Device and method for realizing double short-range coupling anammox deep denitrification and phosphorus recovery by using in-situ sludge fermentation

Abstract

The invention discloses a device and a method for realizing double short-range coupling anammox deep denitrification and phosphorus recovery by using in-situ sludge fermentation. The method comprises the following steps: adding a calcium chloride solution into a rear-end anammox reactor of a two-stage PNA process to form recyclable phosphorus crystal substances such as Ca-P precipitate, and enabling anaerobic ammonium oxidation bacteria to be attached to the surface of the precipitate and to be enriched and intercepted in the anammox reactor; in the continuous forming process of anaerobic ammonia oxidation particles, unfermented waste activated sludge is added into the PNA technology, a carbon source is provided for short-cut denitrifying bacteria by means of slow hydrolysis and acidification of the waste activated sludge, and conversion from single-stage PNA autotrophic nitrogen removal to double short-cut coupling anammox synergistic nitrogen removal is completed. The anaerobic ammonium oxidation bacteria in the operated granular sludge can reach 12%, 73% of the sludge has the sludge particle size of 200 [mu] m or above, the total nitrogen removal rate is kept to be 90% or above, and most phosphorus exists in a recyclable form of Ca-P crystal substances.

Description

Technical Field

[0001] The invention relates to a device and a method for realizing double short-range coupling anammox deep denitrification and phosphorus recovery by utilizing in-situ sludge fermentation, and belongs to the field of sewage biological treatment. Background Art

[0002] Anaerobic ammonium oxidation (anammox) is an autotrophic denitrification process. Its application in mainstream urban sewage treatment promotes the removal of nitrogen pollutants from energy-consuming to energy-saving, such as saving aeration and carbon-free requirements. At present, the coupling of partial nitrification coupled with anammox (PN / A) is the most important process used in anaerobic ammonium oxidation in sewage treatment plants. However, the PN / A process has the problem of excessive byproduct nitrate (Nitrate, NO3 - -N), nitrite, NO2 - The unstable supply of anaerobic ammonia-oxidizing bacteria (Anammox bacteria, AnAOB) and other shortcomings lead to poor effluent quality.

[0003] The researchers observed that the byproduct of the PN / A process, NO3 - -N can be removed through heterotrophic denitrification, and there are short-range denitrification (partial denitrification, PD) and other heterotrophic bacteria that can convert NO3 - -N is reduced to NO2 - -N, providing another pathway to provide substrate NO2 for anammox - -N, the coupling of PD, PN and anammox can theoretically achieve a 100% denitrification effect. Carbon source is an indispensable substrate matrix for the PD process, but the addition of a large amount of carbon source will inhibit the activity of AnAOB. ​​Moreover, allowing heterotrophic bacteria to grow at will will lead to the collapse of the PN / A system. Waste activated sludge contains a large amount of organic matter, which can actually serve as a new driving force for the deep denitrification process. After fermentation, waste activated sludge can provide a carbon source for heterotrophic denitrifying bacteria. However, the direct addition of sludge fermentation liquid also causes a huge inhibition of the activity of AnAOB. ​​Therefore, adding unfermented waste activated sludge to a long-term anaerobic reactor to provide a carbon source through slow hydrolysis and acid production in a weakly alkaline environment is beneficial to anammox. The anammox process consumes H +This results in an alkaline environment, which provides the necessary conditions for in-situ sludge alkaline fermentation. At the same time, in order to further resist the adverse effects of carbon sources on anammox, weakly alkaline CaCl2 is added to the reactor to form Ca-P precipitation to achieve the phosphorus recovery process, while further promoting in-situ sludge alkaline fermentation, providing a carbon source for PDA, and ultimately achieving dual short-range coupling anammox deep denitrification and phosphorus recovery in domestic sewage.

[0004] Through a two-stage reactor, anaerobic ammonium oxidation sludge is inoculated in the long-term anaerobic EGSB reactor at the back end, and calcium chloride is added for a long time to form anammox granular sludge. Then the waste activated sludge is directly added to the EGSB reactor, and slowly hydrolyzed and acidified under anaerobic conditions to provide a carbon source for short-range denitrifying bacteria. The slowly hydrolyzed sludge prevents heterotrophic denitrifying bacteria from growing too fast, and finally the in-situ sludge fermentation is used to achieve a dual short-range coupled anammox deep denitrification and phosphorus recovery process. This combined process achieves a more stable deep denitrification effect, which is conducive to the recycling of waste resources (C, P) and the realization of deep denitrification of low C / N domestic sewage. Summary of the invention

[0005] The purpose of the present invention is to achieve a double short-range coupling anammox deep denitrification and phosphorus recovery process by long-term addition of calcium salt mixed with unfermented waste activated sludge to a long-term anaerobic anaerobic ammonium oxidation reactor, and finally achieve a deep denitrification effect without the need for an external carbon source and the recycling of waste resources (C, P) in the process of treating domestic sewage. First, a calcium chloride solution is added to the rear end anammox reactor of the two-stage PNA process to form recyclable phosphorus crystalline substances such as Ca-P precipitation, and anaerobic ammonium oxidizing bacteria are attached to the surface of the precipitate, thereby being enriched and trapped in the anammox reactor. In the process of continuous formation of anaerobic ammonium oxidation particles, unfermented waste activated sludge is added to the PNA process, and the slow hydrolysis and acidification of the waste activated sludge are relied on to provide a carbon source for the short-range denitrification bacteria, completing the transformation from single-stage PNA autotrophic denitrification to double short-range coupling anammox synergistic denitrification. The content of the invention is conducive to the promotion and application of anaerobic ammonium oxidation technology in sewage treatment and the recycling of waste resources, and has important research significance and application value.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A device for realizing dual short-range coupled anammox deep denitrification and phosphorus recovery by in-situ sludge fermentation, comprising a water inlet tank (1), an SBR water inlet peristaltic pump (2-1), an air pump (2-2), a rotor flowmeter (2-3), an aeration plate (2-4), a stirring device (2-5), a WTW real-time monitoring host (2-6), a pH probe (2-7), a dissolved oxygen probe (2-8), a sequencing batch reactor (2), a sludge discharge peristaltic pump (2-9), an SBR drainage peristaltic pump (2-10), an anaerobic sludge storage tank (3), an intermediate water tank (4), an EGSB water inlet peristaltic pump (5-1), an EGSB sludge inlet peristaltic pump (5-2), a dosing peristaltic pump (5-3), a heating belt (5-4), a temperature control device (5-5), a temperature probe (5-6), a U-shaped water outlet (5-7), an EGSB reactor (5), and a dosing tank (6);

[0008] The inlet water tank (1) storing actual domestic sewage is connected to the sequencing batch reactor (2) through the SBR inlet peristaltic pump (2-1), the sequencing batch reactor (2) is connected to the intermediate water tank (4) through the SBR discharge peristaltic pump (2-10), the intermediate water tank (4) is connected to the EGSB reactor (5) through the EGSB inlet peristaltic pump (5-1), the sequencing batch reactor (2) is connected to the anaerobic sludge storage tank (3) through the sludge discharge peristaltic pump (2-9), the anaerobic sludge storage tank (3) is connected to the ESB through the EGSB sludge inlet peristaltic pump (5-2). The GSB reactor (5) is connected to the dosing box (6) through the dosing peristaltic pump (5-3), the sequencing batch reactor (2) is provided with a stirring device (2-5), the air pump (2-2) controls the aeration amount through the rotor flow meter (2-3), and aerates the sequencing batch reactor (2) through the aeration disk (2-4), and the EGSB reactor (5) is provided with a temperature control device (5-5), and the temperature of the EGSB reactor (5) is controlled in real time through the heating belt (5-4) and the temperature probe (5-6);

[0009] The method of using the device comprises the following steps:

[0010] 1) Establishment of short-range nitrification coupled anammox process:

[0011] a. The cultured short-cut nitrification sludge is directly added to the sequencing batch reactor (2), and the sludge concentration in the reactor is ensured to be 3500-4000 mg / L after the sludge is fed, and the anaerobic ammonium oxidation sludge in the actual sewage treatment plant is directly added to the EGSB reactor (5), and the sludge concentration in the reactor is ensured to be 4000-5000 mg / L after the sludge is fed;

[0012] b. Start the WTW real-time monitoring host (2-6) and the temperature control device (5-5), and use the pH probe (2-7), dissolved oxygen probe (2-8) and temperature probe (5-6) to control the operating state of the reaction device in real time to ensure that the dissolved oxygen in the sequencing batch reactor (2) is 0.1-2.0 mg / L, the pH is 7-8, and the temperature in the EGSB reactor (5) is maintained at 28-32°C;

[0013] c. The sequencing batch reactor (2) is operated for 2-4 cycles per day, including water inlet for 0.1-0.2 h, anaerobic stirring for 1.5-2.0 h, aerobic aeration for 3.0-5.0 h, idle for 1.0-1.5 h, and a drainage ratio of 50-60%. Sludge is discharged from the sequencing batch reactor (2) once a day to maintain the sludge age for 15-25 days;

[0014] d. The water inlet tank (1) contains actual domestic sewage, the water quality characteristics of which are: organic matter COD is 150-250 mg / L, ammonia nitrogen NH4 + -N is 60-90mg / L, phosphorus PO4 3- -P is 6-10 mg / L, the domestic sewage in the water inlet tank (1) is first pumped into the sequencing batch reactor (2) by the SBR water inlet peristaltic pump (2-1), and then discharged into the intermediate water tank (4) by the SBR water discharge peristaltic pump (2-10) after being treated in the sequencing batch reactor (2), and then pumped into the EGSB reactor (5) by the EGSB water inlet peristaltic pump (5-1), and finally discharged from the U-shaped outlet (5-7) of the EGSB reactor (5);

[0015] e. The EGSB reactor (5) adopts a continuous water inlet mode, the hydraulic retention time is 1.0-3.0h, the temperature control device (5-5) is adjusted to 28-32°C, and no reflux device is set;

[0016] f. Take water samples from the U-shaped outlet (5-7) every day to monitor nitrogen removal. When the total nitrogen removal is stable at more than 80% and maintained for at least 20 days, it indicates that the short-range nitrification coupled anammox process has been successfully started.

[0017] 2) In-situ sludge fermentation promotes the establishment of dual short-range coupled anammox process and the recovery of soluble phosphorus:

[0018] a. After the short-range nitrification coupled anammox process is successfully started, the pump speed of the dosing peristaltic pump (5-3) is set so that the EGSB reactor (5) continuously pumps the CaCl2 solution in the dosing tank (6) into the EGSB reactor (5) with a hydraulic retention time of 1.0-3.0h, and controls the CaCl2 solution in the dosing tank (6). 2+ The concentration range is 30-100 mg / L, which is consistent with the PO4 3--P mass concentration ratio is between 3-5;

[0019] b. After 30-50 days, the average particle size of the sludge in the EGSB reactor (5) is greater than 200 μm after detection by a laser particle size analyzer, and it is considered that anaerobic ammonium oxidation granular sludge is formed in the reactor. Then, the sludge discharge mode of the sequencing batch reactor (2) is changed from "large amount at a time" to "small amount at multiple times" to maintain the freshness of the discharged sludge. The sequencing batch reactor (2) operates 2-4 cycles per day. "Large amount at a time" means that a fixed cycle of aerobic sludge is selected from 2-4 cycles every day to discharge sludge at one time to maintain the sludge age of the sequencing batch reactor (2) at 15-25 days. "Small amount at multiple times" means that aerobic sludge is discharged at the end of 2-4 cycles. The sludge is discharged 2-4 times a day and the total amount of sludge discharged is such that the sludge age of the sequencing batch reactor (2) is maintained at 15-25 days. The discharged waste activated sludge is transported by the sludge discharge peristaltic pump (2-9) and stored in the anaerobic sludge storage box (3);

[0020] c. Set the pump speed of the EGSB mud peristaltic pump (5-2) so that the EGSB reactor (2) continuously pumps the mud-water mixture stored in the anaerobic mud storage box (3) into the long-term anaerobic EGSB reactor (5) with a hydraulic retention time of 1.0-3.0h. Do not allow the mud-water mixture to remain in the anaerobic mud storage box (3) for more than 2 days;

[0021] d. After 30-50 days, 25-50 mL of the mud-water mixture was taken out from the EGSB reactor (5), and the mud sample with particles larger than 200 μm was screened out through a 75-mesh sieve. The precipitated Ca-P crystalline material was detected by SEM-EDS, indicating that the soluble phosphorus in the EGSB reactor (5) was successfully recovered;

[0022] e. Take water samples from the U-shaped outlet (5-7) every day to monitor nitrogen removal. When the total nitrogen removal is stable at more than 90% and maintained for at least 20 days, and the existence of PNA and PDA is confirmed by short-range nitrification anaerobic ammonium oxidation (PNA) and short-range denitrification anaerobic ammonium oxidation (PDA) verification experiments, it indicates that the dual short-range coupled anammox process has been successfully established;

[0023] The present invention provides a device and method for achieving sludge reduction and microparticle autotrophic and heterotrophic synergistic denitrification in domestic sewage, which has the following advantages:

[0024] 1) The present invention forms a calcium-phosphorus precipitate (Ca-P precipitation) by adding CaCl2, which provides attachment points for anaerobic ammonium-oxidizing bacteria, is conducive to the enrichment of anaerobic ammonium-oxidizing bacteria, and finally the enrichment of anaerobic ammonium-oxidizing bacteria in the particles reaches more than 12%. At the same time, the formation of Ca-P precipitation is conducive to the recovery of phosphorus;

[0025] 2) The present invention achieves a dual short-range coupled anammox synergistic denitrification process dominated by autotrophic anammox by adding unfermented waste activated sludge for slow hydrolysis and acidification, thereby ultimately improving the denitrification performance and operational stability of the treatment system, and the denitrification efficiency is stabilized at more than 90%;

[0026] 3) The present invention adds unfermented waste activated sludge for slow hydrolysis and acidification, thereby solving the problem of the cost increase of adding an additional carbon source due to insufficient carbon source in urban domestic sewage, and at the same time can achieve the reduction of excess sludge and resource utilization; BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0028] Figure 2 It is a graph showing the changes in conventional pollution indicators in the EGSB reactor before and after adding waste activated sludge;

[0029] Figure 3 It is a graph showing the change in particle size of anaerobic ammonium oxidation sludge during the particle formation process of the process;

[0030] Figure 4 It is a comparison chart of the microbial community structure at the genus level between granular sludge larger than 200 μm and floc sludge smaller than 200 μm in the EGSB reactor;

[0031] Figure 5 It is the surface morphology of granular sludge, the elemental proportion of inorganic matter in the granules, and the verification diagram of PNA and PDA denitrification pathways;

[0032] Figure 1 Among them, 1—water inlet tank, 2-1—SBR water inlet peristaltic pump, 2-2—air pump, 2-3—rotor flowmeter, 2-4—aeration plate, 2-5—stirring device, 2-6—WTW real-time monitoring host, 2-7—pH probe, 2-8—dissolved oxygen probe, 2—sequencing batch reactor, 2-9—sludge peristaltic pump, 2-10—SBR drainage peristaltic pump, 3—anaerobic sludge storage box, 4—intermediate water tank, 5-1—EGSB water inlet peristaltic pump, 5-2—EGSB sludge peristaltic pump, 5-3—dosing peristaltic pump, 5-4—heating belt, 5-5—temperature control device, 5-6—temperature probe, 5-7—U-shaped water outlet, 5—EGSB reactor, 6—dosing box. DETAILED DESCRIPTION

[0033] The present invention is described in detail with reference to the accompanying drawings and implementation examples.

[0034] like Figure 1As shown, the system device of the present invention comprises a water inlet tank (1) with a volume of 50L, an SBR water inlet peristaltic pump (2-1) with a power range of 0-300mL / min, an air pump (2-2) of 30L / min, a gas flow meter (2-3) with a range of 0-2.0L / min, an aeration disk (2-4) with a conventional diameter of 10cm, a stirring device (2-5), a WTW real-time monitoring host (2-6), a pH probe (2-7), a dissolved oxygen probe (2-8), a 10L sequencing batch reactor (2), a sludge discharge peristaltic pump (2-9) with a power range of 0 -300mL / min SBR drainage peristaltic pump (2-10), 1.0L anaerobic sludge storage box (3), 25L intermediate water tank (4), EGSB water inlet peristaltic pump (5-1) with a power range of 0-300mL / min, EGSB sludge inlet peristaltic pump (5-2) with a power range of 0-100mL / min, dosing peristaltic pump (5-3) with a power range of 0-100mL / min, heating belt (5-4), temperature control device (5-5), temperature probe (5-6), U-shaped water outlet (5-7), 2.0L EGSB reactor (5), 5.0L dosing box (6).

[0035] The device is connected as follows: the inlet water tank (1) storing actual domestic sewage is connected to the sequencing batch reactor (2) via the SBR inlet peristaltic pump (2-1), the sequencing batch reactor (2) is connected to the intermediate water tank (4) via the SBR discharge peristaltic pump (2-10), the intermediate water tank (4) is connected to the EGSB reactor (5) via the EGSB inlet peristaltic pump (5-1), the sequencing batch reactor (2) is connected to the anaerobic sludge storage tank (3) via the sludge discharge peristaltic pump (2-9), the anaerobic sludge storage tank (3) is connected to the EGSB inlet peristaltic pump (5-10), the intermediate water tank (4) is connected to the EGSB reactor (5) via the EGSB inlet peristaltic pump (5-11), the sequencing batch reactor (2) is connected to the anaerobic sludge storage tank (3) via the sludge discharge peristaltic pump (2-9), the anaerobic sludge storage tank (3) is connected to the EGSB inlet peristaltic pump (5-11). -2) is connected to an EGSB reactor (5), a dosing box (6) is connected to the EGSB reactor (5) via a dosing peristaltic pump (5-3), a sequencing batch reactor (2) is provided with a stirring device (2-5), an air pump (2-2) controls an aeration amount via a gas flow meter (2-3), and aerates the sequencing batch reactor (2) via an aeration disk (2-4), and an EGSB reactor (5) is provided with a temperature control device (5-5), and real-time temperature control of the EGSB reactor (5) is performed via a heating belt (5-4) and a temperature probe (5-6).

[0036] The present invention realizes the startup and stable operation of the combined process of multi-path micro-particle autotrophic and heterotrophic coupled denitrification, comprising the following steps:

[0037] 1) Establishment of short-range nitrification coupled anammox process:

[0038] a. The two-stage reactor is composed of a 10L sequencing batch reactor (2) and a 2.0L EGSB reactor (5). The cultured short-cut nitrification sludge is directly added to the sequencing batch reactor (2). After the sludge is fed, the sludge concentration in the reactor is ensured to be 3500mg / L. At the same time, the anaerobic ammonium oxidation sludge taken from the Beijing Gaobeidian Wastewater Treatment Plant is directly added to the EGSB reactor (5). After the sludge is fed, the sludge concentration in the reactor is ensured to be 4500mg / L.

[0039] b. Start the WTW real-time monitoring host (2-6) and the temperature control device (5-5), immerse the pH probe (2-7) and the dissolved oxygen probe (2-8) 10 cm below the liquid level of the sequencing batch reactor (2), and insert the temperature probe (5-6) into the rubber port on the side of the EGSB reactor to control the operating status of the reaction device in real time, ensure that the gas flow meter (2-3) in the sequencing batch reactor (2) is 0.8 L / min, the pH is 7, and the temperature in the EGSB reactor (5) is maintained at 30°C;

[0040] c. The sequencing batch reactor (2) was operated for 4 cycles per day, including water inlet for 0.1 h, anaerobic stirring for 1.5 h, aerobic aeration for 3.0 h, idle for 1.4 h, a drainage ratio of 55.6%, and 300 mL of sludge was discharged per day to maintain the sludge age of 18.75 days;

[0041] d. The water inlet tank (1) contains actual domestic sewage, the water quality characteristics of which are: organic matter COD, 150-250 mg / L, ammonia nitrogen NH4 + -N, 60-90mg / L, phosphorus PO4 3- -P, 6-10 mg / L, the domestic sewage in the water inlet tank (1) is first pumped into the sequencing batch reactor (2) by the SBR water inlet peristaltic pump (2-1), and then discharged into the intermediate water tank (4) by the SBR water discharge peristaltic pump (2-10) after being treated in the sequencing batch reactor (2), and then pumped into the EGSB reactor (5) by the EGSB water inlet peristaltic pump (5-1), and finally discharged from the U-shaped outlet (5-7) of the EGSB reactor (5);

[0042] e. The EGSB reactor (5) was continuously fed with water, the hydraulic retention time was 2.0 h, the temperature control device (5-5) was adjusted to 30° C., and no reflux device was set;

[0043] f. Take water samples from the U-shaped outlet (5-7) every day to monitor nitrogen removal. When the total nitrogen removal is stable at more than 80% and maintained for at least 20 days, it indicates that the short-range nitrification coupled anammox process has been successfully started.

[0044] 2) In-situ sludge fermentation promotes the establishment of dual short-range coupled anammox process and the recovery of soluble phosphorus:

[0045] a. After the short-range nitrification coupled anammox process is successfully started, the pump speeds of the dosing peristaltic pump (5-3) and the EGSB water inlet peristaltic pump (5-1) are set to 1.0 L / min, and the hydraulic retention time of the EGAB reactor (5) is 2.0 h, so that the weakly alkaline CaCl2 solution in the dosing box (6) is continuously pumped into the EGSB reactor (5), and the CaCl2 solution in the dosing box (6) is controlled. 2+ The concentration is 30±5mg / L, which is the same as PO4 in the EGSB reactor (5). 3- -P mass concentration ratio is about 3;

[0046] b. After 50 days, the average particle size of the sludge in the EGSB reactor (5) was greater than 200 μm after detection by a laser particle size analyzer, and it was considered that anaerobic ammonium oxidation granular sludge was formed in the reactor. Subsequently, the sludge discharge mode of the sequencing batch reactor was changed from "large amount at a time" to "small amount at multiple times" to maintain the freshness of the discharged sludge. The sequencing batch reactor (2) was operated for 4 cycles per day. "Large amount at a time" means that 300 mL of sludge was discharged at the end of the aerobic cycle from 9:00 to 15:00 every day to maintain the sludge age of the sequencing batch reactor (2) at 18.75 days. "Small amount at multiple times" means that 75 mL of sludge was discharged at the end of the aerobic cycle of 4 cycles. The sludge was discharged 4 times a day and the total amount of sludge discharged was 300 mL, so that the sludge age of the sequencing batch reactor (2) was maintained at 18.75 days. The discharged waste activated sludge was transported by the sludge discharge peristaltic pump (2-9) and stored in the anaerobic sludge storage box (3);

[0047] c. While feeding the sludge, set the pump speeds of the dosing peristaltic pump (5-3), the EGSB water inlet peristaltic pump (5-1) and the EGSB sludge inlet peristaltic pump (5-2) to 0.7L / min, and still maintain the hydraulic retention time of the EGSB reactor at 2.0h, so that the EGSB sludge inlet peristaltic pump (5-2) continuously pumps the sludge-water mixture stored in the anaerobic sludge storage box (3) into the long-term anaerobic EGSB reactor (5), and utilizes the alkaline environment generated after the anammox reaction and the addition of CaCl2 to slowly hydrolyze part of the flocculent sludge. Do not allow the sludge-water mixture to remain in the anaerobic sludge storage box (3) for more than 2 days;

[0048] d. After 30-50 days, 50 mL of the mud-water mixture was taken out from the EGSB reactor (5), and the mud sample with particles larger than 200 μm was screened out through a 75-mesh sieve. The precipitate was found to be Ca-P crystalline material after SEM-EDS detection, indicating that the soluble phosphorus in the EGSB reactor (5) was successfully recovered;

[0049] e. Take 10mL of water sample from the U-shaped outlet (5-7) every day to monitor the removal of nitrogen. When the total nitrogen removal is stable at more than 90% and maintained for at least 20 days, and the existence of PNA and PDA is confirmed by short-range nitrification anaerobic ammonium oxidation (PNA) and short-range denitrification anaerobic ammonium oxidation (PDA) verification experiments, it indicates that the dual short-range coupled anammox process is successfully established;

[0050] Monitor various indicators during the entire system startup and operation process. For details, see Figure 2 to Figure 5 .

[0050] Detection method: NH4 + -N was detected by nanometer reagent photometry, NO2 - -N was detected by N-(1-naphthyl)-ethylenediamine photometry, NO3 - -N is detected by thymol method, PO4 3- -P was detected by molybdenum antimony anti-spectrophotometry, COD (including volatile fatty acids) was detected by a rapid analyzer; MLSS and MLVSS were detected by an ash meter; pH and DO were detected using a pH meter and dissolved oxygen meter from WTW in Germany; particle size was determined by a laser particle size analyzer; sludge surface and properties were determined by SEM-EDS; changes in microbial community structure were determined using high-throughput sequencing technology.

[0051] Depend on Figure 2 It can be seen that from 1 to 22 days, after the two-stage reactor was operated and regulated, the anaerobic ammonia-oxidizing bacteria in the system gradually adapted to the actual domestic sewage, and the total nitrogen removal rate continued to rise, stabilizing to more than 82%, and maintained for more than 22 days. From 23 to 81 days, with the addition of CaCl2, the total nitrogen removal rate still maintained a high proportion, reaching more than 90%. With the reduction of influent C / N and the continuous addition of CaCl2, the average total nitrogen can reach more than 95%.

[0052] Depend on Figure 3 It can be seen that the sludge particle size of the EGSB reactor continued to increase during the transition from the PNA process to the dual short-range coupled anammox synergistic denitrification process. The particle size was divided into 4 groups: 0-200μm (Group A), 200-500μm (Group B), 500-1000μm (Group C) and 1000-2000μm (Group D). From stage I (Day 1) to stage II (Day 50), the proportions of Group C and Group D increased by 9.75% and 141.51%, respectively, and the proportions of Group A and Group B decreased by 8.44% and 2.77%, respectively, indicating that anaerobic ammonium oxidation sludge has a tendency to develop into large-particle sludge. In stage III (Day 144), the proportion of Group A even dropped by 31.36% compared with stage I, and 73% of the sludge in AMX-UASB showed a particle state of more than 200μm. In addition, Figure 4The abundance of Ca_Brocadia and Ca_kuenenia, which represent anaerobic ammonium oxidizing bacteria, was highly enriched in granular sludge, at 12.37% and 1.90% respectively (day 150). Figure 5 It can be seen that Ca-X precipitates (such as CaCO3 and Ca-P precipitates, etc.) are formed in the system by adding CaCl2.

[0053] Depend on Figure 4 and Figure 5 It can be seen that there are three denitrification processes in the system, namely PDA, PNA and complete denitrification, and deep denitrification in actual low C / N domestic sewage is achieved in the form of dual short-range coupled anammox synergistic denitrification. In general, the biomineralization caused by the addition of CaCl2 provides attachment points for anaerobic ammonia-oxidizing bacteria, promoting the formation of anaerobic ammonia-oxidizing granular sludge. At the same time, the addition of waste activated sludge prompts the single-stage PN / A process to complete the transformation to a dual short-range coupled anammox synergistic denitrification combined process, and promotes the formation of multiple pathways for nitrite supply, which can meet the demand for nitrite by anaerobic ammonia-oxidizing bacteria, is conducive to the stable deep denitrification process in actual domestic sewage and the recycling of waste resources, and has certain practical significance for sewage treatment.

Claims

1. A device for realizing dual short-range coupled anammox deep denitrification and phosphorus recovery by in-situ sludge fermentation, characterized in that: It includes a water inlet tank (1), an SBR water inlet peristaltic pump (2-1), an air pump (2-2), a rotor flowmeter (2-3), an aeration plate (2-4), a stirring device (2-5), a WTW real-time monitoring host (2-6), a pH probe (2-7), a dissolved oxygen probe (2-8), a sequencing batch reactor (2), a sludge discharge peristaltic pump (2-9), an SBR drainage peristaltic pump (2-10), an anaerobic sludge storage tank (3), an intermediate water tank (4), an EGSB water inlet peristaltic pump (5-1), an EGSB sludge discharge peristaltic pump (5-2), a dosing peristaltic pump (5-3), a heating belt (5-4), a temperature control device (5-5), a temperature probe (5-6), a U-shaped water outlet (5-7), an EGSB reactor (5), and a dosing tank (6); The inlet water tank (1) storing actual domestic sewage is connected to the sequencing batch reactor (2) through the SBR inlet peristaltic pump (2-1), the sequencing batch reactor (2) is connected to the intermediate water tank (4) through the SBR discharge peristaltic pump (2-10), the intermediate water tank (4) is connected to the EGSB reactor (5) through the EGSB inlet peristaltic pump (5-1), the sequencing batch reactor (2) is connected to the anaerobic sludge storage tank (3) through the sludge discharge peristaltic pump (2-9), the anaerobic sludge storage tank (3) is connected to the ESB through the EGSB sludge inlet peristaltic pump (5-2). The invention relates to a sequencing batch reactor (2) and a GSB reactor (5); a dosing box (6) is connected to the EGSB reactor (5) through a dosing peristaltic pump (5-3); the sequencing batch reactor (2) is provided with a stirring device (2-5); an air pump (2-2) controls an aeration amount through a rotor flow meter (2-3) and aerates the sequencing batch reactor (2) through an aeration disk (2-4); and the EGSB reactor (5) is provided with a temperature control device (5-5) for performing real-time temperature control on the EGSB reactor (5) through a heating belt (5-4) and a temperature probe (5-6).

2. A method for applying the device as claimed in claim 1, comprising the following steps: 1) Establishment of short-range nitrification coupled anammox process: a. The cultured short-cut nitrification sludge is directly added to the sequencing batch reactor (2), and the sludge concentration in the reactor is ensured to be 3500-4000 mg / L after the sludge is fed, and the anaerobic ammonium oxidation sludge in the actual sewage treatment plant is directly added to the EGSB reactor (5), and the sludge concentration in the reactor is ensured to be 4000-5000 mg / L after the sludge is fed; b. Start the WTW real-time monitoring host (2-6) and the temperature control device (5-5), and use the pH probe (2-7), dissolved oxygen probe (2-8) and temperature probe (5-6) to control the operating state of the reaction device in real time to ensure that the dissolved oxygen in the sequencing batch reactor (2) is 0.1-2.0 mg / L, the pH is 7-8, and the temperature in the EGSB reactor (5) is maintained at 28-32°C; c. The sequencing batch reactor (2) is operated for 2-4 cycles per day, including water inlet for 0.1-0.2 h, anaerobic stirring for 1.5-2.0 h, aerobic aeration for 3.0-5.0 h, idle for 1.0-1.5 h, and a drainage ratio of 50-60%. Sludge is discharged from the sequencing batch reactor (2) once a day to maintain the sludge age for 15-25 days; d. The water inlet tank (1) contains actual domestic sewage, the water quality characteristics of which are: organic matter COD is 150-250 mg / L, ammonia nitrogen NH4 + -N is 60-90mg / L, phosphorus PO4 3- -P is 6-10 mg / L, the domestic sewage in the water inlet tank (1) is first pumped into the sequencing batch reactor (2) by the SBR water inlet peristaltic pump (2-1), and then discharged into the intermediate water tank (4) by the SBR water discharge peristaltic pump (2-10) after being treated in the sequencing batch reactor (2), and then pumped into the EGSB reactor (5) by the EGSB water inlet peristaltic pump (5-1), and finally discharged from the U-shaped outlet (5-7) of the EGSB reactor (5); e. The EGSB reactor (5) adopts a continuous water inlet mode, the hydraulic retention time is 1.0-3.0h, the temperature control device (5-5) is adjusted to 28-32°C, and no reflux device is set; f. Take water samples from the U-shaped outlet (5-7) every day to monitor the removal of nitrogen. When the total nitrogen removal is stable at more than 80% and maintained for at least 20 days, it indicates that the short-range nitrification coupled anammox process has been successfully started; 2) In-situ sludge fermentation promotes the establishment of dual short-range coupled anammox process and the recovery of soluble phosphorus: a. After the short-range nitrification coupled anammox process is successfully started, the pump speed of the dosing peristaltic pump (5-3) is set so that the EGSB reactor (5) continuously pumps the CaCl2 solution in the dosing tank (6) into the EGSB reactor (5) with a hydraulic retention time of 1.0-3.0h, and controls the CaCl2 solution in the dosing tank (6). 2+ The concentration range is 30-100 mg / L, which is consistent with the PO4 3- -P mass concentration ratio is between 3-5; b. After 30-50 days, the average particle size of the sludge in the EGSB reactor (5) is greater than 200 μm after detection by a laser particle size analyzer, and it is considered that anaerobic ammonium oxidation granular sludge is formed in the reactor. Then, the sludge discharge mode of the sequencing batch reactor (2) is changed from "large amount at a time" to "small amount at multiple times" to maintain the freshness of the discharged sludge. The sequencing batch reactor (2) operates 2-4 cycles per day. "Large amount at a time" means that a fixed cycle of aerobic sludge is selected from 2-4 cycles every day to discharge sludge at one time to maintain the sludge age of the sequencing batch reactor (2) at 15-25 days. "Small amount at multiple times" means that aerobic sludge is discharged at the end of 2-4 cycles. The sludge is discharged 2-4 times a day and the total amount of sludge discharged is such that the sludge age of the sequencing batch reactor (2) is maintained at 15-25 days. The discharged waste activated sludge is transported by the sludge discharge peristaltic pump (2-9) and stored in the anaerobic sludge storage box (3); c. Set the pump speed of the EGSB mud peristaltic pump (5-2) so that the EGSB reactor (2) continuously pumps the mud-water mixture stored in the anaerobic mud storage box (3) into the long-term anaerobic EGSB reactor (5) with a hydraulic retention time of 1.0-3.0h. Do not allow the mud-water mixture to remain in the anaerobic mud storage box (3) for more than 2 days; d. After 30-50 days, 25-50 mL of the mud-water mixture was taken out from the EGSB reactor (5), and the mud sample with particles larger than 200 μm was screened out through a 75-mesh sieve. The precipitated Ca-P crystalline material was detected by SEM-EDS, indicating that the soluble phosphorus in the EGSB reactor (5) was successfully recovered; e. Take 5-10 mL of water sample from the U-shaped outlet (5-7) every day to monitor the removal of nitrogen. When the total nitrogen removal is stable at more than 90% and maintained for at least 20 days.

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