CN218174751U

CN218174751U - Two-stage A/O activated sludge process sewage treatment system

Info

Publication number: CN218174751U
Application number: CN202222133379.6U
Authority: CN
Inventors: 李子健; 王舜和; 李晓岩
Original assignee: Yuxing Environmental Protection Engineering Co ltd
Current assignee: Yuxing Environmental Protection Engineering Co ltd
Priority date: 2022-08-15
Filing date: 2022-08-15
Publication date: 2022-12-30
Anticipated expiration: 2032-08-15

Abstract

The utility model provides a two-stage AO activated sludge process sewage treatment system relates to sewage treatment technical field. The device comprises a primary treatment system and a secondary treatment system, wherein the primary treatment system comprises a primary anaerobic tank, a primary anoxic tank, a primary aerobic tank and a primary internal reflux well which are sequentially communicated, and the secondary treatment system comprises a secondary mobile tank, a secondary anoxic tank, a secondary aerobic tank and a secondary internal reflux well which are sequentially communicated; a water inlet channel is arranged between the first-stage treatment system and the second-stage treatment system in a penetrating mode, a water outlet channel is arranged on the outer side of the first-stage treatment system and the second-stage treatment system, the water outlet channel is communicated with the second-stage mobile pool through a series connection water inlet point gate, a water outlet channel weir gate is arranged in the water outlet channel, an internal backflow channel is arranged below the water inlet channel, the two-stage aerobic pool is communicated with inlets of the two-stage backflow wells respectively, outlets of the two-stage backflow wells are communicated with the internal backflow channel respectively, and the internal backflow channel flows to the two-stage anoxic pool. The switching of the series-parallel mode of the two-stage system is realized by controlling the weir gate and the gate, and the switching of the sewage treatment process when the water quality standard changes is solved.

Description

Two-stage A/O activated sludge process sewage treatment system

Technical Field

The utility model relates to a sewage treatment technical field particularly, relates to a two-stage AO activated sludge process sewage treatment system.

Background

The rapid development of society and the acceleration of urban industrialization process do not promote the improvement of the utilization rate of the water resources, but the serious water eutrophication phenomenon comes along with the development of society. In order to solve the problem of water environment pollution caused by economic development, a series of measures are also taken in multiple countries in the world, such as improving the sewage discharge standard, changing a drainage system, perfecting the construction of sewage pipe networks and sewage plants, and the like. How to economically and effectively remove nitrogen and phosphorus in eutrophic sewage and make the water quality reach the standard and discharge becomes a key problem in the sewage treatment industry of China.

In order to achieve the aims of denitrification and dephosphorization of town sewage and standard discharge, an anaerobic/anoxic/aerobic process (A) is adopted ² O) is widely popularized and applied in China. As shown in fig. 1, conventional a ² The sewage in the/O process goes through three stages of anaerobic treatment, anoxic treatment and aerobic treatment from water inlet to water outlet, and phosphorus accumulating bacteria, nitrifying bacteria and denitrifying bacteria in the sewage play respective roles in different environments to realize the effects of nitrogen and phosphorus removal. However, A is ² In the aspect of carbon source utilization in the nitrogen and phosphorus removal process of the/O process system, the competitive relationship of denitrifying bacteria and phosphorus accumulating bacteria to the carbon source in sewage exists, so that the nitrogen and phosphorus removal is difficult to meet at the same time, and the anoxic zone is positioned in the middle area of the process, and the denitrification is in a negative position on the carbon source distribution, so that the nitrogen removal effect of the system can be influenced. Tradition A ² Nitrate nitrogen generated in the aerobic zone at the tail end of the O process can directly flow into a subsequent secondary sedimentation tank, so in order to achieve the effect of effective denitrification, nitrification liquid is required to be arranged at the tail end of the aerobic zone for refluxing to remove redundant nitrate nitrogen. However, the nitrate existing in the sludge returned to the anaerobic zone can inhibit the physiological activity of the phosphorus-accumulating bacteria in the anaerobic zone, and the phosphorus removal efficiency is reduced. Therefore, the above disadvantages limit the conventional A ² The wide application of the/O process only makes the process suitable for sewage plants with low requirements on nitrogen and phosphorus removal.

To meet the more stringent total nitrogen requirements of effluent discharge standards, tradition A ² The transformation process of/O, the "Bardenpho" process, is applied in the tradition A ² An anoxic tank and an aerobic tank are added at the rear end of the/O process, and a carbon source is added into the anoxic tank. The oxygen-poor tank additionally arranged at the rear end aims at NO in the mixed liquid flowing from the front-end aerobic tank ₃ And N carries out denitrification nitrogen removal under the action of denitrifying bacteria, and simultaneously, a carbon source is added in the anoxic section to provide electrons for denitrification. Meanwhile, the aerobic section additionally arranged at the rear end can oxidize the carbon source which is not used up, simultaneously improve the DO concentration in the effluent mixed liquor and improve the sedimentation performance of the sludge in the secondary sedimentation tank. The Bardenpho process provides a better idea for biochemical denitrification, but because a carbon source needs to be added in an anoxic section additionally arranged at the rear end, the adding amount of the carbon source is difficult to control and is often added excessively, the cost for operation is higher.

On the other hand, the existing tradition A in sewage treatment plants ² the/O process is generally designed to be a mode of multi-series parallel operation, and sewage enters each group A respectively ² Processing in an/O processing system. A plurality of series are connected in parallel, so that when part of equipment is overhauled, the rest series can work, and the influence of equipment maintenance on the operation of a sewage treatment plant is reduced. However, in this mode, the wastewater treatment plant lacks flexibility in being exposed to future effluent treatment due to the conventional A ² the/O system is only suitable for sewage plants with low requirements on nitrogen and phosphorus removal, so that the existing biochemical tank needs to be modified or advanced treatment facilities are added after the biochemical tank when the sewage plants are upgraded and modified, the engineering investment is increased, and the operation of the sewage plants is inconvenient. In addition, a are connected in parallel in multiple series ² the/O process causes the underground pipeline of the sewage plant to be complicated, is difficult to regulate and control and maintain the pipeline, is inconvenient for the operation of the sewage plant, and has certain difficulty in design, construction and later reconstruction.

Therefore, in view of the deficiencies of the prior art, it would be desirable to provide a two-stage a/O activated sludge process wastewater treatment system that addresses the problems set forth above in the background.

SUMMERY OF THE UTILITY MODEL

The true bookAiming at the defects in the prior art, the novel sewage treatment system adopting the two-stage A/O activated sludge process can provide a solution, utilizes a special internal pool type layout structure design, controls the operation mode of a biochemical pool according to the change of an inflow water quality standard or an outflow water quality standard, and adopts the technical scheme that ² The mode of the/O parallel connection and the mode of the two-stage A/O series connection are switched, so that the problem that sewage plants cannot flexibly deal with different water quantities and different water qualities in different periods or in later lifting is solved.

The embodiment of the utility model provides a two-stage AO activated sludge process sewage treatment system, including the primary treatment system and the secondary treatment system that set up side by side, the primary treatment system includes the one-level anaerobism pond, one-level oxygen deficiency pond, one-level good oxygen pond and the one-level internal reflux well that communicate in proper order, the external one-level sludge return pipe in one-level anaerobism pond, the secondary treatment system includes the flexible pond of second grade, second grade oxygen deficiency pond, second grade good oxygen pond and the second grade internal reflux well that communicate in proper order, the flexible pond of second grade external second grade sludge return pipe; stirrers are arranged in the primary anaerobic tank, the primary anoxic tank, the secondary mobile tank and the secondary anoxic tank;

an inlet channel is arranged between the primary treatment system and the secondary treatment system in a penetrating manner, two water outlets of the inlet channel are respectively communicated with the primary anaerobic tank and the secondary mobile tank through a first gate and a second gate, and a water inlet of the inlet channel is connected with a water inlet pipe;

the water outlets of the primary aerobic pool and the secondary aerobic pool are respectively communicated with the water outlet channel through a first water outlet weir and a second water outlet weir, the water outlet of the water outlet channel is connected with a water outlet pipe, the water outlet channel is communicated with the secondary mobile pool through a series connection water inlet point gate, a water outlet channel weir door is further arranged in the water outlet channel, and the series connection water inlet point gate and the second water outlet weir are separated by the water outlet channel weir door;

the below of inlet channel is equipped with in one-level backward flow canal and second grade backward flow canal, one-level good oxygen pond with second grade good oxygen pond respectively with in the one-level backward flow well with the entry intercommunication of backward flow well in the second grade, the backward flow well in the one-level with the export of backward flow well in the second grade is respectively through first backflow point and second backflow point the backward flow canal in the one-level with the entry intercommunication of backward flow canal in the second grade, the export of backward flow canal in the one-level with one-level oxygen deficiency pond intercommunication, the export of backward flow canal in the second grade respectively with the second grade motor-driven pond with second grade oxygen deficiency pond intercommunication.

In some embodiments of the present invention, the first-stage anoxic tank and the second-stage anoxic tank are at least one provided respectively.

In some embodiments of the present invention, the first-stage anoxic tank and the second-stage anoxic tank are respectively provided in three.

In some embodiments of the present invention, the primary anaerobic tank, the primary anoxic tank, the secondary mobile tank, and the secondary anoxic tank are rectangular tanks having an aspect ratio of less than or equal to 1.5.

In some embodiments of the present invention, the first-stage aerobic tank and the second-stage aerobic tank are of a gallery type and have a length and a width greater than those of the first-stage anaerobic tank, the first-stage anoxic tank, the second-stage mobile tank and the second-stage anoxic tank.

In some embodiments of the present invention, the agitator is a vertical circulation agitator.

In some embodiments of the present invention, the first-stage aerobic tank and the second-stage aerobic tank are separated from the first-stage internal reflux well and the second-stage internal reflux well by a partition wall, and a first wall-through pump and a second wall-through pump are respectively arranged on the partition wall.

In some embodiments of the utility model, the one-level anaerobism pond is three two liang of first-level oxygen deficiency ponds set up side by side, the second grade moves the pond and is three two liang of second grade oxygen deficiency ponds set up side by side.

In some embodiments of the present invention, the water inlet channel, the first-stage internal reflux channel and the second-stage internal reflux channel transversely penetrate through two of the first-stage anaerobic tank and three of the first-stage anoxic tank and the second-stage mobile tank and three of the second-stage anoxic tank, which are arranged side by side.

Compared with the prior art, the embodiment of the utility model has following advantage or beneficial effect at least:

the utility model discloses a primary treatment system and secondary treatment system that set up side by side, the primary treatment system includes the one-level anaerobism pond, one-level oxygen deficiency pond, one-level good oxygen pond and the one-level internal reflux well that communicate in proper order, the external one-level sludge reflux pipe of one-level anaerobism pond, the secondary treatment system includes the flexible pond of second grade, second grade oxygen deficiency pond, second grade good oxygen pond and the second grade internal reflux well that communicate in proper order, the flexible pond of second grade external second grade sludge reflux pipe; stirrers are arranged in the primary anaerobic tank, the primary anoxic tank, the secondary mobile tank and the secondary anoxic tank; a water inlet channel is arranged between the primary treatment system and the secondary treatment system in a penetrating manner, two water outlets of the water inlet channel are respectively communicated with the primary anaerobic tank and the secondary mobile tank through a first gate and a second gate, and a water inlet of the water inlet channel is connected with a water inlet pipe; the water outlets of the primary aerobic pool and the secondary aerobic pool are respectively communicated with the water outlet channel through a first water outlet weir and a second water outlet weir, the water outlet of the water outlet channel is connected with a water outlet pipe, the water outlet channel is communicated with the secondary mobile pool through a series connection water inlet point gate, a water outlet channel weir door is further arranged in the water outlet channel, and the series connection water inlet point gate and the second water outlet weir are separated by the water outlet channel weir door; the below of inlet channel is equipped with in one-level backward flow canal and second grade backward flow canal, one-level good oxygen pond with second grade good oxygen pond respectively with in the one-level backward flow well with the entry intercommunication of backward flow well in the second grade, the backward flow well in the one-level with the export of backward flow well in the second grade is respectively through first backflow point and second backflow point the backward flow canal in the one-level with the entry intercommunication of backward flow canal in the second grade, the export of backward flow canal in the one-level with one-level oxygen deficiency pond intercommunication, the export of backward flow canal in the second grade respectively with the second grade motor-driven pond with second grade oxygen deficiency pond intercommunication. By two-stage A/O treatmentThe system can realize a 'two-stage A/O series connection' mode or 'A' by controlling a weir gate and a gate in a biochemical pool according to different water inlet amount, water quality or water outlet standards ² The switching of the/O parallel mode brings certain energy conservation and great convenience to the operation of a sewage plant; meanwhile, under an A/O series mode, sewage respectively enters a primary treatment system and a secondary treatment system in a step-by-step water inlet mode according to a certain proportion, namely the secondary A/O treatment system treats the effluent of the primary A/O system and also receives raw water of a part of proportion of sewage, so that a carbon source is provided for the denitrification reaction of a secondary anoxic tank, and the defect that a large amount of carbon source needs to be added in a post anoxic zone in a Bardenphos process is effectively overcome; in addition, when a certain unit device in the biochemical pool needs to be overhauled, the operation mode of the biochemical pool can be adjusted to be A ² the/O parallel connection mode is adopted, a water inlet point gate on the water inlet channel is controlled, serial water inlet is suspended for maintenance, and other serial water inlet can be treated normally, so that convenience is brought to operation.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on these drawings without inventive efforts.

FIG. 1 shows a conventional scheme A in the prior art ² The structure of the/O system is schematic;

FIG. 2 is a schematic structural diagram of a two-stage A/O activated sludge process sewage treatment system according to an embodiment of the present invention;

FIG. 3 is a flow chart showing the steps of a two-stage A/O activated sludge process for treating wastewater according to an embodiment of the present invention.

Reference numerals: 100. a primary treatment system; 110. a primary anaerobic tank; 111. a first gate; 120. A first-stage anoxic tank; 130. a primary aerobic tank; 131. a first effluent weir; 140. a primary internal return well; 141. a first through-wall pump; 142. a first reflux point; 200. a secondary processing system; 210. a secondary mobile pool; 211. a second gate; 212. a water inlet point gate is connected in series; 220. a secondary anoxic tank; 230. A secondary aerobic tank; 231. a second effluent weir; 240. a secondary internal return well; 241. a second through-wall pump; 242. a second reflow point; 300. a stirrer; 400. a water inlet channel; 500. a water inlet pipe; 600. A water outlet channel; 610. a water outlet channel weir gate; 700. a water outlet pipe; 800. a primary sludge return pipe.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that, if the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear based on the directions or positional relationships shown in the drawings, or the directions or positional relationships that the products of the present invention are usually placed when used, it is only for convenience of description of the present invention and simplification of description, but not for indication or suggestion that the indicated device or element must have a specific direction, be constructed and operated in a specific direction, and therefore, the present invention should not be construed as being limited thereby.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not require that the components be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present invention, it should be further noted that unless explicitly stated or limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

Examples

Referring to fig. 1-2, fig. 1 shows a conventional a in the prior art ² A schematic structure diagram of the/O system; FIG. 2 is a schematic structural diagram of a two-stage A/O activated sludge process sewage treatment system according to an embodiment of the present invention;

the embodiment of the utility model provides a two-stage AO activated sludge process sewage treatment system specifically includes: the system comprises a primary treatment system 100 and a secondary treatment system 200 which are arranged in parallel, wherein the primary treatment system 100 comprises a primary anaerobic tank 110, a primary anoxic tank 120, a primary aerobic tank 130 and a primary internal return well 140 which are sequentially communicated, the primary anaerobic tank 110 is externally connected with a primary sludge return pipe 800, the secondary treatment system 200 comprises a secondary maneuvering tank 210, a secondary anoxic tank 220, a secondary aerobic tank 230 and a secondary internal return well 240 which are sequentially communicated, and the secondary maneuvering tank 210 is externally connected with a secondary sludge return pipe; stirrers 300 are arranged in the primary anaerobic tank 110, the primary anoxic tank 120, the secondary mobile tank 210 and the secondary anoxic tank 220;

a water inlet channel 400 is arranged between the primary treatment system 100 and the secondary treatment system 200 in a penetrating manner, two water outlets of the water inlet channel 400 are respectively communicated with the primary anaerobic tank 110 and the secondary mobile tank 210 through a first gate 111 and a second gate 211, and a water inlet of the water inlet channel 400 is connected with a water inlet pipe 500;

the outer sides of the primary treatment system 100 and the secondary treatment system 200 are provided with an outlet channel 600, the water outlets of the primary aerobic tank 130 and the secondary aerobic tank 230 are respectively communicated with the outlet channel 600 through a first outlet weir 131 and a second outlet weir 231, the water outlet of the outlet channel 600 is connected with a water outlet pipe 700, the outlet channel 600 is communicated with the secondary mobile tank 210 through a series-connection inlet point gate 212, an outlet channel weir door 610 is further arranged in the outlet channel 600, and the outlet channel weir door 610 separates the series-connection inlet point gate 212 from the second outlet weir 231;

a first-stage internal reflux channel and a second-stage internal reflux channel are arranged below the water inlet channel 400, the first-stage aerobic tank 130 and the second-stage aerobic tank 230 are respectively communicated with inlets of the first-stage internal reflux well 140 and the second-stage internal reflux well 240, outlets of the first-stage internal reflux well 140 and the second-stage internal reflux well 240 are respectively communicated with inlets of the first-stage internal reflux channel and the second-stage internal reflux channel through a first reflux point and a second reflux point, an outlet of the first-stage internal reflux channel is communicated with the first-stage anoxic tank 120, and an outlet of the second-stage internal reflux channel is respectively communicated with the second-stage motorized tank 210 and the second-stage anoxic tank 220.

Next, a two-stage A/O activated sludge process sewage treatment system in the present exemplary embodiment will be further described.

In an implementation manner of this embodiment, the primary treatment system 100 includes a primary anaerobic tank 110, a primary anoxic tank 120, a primary aerobic tank 130, and a primary internal recirculation well 140, which are sequentially connected, the primary anaerobic tank 110 is externally connected with a primary sludge recirculation pipe 800, the secondary treatment system 200 includes a secondary mobile tank 210, a secondary anoxic tank 220, a secondary aerobic tank 230, and a secondary internal recirculation well 240, which are sequentially connected, and the secondary mobile tank 210 is externally connected with a secondary sludge recirculation pipe; in the present embodiment, preferably, there are three primary anoxic tanks 120 and three secondary anoxic tanks 220, where the primary anoxic tank 110 and the three primary anoxic tanks 120 are arranged in parallel in pairs, and the secondary mobile tank 210 and the three secondary anoxic tanks 220 are arranged in parallel in pairs; the first-stage anaerobic tank 110, the first-stage anoxic tank 120, the second-stage mobile tank 210 and the second-stage anoxic tank 220 are internally provided with stirrers 300.

A water inlet channel 400 is arranged between the primary treatment system 100 and the secondary treatment system 200 in a penetrating manner, the water inlet channel 400, the primary internal backflow channel and the secondary internal backflow channel are transversely arranged between the primary anaerobic tank 110 and the three primary anoxic tank 120 which are arranged in parallel in a penetrating manner, and the secondary mobile tank 210 and the three secondary anoxic tank 220 in a penetrating manner, two water outlets of the water inlet channel 400 are respectively communicated with the primary anaerobic tank 110 and the secondary mobile tank 210 through a first gate 111 and a second gate 211, a water inlet pipe 500 is connected with a water inlet port 400, namely sewage pretreated by a sewage plant flows into the water inlet channel 400 from the water inlet pipe 500, and then respectively enters the primary anaerobic tank 110 and the secondary mobile tank 210 through two water outlets of the water inlet channel 400, wherein the first gate 111 and the second gate 211 are used for controlling the opening and closing of the two water inlets;

the outer sides of the primary treatment system 100 and the secondary treatment system 200 are provided with an outlet channel 600, the water outlets of the primary aerobic tank 130 and the secondary aerobic tank 230 are respectively communicated with the outlet channel 600 through a first outlet weir 131 and a second outlet weir 231, the water outlet of the outlet channel 600 is connected with a water outlet pipe 700, that is, the sewage treated by the aerobic tanks of the two treatment systems can respectively flow out from the water outlet pipe 700 through the outlet channel 600, wherein the first outlet weir 131 and the second outlet weir 231 are used for controlling whether the two aerobic tanks are respectively communicated with the outlet channel 600; the outlet channel 600 is communicated with the secondary motorized pool 210 through the serial inlet point gate 212, an outlet channel weir gate 610 is further arranged in the outlet channel 600, the outlet channel weir gate 610 separates the serial inlet point gate 212 from the second outlet weir 231, when the primary treatment system 100 and the secondary treatment system 200 are connected in series, the serial inlet point gate 212 is opened to communicate the outlet channel 600 with the secondary motorized pool 210, and the outlet channel weir gate 610 is closed, so that the sewage of the primary treatment system 100 does not flow out of the outlet channel 600, but only flows into the secondary motorized pool 210 of the secondary treatment system 200;

a first-stage internal backflow channel and a second-stage internal backflow channel are arranged below the water inlet channel 400, the first-stage aerobic tank 130 and the second-stage aerobic tank 230 are respectively communicated with inlets of the first-stage internal backflow well 140 and the second-stage internal backflow well 240, outlets of the first-stage internal backflow well 140 and the second-stage internal backflow well 240 are respectively communicated with inlets of the first-stage internal backflow channel and the second-stage internal backflow channel through a first backflow point 142 and a second backflow point 242, an outlet of the first-stage internal backflow channel is communicated with the first-stage anoxic tank 120, and outlets of the second-stage internal backflow channel are respectively communicated with the second-stage motorized tank 210 and the second-stage anoxic tank 220, namely, sewage of the two treatment systems flows into the water outlet channel 600 to be discharged after being treated by the aerobic tanks, wherein the mixed liquid can also circulate inside the system, flows into the backflow channel through the backflow well, and flows into the anoxic tank again to be treated. The primary aerobic tank 130 and the secondary aerobic tank 230 are separated from the primary internal reflux well 140 and the secondary internal reflux well 240 by partition walls, and a first wall-penetrating pump 141 and a second wall-penetrating pump 241 are respectively arranged on the two partition walls in a penetrating manner. Based on the internal reflux well and the tail end of the aerobic tank are connected through a partition wall, the internal reflux wall-penetrating pump is arranged on the partition wall, the internal reflux of the mixed liquid adopts a channel form, and the wall-penetrating pump saves a part of pipelines compared with the traditional submersible sewage pump.

It should be noted that the utility model discloses a "two-stage AO" system accessible changes the entry point of sewage and controls the flexible operational mode who changes whole biochemical pond of backward flow, and according to the difference that goes out the water standard requirement, biochemical pond accessible weir gate realizes "two-stage AO establishes ties", "A/O series connection" under the same condition of dwell time with the control of gate ² The switching of the operation mode of the/O parallel connection brings convenience to the operation of the sewage plant, the secondary mobile pool 210 is used as a change medium for the serial-parallel switching of the primary treatment system 100 and the secondary treatment system 200, and when the system is in the state of A ² In the/O parallel mode (i.e., the two systems are connected in parallel in an anaerobic-anoxic-aerobic series), the secondary mobile tank 210 serves as an anaerobic tank to ensure the dephosphorization efficiency of each series when connected in parallel, and at the moment, the two wall-through pumps pump the nitrified liquid at the tail end of each series of aerobic tanks to the current series of anoxic tanks through the internal reflux channel to ensure the total nitrogen removal rate; when the system is in a 'two-stage A/O series' mode, the first compartment in the first-stage treatment system 100 serves as an anaerobic tank to provide a phosphorus release environment for phosphorus accumulating bacteria, and meanwhile, the first-stage internal reflux is stopped, and the second-stage internal reflux is started from the first stage internal refluxThe tail end of the secondary aerobic tank 230 returns to the mobile tank through a through-wall pump, the internal return flow of the aerobic zone can bring part of dissolved oxygen into the mobile tank to cause the mobile tank to be changed from an anaerobic environment to an anoxic environment, and at the moment, the secondary mobile tank 210 serves as an anoxic tank. The phosphorus accumulating bacteria in the sewage in the anaerobic stage release phosphorus in the anaerobic environment to enable the phosphorus accumulating bacteria to reach a starvation state, the phosphorus accumulating bacteria absorb a large amount of phosphorus in the sewage in the aerobic stage, the denitrifying bacteria reproduce faster in the anoxic environment in the anoxic stage to become dominant bacteria, nitrite and nitrate in the sewage, namely nitrate nitrogen, are denitrifying to be nitrogen gas to be released, organic carbon in the sewage and ammonia nitrogen are degraded in the aerobic stage, the ammonia nitrogen is oxidized to be the nitrate nitrogen, and microorganisms such as the phosphorus accumulating bacteria, the nitrifying bacteria and the denitrifying bacteria in the sewage in the three stages play respective roles in different environments to realize nitrogen and phosphorus removal.

In one specific implementation, the operational mode is flexibly adjusted according to the water quality change of the inlet water or when the water quality standard of the outlet water is increased, "A ² the/O parallel operation mode is suitable for the condition that the earlier stage effluent standard of some sewage plants is low and is not improved temporarily, and the two-stage A/O series operation mode is suitable for the condition that the effluent standard of sewage plants is high (especially for TN emission standard improvement) after the later stage upgrading and transformation of the sewage plants, the two-stage A/O series process is composed of two groups of anoxic/aerobic sections which are connected in series, when the system of the utility model operates according to the two-stage A/O series operation mode, the second-stage mobile pool 210 serves as an anoxic pool, sewage flows into the water inlet channel 400 from the water inlet pipe 500, the proportion of water inlet of each stage is controlled through the opening and closing degree of the first water inlet gate 111 and the second water inlet gate 211 and respectively enters each stage of system for treatment, the sewage simultaneously enters the first-stage anaerobic pool 110 and the second-stage mobile pool 210 according to a certain proportion, the water inlet point gate 212 of the series connection keeps an open state, the water outlet channel weir gate 610 is closed, and the first wall penetrating pump 141 in the first backflow well keeps closed. At the moment, the first stage A/O of the internal reflux system of the whole biochemical pond is closed, the second stage A/O is opened, the second wall-penetrating pump 241 in the second reflux well is opened, the mixed liquid flows back to the secondary mobile pond 210 from the reflux well through the internal reflux channel, the effluent of the first stage aerobic pond 130 flows into the secondary mobile pond 210 through the effluent channel 600 to bring a certain amount of dissolved oxygen, and at the moment, the secondary mobile pond210 is used as an anoxic tank, the effluent of the second-stage A/O system flows into the effluent channel 600 from the second effluent weir 231 and finally flows out of the system through the water outlet pipe 700, and the return sludge of the secondary sedimentation tank flows back to the first-stage anaerobic tank 110 of the system through the first-stage sludge return pipe 800; when the system is marked with' A ² When the/O parallel mode is operated, the secondary mobile pool 210 is used as an anaerobic pool, sewage enters the first gate 111 and the second gate 211 of the water inlet point in equal proportion, the gate 212 of the water inlet point in series connection is closed, the weir gate 610 of the water outlet channel is opened, and two groups A of the water inlet points A and B of the water outlet channel A are connected in series ² Effluent of the/O system enters the effluent channel 600 from the first effluent weir 131 and the second effluent weir 231 respectively and finally flows into the water outlet pipe 700, meanwhile, two groups of internal reflux systems in the biochemical pond start to operate, an internal reflux wall-through pump in the reflux well enables nitrified liquid at the tail end of each series of aerobic ponds to respectively reflux to the series of anoxic ponds through the internal reflux channel below the water inlet channel 400, and the primary internal reflux channel and the secondary internal reflux channel are separated in the first-stage system and the second-stage system and are not communicated with each other; when in parallel connection, the return sludge respectively returns to the first-stage anaerobic tank 110 of the system through the first-stage sludge return pipe 800 and returns to the second-stage mobile tank 210 of the system through the second-stage sludge return pipe.

In one embodiment of this embodiment, the primary anaerobic tank 110, the primary anoxic tank 120, the secondary mobile tank 210 and the secondary anoxic tank 220 are rectangular tanks, and have an aspect ratio of 1.5 or less; the above-mentioned one-level aerobic tank 130 and second grade aerobic tank 230 are corridor type pool types, and its length and width all are greater than the length and width of one-level anaerobism pond 110, one-level oxygen deficiency pond 120, second grade mobile pool 210 and second grade oxygen deficiency pond 220, and the setting up of a plurality of rectangle ponds makes the agitator 300 dismouting of being convenient for, and corridor type's aerobic tank can avoid the short-term flow, maintain good flow state and help in the pond sewage and microorganism to mix.

As an example, when the length-width ratio is 1:1, that is, the tank is a square tank, the stirrer 300 adopts a vertical circulation stirrer 300, which has a good stirring effect on the square tank with a small length-width ratio, eliminates a stirring dead angle, makes the space distribution of the activated sludge in the tank uniform, and effectively reduces the sedimentation of the activated sludge in the anaerobic and anoxic tank; when the tank is a rectangular tank other than a square tank, other stirrers may be used.

The utility model discloses a "two-stage AO" system utilizes the design of special inside pond type overall arrangement structure, especially its inlet channel 400, outlet channel 600, the arrangement form of internal reflux canal, the arrangement of inlet channel 400 is located in the middle of whole biochemical system, run through each grade of entire system, and can set up the water inlet point at the anaerobism pond of first order and the oxygen deficiency pond of second level, outlet channel 600 communicates each grade aerobic section and the outer oxygen deficiency section of second level, the weir gate on outlet channel 600 is closed when establishing ties, outlet channel 600 both had been regarded as the outlet channel 600 of last level and also was the inlet channel 400 of next level system at the same time at this moment; when the parallel operation is performed, the weir gate on the water outlet channel 600 is opened, and the water inlet of the anoxic section on the water outlet channel 600 is closed, at this time, the water outlet channel 600 is a main water outlet channel for collecting each series A ² The two channels are arranged to functionally meet the series-parallel conversion of the system, and the spatial layout is neat and beautiful. The internal reflux channel is positioned under the water inlet channel 400 and is respectively communicated with the reflux well and the anoxic tank of the first-stage system, the reflux well and the motorized tank of the second-stage system and the first grid of the second-stage anoxic zone to form the characteristic that each stage of anoxic/aerobic sections can be connected in series and in parallel, and the operation mode of the biochemical tank can be controlled by the gate and the weir gate on the 600 channels of the water inlet and outlet channel ² The switching between the/O parallel mode and the two-stage A/O series mode solves the problem that the sewage plant can not flexibly deal with different water quantities and water qualities in different periods or the later period of upgrading (especially the improvement of total nitrogen index), namely the problem can be solved without increasing the investment of additionally modifying the biochemical tank, so that the sewage undergoes two-stage anoxic/aerobic treatment in the biochemical tank, the removal rate of pollutants is greatly improved, the modification investment is saved, and good conditions are provided for the operation of the sewage plant; in addition, when a certain unit device in the biochemical pool needs to be overhauled, the operation mode of the biochemical pool can be adjusted to be A ² The mode of the/O parallel connection is adopted, the water inlet point gate on the water inlet channel 400 is controlled, the serial water inlet is temporarily stopped to be maintained, and other serial water inlet can be normally treated, so that convenience is brought to operation.

If the biochemical pool of a sewage treatment plant adopts the arrangement form of the utility model, the recent scale of the sewage treatment plant is smaller,the effluent standard is a first-grade A standard, the emission requirements on nitrogen and phosphorus are not high, and then 'A' can be adopted ² The operation mode of the/O parallel connection enables the total nitrogen removal rate to be about 60 percent, and the standard discharge can be achieved by matching with the subsequent advanced treatment. The sewage plant can only operate one series when the initial water amount of the sewage plant is small, the number of the series of operation can be increased when the recent water amount gradually rises, and the whole series of operation is performed when the sewage plant is not in the initial water amount, so that the early operation cost of the sewage plant is saved. When the effluent quality of the sewage plant is raised to the standard of class III on the ground surface in the later period, the A of the biochemical pool can be used ² the/O parallel mode is switched to a two-stage A/O series mode, the two anoxic/aerobic sections are connected in parallel, the denitrification effect of the sewage is improved, the total nitrogen removal rate is about 70%, meanwhile, the sewage enters from the anoxic zones at all stages according to a certain design proportion, the carbon source in the systems at all stages is ensured to be sufficient, the sewage treatment effect is improved under the condition that the hydraulic retention time is kept to be the same, and the operation mode facing different water quality standards of inlet and outlet water can be provided for sewage plants.

Referring to fig. 3, fig. 3 is a flow chart illustrating steps of a two-stage a/O activated sludge process for sewage treatment according to an embodiment of the present invention;

the embodiment of the utility model provides a two-stage AO activated sludge process sewage treatment process specifically includes following step:

s110, switching the primary treatment system 100 and the secondary treatment system 200 into a parallel mode or a series mode according to the change of the inlet water quality standard or the outlet water quality standard of the sewage;

s120, when the water quality of inlet water or the water quality of outlet water is lower than a preset standard, switching the primary treatment system 100 and the secondary treatment system 200 into a parallel mode, adjusting the dissolved oxygen in the secondary mobile tank 210 into an anaerobic tank, and discharging sewage through an outlet channel 600 after anaerobic, anoxic and aerobic and reflux process treatment are sequentially carried out in the primary treatment system 100 and the secondary treatment system 200 respectively;

s130, when the water quality of the inlet water or the water quality of the outlet water is higher than a preset standard, the primary treatment system 100 and the secondary treatment system 200 are switched to be in a series connection mode, the dissolved oxygen in the secondary mobile tank 210 is adjusted to be an anoxic tank, and the sewage is subjected to anaerobic, anoxic, aerobic, anoxic and aerobic treatment and backflow treatment sequentially through the primary treatment system 100 and the secondary treatment system 200 and then is discharged through the water outlet channel 600.

Next, a two-stage A/O activated sludge process for wastewater treatment in the present exemplary embodiment will be further described.

In an embodiment of the present invention, as step S120, "when the water quality of the inlet water or the water quality standard of the outlet water is lower than the predetermined standard, the primary treatment system 100 and the secondary treatment system 200 are switched to be in parallel connection, the dissolved oxygen in the secondary mobile tank 210 is adjusted to be an anaerobic tank, and the sewage is sequentially treated by anaerobic, anoxic and aerobic and reflux processes in the primary treatment system 100 and the secondary treatment system 200, and then discharged through the outlet channel 600" specifically includes the following steps.

When the amount of influent water is low or the influent concentration is low and below a predetermined level, the series entry point gates 212 are closed, the effluent channel weir 610 is opened, and the amount of dissolved oxygen in the secondary mobile tank 210 is adjusted to an anaerobic tank to switch the primary treatment system 100 and the secondary treatment system 200 to a parallel mode, as described in the following steps.

As an example, sewage enters the primary anaerobic tank 110 and the secondary mobile tank 210 from the water inlet channel 400, the primary anaerobic tank 110 releases phosphorus in raw sewage, the sewage sequentially flows into the plurality of subsequent primary anoxic tanks 120 for denitrification, the sewage flows into the primary aerobic tank 130 for oxidative degradation of organic carbon and oxidative ammonia nitrogen, then a mixed solution flows out through the water outlet channel 600, part of the mixed solution also circulates in the system, and the mixed solution flows back into the primary anoxic tank 120 through the primary internal return well 140 to generate nitrogen gas through denitrification again for discharge; after the sewage in the secondary mobile tank 210 is subjected to denitrification in the secondary anoxic tank 220 and oxidative degradation in the secondary aerobic tank 230, the mixed liquor flows out through the water outlet channel 600, wherein the mixed liquor also circulates in the system and flows back into the secondary anoxic tank 220 through the secondary internal reflux well 240 to perform denitrification again to discharge nitrogen.

In an embodiment of the present invention, as step S130, "when the water quality of the inlet water or the water quality standard of the outlet water is higher than the predetermined standard, the primary treatment system 100 and the secondary treatment system 200 are switched to be in the series mode, the dissolved oxygen in the secondary mobile tank 210 is adjusted to be the anoxic tank, and the sewage is discharged through the outlet channel 600 after being sequentially processed by the primary treatment system 100 and the secondary treatment system 200 through the anaerobic, anoxic, aerobic, anoxic and aerobic and reflux processes" as follows.

When the effluent amount is larger, the effluent concentration is higher or the total nitrogen discharge standard is improved and is higher than the preset standard, the serial water inlet point gate 212 is opened, the effluent channel weir gate 610 and the first through-wall pump 141 are closed, and the dissolved oxygen in the secondary mobile pool 210 is adjusted to be an anoxic pool, so that the primary treatment system 100 and the secondary treatment system 200 are switched to be in a serial mode.

As an example, sewage enters the primary anaerobic tank 110 and the secondary mobile tank 210 from the water inlet channel 400, the sewage treated by the primary anaerobic tank 110 enters the secondary mobile tank 210 through the water outlet channel 600 after being treated by the primary anoxic tank 120 and the primary aerobic tank 130, at this time, the secondary mobile tank 210 serves as an anoxic tank, and is treated by the secondary anoxic tank 220 and the secondary aerobic tank 230, a mixed solution flows out through the water outlet channel 600, that is, the mixed solution flowing out through the primary aerobic tank 130 enters the four secondary anoxic tanks 220 for denitrification, denitrification is performed on nitrate nitrogen from the primary aerobic tank 130, ammonia nitrogen and organic carbon in the sewage are oxidized by the secondary aerobic tank 230 and then discharged, part of the mixed solution can be circulated in the system, and flows back to the secondary mobile tank 210 through the secondary internal backflow well 240 for denitrification again; the sewage entering the secondary mobile tank 210 is treated by the secondary mobile tank 210, the secondary anoxic tank 220 and the secondary aerobic tank 230 respectively, and then the mixed liquid is discharged through the water outlet channel 600, wherein the mixed liquid can realize circulation in the system and flows back to the secondary mobile tank 210 through the secondary internal return well 240 for treatment. It should be noted that when connected in series, the secondary mobile tank 210 receives a portion of raw water of the sewage, and mainly provides a carbon source for the denitrification reaction in the second-stage anoxic zone. In the series mode, the sewage entering the primary anaerobic tank 110 and the secondary mobile tank 210 is discharged in proportion.

The embodiment of the utility model provides a pair of two-stage AO activated sludge process sewage treatment system, for the sewage plant in daily operation meet with quality of water undulant lead to the condition that the effluent is not up to standard (especially for total nitrogen index), or when upgrading the transformation for sewage plant in the future, during the improvement of total nitrogen emission requirement, provide a design idea of biochemical pond, provide a two-stage AO system that both can establish ties and can parallelly connected operation, adopt the form of arranging of the inside pond type of special biochemical pond, with two parallelly connected A ² the/O series are integrated in one system, and are converted into a series multistage A/O process by controlling a weir gate and a gate when the water quality concentration of inlet water is high or the water quality standard of outlet water is improved (especially total nitrogen), so that two series of A connected in parallel are realized ² The free switching between the/O operation mode and the two-stage A/O operation mode in series brings great convenience to the operation of the sewage plant, and when the water inflow of the sewage plant is small in the early stage of construction, the parallel A operation can be adjusted ² The serial number of the/O system saves certain energy consumption and has extremely high use value.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A two-stage A/O activated sludge process sewage treatment system is characterized by comprising a primary treatment system and a secondary treatment system which are arranged in parallel, wherein the primary treatment system comprises a primary anaerobic tank, a primary anoxic tank, a primary aerobic tank and a primary internal return well which are sequentially communicated, the primary anaerobic tank is externally connected with a primary sludge return pipe, the secondary treatment system comprises a secondary maneuvering tank, a secondary anoxic tank, a secondary aerobic tank and a secondary internal return well which are sequentially communicated, and the secondary maneuvering tank is externally connected with a secondary sludge return pipe; stirrers are arranged in the primary anaerobic tank, the primary anoxic tank, the secondary mobile tank and the secondary anoxic tank;

a water inlet channel is arranged between the primary treatment system and the secondary treatment system in a penetrating manner, two water outlets of the water inlet channel are respectively communicated with the primary anaerobic tank and the secondary mobile tank through a first gate and a second gate, and a water inlet of the water inlet channel is connected with a water inlet pipe;

2. The two-stage a/O activated sludge process wastewater treatment system of claim 1 wherein at least one of said primary anoxic tank and said secondary anoxic tank is provided.

3. The two-stage a/O activated sludge process wastewater treatment system of claim 2 wherein there are three of said primary anoxic tanks and three of said secondary anoxic tanks, respectively.

4. The two-stage a/O activated sludge process wastewater treatment system of claim 1 wherein said primary anaerobic tank, said primary anoxic tank, said secondary mobile tank and said secondary anoxic tank are rectangular tank shaped with an aspect ratio of 1.5 or less.

5. The two-stage a/O activated sludge process wastewater treatment system of claim 1 wherein said primary aerobic tank and said secondary aerobic tank are of a gallery type and have a length and width greater than the length and width of said primary anaerobic tank, said primary anoxic tank, said secondary mobile tank, and said secondary anoxic tank.

6. The two-stage a/O activated sludge process wastewater treatment system of claim 1 wherein the agitator is a vertical loop agitator.

7. The two-stage a/O activated sludge process wastewater treatment system according to claim 1, wherein said primary aerobic tank and said secondary aerobic tank are separated from said primary internal recirculation well and said secondary internal recirculation well by a partition wall, and a first wall-penetrating pump and a second wall-penetrating pump are respectively disposed through both said partition walls.

8. The two-stage a/O activated sludge process wastewater treatment system of claim 1 wherein said primary anaerobic tank and said three primary anoxic tanks are arranged in parallel, and said secondary mobile tank and said three secondary anoxic tanks are arranged in parallel, in pairs.

9. The two-stage a/O activated sludge process wastewater treatment system of claim 8 wherein the inlet channel, the first-stage internal return channel and the second-stage internal return channel are transversely disposed through the first-stage anaerobic tank and the three first-stage anoxic tanks, and between the second-stage mobile tank and the three second-stage anoxic tanks, in pairs.