A primary treatment system and treatment method for urban suburban sewage

Abstract

The present invention provides a primary treatment system for urban suburban sewage, comprising a grid well, a sedimentation tank and an aeration tank connected in sequence, a filter cartridge is arranged between the grid well and the sedimentation tank, and between the sedimentation tank and the aeration tank as a water passage, the filter cartridge is tilted as a whole, a combined filter frame matching the inner cross section of the cartridge is arranged in the filter cartridge, the combined filter frame comprises two cylindrical hollow rotating frames arranged along the length direction of the filter cartridge, each of the hollow rotating frames is provided with a spiral blade, the filter cartridge is formed with a gap space between the two hollow rotating frames, two spiral blades are equipped with nylon fiber bristles in a spiral manner, the nylon fiber bristles equipped on the two spiral blades are in opposite directions and are close to the inner cylinder surface of the filter cartridge. A primary treatment method for urban suburban sewage is also provided, which can effectively improve the quality of sewage entering the subsequent secondary treatment system and tertiary treatment system, and reduce the proportion of particulate matter and suspended matter content.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a primary treatment system and a treatment method for urban suburban sewage. Background Art

[0002] In the suburban area, as a transition zone between urban and rural areas, the production mode is mainly agricultural production, supplemented by industry and commerce. Therefore, its water use is also affected by residents' daily life, agricultural production, and industrial production. The water use situation has the characteristics of both urban and rural water use. The sewage generated in the corresponding area has the following characteristics:

[0003] 1. Water quantity and quality are periodic: The quantity and quality of suburban sewage change over time, with diurnal and seasonal periodicity.

[0004] 2. Many types of pollutants: Suburban sewage contains a variety of pollutants, such as organic matter, suspended solids, nutrients, heavy metals, etc. Among them, organic matter is one of the most common pollutants in suburban sewage, including protein, carbohydrates, fat, urea, ammonia nitrogen, etc.

[0005] 3. Difficulty in treatment: Since the amount and quality of suburban sewage fluctuate greatly and the treatment facilities are relatively imperfect, it is difficult to treat.

[0006] 4. Great impact on the environment: Direct discharge of untreated suburban sewage will have serious impacts on the environment, such as eutrophication of water bodies, excessive growth of algae, and destruction of aquatic ecosystems.

[0007] The primary treatment of sewage, also known as primary treatment, includes operation and treatment steps such as screen treatment, water quality and quantity adjustment, pre-sedimentation treatment, sand settling treatment and sedimentation treatment. It removes suspended solids, floating objects, floating oil and other impurities and some dissolved organic matter in sewage through simple physical methods such as sedimentation, filtration or appropriate aeration, and adjusts the pH value of sewage and reduces the degree of corruption and deformation of sewage. Due to the above characteristics, the sewage in suburban areas is different from the treatment of community sewage, industrial sewage and rural sewage in cities. It is easy to have a relatively shallow treatment degree under the conditions of traditional primary treatment equipment. Therefore, it is necessary to take effective treatment measures to improve and optimize the front-end primary treatment stage of sewage treatment according to the characteristics of suburban sewage, reduce its impact on the environment, and improve the collection rate and treatment rate of sewage; so that sewage can be treated as stably and effectively as possible in the initial treatment stage, and prepare for the subsequent secondary treatment stage and tertiary treatment stage, so as to ensure the treatment effect of the entire sewage treatment system, so that sewage can be effectively purified and meet the requirements of emission standards. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention provides a primary treatment system for urban suburban sewage. In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0009] A primary treatment system for urban suburban sewage, comprising a grid well, a sedimentation tank and an aeration tank connected in sequence, wherein a filter cartridge is provided between the grid well and the sedimentation tank, and between the sedimentation tank and the aeration tank as a water passage;

[0010] The filter cartridge is tilted as a whole, with the water inlet side at the top and the water outlet side at the bottom. A combined filter frame matching the cross-section of the inner cavity of the cartridge is arranged in the filter cartridge. The combined filter frame includes two cylindrical hollow rotating frames arranged along the length direction of the filter cartridge. Each of the hollow rotating frames is provided with a spiral blade, which can be rotated by the corresponding hollow rotating frame. The filter cartridge is formed with a gap space between the two hollow rotating frames. Nylon fiber bristles are spirally mounted on the two spiral blades. The nylon fiber bristles mounted on the two spiral blades have opposite rotation directions and are close to the inner cylinder surface of the filter cartridge, so that when the two hollow rotating frames rotate, the combined filter frame can form a counter-rotating flow in the cylinder cavity of the filter cartridge through the spiral thrust of the spirally mounted nylon fiber bristles.

[0011] Of the two hollow rotating frames, the upper hollow rotating frame is a non-powered structure, which is powered by the flow of water in the filter cartridge, and the lower hollow rotating frame is connected to an external power motor and rotated by the motor drive;

[0012] The filter cartridge is formed with a circle of annular protrusions at the position of the gap space as a debris storage space, a slag discharge port is provided on the debris storage space, and a non-return structure is correspondingly formed at the base of the ring section of the annular protrusion to prevent debris in the debris storage space from returning to the filter cartridge.

[0013] Furthermore, the non-return structure includes a first baffle and a second baffle that are relatively arranged. The first baffle and the second baffle are both formed of plastic materials. The first baffle and the second baffle together form a V-shaped structure protruding outward. The V-shaped structure has a gap in the middle, and the gap is used as a passage space for debris.

[0014] Furthermore, the grid well is a combined grid well, and a coarse grid, a medium grid and a fine grid are respectively arranged in the well cavity from top to bottom to intercept large pieces of solid pollutants in a suspended or floating state.

[0015] Furthermore, the aspect ratio of the filter cartridge is 5:1-10:1, and the projected contour area of ​​the nylon fiber bristles on the corresponding cross-section of the filter cartridge cross-section accounts for 75-85%.

[0016] Furthermore, among the two hollow rotating frames, the length of the hollow rotating frame at the lower position is 1 / 2 to 2 / 3 of the length of the hollow rotating frame at the upper position, and the porosity of the nylon fiber bristles assembled on the hollow rotating frame at the lower position is smaller than the porosity of the nylon fiber bristles assembled on the hollow rotating frame at the upper position.

[0017] Furthermore, the power motor externally connected to the hollow rotating frame at the lower position is a variable frequency motor, and a water flow velocity sensor is provided at the water inlet end of the filter cartridge to correct the rotation speed of the hollow rotating frame through the liquid flow velocity in the filter cartridge.

[0018] Furthermore, the nylon fiber bristles are provided with a plurality of insertion holes evenly spaced along the length direction of the spiral blade, and the insertion holes are used to assemble and shape the nylon fiber bristles, so that the hollow rotating frame at the water inlet end and the hollow rotating frame at the water outlet end are formed with nylon fiber bristles arranged in a spiral manner to serve as a dynamic screening structure. The nylon fiber bristles extend from the upper and lower surfaces of the insertion holes, and the outer surfaces thereof are abutted against the inner cylinder surface of the filter cartridge body. A hole is reserved at the center of the spiral blade corresponding to the axial position of the filter cartridge body to facilitate the passage of the rotating shaft and to facilitate pressure relief when the water pressure is too high.

[0019] Furthermore, a movable door that opens upward is provided on the upper part of the body of the filter cartridge, so that when blockage occurs in the filter cartridge, immediate unblocking can be performed by opening the movable door.

[0020] Furthermore, the filter cartridge maintains an angle of 10-20° with the horizontal plane, and the aeration tank is sequentially connected to a flotation tank and a disinfection tank.

[0021] The present invention also adopts another technical solution:

[0022] A primary treatment method for urban suburban sewage, using the above-mentioned treatment system, comprises the following steps:

[0023] Sequentially assemble the grid well, filter cartridge, sedimentation tank, aeration tank, flotation tank and disinfection tank;

[0024] When treating the sewage collected in the sewage collection tank, firstly, the large-sized solid debris is removed by using the grid well and most of the particulate matter with a particle size of more than 100 microns is removed by sedimentation. The remaining sewage is passed through the filter cartridge between the grid well and the sedimentation tank and the filter cartridge between the sedimentation tank and the aeration tank to enter the next process;

[0025] When sewage passes through the filter cartridge, the water flow first drives the hollow rotating frame at the water inlet end to rotate, and at the same time, the hollow rotating frame at the water inlet end can achieve the technical purpose of slow flow. Then, after entering the second half of the filter cartridge, the driving motor drives the hollow rotating frame at the water outlet end to rotate, so as to form a convection in the filter cartridge cavity opposite to the water inlet side, thereby generating a vortex in the gap space. This vortex can send the impurities in the sewage that have not been removed by the front-end process into the impurity storage space through the centrifugal force of the vortex, and store them in the impurity storage space. The nylon fiber bristles installed on the spiral blades can further screen and filter out the fine substances in the wastewater, and leave the above fine substances in the corresponding two filter cartridges.

[0026] A flow rate sensor is used to correct the rotation speed of the hollow rotating frame at the water outlet end to prevent sewage backflow in the filter cartridge. The speed range when driven by a power motor also needs to be controlled within the range of 20~40 rpm to ensure that the sewage flow rate in the corresponding filter cartridge is within the optimal flow rate range.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The primary treatment system for urban suburban sewage of the present invention can be newly built or rebuilt on the basis of a traditional primary sewage treatment system. It has low construction and maintenance costs and is easy to maintain and adjust during use. In the process of sewage treatment, it can perform multiple static and dynamic combined filtrations on sediment and suspended matter, and has good adaptability to different types of secondary treatment systems and tertiary treatment systems.

[0029] 2. It uses an inclined filter cartridge as a water passage to connect the grille well, sedimentation tank, sedimentation tank and aeration tank, so that a vortex is formed in the filter cartridge between the grille well and the sedimentation tank, and between the sedimentation tank and the aeration tank using nylon fiber bristles to assist in filtering the sewage in the flow process, which can effectively improve the treatment effect of suspended matter, floating matter and other debris in the sewage, avoid it from entering the secondary treatment system and having an adverse effect on the biological treatment effect of the secondary treatment, ensure the quality of biofilm formation in the bioreactor in the secondary treatment system, ensure the treatment effect of the biological reaction in the secondary treatment system, and effectively reduce the burden of subsequent tertiary treatment, improve its sewage treatment efficiency and treatment effect, and have a positive effect on improving the stability, reliability and service life of the subsequent secondary treatment system and tertiary treatment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0031] Figure 1 A schematic diagram of system assembly of a preferred embodiment of the present invention;

[0032] Figure 2 for Figure 1 Bottom view of the structure of the middle filter cartridge.

[0033] Among them: 1. grid well; 2. first filter cartridge; 3. flocculation sedimentation tank cavity; 4. grit chamber cavity; 5. second filter cartridge; 6. aeration tank; 7. flotation tank; 8. disinfection tank; 9. water inlet end joint; 10. water inlet end hollow rotating frame; 11. spiral blades; 12. annular protrusion; 13. storage space; 14. check structure; 15. gap space; 16. water outlet end hollow rotating frame; 17. water outlet end joint; 18. slag discharge port seal; 19. slag discharge port. DETAILED DESCRIPTION

[0034] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0037] See also Figure 1~Figure 2 A preferred embodiment of a primary treatment system for urban suburban sewage is provided. In this embodiment, the primary treatment system for urban suburban sewage is arranged at the rear of a sewage collection tank, and serves as a front-end treatment device to physically remove impurities such as suspended solids, floating objects, floating oil, and partially dissolved organic matter in the sewage collected in the sewage collection tank. The rear of the primary treatment system is sequentially connected to a secondary treatment system and a tertiary treatment system. The secondary treatment system and the tertiary treatment system adopted can be the secondary treatment system and the tertiary treatment system already available in the prior art for treating domestic sewage.

[0038] Reference Figure 1The schematic diagram of the primary treatment system for urban suburban sewage of the present embodiment comprises a grid well 1, a sedimentation tank, an aeration tank 6, a flotation tank 7 and a disinfection tank 8 connected in sequence as main treatment units, wherein the grid well 1 and the sedimentation tank are connected via a first filter cartridge 1 as a water passage, and the sedimentation tank and the aeration tank 6 are connected via a second filter cartridge 5 as a water passage; and the aeration tank 6 and the flotation tank 7, as well as the flotation tank 7 and the disinfection tank 8, are connected via ordinary water supply pipes as water passages.

[0039] The screen well 1 is a combined screen well, in which a coarse screen, a medium screen and a fine screen are arranged from top to bottom in the well cavity. These screens are obliquely placed in the well cavity through which the wastewater flows, and are used to intercept suspended or floating solid pollutants in the sewage that are larger than the gap between the screen bars, so as to avoid clogging the mud discharge pipes of the water pump and the sedimentation tank, and effectively reduce the probability of clogging of pipelines, mechanical equipment and other devices; and the screen residue blocked by the screen needs to be cleaned regularly.

[0040] The sedimentation tank connected to the grid well 1 at the outlet through the first filter cartridge 2 is a double-chamber sedimentation tank in this embodiment, including a flocculation sedimentation tank chamber 3 arranged at the water inlet end and a grit chamber 4 designed at the outlet end, and the flocculation sedimentation tank chamber 3 and the grit chamber 4 are not connected by built-in pipes. The flocculation sedimentation tank chamber 3 is added with flocculants to make part of the pollutants produce natural flocculation or biological flocculation, so that the tiny particles in the sewage are condensed into large particles for precipitation and separation. In other embodiments, in order to improve the flocculation effect of the sedimentation tank, a pre-aeration tank can also be set before the sedimentation tank, and the pre-aeration tank can also be built together with the flocculation sedimentation tank chamber 3. The grit chamber 4 can be a horizontal flow grit chamber or an aerated grit chamber in different embodiments according to the actual source or form of pollutants. The grit chamber 4 controls the sewage flow rate in the grit chamber 4 to allow only inorganic particles with a large specific gravity to precipitate, but not lighter organic particles to precipitate, so as to separate inorganic particles from organic particles and treat them separately; thereby achieving the purpose of separating inorganic particles such as sand with a large specific gravity in wastewater. The sedimentation tank can be used to remove most of the suspended solids that can be settled in sewage, and can be used as a pretreatment for chemical or biochemical treatment to reduce the load of subsequent treatment processes and improve the treatment effect.

[0041] The sewage from the sedimentation tank is connected to the flotation tank 7 through the second filter cartridge 5, which makes some pollutants (mainly organic matter such as oil particles) flocculate and float and then be skimmed off by adding reagents, pressurizing and dissolving air, etc. At the same time, it can also oxidize the reducing substances in the wastewater, adjust the pH value, increase the dissolved oxygen in the sewage, reduce the degree of corruption of the sewage, and improve the stability of the sewage.

[0042] The disinfection tank 8 connected to the rear of the flotation tank 7 is used to kill some bacteria and viruses in the sewage when a disinfectant is added, thereby ensuring the disinfection and sterilization effect on the sewage entering the secondary treatment system.

[0043] In this embodiment, the first filter cartridge 2 and the second filter cartridge 5 serving as water passages between the grid well 1 and the sedimentation tank and between the sedimentation tank and the aeration tank 6 are similar in structure. Figure 2 The style shown: it includes a filter cartridge body, and both ends of the filter cartridge body are respectively provided with an inlet end joint 9 and an outlet end joint 17 for quick assembly connection with the corresponding grid well 1, flocculation tank, and aeration tank 6.

[0044] The filter cartridge is provided with a combined filter frame matching the cross section of the inner cavity of the cartridge, and the combined filter frame includes two cylindrical hollow rotating frames arranged along the length direction of the filter cartridge, that is, Figure 2 The hollow rotating frame 10 at the water inlet end and the hollow rotating frame 16 at the water outlet end shown in the figure are both provided with a spiral blade 11, and the spiral blade 11 can be rotated through the corresponding hollow rotating frame, and at the same time, a number of insertion holes are evenly spaced along the length direction of the spiral blade 11, and the insertion holes are used to assemble and shape nylon fiber bristles, so that the hollow rotating frame 10 at the water inlet end and the hollow rotating frame 16 at the water outlet end are formed with nylon fiber bristles arranged in a spiral manner as a dynamic screening structure, and the nylon fiber bristles extend from the upper and lower surfaces of the insertion holes, and the outer surface thereof is in contact with the inner cylinder surface of the filter cartridge body, and a hole is reserved on the inner side corresponding to the axial center position of the filter cartridge body to facilitate the passage of the rotating shaft and to facilitate pressure relief when the water pressure is too high.

[0045] The length of the hollow rotating frame 16 at the water outlet end assembled in the filter cartridge body in the axial direction of the filter cartridge body is 2 / 3 of the length of the hollow rotating frame 10 at the water inlet end in the axial direction of the filter cartridge body; and the porosity of the nylon fiber bristles assembled on the hollow rotating frame 16 at the water outlet end is smaller than that of the nylon fiber bristles assembled on the hollow rotating frame 10 at the water inlet end.

[0046] In the technical solution of the present invention, the rotation directions of the nylon fiber bristles correspondingly assembled on the hollow rotating frame 10 at the water inlet end and the hollow rotating frame 16 at the water outlet end are opposite. At the same time, the hollow rotating frame 10 at the water inlet end is a non-powered structure, while the hollow rotating frame 16 at the water outlet end is externally connected to a variable frequency motor as a power motor to drive the hollow rotating frame 16 at the water outlet end to rotate.

[0047] Of the two hollow rotating frames, the length of the lower hollow rotating frame is 1 / 2 to 2 / 3 of the length of the upper hollow rotating frame; and the porosity of the nylon fiber bristles assembled on the lower hollow rotating frame is less than the porosity of the nylon fiber bristles assembled on the upper hollow rotating frame.

[0048] In this embodiment, the length-to-diameter ratio of the cylinder structure used as the first filter cartridge 2 and the second filter cartridge 5 is 8:1, and the projected contour area of ​​the nylon fiber bristles on the corresponding section of the filter cartridge cross-section accounts for 80%, and a hole size corresponding to the axial position of the filter cartridge body is reserved, which is 20% of the projected contour area on the filter cartridge inner diameter section. The only difference between the first filter cartridge 2 and the second filter cartridge 5 is that the first filter cartridge 2 serves as a front-end screening structure, and the arrangement density of the nylon fiber bristles used on the hollow rotating frame 10 at the water inlet end and the hollow rotating frame 16 at the water outlet end at the same position is smaller than the arrangement density of the nylon fiber bristles in the second filter cartridge 5, that is, the arrangement density of the nylon fiber bristles on the hollow rotating frame 10 at the water inlet end of the first filter cartridge 2 is smaller than the arrangement density of the nylon fiber bristles on the hollow rotating frame 10 at the water inlet end of the second filter cartridge 5, and the arrangement density of the nylon fiber bristles on the hollow rotating frame 16 at the water outlet end of the first filter cartridge 2 is smaller than the arrangement density of the nylon fiber bristles on the hollow rotating frame 10 at the water inlet end of the second filter cartridge 5.

[0049] In addition, a gap space 15 is reserved between the hollow rotating frame 10 at the water inlet end and the hollow rotating frame 16 at the water outlet end in the filter cartridge body. The filter cartridge body is formed with an annular protrusion 12 at the position of the gap space 15. The annular space between the annular protrusion 12 and the gap space 15 is a storage space 13. The bottom of the storage space 13 is formed with a slag discharge port 19 closed by a slag discharge port seal 18. At the same time, at the base of the storage space 13, a slag discharge port seal 18 is formed. Figure 2 The style shown is formed with a ring-shaped non-return structure 14, which includes a first baffle and a second baffle that are relatively arranged. The first baffle and the second baffle are both formed of plastic materials. The first baffle and the second baffle together form a V-shaped structure protruding outward. The V-shaped structure has a slit in the middle, and the slit serves as a passage space for debris. The non-return structure 14 is set to prevent debris entering the debris storage space 13 from returning to the gap space 15 of the filter cartridge.

[0050] The first filter cartridge 2 and the second filter cartridge 5 in the technical solution of the present invention are both installed obliquely, with the water inlet side at the top and the water outlet side at the bottom, and the entire filter cartridge maintains an angle of 10 to 20 degrees with the horizontal plane, and the above different angles can be matched with different water pressures set at the corresponding water inlet side pool body assembly position to achieve different initial flow rates on the filter cartridge. For example, in this embodiment, the first filter cartridge 2 and the second filter cartridge 5 maintain an angle of 15 degrees with the horizontal plane when assembled.

[0051] Under the technical solution conditions of this embodiment, when the assembled primary treatment system for urban suburban sewage treats the sewage collected in the sewage collection tank, the sewage first removes large-sized solid debris by using the grid well and removes most of the particulate matter with a particle size of more than 100 microns by sedimentation, and then passes through the first filter cartridge 2 and the second filter cartridge 5 to enter the next process. When passing through the first filter cartridge 2 and the second filter cartridge 5, the hollow rotating frame 10 at the water inlet end is first driven by the water flow to rotate, and at the same time, the hollow rotating frame 10 at the water inlet end can achieve a technical purpose of slow flow, and then enters the second filter cartridge 5. After half a section, the hollow rotating frame 16 at the water outlet end is driven by a driving motor to rotate to form a convection in the filter cartridge cavity opposite to the water inlet side, thereby generating a vortex in the gap space 15. This vortex can send the debris in the sewage that has not been removed by the front-end process into the storage space 13 through the centrifugal force of the vortex and store it in the debris storage space 13. The nylon fiber bristles assembled on the spiral blades 13 can further screen and filter out fine substances in the wastewater, such as fibers, pulp, etc., and the above-mentioned fine substances are retained in the corresponding first filter cartridge 2 or the second filter cartridge 5 to ensure the normal operation and treatment effect of the subsequent treatment unit.

[0052] In order to prevent sewage backflow in the first filter cartridge 2 and the second filter cartridge 5, the corresponding filter cartridge can also be provided with a water flow velocity sensor at the water inlet end; the rotation speed of the hollow rotating frame 16 at the water outlet end is corrected by the sewage flow velocity in the filter cartridge, and in order to ensure that the sewage flow velocity in the corresponding filter cartridge is within a preferred flow velocity range, the rotation speed range of the corresponding hollow rotating frame 16 at the water outlet end when driven by a power motor also needs to be controlled within the range of 20 to 40 rpm.

[0053] In another embodiment, in order to improve the practicality of the first filter cartridge 2 and the second filter cartridge 5, the water inlet hollow rotating frame 10 and the water outlet hollow rotating frame 16 in the first filter cartridge 2 and the second filter cartridge 5 are both detachable assembly structures, and the nylon fiber bristle connecting spiral blades 11 on the water inlet hollow rotating frame 10 and the water outlet hollow rotating frame 16 are also detachable structures. In addition, the upper part of the cylinder of the first filter cartridge 2 and the second filter cartridge 5 is provided with a movable door that opens upwards, so that when blockage occurs in the filter cartridge, it can be immediately unblocked by opening the movable door.

[0054] The primary treatment system for urban suburban sewage in this embodiment is composed of physical treatment structures such as screening, gravity sedimentation and flotation in series, wherein the filtering structure can remove most of the particulate matter with a particle size of more than 100 microns in the sewage; screening can remove larger substances; gravity sedimentation can remove inorganic particles and cohesive organic particles with a relative density greater than 1; flotation can remove particulate matter (oil, etc.) with a relative density less than 1. After the above steps, the primary treatment of sewage is basically completed. The primary treatment is mainly pretreatment, which prepares for the subsequent treatment steps, and then sends it to the secondary treatment, with the secondary treatment as the main body. If necessary, the tertiary treatment, that is, the advanced treatment, is carried out to make the sewage meet the discharge standard or supplement industrial water and urban water supply. The removal effect of its primary treatment can usually reach 30% of EBOD (biodegradable organic matter) and 50% of ESS (suspended solids).

[0055] The primary treatment method for urban suburban sewage, using the treatment system as described above, comprises the following steps:

[0056] Sequentially assemble the grid well 1, the filter cartridge, the sedimentation tank, the aeration tank 6, the flotation tank 7 and the disinfection tank 8;

[0057] When treating the sewage collected in the sewage collection tank, firstly, large-sized solid impurities are removed by using the grid well 1 and most of the particulate matter with a particle size of more than 100 microns is removed by sedimentation. The remaining sewage is respectively passed through the filter cartridge between the grid well 1 and the sedimentation tank and the filter cartridge between the sedimentation tank and the aeration tank 6 to enter the next process;

[0058] When the sewage passes through the filter cartridge, the water flow first drives the hollow rotating frame 10 at the water inlet end to rotate, and at the same time, the hollow rotating frame at the water inlet end can achieve the technical purpose of slow flow. Then, after entering the second half of the filter cartridge, the driving motor drives the hollow rotating frame 16 at the water outlet end to rotate, so as to form a convection in the filter cartridge cavity opposite to the water inlet side, thereby generating a vortex in the gap space 15. This vortex can send the impurities in the sewage that have not been removed by the front-end process into the impurity storage space 13 through the centrifugal force of the vortex, and store them in the impurity storage space 13. The nylon fiber bristles assembled on the spiral blades 11 can further screen and filter out the fine substances in the wastewater, and leave the above-mentioned fine substances in the corresponding two filter cartridges.

[0059] A flow rate sensor is used to correct the rotation speed of the hollow rotating frame 16 at the water outlet to prevent sewage backflow in the filter cartridge. The rotation speed range when driven by a power motor also needs to be controlled within the range of 20 to 40 rpm to ensure that the sewage flow rate in the corresponding filter cartridge is within a better flow rate range.

[0060] The primary treatment system for urban suburban sewage of the present invention can be newly built or rebuilt on the basis of a traditional primary sewage treatment system. It has low construction and maintenance costs and is easy to maintain and adjust during use. In the process of sewage treatment, it can perform multiple static and dynamic combined filtrations on sediment and suspended matter, and has good adaptability to different types of secondary treatment systems and tertiary treatment systems.

[0061] It utilizes an inclined filter cartridge as a water passage to connect the screen well 1, the sedimentation tank, and the sedimentation tank and the aeration tank 6, so that a vortex is formed in the filter cartridge between the screen well 1 and the sedimentation tank and between the sedimentation tank and the aeration tank 6 by using nylon fiber bristles to assist in filtering the sewage in the flow process, which can effectively improve the treatment effect of suspended matter, floating matter and other debris in the sewage, prevent it from entering the secondary treatment system and having an adverse effect on the biological treatment effect of the secondary treatment, ensure the quality of biofilm formation in the bioreactor in the secondary treatment system, ensure the treatment effect of the biological reaction in the secondary treatment system, and effectively reduce the burden of the subsequent tertiary treatment, improve its treatment efficiency and treatment effect on sewage, and have a positive effect on improving the stability, reliability and service life of the subsequent secondary treatment system and tertiary treatment system.

[0062] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A primary treatment system for urban suburban sewage, characterized in that: It comprises a grid well, a sedimentation tank and an aeration tank connected in sequence, and a filter cartridge is arranged between the grid well and the sedimentation tank, and between the sedimentation tank and the aeration tank as a water passage; The filter cartridge is tilted as a whole, with the water inlet side at the top and the water outlet side at the bottom. A combined filter frame matching the cross-section of the inner cavity of the cartridge is arranged in the filter cartridge. The combined filter frame includes two cylindrical hollow rotating frames arranged along the length direction of the filter cartridge. Each of the hollow rotating frames is provided with a spiral blade, which can be rotated by the corresponding hollow rotating frame. The filter cartridge is formed with a gap space between the two hollow rotating frames. Nylon fiber bristles are spirally mounted on the two spiral blades. The nylon fiber bristles mounted on the two spiral blades have opposite rotation directions and are close to the inner cylinder surface of the filter cartridge, so that when the two hollow rotating frames rotate, the combined filter frame can form a counter-rotating flow in the cylinder cavity of the filter cartridge through the spiral thrust of the spirally mounted nylon fiber bristles. Of the two hollow rotating frames, the upper hollow rotating frame is a non-powered structure, which is powered by the flow of water in the filter cartridge, and the lower hollow rotating frame is connected to an external power motor and rotated by the motor drive; The filter cartridge is formed with a circle of annular protrusions at the position of the gap space as a debris storage space, a slag discharge port is provided on the debris storage space, and a non-return structure is correspondingly formed at the base of the ring section of the annular protrusion to prevent debris in the debris storage space from returning to the filter cartridge.

2. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: The non-return structure includes a first baffle and a second baffle that are arranged opposite to each other. The first baffle and the second baffle are both formed of plastic materials. The first baffle and the second baffle together form a V-shaped structure protruding outward. The V-shaped structure has a slit in the middle, and the slit serves as a passage space for debris.

3. A primary treatment system for urban suburban sewage as claimed in claim 2, characterized in that: The grid well is a combined grid well, and a coarse grid, a medium grid and a fine grid are respectively arranged in the well cavity from top to bottom to intercept large pieces of solid pollutants in a suspended or floating state.

4. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: The aspect ratio of the filter cartridge is 5:1-10:1, and the projected contour area of ​​the nylon fiber bristles on the corresponding cross-section of the filter cartridge accounts for 75-85%.

5. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: Of the two hollow rotating frames, the length of the lower hollow rotating frame is 1 / 2 to 2 / 3 of the length of the upper hollow rotating frame, and the porosity of the nylon fiber bristles assembled on the lower hollow rotating frame is smaller than the porosity of the nylon fiber bristles assembled on the upper hollow rotating frame.

6. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: The power motor externally connected to the hollow rotating frame at the lower position is a variable frequency motor, and a water flow velocity sensor is provided at the water inlet end of the filter cartridge to correct the rotation speed of the hollow rotating frame according to the liquid flow velocity in the filter cartridge.

7. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: The nylon fiber bristles are provided with a plurality of mounting holes evenly spaced along the length direction of the spiral blade. The mounting holes are used to assemble and shape the nylon fiber bristles, so that the hollow rotating frame at the water inlet end and the hollow rotating frame at the water outlet end are formed with nylon fiber bristles arranged in a spiral manner to serve as a dynamic screening structure. The nylon fiber bristles extend from the upper and lower surfaces of the mounting holes, and the outer surfaces thereof are abutted against the inner cylinder surface of the filter cartridge body. A hole is reserved at the center of the spiral blade corresponding to the axial position of the filter cartridge body to facilitate the passage of the rotating shaft and to facilitate pressure relief when the water pressure is too high.

8. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: The upper part of the cylinder body of the filter cartridge is provided with a movable door which opens upwards, so that when blockage occurs in the filter cartridge, immediate unblocking can be performed by opening the movable door.

9. A primary treatment system for urban suburban sewage as claimed in claim 1, characterized in that: The filter cartridge maintains an angle of 10-20° with the horizontal plane, and the aeration tank is sequentially connected to a flotation tank and a disinfection tank.

10. A primary treatment method for urban suburban sewage, characterized in that: Using the processing system as claimed in claims 1 to 9, comprising the following steps: Sequentially assemble the grid well, filter cartridge, sedimentation tank, aeration tank, flotation tank and disinfection tank; When treating the sewage collected in the sewage collection tank, firstly, large-sized solid debris is removed by using the grid well and particulate matter with a particle size of more than 100 microns is removed by sedimentation. The remaining sewage is passed through the filter cartridge between the grid well and the sedimentation tank and the filter cartridge between the sedimentation tank and the aeration tank to enter the next process; When sewage passes through the filter cartridge, the water flow first drives the hollow rotating frame at the water inlet end to rotate, and at the same time, the hollow rotating frame at the water inlet end can achieve the technical purpose of slow flow. Then, after entering the second half of the filter cartridge, the driving motor drives the hollow rotating frame at the water outlet end to rotate, and forms a convection opposite to the water inlet side in the cylinder cavity of the filter cartridge, thereby generating a vortex in the gap space. This vortex can send the impurities in the sewage that have not been removed by the front-end process into the storage space through the centrifugal force of the vortex and store them in the impurity storage space. The nylon fiber bristles installed on the spiral blades can further screen and filter out the fine substances in the wastewater, and leave the above fine substances in the corresponding two filter cartridges. A flow rate sensor is used to correct the rotation speed of the hollow rotating frame at the water outlet end to prevent sewage backflow in the filter cartridge. The rotation speed range is controlled within the range of 20 to 40 rpm when driven by a power motor.

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