CN113880254B

CN113880254B - Sewage treatment process of multistage AO cooperative biological rotating disc

Info

Publication number: CN113880254B
Application number: CN202111335074.7A
Authority: CN
Inventors: 柴伟贺; 王伟伟; 左浩; 苏延强; 纳守军
Original assignee: Qinghai Jieshen Environmental Technology Co ltd
Current assignee: Qinghai Jieshen Environmental Technology Co ltd
Priority date: 2021-11-11
Filing date: 2021-11-11
Publication date: 2023-06-09
Anticipated expiration: 2041-11-11
Also published as: CN113880254A

Abstract

The invention relates to a sewage treatment process of a multistage AO cooperative biological rotating disc, which comprises the following steps: s100: after pretreatment, sewage is divided into a plurality of parts to enter a biochemical treatment unit in a segmented mode, and the biochemical treatment unit sequentially comprises a group of anaerobic-aerobic modules and a plurality of groups of anoxic-aerobic modules; the anaerobic-aerobic module comprises an anaerobic tank and an aerobic tank, and the anoxic-aerobic module comprises an anoxic tank and an aerobic tank; s200: one part of sewage is subjected to anaerobic and aerobic treatment sequentially through the anaerobic-aerobic modules, and the other parts of sewage enter a plurality of groups of anoxic-aerobic modules in a segmented manner to be subjected to anoxic and aerobic treatment sequentially; s300: the mixed liquid of each aerobic tank is discharged into an anoxic tank at the downstream side, and nitrified liquid in the last aerobic tank flows back to the anaerobic tank or the first anoxic tank; s400: after being treated by the biochemical treatment unit, the sewage enters a secondary sedimentation tank for treatment, and sludge discharged from the secondary sedimentation tank flows back to the pretreatment tank and the anaerobic tank respectively.

Description

Sewage treatment process of multistage AO cooperative biological rotating disc

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to a sewage treatment process of a multistage AO cooperative biological rotating disc.

Background

The existing biochemical sewage treatment method mainly comprises a BBR process, an A2O process, a multi-stage AO process, an MBR process and the like, and has the respective characteristics and application conditions. Wherein, the BBR technology uses Bacillus bacteria (Bacillus) as dominant bacteria, and adopts a combined biochemical treatment technology combining a biomembrane method (BBR device) and an activated sludge method (BBR biochemical pool). A multistage AO sewage treatment technology is that a plurality of groups of anoxic tanks and aerobic tanks are connected in series for biochemical treatment, and meanwhile, sewage enters each group of anoxic tanks in a segmented way respectively and is mixed with sewage treated by the previous group of aerobic tanks, so that the biochemical treatment efficiency is improved. The A2O process is to execute an anaerobic-anoxic-aerobic flow, and is formed by serially connecting an anaerobic tank, an anoxic tank and an aerobic tank, so that NH is improved ₃ -N removal efficiency.

With the continuous importance of people on environmental treatment and water safety, environmental protection departments increase the supervision force of effluent discharge of sewage treatment plants and gradually increase the discharge standard, and part of constructed sewage treatment plants running cannot meet the new discharge standard by utilizing the traditional biochemical treatment process, and the traditional process is used for continuously upgrading and reforming, so that the construction land, equipment and the like are increased, the cost is high, the reforming period is long, and the shutdown reformation is also needed. How to fully utilize the existing sewage treatment equipment and process, improve BOD removal rate, meet the requirements of new emission standards and are the problems faced by the technicians in the field.

Disclosure of Invention

Aiming at the problems, the invention provides a sewage treatment process of a multistage AO cooperative biological rotating disc, which is innovated on the basis of the traditional multistage AO process and BBR process, utilizes a plurality of existing biochemical reaction tanks of the multistage AO to implement the repeated processes of anaerobism-aerobiotic-anoxic-aerobiotic, fully carries out the nitrification and denitrification reaction, adopts BBR process in each group of anaerobism-aerobiotic and anoxic-aerobiotic biochemical tanks, namely adopts biological rotating disc to mount microbial films in the anaerobism tank and the anoxic tank, effectively degrades the organic matters, ammonia nitrogen, total nitrogen and total phosphorus of the inlet water, and improves the pollutant removal efficiency; and treating sewage by using the activated sludge in an oxidation pond. The sewage treatment process of the multistage AO collaborative biological rotating disc can not only enable the effluent quality to meet higher emission standards, but also realize the non-stop production transformation of sewage plants, has short transformation period, and solves the problems that most sewage plants cannot stop production, cannot newly increase occupied area, has long transformation period and the like in the process of upgrading and transformation.

The sewage treatment process of the multistage AO cooperative biological rotating disc comprises the following steps:

s100: after pretreatment, sewage is divided into a plurality of parts to enter a biochemical treatment unit in a segmented mode, and the biochemical treatment unit sequentially comprises a group of anaerobic-aerobic modules and a plurality of groups of anoxic-aerobic modules; the anaerobic-aerobic module comprises an anaerobic tank and an aerobic tank, and the anoxic-aerobic module comprises an anoxic tank and an aerobic tank;

BBR biological turntables are arranged in the anaerobic tank and the anoxic tank, and activated sludge is arranged in each aerobic tank;

s200: one part of sewage is subjected to anaerobic and aerobic treatment sequentially through the anaerobic-aerobic modules, and the other parts of sewage enter a plurality of groups of anoxic-aerobic modules in a segmented manner to be subjected to anoxic and aerobic treatment sequentially;

s300: the mixed liquid of each aerobic tank is discharged into an anoxic tank at the downstream side, and nitrified liquid in the last aerobic tank flows back to the anaerobic tank or the first anoxic tank;

s400: after being treated by the biochemical treatment unit, the sewage enters a secondary sedimentation tank for treatment, and sludge discharged from the secondary sedimentation tank flows back to the pretreatment tank and the anaerobic tank respectively;

s500: the sewage is treated by a secondary sedimentation tank, and then is subjected to advanced treatment and disinfection treatment in sequence, so that the sewage can reach the discharge standard.

Optionally, the biochemical treatment unit comprises a group of anaerobic-aerobic modules and a plurality of groups of anoxic-aerobic modules which are sequentially connected, the anaerobic-aerobic modules comprise an anaerobic tank and an aerobic tank which are sequentially connected, and the anoxic-aerobic modules comprise an anoxic tank and an aerobic tank which are sequentially connected.

Optionally, in step S200, the first part of sewage enters the anaerobic-aerobic module to be subjected to anaerobic treatment and aerobic treatment in sequence; meanwhile, other parts of sewage are in one-to-one correspondence with the groups of anoxic-aerobic modules, and the other parts of sewage respectively enter the corresponding anoxic-aerobic modules, are mixed with sewage in the corresponding anoxic tanks, and are subjected to anoxic and aerobic treatment in sequence.

Optionally, step S300 is specifically that after the first part of sewage passes through the anaerobic-aerobic modules, the first part of sewage sequentially enters a plurality of groups of anoxic-aerobic modules on the downstream side, and is sequentially subjected to anoxic and aerobic treatments; meanwhile, the mixed liquid in the aerobic tank of each anoxic-aerobic module enters the anoxic tank of the next anoxic-aerobic module, and is continuously mixed with the sewage newly entering the anoxic tank in the step S200, and then anoxic treatment is carried out; and the nitrifying liquid in the last aerobic tank flows back to the anaerobic tank or the first anoxic tank, and the reflux ratio is 50-300% of the total water inflow. Preferably, the reflux ratio is 100-250%. And the reflux ratio of the nitrified liquid is flexibly adjusted according to the total nitrogen concentration of the inflow water, so that the denitrification reaction is fully carried out, and the high-efficiency degradation of the total nitrogen is ensured.

Optionally, in step S400, the sludge discharged from the secondary sedimentation tank is discharged into a sludge reflux pump room, and then a part of residual sludge in the sludge reflux pump room is refluxed to the pretreatment tank, wherein the reflux amount is 1-20 per mill, so that biological deodorization of the whole process is realized, and a deodorizing system is not required to be newly added separately; and then, refluxing part of the residual sludge in the sludge reflux pump house to the anaerobic tank, wherein the reflux amount is 50-100%.

In the traditional multistage and multistage AO process, sewage flowing into the anoxic section of each stage from the water inlet pipe is segmented, so that the interference of the dissolved oxygen concentration and the pH value of the effluent of the front stage on the anoxic treatment of the rear stage is reduced, and a sufficient carbon source is provided for denitrifying bacteria. According to the invention, when the mixed solution in the anaerobic zone or the anoxic zone enters the aerobic tank, the influence of dissolved oxygen concentration, pH value and a small amount of microorganisms of the inlet water on the next-stage aerobic tank still exists, a period of operation is required to stabilize the state of the next-stage aerobic tank, and the treatment effect of a region close to the water inlet of the next-stage aerobic tank is not ideal; the problems are particularly prominent when sewage pollution load fluctuation is large.

Optionally, a first regulating tank is arranged between the anaerobic tank and the aerobic tank and between the anoxic tank and the aerobic tank, the first regulating tank sequentially comprises an oxygen-deficient area, a plurality of dissolved oxygen areas and regulating areas along the water flow direction, different areas are separated by a baffle, and effluent water treated by the anaerobic tank or the anoxic tank enters the oxygen-deficient area;

the top of each dissolved oxygen area is provided with a split flow dissolved oxygen device, and the effluent of the former area enters the split flow dissolved oxygen device of the latter dissolved oxygen area, and the dissolved oxygen enters the latter dissolved oxygen area after split flow;

the top of the regulating area is provided with a flow divider, the mixed solution of the aerobic tank at the downstream side of the first regulating tank enters the regulating area through the flow divider, and the sewage of the last dissolved oxygen area at the upstream side of the regulating area enters the regulating area and is mixed with the mixed solution of the aerobic tank;

the water outlet of the first regulating tank is arranged on the downstream side wall surface of the regulating area and is lower than the flow divider in height, and the water outlet of the first regulating tank is connected with the downstream aerobic tank.

Further optionally, the water inlet of the first regulating tank is arranged at the middle upper part of the upstream side wall surface of the oxygen-deficient zone, the oxygen-deficient zone is a closed space, and the downstream side of the oxygen-deficient zone is provided with a first baffle plate to separate the oxygen-deficient zone from the first dissolved oxygen zone;

the upper part of the first partition plate is provided with an oxygen-deficient area water outlet which is connected with a diversion oxygen dissolving device at the top of the first oxygen dissolving area;

all the dissolved oxygen areas and the regulating areas are open spaces, and a blower is preferably arranged to purge, so that the dissolved oxygen amount of the dissolved oxygen areas is improved;

an oxygen dissolving area water outlet is formed in the upper part of the downstream side partition plate of the oxygen dissolving area and is connected with a diversion oxygen dissolving device at the top of the next oxygen dissolving area; the upper part of the baffle plate at the downstream side of the last dissolved oxygen area is provided with a dissolved oxygen area water outlet, the height of the dissolved oxygen area water outlet is between the diverter and the water outlet of the first regulating tank, and the sewage of the last dissolved oxygen area directly enters the regulating area.

Optionally, the diversion oxygen dissolving device comprises a water outlet tank, a first water inlet pipe and a water separator from top to bottom, wherein the top of the water outlet tank is open, and a water outlet of an oxygen-deficient area or a water outlet of an oxygen-dissolving area of a previous oxygen-dissolving area is connected with the water outlet tank;

the top end of the first water inlet pipe is connected with the bottom of the water outlet tank, and the bottom end of the first water inlet pipe is connected with the water inlet of the water separator;

the middle part in the water knockout drum is equipped with the breakwater, and the breakwater is perpendicular to first inlet tube, and the water knockout drum bottom evenly sets up a plurality of hole for water spraying.

Drawings

FIG. 1 is a flow chart of a sewage treatment process of the multi-stage AO cooperative biological rotating disc;

FIG. 2 is a schematic diagram of the structure of a first regulating reservoir;

FIG. 3 is a schematic diagram of a split stream oxygen dissolver.

In the drawing, a 1-pretreatment tank, a 2-primary sedimentation tank, a 3-anaerobic tank, a 4-aerobic tank, a 5-anoxic tank, a 6-secondary sedimentation tank, a 7-sludge reflux pump room, an 8-sludge concentration tank, a 9-sludge concentration room, a 10-primary sedimentation tank sludge pump room, a 11-first regulating tank, 1101-oxygen-deficient areas, 1102-dissolved oxygen areas, 1103-regulating areas, 1104-partition boards, 1105-oxygen-deficient area water outlets, 1106-dissolved oxygen area water outlets, 12-split flow oxygen dissolving devices, 1201-water outlet tanks, 1202-first water inlet pipes, 1203-water separators, 1204-water baffle plates and 13-splitters.

Detailed Description

The sewage treatment process of the multistage AO cooperative biological rotating disc provided in this embodiment, as shown in fig. 1, includes the following steps:

s100: after pretreatment, sewage is divided into a plurality of parts to enter a biochemical treatment unit in a segmented mode, and the biochemical treatment unit sequentially comprises a group of anaerobic-aerobic modules and a plurality of groups of anoxic-aerobic modules; the anaerobic-aerobic module comprises an anaerobic tank 3 and an aerobic tank 4, and the anoxic-aerobic module comprises an anoxic tank 5 and an aerobic tank 4;

BBR biological turntables are arranged in the anaerobic tank 3 and the anoxic tank 5, and activated sludge is arranged in each aerobic tank 4;

s300: the mixed liquid of each aerobic tank 4 is discharged into an anoxic tank 5 at the downstream side, and the nitrified liquid in the last aerobic tank 4 flows back into the anaerobic tank or the first anoxic tank 5;

s400: after being treated by the biochemical treatment unit, the sewage enters a secondary sedimentation tank 6 for treatment, and sludge discharged by the secondary sedimentation tank 6 flows back to the pretreatment tank 1 and the anaerobic tank 3 respectively;

s500: the sewage is treated by the secondary sedimentation tank 6 and then is subjected to advanced treatment and disinfection treatment in sequence, and then the sewage can reach the discharge standard.

Optionally, in step S100, the pretreatment step of the sewage specifically includes: the sewage is discharged into the biochemical treatment unit after being treated by the pretreatment tank 1 and the primary sedimentation tank 2 in sequence; when suspended matters in the sewage are less, the sewage can be directly discharged into the biochemical treatment unit from the pretreatment tank 1 through an overrun pipeline.

Optionally, a grid perpendicular to the water flow direction is arranged in the pretreatment tank 1 and is used for filtering a larger volume of suspended matters in the sewage; coagulant and/or flocculant can be added into the pretreatment tank 1.

Optionally, the biochemical treatment unit comprises a group of anaerobic-aerobic modules and a plurality of groups of anoxic-aerobic modules which are sequentially connected, the anaerobic-aerobic modules comprise an anaerobic tank 3 and an aerobic tank 4 which are sequentially connected, and the anoxic-aerobic modules comprise an anoxic tank 5 and an aerobic tank 4 which are sequentially connected.

Optionally, the dominant strain on the BBR biological rotating disc is bacillus, the BBR biological rotating disc carries out microbial film hanging under the action of the bacillus, and simultaneously forms an oxygen dissolving gradient of oxygen deficiency outside and inside the biological film, thereby realizing synchronous nitrification and denitrification processes in the BBR biological rotating disc and improving the sewage treatment efficiency.

In one embodiment of the present invention, the biochemical treatment unit includes an anaerobic tank 3, a first aerobic tank 4, a first anoxic tank 5, a second aerobic tank 4, a second anoxic tank 5, a third aerobic tank 4, a third anoxic tank 5, and a fourth aerobic tank 4, which are sequentially connected.

Optionally, in step S200, the first part of sewage enters the anaerobic-aerobic module to be subjected to anaerobic treatment and aerobic treatment in sequence; meanwhile, other parts of sewage are in one-to-one correspondence with the groups of anoxic-aerobic modules, and the other parts of sewage respectively enter the corresponding anoxic-aerobic modules, are mixed with the sewage in the corresponding anoxic tank 5, and are subjected to anoxic and aerobic treatment in sequence.

Optionally, step S300 is specifically that after the first part of sewage passes through the anaerobic-aerobic modules, the first part of sewage sequentially enters a plurality of groups of anoxic-aerobic modules on the downstream side, and is sequentially subjected to anoxic and aerobic treatments; meanwhile, the mixed liquid in the aerobic tank 4 of each anoxic-aerobic module enters the anoxic tank 5 of the next anoxic-aerobic module, and is continuously mixed with the sewage newly entering the anoxic tank 5 in the step S200, and then anoxic treatment is carried out; the nitrifying liquid in the last aerobic tank 4 flows back to the anaerobic tank 3 or the first anoxic tank 5.

In one embodiment of the invention, a first portion of sewage enters the anaerobic tank 3, while a second portion of sewage enters the first anoxic tank 5, a third portion of sewage enters the second anoxic tank 5, and a fourth portion of sewage enters the third anoxic tank 5; the first part of sewage sequentially passes through the biochemical treatment of the anaerobic tank 3 and the first aerobic tank 4, then enters the first anoxic tank 5, is mixed with the second part of sewage, and then sequentially passes through the biochemical treatment of the first anoxic tank 5 and the second aerobic tank 4; the mixed solution obtained after the mixing and treatment of the first part of sewage and the second part of sewage enters the second anoxic tank 5, is mixed with the third part of sewage, and then sequentially passes through the biochemical treatment of the second anoxic tank 5 and the third aerobic tank 4; the mixed solution obtained after the first part, the second part and the third part of sewage are mixed and treated enters the third anoxic tank 5, and after being mixed with the fourth part of sewage, the mixed solution sequentially passes through the biochemical treatment of the third anoxic tank 5 and the fourth aerobic tank 4, and the part of the nitrified solution obtained after the treatment flows back to the anaerobic tank 3 or the first anoxic tank 5, wherein the backflow proportion is 50-300% of the total water inflow. Preferably, the reflux ratio is 100-250%.

Optionally, in step S200, a carbon source nutrient solution is added to the anaerobic tank 3.

Optionally, in step S400, the sludge discharged from the secondary sedimentation tank 6 is discharged into a sludge recirculation pump room 7, and then a part of the residual sludge in the sludge recirculation pump room 7 is recirculated to the pretreatment tank 1, wherein the recirculation amount is 1-20%; and then, part of the residual sludge in the sludge reflux pump room 7 is refluxed to the anaerobic tank 3, and the reflux amount is 50-100%.

Further optionally, the sludge reflux pump room 7 is sequentially connected with the sludge concentration tank 8 and the sludge concentration room 9, and is used for carrying out reduction treatment on the residual sludge.

Optionally, the primary sludge in the primary sedimentation tank 2 is discharged into a primary sedimentation tank sludge pump room 10, and the primary sedimentation tank sludge pump room 10 is connected with the sludge concentration tank 8 to carry out reduction treatment on the primary sludge.

As shown in fig. 2, optionally, a first adjusting tank 11 is arranged between the anaerobic tank 3 and the aerobic tank 4 and between the anoxic tank 5 and the aerobic tank 4, the first adjusting tank 11 sequentially comprises an oxygen-deficient zone 1101, a plurality of dissolved oxygen zones 1102 and an adjusting zone 1103 along the water flow direction, different zones are separated by a partition 1104, and the effluent water treated by the anaerobic tank 3 or the anoxic tank 5 enters the oxygen-deficient zone 1101;

the top of each dissolved oxygen area 1102 is provided with a split flow oxygen dissolving device 12, the effluent of the former area enters the split flow oxygen dissolving device 12 of the latter dissolved oxygen area 1102, and the dissolved oxygen enters the latter dissolved oxygen area 1102 after split flow;

the top of the regulating area 1103 is provided with a flow divider 13, the mixed solution of the aerobic tank 4 at the downstream side of the first regulating tank 11 enters the regulating area 1103 through the flow divider 13, and the sewage of the last dissolved oxygen area 1102 at the upstream side of the regulating area 1103 enters the regulating area 1103 and is mixed with the mixed solution of the aerobic tank 4;

the water outlet of the first regulating tank 11 is arranged on the downstream side wall surface of the regulating area 1103, and the height of the water outlet is lower than that of the flow divider 13, and the water outlet of the first regulating tank 11 is connected with the downstream aerobic tank 4.

Further optionally, the water inlet of the first regulating tank 11 is disposed at the middle upper part of the upstream side wall surface of the oxygen-deficient zone 1101, the oxygen-deficient zone 1101 is a closed space, and a first partition plate is disposed at the downstream side of the oxygen-deficient zone 1101 to separate the oxygen-deficient zone 1101 from the first dissolved oxygen zone 1102;

an oxygen-deficient area water outlet 1105 is arranged at the upper part of the first partition board, and the oxygen-deficient area water outlet 1105 is connected with a diversion oxygen dissolving device 12 at the top of the first oxygen dissolving area 1102;

all the dissolved oxygen areas 1102 and the regulating areas 1103 are open spaces, and a blower is preferably arranged to blow so as to improve the dissolved oxygen;

an oxygen dissolving area water outlet 1106 is arranged at the upper part of the downstream side partition plate of the oxygen dissolving area 1102, and the oxygen dissolving area water outlet 1106 is connected with the diversion oxygen dissolving device 12 at the top of the next oxygen dissolving area 1102; an oxygen dissolving area water outlet 1106 is arranged at the upper part of a partition 1104 at the downstream side of the last oxygen dissolving area 1102, the height of the oxygen dissolving area water outlet is between the diverter 13 and the water outlet of the first regulating tank 11, and sewage in the last oxygen dissolving area 1102 directly enters the regulating area 1103.

The sewage treated by the anaerobic tank 3 or the anoxic tank 5 enters an anoxic zone 1101 from a water inlet of a first regulating tank 11, a small amount of anaerobic microorganisms or anoxic microorganisms and partial suspended matters carried by sedimentation under the action of gravity, and then enters a diversion oxygen dissolver 12 of an adjacent first oxygen dissolving zone 1102 from a water outlet 1105 of the anoxic zone on a first partition plate; due to the sedimentation and retention of part of anaerobic microorganisms or anoxic microorganisms in the oxygen-deficient zone 1101 and the closed environment of the oxygen-deficient zone 1101, sewage entering the oxygen-deficient zone 1101 can be continuously subjected to anaerobic or anoxic treatment. After the sewage sequentially enters the diversion oxygen dissolving device 12 of each oxygen dissolving area 1102, the dissolved oxygen is increased in the open environment, suspended matters are precipitated at the same time, and then the sewage enters the last adjusting area 1103, part of mixed liquid flows back to the adjusting area 1103 through the diverter 13 by the aerobic tank 4 at the downstream side, is mixed with the sewage passing through the oxygen dissolving area 1102, and is input into the aerobic tank 4 at the downstream after being mixed.

Optionally, the split-flow oxygen dissolving device 12 comprises a water outlet tank 1201, a first water inlet pipe 1202 and a water separator 1203 from top to bottom, wherein the top of the water outlet tank 1201 is open, and an oxygen-poor region water outlet 1105 or an oxygen-dissolving region water outlet 1106 of the previous oxygen-dissolving region is connected with the water outlet tank 1201;

the top end of the first water inlet pipe 1202 is connected with the bottom of the water outlet tank 1201, and the bottom end is connected with the water inlet of the water separator 1203;

the middle part in the water knockout drum 1203 is provided with a water baffle 1204, the water baffle 1204 is perpendicular to the first water inlet pipe 1202, and a plurality of water spray holes are uniformly arranged at the bottom of the water knockout drum 1203.

Preferably, the water outlet tank 1201 has a flat cubic structure, which is beneficial to the water body with a larger surface area and sufficient dissolved oxygen.

Preferably, a gravity spring valve is arranged in the first water inlet pipe 1202, when the weight of the water body in the water outlet tank 1201 reaches the threshold value of the gravity spring valve, the gravity spring valve is jacked up, and the water body in the water outlet tank 1201 enters the water separator 1203; when the water volume in the water outlet tank 1201 is reduced, the gravity spring valve is automatically closed, and water is stored again. The gravity spring valve can use ordinary gravity spring valve in market, for example one side swing joint first inlet tube 1202 inner wall of single valve, the opposite side is unsettled, the top of spring is connected to the bottom of single valve, the first inlet tube 1202 inner wall is connected to the bottom of spring, the spring slope sets up, the first inlet tube inner wall of connecting spring is in same one side with the first inlet tube inner wall of connecting single valve.

The sewage of the oxygen-deficient zone 1101 or the previous dissolved oxygen zone 1102 overflows to the water outlet tank 1201 of the split stream oxygen dissolver 12, and before reaching the threshold of the gravity spring valve, the sewage is stored in the water outlet tank 1201 and dissolved oxygen in the open environment; when the threshold value of the gravity spring valve is reached, sewage in the water outlet tank 1201 is input into the water separator 1203 through the first water inlet pipe 1202, flows to the bottom uniformly under the blocking effect of the water baffle 1204, and flows from the oxygen dissolving area 1102 corresponding to the water spray Kong Penru.

Optionally, a flushing device and a sludge discharge port are arranged at the bottom of the first regulating tank 11 and used for cleaning the sludge deposited at the bottom of the first regulating tank 11, and the sludge discharge port is connected with the sludge reflux pump house 7.

Optionally, the diverter 13 includes a second water inlet pipe and a plurality of nozzles, the second water inlet pipe is horizontally arranged, and the bottom is uniformly provided with a plurality of nozzles. The mixed liquor of the aerobic tank 4 flows back and is uniformly distributed by the flow divider 13 and flows into the regulating area 1103, so that the mixed liquor of the aerobic tank 4 is convenient to be fully mixed with sewage which is fully dissolved with oxygen from the dissolved oxygen area 1102, and the pH value of the mixed liquor of the aerobic tank 4 is approximate.

Claims

1. The sewage treatment process of the multistage AO cooperative biological rotating disc is characterized by comprising the following steps of:

s500: the sewage is treated by a secondary sedimentation tank, and then is subjected to advanced treatment and disinfection treatment in sequence, so that the sewage can reach the discharge standard;

a first regulating tank is arranged between the anaerobic tank and the aerobic tank and between the anoxic tank and the aerobic tank, the first regulating tank sequentially comprises an oxygen-deficient area, a plurality of dissolved oxygen areas and regulating areas along the water flow direction, the different areas are separated by a baffle, and effluent water treated by the anaerobic tank or the anoxic tank enters the oxygen-deficient area;

the water outlet of the first regulating tank is arranged on the downstream side wall surface of the regulating area and is lower than the flow divider in height, and the water outlet of the first regulating tank is connected with the downstream aerobic tank;

the split-flow oxygen-dissolving device comprises a water outlet tank, a first water inlet pipe and a water separator from top to bottom, wherein the top of the water outlet tank is open, and a water outlet of an oxygen-deficient area or a water outlet of an oxygen-dissolving area of a previous oxygen-dissolving area is connected with the water outlet tank;

the middle part in the water separator is provided with a water baffle which is perpendicular to the first water inlet pipe, and a plurality of water spray holes are uniformly formed in the bottom of the water separator;

the water outlet tank is of a flat cube structure, a gravity spring valve is arranged in the first water inlet pipe, when the weight of water in the water outlet tank reaches the threshold value of the gravity spring valve, the gravity spring valve is jacked up, the water in the water outlet tank enters the water separator, uniformly flows to the bottom under the blocking effect of the water baffle, and flows out of the dissolved oxygen area corresponding to the water spray Kong Penru; when the water quantity in the water outlet tank is reduced, the gravity spring valve is automatically closed, and water is stored again.

2. The sewage treatment process according to claim 1, wherein the biochemical treatment unit comprises a group of anaerobic-aerobic modules and a plurality of groups of anoxic-aerobic modules which are sequentially connected, the anaerobic-aerobic modules comprise an anaerobic tank and an aerobic tank which are sequentially connected, and the anoxic-aerobic modules comprise an anoxic tank and an aerobic tank which are sequentially connected.

3. The sewage treatment process according to claim 2, wherein step S200 is specifically that a first portion of sewage enters the anaerobic-aerobic module to be subjected to anaerobic treatment and aerobic treatment in sequence; meanwhile, other parts of sewage are in one-to-one correspondence with the groups of anoxic-aerobic modules, and the other parts of sewage respectively enter the corresponding anoxic-aerobic modules, are mixed with sewage in the corresponding anoxic tanks, and are subjected to anoxic and aerobic treatment in sequence.

4. The sewage treatment process according to claim 3, wherein step S300 is specifically that the first portion of sewage passes through the anaerobic-aerobic modules and then sequentially enters the plurality of groups of anaerobic-aerobic modules on the downstream side to sequentially perform anaerobic and aerobic treatments; meanwhile, the mixed liquid in the aerobic tank of each anoxic-aerobic module enters the anoxic tank of the next anoxic-aerobic module, and is continuously mixed with the sewage newly entering the anoxic tank in the step S200, and then anoxic treatment is carried out.

5. The sewage treatment process according to claim 4, wherein the nitrified liquid in the last aerobic tank is returned to the anaerobic tank or the first anoxic tank at a ratio of 50 to 300%.

6. The sewage treatment process according to claim 1, wherein in step S400, the sludge discharged from the secondary sedimentation tank is discharged into a sludge recirculation pump house, and a part of the surplus sludge in the sludge recirculation pump house is recirculated to the pretreatment tank, and the recirculation amount is 1-20%.

7. The wastewater treatment process according to claim 1, wherein the water inlet of the first regulating reservoir is provided at the middle upper part of the upstream side wall surface of the oxygen-deficient zone, the oxygen-deficient zone is a closed space, and a first partition plate is provided at the downstream side thereof to separate the oxygen-deficient zone from the first dissolved oxygen zone;

all dissolved oxygen areas and regulating areas are open spaces.

8. The sewage treatment process according to claim 7, wherein an oxygen dissolving zone water outlet is formed in the upper part of the downstream side partition plate of the oxygen dissolving zone, and the oxygen dissolving zone water outlet is connected with a diversion oxygen dissolving device at the top of the next oxygen dissolving zone; the upper part of the baffle plate at the downstream side of the last dissolved oxygen area is provided with a dissolved oxygen area water outlet, the height of the dissolved oxygen area water outlet is between the diverter and the water outlet of the first regulating tank, and the sewage of the last dissolved oxygen area directly enters the regulating area.