Carrier biological fluidized bed process system and application

Abstract

The invention relates to a carrier biological fluidized bed process system and application. Comprising a water inlet end, a biochemical reaction tank, a selective sedimentation tank and a water outlet end which are sequentially communicated, the biochemical reaction tank comprises an anoxic tank and an aerobic tank which are communicated with each other, the anoxic tank is provided with a first inlet, the first inlet is communicated with the water inlet end to receive activated sludge microorganisms, and the aerobic tank is provided with a second inlet; functional porous powder carriers are respectively added into the anoxic tank and the aerobic tank, part of the activated sludge is attached to the functional porous powder carriers to form a biological membrane, and the rest of the activated sludge is suspended in the anoxic tank or the aerobic tank. The system has the advantages of high efficiency, high applicability, low cost and the like. According to the invention, double sludge regulation and control of a biochemical system and high-flux precipitation and compaction of loaded sludge are realized, and the concentration of returned sludge and sludge in a biochemical pool is improved, so that high biochemical reaction rate is realized and the load level of activated sludge is improved in situ.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a carrier biological fluidized bed process system and application thereof. Background Art

[0002] With the continuous acceleration of urbanization, the expansion of sewage treatment plants is imminent. According to the existing land and environmental protection requirements, it is urgent to adopt more efficient biochemical treatment processes. However, the traditional activated sludge biochemical treatment process has problems such as low sludge concentration in the biochemical treatment system, limited volume load capacity of the biochemical pool, poor resistance to water quality and hydraulic shock load, which seriously limits the sewage treatment capacity, makes the sewage treatment efficiency low, and is difficult to cope with large shock loads, and cannot meet the needs of efficient biochemical removal of pollutants. Secondly, in response to the national call for energy conservation and emission reduction, the sewage treatment industry in many places has upgraded its emission standards from the Class B standard in the "Pollutant Emission Standard for Urban Sewage Treatment Plants" GB18918-2002 to the Class A standard or even higher. In order to meet higher emission requirements, many sewage treatment plants have been unable to meet the existing needs due to various design reasons. The original treatment units of many sewage treatment plants need to be expanded and upgraded accordingly. Therefore, based on the above problems faced by the current sewage treatment industry, it is urgent to develop efficient and integrated sewage treatment processes. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a carrier biological fluidized bed process system, which has the advantages of high efficiency, strong applicability, and low cost. The present invention constructs a double sludge system of suspended sludge and carrier-attached growth biofilm by integrating a multifunctional powder carrier into an activated sludge system. The concentration of return sludge and biochemical pool sludge is increased to achieve a high biochemical reaction rate and increase the activated sludge load level in situ. Through the introduction of multi-stage high-efficiency selective sedimentation tanks, efficient recovery of functional porous powder carriers is achieved. The operating cost of carrier addition is reduced, the indiscriminate discharge of residual sludge in traditional processes is changed, and the selection and enrichment of functional microorganisms are achieved.

[0004] The first object of the present invention is to provide a carrier biological fluidized bed process system, comprising:

[0005] The water inlet, biochemical reaction tank, selective sedimentation tank and water outlet are connected in sequence:

[0006] A water inlet end, the water inlet end is used to introduce sewage and activated sludge microorganisms;

[0007] A biochemical reaction tank, wherein the biochemical reaction tank comprises an anoxic tank and an aerobic tank connected to each other, wherein a first inlet is arranged on the anoxic tank, and the first inlet is connected to the water inlet end to receive the activated sludge microorganisms, and functional porous powder carriers are added to the anoxic tank and the aerobic tank respectively, and part of the activated sludge is attached to the functional porous powder carrier to form a biofilm, and the remaining part of the activated sludge is suspended in the anoxic tank or the aerobic tank;

[0008] A selective sedimentation tank, wherein the multi-stage high-efficiency selective sedimentation tank comprises a primary sedimentation tank and a secondary sedimentation tank which are interconnected, and the primary sedimentation tank is connected to the aerobic tank;

[0009] The water outlet is connected to the secondary sedimentation tank to discharge the treated sewage.

[0010] Furthermore, in the anoxic tank and the aerobic tank, the total addition concentration of the functional porous powder carrier in the biochemical reaction tank ranges from 1.0 to 10.0 g / L, and the total addition concentration of the activated sludge microorganisms in the biochemical reaction tank ranges from 3.0 to 6.0 g / L.

[0011] Furthermore, the functional porous powder carrier is a modified zeolite obtained by modifying zeolite with magnesium salt at 500°C, the particle size of the functional porous powder carrier is 23-74 μm, and the density of the functional porous powder carrier is 2.0-3.0 g / cm 3 .

[0012] Furthermore, the aerobic pool is provided with an aeration device for pumping oxygen into the aerobic pool, and the dissolved oxygen concentration in the aerobic pool is 2.0-4.0 mg / L;

[0013] The aeration device comprises:

[0014] an aeration pipe, wherein the aeration pipe is arranged at the bottom of the aerobic tank;

[0015] An air pump connected to the aeration pipe;

[0016] A gas flow meter is provided between the air pump and the aeration pipe.

[0017] Furthermore, it also includes: a digestive liquid reflux device, the digestive liquid reflux device including:

[0018] A digestive liquid return pipe, one end of which is connected to the second outlet of the aerobic tank, and the other end is connected to the second inlet of the anoxic tank; the digestive liquid return pipe is used to transport the digester in the aerobic tank back to the anoxic tank, and the reflux ratio of the digestive liquid is 100-200%;

[0019] A digestive liquid reflux pump is connected to the digestive liquid reflux pipe, and is used to provide power to the digestive liquid in the digestive liquid reflux pipe.

[0020] Furthermore, it also includes:

[0021] an aerobic tank outlet pipe, one end of which is connected to the third outlet of the aerobic tank, and the other end of which is connected to the third inlet of the high-efficiency selective primary sedimentation tank;

[0022] A water distribution weir is provided on a side of the high-efficiency selective primary sedimentation tank close to the third inlet, and is used to introduce sewage discharged from the aerobic tank into the high-efficiency selective primary sedimentation tank.

[0023] Furthermore, a first sludge hopper is provided at the bottom of the high-efficiency selective primary sedimentation tank, and the bottom of the first sludge hopper is connected to a sludge return device, and the sludge return device includes:

[0024] A sludge return pipe, one end of which is connected to the fourth outlet of the first sludge hopper, and the other end is connected to the fourth inlet of the anoxic tank; the sludge return pipe is used to transport the activated sludge in the first sludge hopper back to the anoxic tank, and the return ratio of the sludge is 100-200%;

[0025] A sludge return pump is connected to the sludge return pipe, and is used to provide power to the activated sludge in the sludge return pipe, and to transport the sludge and excess functional porous powder carriers and activated sludge microorganisms in the sludge from the first sludge hopper back to the anoxic tank through the sludge return pipe, wherein the return ratio of the sludge is 100-200%.

[0026] Furthermore, a second sludge hopper is provided at the bottom of the high-efficiency selective secondary sedimentation tank, and a sludge discharge device is provided at the bottom of the second sludge hopper, and the sludge discharge device includes:

[0027] A residual sludge discharge pipe, the residual sludge discharge pipe is connected to the fifth outlet of the second sludge storage hopper, and the residual sludge discharge pipe is used to discharge the residual sludge;

[0028] A solenoid valve is connected to the residual sludge discharge pipe, and the residual sludge discharge pipe is used to discharge the residual sludge.

[0029] Furthermore, a partition is also arranged in the high-efficiency selective secondary sedimentation tank, and the partition is arranged at 1 / 5 to 1 / 3 of a side close to the high-efficiency selective primary sedimentation tank.

[0030] Furthermore, it also includes:

[0031] An overflow weir is arranged on a side of the high-efficiency selective secondary sedimentation tank close to the first outlet, and the overflow weir is used to introduce the treated sewage into the outlet pipe.

[0032] The second object of the present invention is to provide an application of a high-concentration carrier biological fluidized bed process system in sewage treatment for enhancing the biological denitrification efficiency of urban sewage.

[0033] The above technical solution of the present invention has the following advantages compared with the prior art:

[0034] 1. When the system provided by the present invention is used to treat urban sewage, it can achieve high sludge concentration and high volumetric load. The device of the invention introduces a functional porous powder carrier, which has good ammonia absorption characteristics, releases free ammonia in situ in the "microenvironment", and locally achieves a higher free ammonia concentration, which is beneficial to the growth and metabolic activity of AOB bacteria, while inhibiting the growth and metabolism of NOB bacteria.

[0035] 2. The system provided by the present invention introduces a functional porous powder carrier, which has excellent surface properties, a higher surface Zeta potential value, and better hydrophilicity, and thus has lower van der Waals potential energy, electrostatic potential energy, and total potential energy. When microorganisms attach to the functional porous powder carrier, they only need to overcome a lower interaction energy barrier, and the process of microbial attachment and biofilm formation can be quickly achieved.

[0036] 3. The system provided by the present invention greatly increases the number of functional microorganisms by introducing functional porous powder carriers. The functional powder carriers provide favorable conditions for the attachment and growth of microorganisms, reduce the impact of water flow on the attached and growing microorganisms, and construct a "double sludge" system of homogeneous symbiosis of suspended sludge and attached carrier sludge, realizing the combination of biofilm technology and activated sludge technology. The application of multi-stage high-efficiency selective sedimentation tanks realizes the efficient recovery of attached carrier sludge, achieves the regulation of double sludge in the biochemical system, and increases the concentration of return sludge and biochemical tank sludge.

[0037] 4. The system provided by the present invention introduces a functional porous powder carrier, and the area near the carrier material can form a microenvironment with high ammonia nitrogen and low dissolved oxygen, thereby promoting the growth of ammonia oxidizing bacteria. At the same time, the introduction of the functional porous powder carrier optimizes the compaction and sedimentation performance of the sludge and improves the problem of sludge swelling.

[0038] 5. The system provided by the present invention significantly increases the volume load of the biochemical pool, so it has the advantage of small footprint. In the biochemical reaction pool, the sludge forms micro-granular sludge with the functional porous powder carrier as the core. Compared with the facility without adding the functional porous powder carrier, the sludge settling ratio SV30 of the sludge with the addition of 4.0g / L functional powder carrier can be reduced by 1.5 to 2.0 times, so the volume of the sedimentation tank can be greatly reduced, and the degree of integration of the device is improved.

[0039] 6. The system provided by the present invention introduces a multi-stage high-efficiency selective sedimentation tank process, which on the one hand improves the effective recovery rate of the functional porous powder carrier, reduces the loss and re-dosage of the functional porous powder carrier, and reduces the operating cost; on the other hand, it achieves efficient selection of activated sludge, helps to eliminate part of the expanded sludge, and selectively retains high-quality microbial communities with corresponding functionality, thereby greatly improving the biochemical reaction effect of the biochemical pool.

[0040] 7. The system provided by the present invention has simple process, simple control, superior functions and high integration. It can be connected with the existing process flow without large-scale facility reconstruction, thus saving cost and time. At the same time, the technology optimizes and enhances the existing treatment unit, improving the treatment efficiency and water purification capacity. Therefore, the present invention provides a feasible and economical solution for the improvement of existing sewage treatment facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0042] Figure 1 It is a structural schematic diagram of a high-concentration carrier biological fluidized bed process system for enhancing the biological denitrification efficiency of urban sewage according to an embodiment of the present invention.

[0043] Reference numerals:

[0044] 1- anoxic tank; 2- aerobic tank; 3- high efficiency selective primary sedimentation tank; 4- high efficiency selective secondary sedimentation tank; 5- partition; 6- water distribution weir; 7- overflow weir; 8- water inlet pump; 9- water inlet pipe; 10- stirring device; 11- digestate reflux pipe; 12- digestate reflux pump; 13- aeration pipe; 14- gas flow meter; 15- air pump; 16- sludge reflux pump; 17- sludge reflux pipe; 18- aerobic tank outlet pipe; 19- residual sludge discharge pipe; 20- solenoid valve; 21- outlet pipe. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0046] The present invention aims to provide a high-concentration carrier biological fluidized bed process system for enhancing the biological denitrification efficiency of urban sewage, comprising an inlet pump 8, a biochemical reaction tank, a multi-stage high-efficiency selective sedimentation tank and an outlet pipe 21, wherein the inlet pump 8 is connected to one end of the inlet pipe 9, and the inlet pump 8 is used to introduce sewage; the biochemical reaction tank comprises an anoxic tank 1 and an aerobic tank 2 which are connected to each other, a first inlet is arranged on the anoxic tank 1, and the first inlet is connected to the other end of the inlet pipe 9 to receive sewage, the anoxic tank 1 and the aerobic tank 2 contain functional porous powder carriers, and the activated sludge microorganisms in the sewage quickly attach and grow on the surface of the functional porous powder carriers to form a biofilm, the multi-stage high-efficiency selective sedimentation tank is connected to the biochemical reaction tank, and the multi-stage high-efficiency selective sedimentation tank comprises a high-efficiency selective primary sedimentation tank 3 connected to the aerobic tank 2 and a high-efficiency selective secondary sedimentation tank 4 connected to the high-efficiency selective primary sedimentation tank 3; the outlet pipe 21 is connected to the first outlet of the high-efficiency selective secondary sedimentation tank 4 to discharge the treated sewage. That is to say, by adding functional porous powder carriers to the anoxic tank 1 and the aerobic tank 2 respectively, the dual sludge regulation of the biochemical system and the high-throughput precipitation and compaction of the loaded sludge are realized, the concentration of the return sludge and the sludge concentration of the biochemical tank are increased, which is conducive to the enrichment of functional microorganisms, thereby further improving the efficiency of the biochemical reaction and increasing the activated sludge load level in situ. By adopting a multi-stage high-efficiency selective sedimentation tank, the efficient recovery of the functional porous powder carrier is achieved, the addition of the functional porous powder carrier is reduced, and the production and operation costs are reduced. And by adding functional porous powder carriers to the anoxic tank 1 and the aerobic tank 2 respectively, a symbiotic system of activated sludge and biofilm is formed with the activated sludge microorganisms in the anoxic tank 1 and the aerobic tank 2, that is, a dual sludge system. Then, the functional porous powder carrier is recycled in the entire biochemical reaction tank through the digestate reflux device and the sludge reflux device.

[0047] Furthermore, in the anoxic tank 1 and the aerobic tank 2, the concentration of the functional porous powder carrier is 4.0g / L, and the concentration of the activated sludge microorganism is 4.0g / L. That is to say, for example, the functional porous powder carrier can be quantitatively added in multiple batches to overcome the impact of fluctuations in the quality and quantity of urban sewage on the activated sludge system of the biochemical pool, and ensure that the concentrations of the activated sludge microorganisms and the functional porous powder carriers are within a reasonable range. Specifically, after the sewage enters the biochemical reaction tank through the water inlet pipe 9, in order to enable the microorganisms in the biochemical reaction tank to better adapt to environmental changes, meet the time requirements for the growth of microorganisms in the activated sludge on the carrier surface, and at the same time increase the concentration of the mixed liquid in the biochemical reaction tank, the functional porous powder carrier can be added in appropriate amounts in sequence. The dosage of the functional porous powder carrier can be, for example, 200.0mg·L -1 ·d, continue adding for 20 days to ensure that the total amount of functional porous powder added in the entire fluidized bed reactor is 4.0 g / L.

[0048] Functional porous powder carriers are added into the biochemical reaction tank. The porous structure and excellent specific surface area of ​​the functional porous powder carriers are utilized to form a local "ammonia-rich micro-oxygen" microenvironment, which is beneficial to the rapid growth of AOB functional bacteria and the enrichment of anaerobic ammonia-oxidizing bacteria. At the same time, the functional porous powder carrier material has a lower total potential energy, which enhances the affinity of microorganisms, can quickly realize the biofilm process of microorganisms, and improve the biochemical efficiency of the reaction system.

[0049] Furthermore, the functional porous powder carrier is a modified zeolite obtained by high-temperature modification of natural zeolite with magnesium salt, the particle size of the functional porous powder carrier is 23-74 μm, and the density of the functional porous powder carrier is 2.0-3.0 g / cm 3 Specifically, the functional porous powder carrier is obtained by modifying natural zeolite by using metal magnesium salt and thermal modification. Zeolite / magnesium chloride solution is mixed in a ratio of 1g:10ml, stirred for 1h, and then heated to 1000°C. - / Mg 2+ The molar ratio of the zeolite to the zeolite is 2:1, a certain concentration of NaOH solution is prepared and slowly added dropwise to the zeolite mixed solution, and the reaction is aged for 24 hours, washed and dried naturally, and the zeolite is placed in a muffle furnace and calcined at 500 degrees for 6 hours for thermal modification to obtain a functional porous powder carrier; the prepared functional porous powder carrier is ground and sieved, the aperture of the filter sieve is 200 mesh, and the particle size range after sieving is between 23 and 74 μm, and the density is 2.0 to 3.0 g / cm 3 Functional porous powder carrier.

[0050] By adding functional porous powder carriers to the biochemical reaction tank, the concentration of activated sludge is increased in situ, and the functional porous powder carriers have the advantages of large specific surface area and developed pore structure, which can act as condensation nuclei during bacterial growth. The functional porous powder carriers are extremely hydrophilic and can be evenly dispersed in water to achieve more complete contact with activated sludge microorganisms, which is conducive to the adsorption of microorganisms to form aggregates, promote microbial aggregation and biomass accumulation. At the same time, the "ammonia absorption" characteristics of the functional porous powder carriers are used to achieve a local high-ammonia micro-oxygen environment, achieve a large number of functional microorganisms, and greatly improve the efficiency of biochemical denitrification of urban sewage.

[0051] Furthermore, an aeration device for pumping oxygen into the aerobic pool 2 is provided in the aerobic pool 2, and the dissolved oxygen concentration in the aerobic pool 2 is 2.0-4.0 mg / L; the aeration device includes an aeration pipe 13, an air pump 15 and a gas flow meter 14, and the aeration pipe 13 is provided at the bottom of the aerobic pool 2; the air pump 15 is connected to the aeration pipe 13; the gas flow meter 14 is provided between the air pump 15 and the aeration pipe 13. In other words, by using the aeration device and evenly arranging the aeration pipes 13 at the bottom of the aerobic pool 2, the requirements of microbial fermentation and nitrification reaction in the aerobic pool 2 can be guaranteed. Specifically, the aeration pipes 13 are evenly arranged at the bottom of the aerobic pool 2, and the air pump 15 provides the required oxygen for the microbial fermentation and sewage nitrification reaction in the aerobic pool 2, and the aeration amount can be effectively adjusted by the gas flow meter 14. Preferably, the dissolved oxygen concentration in the aerobic pool 2 is controlled within a range of 2.0 to 4.0 mg / L, which can fully meet the biochemical demand in the aerobic pool 2 .

[0052] As an embodiment of the present invention, the anoxic tank 1 and the aerobic tank 2 are respectively equipped with a stirring device 10. The stirring device 10 is used to stir the mixed liquid in the corresponding unit, so as to ensure that the sewage and sludge in the entire reaction zone are evenly mixed, and the short-circuit phenomenon is prevented. The full mixing is beneficial to the biological mass transfer process and accelerates the biochemical reaction rate in the biochemical pool.

[0053] Furthermore, the high-concentration carrier biological fluidized bed process system for enhancing the efficiency of biological denitrification of urban sewage also includes a digestion liquid reflux device, which includes a digestion liquid reflux pipe 11 and a digestion liquid reflux pump 12, one end of the digestion liquid reflux pipe 11 is connected to the second outlet of the aerobic tank 2, and the other end is connected to the second inlet of the anoxic tank 1; the digestion liquid reflux pump 12 is connected to the digestion liquid reflux pipe 11, and the digestion liquid reflux pump 12 is used to transport the digestion liquid from the aerobic tank 2 to the anoxic tank 1 through the digestion liquid reflux pipe 11, and the reflux ratio of the digestion liquid is 100-200%. In other words, a digestion liquid internal reflux pipe is set, the digestion liquid reflux pipe 11 is connected to the digestion liquid reflux pump 12, and the digestion liquid is transported and refluxed through the digestion liquid reflux pump 12, and the digestion liquid reflux ratio can be set to 100% or 200%. The nitrate nitrogen in the digestion liquid is returned to the front end of the anoxic tank 1, and the organic matter in the raw sewage can be fully utilized without adding an organic carbon source, and the organic pollutants in the influent can be treated by using nitrate as an electron acceptor. A second outlet is set at the end of the aerobic tank 2, and the digestion liquid sewage of the aerobic tank 2 is returned to the front end of the anoxic tank 1 through the digestion liquid return pipe, and the influent organic carbon source of the anoxic tank 1 is used as an electron donor, and the nitrate nitrogen is used as an electron acceptor to achieve denitrification in the anoxic tank 1.

[0054] Furthermore, the high-concentration carrier biological fluidized bed process system for enhancing the biological denitrification efficiency of urban sewage also includes an aerobic tank outlet pipe 18 and a water distribution weir 6. One end of the aerobic tank outlet pipe 18 is connected to the third outlet of the aerobic tank 2, and the other end is connected to the third inlet of the high-efficiency selective primary sedimentation tank 3. The water distribution weir 6 is arranged on the side of the high-efficiency selective primary sedimentation tank 3 close to the third inlet. The water distribution weir 6 is used to introduce the biochemical sewage into the high-efficiency selective primary sedimentation tank 3. The sewage flows out of the aerobic tank 2 and enters the high-efficiency selective primary sedimentation tank 3 through the aerobic tank outlet pipe 18. In order to achieve better mud and water separation in the first area of ​​the selective sedimentation tank and avoid short-flow phenomenon, the water distribution weir 6 can be arranged at the front end of the high-efficiency selective primary sedimentation tank 3 to change the water flow from point flow to surface flow, and the sewage enters the high-efficiency selective primary sedimentation tank 3 evenly through the water distribution weir 6. The water distribution weir 6 is arranged at the third inlet of the high-efficiency selective primary sedimentation tank 3 so that the effluent of the aerobic tank 2 is evenly distributed through the water distribution weir 6 to enter the sedimentation area, preventing the short-flow phenomenon from occurring, and realizing the recovery of functional porous powder carriers and mud and water separation.

[0055] Further, a first sludge hopper is provided at the bottom of the high-efficiency selective primary sedimentation tank 3, and a sludge return device is connected to the bottom of the first sludge hopper. The sludge return device includes a sludge return pipe 17 and a sludge return pump 16. One end of the sludge return pipe 17 is connected to the fourth outlet of the first sludge hopper, and the other end is connected to the fourth inlet of the anoxic tank 1. The sludge return pump 16 is connected to the sludge return pipe 17. The sludge return pump 16 is used to transport the sludge and the excess functional porous powder carrier and activated sludge microorganisms in the sludge from the first sludge hopper to the anoxic tank 1 through the sludge return pipe 17. The sludge return ratio is 100-200%. A sludge return pipe 17 is provided, and the sludge return pipe 17 is connected to the first sludge hopper at the bottom of the high-efficiency selective primary sedimentation tank 3. The sludge in the first sludge hopper is returned through the sludge return pipe 17 and transported through the sludge return pump 16. The sludge return ratio is set to 100-200%. All the sludge is returned to the front end of the anoxic tank 1. The sludge return liquid contains a large amount of functional porous powder carriers. The return flow can effectively recover the functional powder carriers and reduce the re-dosage of the functional porous powder carriers. On the other hand, it can supplement the amount of microorganisms for the biochemical pool.

[0056] In other words, a sedimentation tank with a multi-level surface load control function is configured. By adjusting the surface load of the sedimentation tank, the functional porous powder carrier can be recycled while ensuring that the effluent quality meets the discharge requirements. In view of the problem of indiscriminate discharge of residual sludge in the traditional activated sludge process, the functional microorganisms can be selected and enriched by adjusting the surface hydraulic load, thereby effectively controlling the occurrence of activated sludge expansion. By designing two sedimentation tanks with different surface hydraulic loads, the functional porous powder carrier can be efficiently and quickly recovered while meeting the sewage discharge standards, reducing the re-dosing and operating costs of the functional porous powder carrier. By adjusting the surface hydraulic load of the sedimentation tank, the shortcomings of the traditional sludge treatment process in indiscriminate discharge of residual sludge can be changed, and the selection and enrichment of functional microorganisms can be achieved. In addition, the high-efficiency selective primary sedimentation tank 3 adopts a large surface hydraulic load operation mode to achieve the recovery of functional porous powder carriers. The surface hydraulic load design is recommended to be 1.5~3.0m 3 ·m -2 ·h -1 , and a sewage return device is provided, and the functional porous powder carrier and sludge are directly returned to the front end of the anoxic tank 1 through the sludge return pipe 17.

[0057] Further, a second sludge hopper is provided at the bottom of the high-efficiency selective secondary sedimentation tank 4, and a sludge discharge device is provided at the bottom of the second sludge hopper. The sludge discharge device includes a residual sludge discharge pipe 19 and a solenoid valve 20. The residual sludge discharge pipe 19 is connected to the fifth outlet of the second sludge hopper; the solenoid valve 20 is connected to the residual sludge discharge pipe 19, and the residual sludge discharge pipe 19 is used to discharge the residual sludge. In other words, the second sludge hopper at the bottom of the high-efficiency selective secondary sedimentation tank 4 is connected to the residual sludge discharge pipe 19. Part of the sludge is discharged through the residual sludge discharge pipe 19, and the discharge of the residual sludge is controlled by the solenoid valve 20. The remaining sludge directly enters the subsequent sludge treatment and disposal facilities through the residual sludge discharge pipe 19 for the next step of harmless, reduced, and resource-based treatment. That is, the high-efficiency selective secondary sedimentation tank 4 is provided with a sludge discharge pipe and a sludge return pipe 17, and the generated sludge part is used as residual sludge and enters the subsequent sludge treatment unit to complete the next step of treatment and disposal. Part of the sludge is returned to the front end of the anoxic tank 1 through the sludge return pipe 17. The high-efficiency selective secondary sedimentation tank 4 adopts a small surface hydraulic load operation mode, and the surface hydraulic load design is recommended to be 1.0-2.0m 3 ·m -2 ·h -1 , further realize mud-water separation, ensure effluent water quality, and achieve SS compliance. That is, the high-efficiency selective secondary sedimentation tank 4 adopts a low surface hydraulic load operation mode to ensure effluent water quality and achieve effluent SS meeting relevant emission standards. Part of the remaining sludge in the sedimentation tank is returned as sludge, and part directly enters the subsequent sludge treatment facility for corresponding treatment and disposal.

[0058] As another embodiment of the present invention, for the high-efficiency selective primary sedimentation tank 3 and the high-efficiency selective secondary sedimentation tank 4, in order to prevent the activated sludge from being in the sedimentation tank for too long and the dissolved oxygen from being exhausted, resulting in an anaerobic environment that affects the activity of microorganisms, causing anaerobic denitrification and causing sludge floating, the volumes of the first sludge hopper and the second sludge hopper are designed according to a sludge storage time of 1.5 hours, and when the first sludge hopper and the second sludge hopper are used to discharge sludge, the inclination angle of the inclined walls of the first sludge hopper and the second sludge hopper is set to 65°.

[0059] Furthermore, a partition 5 is also provided in the high-efficiency selective secondary sedimentation tank 4, and the partition 5 is provided at 1 / 5 to 1 / 3 of the side close to the high-efficiency selective primary sedimentation tank 3. The partition 5 can change the direction of the influent water flow, increase the hydraulic retention time, and ensure the effluent water quality. For example, a partition 5 can be provided at 1 / 5 of the front end of the high-efficiency selective secondary sedimentation tank 4, and the partition 5 can change the direction of the water flow from horizontal flow to vertical flow, and effectively remove SS in the sewage by extending the hydraulic retention time of the sewage in the high-efficiency selective secondary sedimentation tank 4, so as to ensure that the effluent meets the Class A emission standard in the Pollutant Emission Standard for Urban Sewage Treatment Plants (GB18918-2002).

[0060] Furthermore, the high-concentration carrier biological fluidized bed process system for enhancing the biological denitrification efficiency of urban sewage also includes an overflow weir 7, which is arranged on the side of the high-efficiency selective secondary sedimentation tank 4 close to the first outlet, and the overflow weir 7 is used to introduce the treated sewage into the outlet pipe 21. In other words, the overflow weir 7 is arranged at the end of the high-efficiency selective secondary sedimentation tank 4, and the middle part of the lower end of the overflow weir 7 is connected to the outlet pipe 21. The weir mouth position of the overflow weir 7 is kept horizontal, and by setting the outlet weir, the water level in the sedimentation tank can be effectively controlled, so that the water in the sedimentation tank is discharged evenly, short-circuiting phenomenon is prevented, and the outlet water quality is guaranteed.

[0061] It is worth noting that all electrical equipment such as the water inlet pump 8, solenoid valve 20, stirring device 10, concentrate reflux pump, digestate reflux pump 12, air pump 15, etc. in the system of the embodiment of the present invention are automatically controlled, have a highly intelligent management level, and significantly reduce costs.

[0062] Another object of the present invention is to provide an application of a high-concentration carrier biological fluidized bed process system in sewage treatment for enhancing the biological denitrification efficiency of urban sewage.

[0063] Comparative Example 1

[0064] The same as in Example 1, except that the zeolite is not modified in any way.

[0065] Comparative Example 2

[0066] The same as in Example 1, except that the zeolite is modified by sodium chloride, and the modification method is the same as that of magnesium salt. Zeolite / sodium chloride solution is mixed in a ratio of 1g:10ml, stirred for 1h, and then heated to 1000C. - / Na + The molar ratio of the zeolite to the zeolite is 1:1, a certain concentration of NaOH solution is prepared and slowly added dropwise to the zeolite mixed solution, and the reaction is aged for 24 hours, washed and dried naturally, and the zeolite is placed in a muffle furnace and calcined at 500 degrees for 6 hours for thermal modification to obtain a functional porous powder carrier; the prepared functional porous powder carrier is ground and sieved, the aperture of the filter sieve is 200 mesh, and the particle size range after sieving is between 23 and 74 μm, and the density is 2.0 to 3.0 g / cm 3 Functional porous powder carrier.

[0067] Comparative Example 3

[0068] The same as in the example, except that no carrier material was added.

[0069] Specific application effect examples

[0070] The sewage water quality conditions are: COD concentration of 550.0 mg / L, total nitrogen concentration of 85.0 mg / L, sludge concentration of 8.0 g / L, hydraulic retention time of 9.0 h. The above sewage is introduced into the high-concentration carrier biological fluidized bed process system for enhancing the biological denitrification efficiency of urban sewage in an embodiment of the present invention through the water inlet pump 8, and the treated sewage flowing out from the outlet of the outlet pipe 21 is collected, and the water quality of the treated sewage is tested.

[0071] Table 1

[0072]

[0073] The results show that the system of the embodiment of the present invention can shorten the hydraulic retention time to 1 / 2 of the previous process without adding functional powder carrier (Comparative Example 3), and the COD concentration of the effluent is less than 30.0 mg / L, the total nitrogen concentration of the effluent is less than 10.0 mg / L, and the effluent water quality fully meets the Class A emission standard in the "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB18918-2002).

[0074] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A carrier biological fluidized bed process system, characterized in that: It includes a water inlet, a biochemical reaction tank, a selective sedimentation tank and a water outlet which are connected in sequence: A water inlet end, the water inlet end is used to introduce sewage and activated sludge microorganisms; A biochemical reaction tank, wherein the biochemical reaction tank comprises an anoxic tank and an aerobic tank connected to each other, wherein a first inlet is arranged on the anoxic tank, and the first inlet is connected to the water inlet end to receive the activated sludge microorganisms, and functional porous powder carriers are added to the anoxic tank and the aerobic tank respectively, and part of the activated sludge is attached to the functional porous powder carrier to form a biofilm, and the remaining part of the activated sludge is suspended in the anoxic tank or the aerobic tank; A selective sedimentation tank, wherein the multi-stage high-efficiency selective sedimentation tank comprises a primary sedimentation tank and a secondary sedimentation tank which are interconnected, and the primary sedimentation tank is connected to the aerobic tank; The water outlet is connected to the secondary sedimentation tank to discharge the treated sewage.

2. The carrier biological fluidized bed process system according to claim 1, characterized in that: The total addition concentration of the functional porous powder carrier in the biochemical reaction tank is in the range of 1.0 to 10.0 g / L, and the total addition concentration of the activated sludge microorganisms in the biochemical reaction tank is in the range of 3.0 to 6.0 g / L.

3. The carrier biological fluidized bed process system according to claim 1, characterized in that: The functional porous powder carrier is a modified zeolite obtained by modifying zeolite with magnesium salt at a high temperature of 500°C. The particle size of the functional porous powder carrier is 23-74 μm, and the density of the functional porous powder carrier is 2.0-3.0 g / cm 3 .

4. The carrier biological fluidized bed process system according to claim 1, characterized in that: The aerobic pool is provided with an aeration device for pumping oxygen into the aerobic pool, and the dissolved oxygen concentration in the aerobic pool is 2.0-4.0 mg / L; The aeration device comprises: an aeration pipe, wherein the aeration pipe is arranged at the bottom of the aerobic tank; An air pump connected to the aeration pipe; A gas flow meter is provided between the air pump and the aeration pipe.

5. The carrier biological fluidized bed process system according to claim 1, characterized in that: Also includes: A digestive liquid reflux device, the digestive liquid reflux device comprising: A digestive liquid return pipe, one end of which is connected to the second outlet of the aerobic tank, and the other end is connected to the second inlet of the anoxic tank; the digestive liquid return pipe is used to transport the digester in the aerobic tank back to the anoxic tank, and the reflux ratio of the digestive liquid is 100-200%; A digestive liquid reflux pump is connected to the digestive liquid reflux pipe, and is used to provide power to the digestive liquid in the digestive liquid reflux pipe.

6. The carrier biological fluidized bed process system according to claim 1, characterized in that: Also includes: an aerobic tank outlet pipe, one end of which is connected to the third outlet of the aerobic tank, and the other end of which is connected to the third inlet of the high-efficiency selective primary sedimentation tank; A water distribution weir is provided on a side of the high-efficiency selective primary sedimentation tank close to the third inlet, and is used to introduce sewage discharged from the aerobic tank into the high-efficiency selective primary sedimentation tank.

7. The carrier biological fluidized bed process system according to claim 1, characterized in that: A first sludge hopper is provided at the bottom of the high-efficiency selective primary sedimentation tank, and a sludge return device is connected to the bottom of the first sludge hopper. The sludge return device includes: A sludge return pipe, one end of which is connected to the fourth outlet of the first sludge hopper, and the other end is connected to the fourth inlet of the anoxic tank; the sludge return pipe is used to transport the activated sludge in the first sludge hopper back to the anoxic tank, and the return ratio of the sludge is 100-200%; A sludge return pump is connected to the sludge return pipe and is used to provide power to the activated sludge in the sludge return pipe.

8. The carrier biological fluidized bed process system according to claim 1, characterized in that: A second sludge hopper is provided at the bottom of the high-efficiency selective secondary sedimentation tank, and a sludge discharge device is provided at the bottom of the second sludge hopper. The sludge discharge device includes: A residual sludge discharge pipe, the residual sludge discharge pipe is connected to the fifth outlet of the second sludge storage hopper, and the residual sludge discharge pipe is used to discharge the residual sludge; A solenoid valve is connected to the residual sludge discharge pipe.

9. The carrier biological fluidized bed process system according to claim 1, characterized in that: A partition is also arranged in the high-efficiency selective secondary sedimentation tank, and the partition is arranged at 1 / 5 to 1 / 3 of a side close to the high-efficiency selective primary sedimentation tank.

10. The carrier biological fluidized bed process system according to claim 1, characterized in that: Also includes: An overflow weir is arranged on a side of the high-efficiency selective secondary sedimentation tank close to the first outlet, and the overflow weir is used to introduce the treated sewage into the outlet pipe.

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