge, and the phosphorus recovery rate was 94%. Among them, phosphorus was recovered in the form of struvite, with an average particle size of 0.55 mm and a purity of 85%.

[0081] Finally, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for achieving efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge, characterized in that, An apparatus for the efficient recovery of phosphorus and PHAs using fermented aerobic phosphorus removal granular sludge is implemented, including the following steps: I. Cultivation of fermented aerobic phosphorus removal granular sludge: 1) Add activated sludge from the wastewater 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) to pump influent of volume V1 containing recalcitrant carbon source, ammonia nitrogen and phosphate into the granular sludge reactor (2), and control V1 to be 40%-80% of the effective volume V of the reactor; 3) Control the settling time to be greater than 1 hour, 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 tank (4), and control V2 to be 30%-90% of V1; 4) Start the first agitator (2.1), and stop agitating when the sewage and sludge are fully mixed; 5) Control the sedimentation time to be less than 20 minutes, start the first sludge discharge pump (2.5), and discharge the fermented aerobic phosphorus removal granular sludge with a volume of V3 into the PHAs recovery tank (3), where V3 is the difference between V1 and V2; 6) Start the first agitator (2.1) and aeration pump (2.2), adjust the flow meter (2.3) to control the dissolved oxygen concentration to be greater than 0.5 mg / L, and turn off the first agitator (2.1) and 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 200μm in the mixed sludge is greater than 30%, and control the settling time in step 5 to less than 10min. 8) Repeat steps 2-6 until the proportion of granular sludge with a particle size greater than 200 μm is greater than 50% of the mixed sludge, and the molar ratio of phosphate to ammonia nitrogen in the anaerobic granular sludge reactor (2) is greater than 1.0, indicating that the cultivation of fermented aerobic phosphorus removal granular sludge has finally been achieved. II. String of guano recycling: 1) Start the second inlet pump (7.1) to pump inlet water of volume V2 into the struvite reactor (7). 2) Start the second mixer (7.4) and the third mixer (7.5) to mix; 3) Start the third inlet pump (7.2) to pump the pH adjuster into the struvite reactor (7) and control the pH value to be greater than 8.0; 4) Start the fourth inlet pump (7.3) to pump the magnesium solution into the struvite reactor (7) and 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 sedimentation time to be greater than 10 minutes, start the second drainage pump (7.9), and discharge the effluent into the effluent tank (9). 7) Start the second sludge pump (7.8) to discharge the struvite sediment into the phosphorus recovery tank (8), and finally realize the recovery of phosphorus resources in the form of struvite.

2. The method for achieving efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge according to claim 1, characterized in that, The device for efficient recovery of phosphorus and PHAs from fermented aerobic phosphorus removal granular sludge includes, in sequence, a recalcitrant carbon source, ammonia nitrogen, and phosphate inlet tank (1), a granular sludge reactor (2), a PHAs recovery tank (3), a phosphorus and ammonia nitrogen outlet tank (4), a pH adjuster inlet tank (5), a magnesium solution inlet tank (6), a struvite reactor (7), a phosphorus recovery tank (8), an outlet tank (9), and an online monitoring and control system (10); wherein the recalcitrant carbon source, ammonia nitrogen, and phosphate inlet tank (1) is connected to the granular sludge reactor (2) via a first inlet pump (2.4); the PHAs recovery tank (3) is connected to the granular sludge reactor (2) via a first sludge discharge pump (2.5); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a first drain pump (2.6); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a first drain pump (2.6); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a second inlet pump (2.6); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a third inlet pump (2.4); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a third inlet pump (2.5); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a third drain pump (2.6); the phosphorus and ammonia nitrogen outlet tank (4) is connected to the granular sludge reactor (2) via a third drain pump (2.6); the phosphorus and ammonia nitrogen outlet tank (4 The second inlet pump (7.1) is connected to the struvite reactor (7); the pH adjuster inlet tank (5) is connected to the struvite reactor (7) via the third inlet pump (7.2); the magnesium solution inlet tank (6) is connected to the struvite reactor (7) via the fourth inlet pump (7.3); the phosphorus recovery tank (8) is connected to the struvite reactor (7) via the second sludge discharge pump (7.8); the outlet tank (9) is connected to the struvite reactor (7) via the second drainage pump (7.9); the granular sludge reactor (2) is connected to the online monitoring and control system (10) via the first phosphate concentration sensor (2.7), the dissolved oxygen concentration sensor (2.8), and the ammonia nitrogen concentration sensor (2.9); the struvite reactor (7) is connected to the online monitoring and control system (10) via the pH sensor (7.6) and the second phosphate concentration sensor (7.7); The inlet tank (1) for the recalcitrant carbon source, ammonia nitrogen and phosphate is equipped with a first overflow pipe (1.1) and a first vent valve (1.2). The granular sludge reactor (2) is equipped with a first agitator (2.1), an aeration pump (2.2), a flow meter (2.3), a first inlet pump (2.4), a first sludge discharge pump (2.5), a first drain 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 recycling bin (3) is equipped with a second overflow pipe (3.1) and a second vent valve (3.2). The phosphorus and ammonia nitrogen outlet tank (4) is equipped with a third overflow pipe (4.1) and a third vent valve (4.2); The pH adjuster inlet tank (5) is equipped with a fourth overflow pipe (5.1) and a fourth vent valve (5.2). The magnesium solution inlet tank (6) is equipped with a fifth overflow pipe (6.1) and a fifth vent valve (6.2). The struvite reactor (7) is equipped with a second inlet pump (7.1), a third inlet pump (7.2), a fourth inlet pump (7.3), a second agitator (7.4), a third agitator (7.5), a pH 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 vent valve (8.2); The outlet tank (9) is equipped with a seventh overflow pipe (9.1) and a seventh vent valve (9.2); The online monitoring and control system (10) includes a built-in aeration pump relay (10.1), first inlet pump relay (10.2), first agitator relay (10.3), dissolved oxygen concentration sensor relay (10.4), ammonia nitrogen concentration sensor relay (10.5), first phosphate concentration sensor relay (10.6), first sludge discharge pump relay (10.7), first drainage pump relay (10.8), second inlet pump relay (10.9), second agitator relay (10.10), third agitator relay (10.11), pH sensor relay (10.12), second phosphate concentration sensor relay (10.13), second sludge discharge pump relay (10.14), fourth inlet pump relay (10.15), second drainage pump relay (10.16), third inlet pump relay (10.17), signal converter A / D converter interface (10.18), signal converter D / A converter interface (10.19), and computer (10.20). The online monitoring and control system (10) includes an aeration pump relay (10.1) connected to an aeration pump (2.2); a first inlet pump relay (10.2) connected to a first inlet pump (2.4); a first agitator relay (10.3) connected to a first agitator (2.1); a dissolved oxygen concentration sensor relay (10.4) connected to a dissolved oxygen concentration sensor (2.8); and an ammonia nitrogen concentration sensor relay (10.5) connected to an ammonia nitrogen concentration sensor (2.9). Connect the first phosphate concentration sensor relay (10.6) to the first phosphate concentration sensor (2.7); connect the first sludge pump relay (10.7) to the first sludge pump (2.5); connect the first drainage pump relay (10.8) to the first drainage pump (2.6); connect the second inlet pump relay (10.9) to the second inlet pump (7.1); connect the second agitator relay (10.10) to the second agitator (7.4); and connect the third agitator relay. The device (10.11) is connected to the third stirrer (7.5); the pH sensor relay (10.12) is connected to the pH sensor (7.6); the second phosphate concentration sensor relay (10.13) is connected to the second phosphate concentration sensor (7.7); the second sludge pump relay (10.14) is connected to the second sludge pump (7.8); the fourth water inlet pump relay (10.15) is connected to the fourth water inlet pump (7.3); the second drain pump relay (10.16) is connected to the third stirrer (7.5); the pH sensor relay (10.12) is connected to the pH sensor (7.6); the second phosphate concentration sensor relay (10.13) is connected to the second phosphate concentration sensor (7.7); the second sludge pump relay (10.14) is connected to the second sludge pump (7.8); the fourth water inlet pump relay (10.15) is connected to the fourth water 0.16) is connected to the second drainage pump (7.9); the third water inlet pump relay (10.17) is connected to the third water inlet pump (7.2); the online monitoring and control system (10) converts analog signals into digital signals and transmits them to the computer (10.20) through the signal converter A / D converter interface (10.18) and cable; the computer (10.20) transmits digital instructions to the online monitoring and control system (10) through the cable and the signal converter D / A converter interface (10.19).

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