CN106745744B - Sewage treatment method and sewage treatment system - Google Patents

Abstract

The invention discloses a sewage treatment method and a sewage treatment system for removing nitrogen and having a good nitrate nitrogen removal effect. The method comprises the following operations: dividing sewage to be treated into a first water body and a second water body; secondly, introducing the first water body into an aerobic denitrification device for carrying out first denitrification treatment aiming at removing ammonia nitrogen, and then leading out a third water body containing nitrate nitrogen generated by the first denitrification treatment from the aerobic denitrification device; and thirdly, respectively introducing and mixing the second water body and the third water body in an anaerobic denitrification device to perform second denitrification treatment aiming at nitrate nitrogen removal, and then leading out a fourth water body subjected to the second denitrification treatment from the anaerobic denitrification device.

Description

Sewage treatment method and sewage treatment system

technical field

The present invention relates to a sewage treatment method and system, in particular to a method and system for urban domestic sewage treatment.

Background technique

At present, anaerobic, aerobic, anoxic and aerobic treatment processes are commonly used in the treatment of urban domestic sewage. The sewage treatment method disclosed in Chinese patent document CN101423294A belongs to this kind of method.

The target water treated by this method can generally reach COD≤50mg/L, BOD5≤10mg/L, ammonia nitrogen≤5(8)mg/L, total nitrogen≤15mg/L, total phosphorus≤0.5mg/L, SS≤ However, the concentration of total nitrogen and total phosphorus in the target water body is generally close to the upper limit specified by the discharge standard; and the total nitrogen in the target water body is generally nitrate nitrogen.

Although the research on technical solutions to significantly improve the removal effect of total nitrogen and total phosphorus has been neglected in the art because the above methods can meet the discharge standards, the inventor of the present application is still aware of the importance of developing a sewage treatment technology with better effect , in order to meet the practical urgency of raising pollutant emission targets.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a sewage treatment method and a sewage treatment system for removing nitrogen and removing nitrate nitrogen with better effect.

The sewage treatment method of the present invention comprises the following operations:

1. Divide the sewage to be treated into the first water body and the second water body;

2. Introduce the first water body into the aerobic nitrogen removal device to carry out the first nitrogen removal treatment whose target includes the removal of ammonia nitrogen, and then draw out the third water body containing nitrate nitrogen produced by the first nitrogen removal treatment from the aerobic nitrogen removal device ;

3. The second water body and the third water body are respectively introduced and mixed in the anaerobic nitrogen removal device to carry out the second nitrogen removal treatment whose target includes the removal of nitrite nitrogen, and then the second water removal treatment is carried out from the anaerobic nitrogen removal device. After the fourth body of water.

The technical idea of the above method is derived from the specific analysis of the reasons for the poor nitrogen removal effect of the existing sewage treatment methods described in the background art and the targeted technical innovation made based on the analysis conclusions.

Since the emission standards have requirements for the concentration of total nitrogen and ammonia nitrogen in the target water body, for sewage treatment methods using anaerobic, aerobic, anoxic, aerobic treatment processes or similar treatment processes, ammonia nitrogen is mainly at the front end. The oxygen section is converted into nitrate nitrogen by nitrification and removed; total nitrogen (including nitrate nitrogen) is mainly removed by denitrification in the anoxic section following the aerobic section. The principle of denitrification is that denitrifying bacteria use nitrogen in nitrate as an electron acceptor under the condition of extremely low dissolved oxygen concentration or hypoxia to oxidize organic matter, thereby reducing nitrogen in nitrate to nitrogen. Therefore, denitrification requires a certain concentration of COD as a carbon source for denitrification. However, since the anaerobic and aerobic sections before the anoxic section have consumed a large amount of COD in the sewage, the denitrification effect is affected by the lack of carbon sources in the anoxic section. , aerobic treatment process or sewage treatment methods similar to it are often not effective in removing total nitrogen.

The above-mentioned sewage treatment method of the present invention first divides the sewage to be treated into a first water body and a second water body, and then introduces the first water body into the aerobic nitrogen removal device for the first nitrogen removal treatment whose target includes removing ammonia nitrogen. The lower ammonia nitrogen is converted into nitrate nitrogen by nitrification and removed, and a large amount of COD in the first water body is oxidized and removed; after that, the third water body enters the anaerobic nitrogen removal device, and in addition, enters the anaerobic nitrogen removal device. There is a second body of water that is diverted from the sewage to be treated. Since the second water body is derived from the sewage to be treated and retains a higher concentration of COD, the COD concentration of the second water body after mixing with the third water body is higher than the COD concentration of the third water body. In the second nitrogen removal treatment, the carbon source is better guaranteed, and the nitrate nitrogen in the water can be effectively removed through denitrification.

The above-mentioned sewage treatment method of the present invention may further include the following operations: 4. leading the fourth water body back to the aerobic nitrogen removal device; and 5. extracting the fifth water body as the source of the target water body from the aerobic nitrogen removal device. Therefore, the concentrations of ammonia nitrogen and total nitrogen in the fifth water body can be controlled more effectively.

The sewage treatment system of the present invention includes:

a sewage diversion control device to be treated, the sewage diversion control device to be treated has a first water body output port and a second water body output port;

an aerobic MBR device, the aerobic MBR device is provided with a first input port on the raw water side, a second input port on the raw water side, a first output port on the raw water side and a first output port on the purified water side; and

An anaerobic nitrogen removal device, the anaerobic nitrogen removal device has a first input port for the water body to be treated, a second input port for the water body to be treated, and a first output port for the treated water body;

Wherein, the first water body output port is connected to the first input port of the raw water side, the second water body output port is connected to the first input port of the water body to be treated, the second input port of the raw water body is connected to the first output port of the treated water body, and the raw water body is connected to the first output port of the treated water body. The side first output port is connected with the second input port of the water body to be treated, and a flow regulating device is also provided on the drainage channel formed between the first output port of the raw water side and the second input port of the water body to be treated.

When the above system is running, the sewage to be treated is divided into a first water body and a second water body under the control of the diversion regulating device, and flows out from the first water body output port and the second water body output port at the adjusted target flow rate respectively; Enter the raw water side of the aerobic MBR device from the first input port on the raw water side (that is, the liquid side of the filter membrane to be filtered), and effectively remove COD, BOD and ammonia nitrogen under aerobic conditions, wherein ammonia nitrogen is converted into nitrate through nitrification. The state nitrogen is removed; the third water body flowing out from the first output port of the raw water side of the aerobic MBR device enters the anaerobic nitrogen removal device from the second input port of the water body to be treated at the adjusted target flow rate, and in addition, enters the anaerobic nitrogen removal device. In the nitrogen device, there is also a second water body flowing in from the first input port of the water body to be treated. Since the second water body comes from the sewage to be treated and retains a higher concentration of COD, the COD after the second water body and the third water body are mixed. The concentration is higher than the COD concentration of the third water body. Since the carbon source is better guaranteed, the nitrate nitrogen in the water can be effectively removed by denitrification in the anaerobic nitrogen removal device; from the first output port of the treated water body The outflowing fourth water body returns to the raw water side of the aerobic MBR device through the second input port on the raw water side. The first output port on the purified water side (that is, the filtered liquid side of the filter membrane) flows out of the fifth water body as the source of the target water body.

The concentrations of ammonia nitrogen and total nitrogen in the fifth water body produced by the above system can be effectively controlled.

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

FIG. 1 is a schematic structural diagram of a sewage treatment system of the present invention.

FIG. 2 is a schematic structural diagram of another sewage treatment system of the present invention.

Detailed ways

First, the related technical terms involved in the application are explained. "COD" refers to chemical oxygen demand, a comprehensive indicator of the amount of reducing substances such as organic matter in water; "BOD5" refers to chemical oxygen demand for 5 days, a comprehensive indicator of the amount of oxygen-demanding pollutants such as organic matter in water; "TP" refers to total phosphorus; "SS" refers to suspended solids; "MBR" refers to membrane bioreactor.

As shown in FIG. 1, the sewage treatment system includes a first pretreatment device 100 for removing solid impurities in sewage, a second pretreatment device 200 for removing total phosphorus in sewage, aerobic nitrogen removal device 300, and anaerobic denitrification device 300. The nitrogen removal device 400 , the disinfection treatment device 500 , and the to-be-treated sewage diversion control device 700 .

Among them, the first pretreatment device 100 adopts the combined form of grid tank and sedimentation tank, the second pretreatment device 200 adopts a phosphorus removal tank for removing total phosphorus by chemical phosphorus removal method on sewage, and the aerobic nitrogen removal device 300 The aerobic MBR device 310 is used, the anaerobic nitrogen removal device 400 uses an anaerobic nitrogen removal tank, and the disinfection treatment device 500 uses an ultraviolet disinfection tank.

Of course, the combination form of the grid tank and the sand settling tank is only a conventional choice of the first pretreatment device 100 , wherein the role of the grid tank is to intercept floating garbage in the water, and the role of the sand settling tank is to settle the sediment in the sewage. It is easy to encounter that the first pretreatment device 100 may optionally adopt other suitable equipment such as ceramic filters to remove solid impurities in the sewage. Similarly, devices such as the second preprocessing device 200 can also be replaced by other devices having the same or similar functions.

The above-mentioned shunt control device 700 includes pipes that are respectively connected with the water outlet of the phosphorus removal pond to introduce the sewage to be treated out of the phosphorus removal pond into the aerobic nitrogen removal device 300 and the anaerobic nitrogen removal device 400 respectively, and the pipes arranged on each pipeline. Control valve. Through the diversion control device 700 , the sewage to be treated from the phosphorus removal tank can be diverted into a first water body with controllable flow that is led to the aerobic nitrogen removal device 300 and a second water body that is led to the anaerobic nitrogen removal device 400 . The water body flows out from the first water body output port and the second water body output port of the diversion regulating device 700 respectively.

The above-mentioned aerobic MBR device 310 is provided with a first input port on the raw water side, a second input port on the raw water side, a first output port on the raw water side, and a first output port on the purified water side; An input port, a second input port for the water body to be treated and a first output port for the treated water body.

The first water body output port of the diversion control device 700 is connected to the first input port of the raw water side of the aerobic MBR device 310, and the second water body output port of the diversion control device 700 is connected to the first water body to be treated of the anaerobic nitrogen removal device 400. The input port is connected; the second input port of the raw water side of the aerobic MBR device 310 is connected to the first output port of the treated water body of the anaerobic nitrogen removal device 400; the first output port of the raw water side of the aerobic MBR device 310 is connected to the anaerobic nitrogen removal device. The second input port of the water body to be treated of the device 400 is connected, and a flow regulating device is also provided on the drainage channel formed between the first output port on the raw water side and the second input port of the water body to be treated. In addition, the first output port on the water purification side of the aerobic MBR device 310 is connected to the ultraviolet disinfection tank.

Using the sewage treatment method of the sewage treatment system shown in Figure 1, the steps are:

1) carry out the first pretreatment operation of removing solid impurities in the sewage through the grid tank and the sedimentation tank;

2) The second pretreatment operation of removing the total phosphorus in the sewage is carried out by introducing the sewage with the solid impurities removed into the phosphorus removal tank. The phosphorus removal agent is evenly mixed in the sewage to carry out chemical reaction to remove phosphorus, which can achieve a higher phosphorus removal rate;

3) The sewage to be treated after the phosphorus removal treatment in the phosphorus removal tank is divided into a first water body and a second water body by the diversion control device 700, and the first water body output port and Outflow from the second water body outlet;

4) the first water body enters the raw water side of the aerobic MBR device 310 from the first input port of the raw water side, and effectively removes COD, BOD and ammonia nitrogen under aerobic conditions, wherein ammonia nitrogen is converted into nitrate nitrogen by nitrification and removed ( That is, the first denitrification treatment), and then the third water body containing nitrate nitrogen produced by the first denitrification treatment is drawn from the first output port of the raw water side of the aerobic MBR device 310;

5) The third water body enters the anaerobic nitrogen removal device 400 (anaerobic nitrogen removal tank) from the second input port of the water body to be treated at the adjusted target flow rate. The second water body that flows into the first input port of the treated water body, because the second water body comes from the sewage to be treated and retains a higher concentration of COD, the COD concentration of the second water body after mixing with the third water body is higher than that of the third water body. Therefore, in the anaerobic nitrogen removal device 400, the nitrate nitrogen in the water can be effectively removed by denitrification (ie, the second nitrogen removal treatment), and then the second nitrogen removal from the treated water body of the anaerobic nitrogen removal device 400 can be used. An output port leads out the fourth water body after the second nitrogen removal treatment;

6) The fourth water body returns to the raw water side of the aerobic MBR device 310 through the second input port on the raw water side. The first output port of the purified water side of the purified water side flows out of the fifth water body;

7) The target water body is obtained after the fifth water body is introduced into an ultraviolet disinfection tank for disinfection and sterilization.

In step 1) of the above sewage treatment method, the ratio of the flow rate of the first water body to the flow rate of the sewage to be treated is a split ratio, which is generally 50%-90%, such as 60%, 70%, 80%, and the like. In addition, the ratio of the flow rate of the third water body to the flow rate of the first water body drawn in step 3) is the reflux ratio, and the reflux ratio is generally 30%-100%, such as 40%, 50%, 60%, 70%, 80%, 90%, etc.

An important feature of the above sewage treatment method is that the diversion ratio and the return ratio can be flexibly adjusted according to the situation of the sewage to be treated or the first water body. If the COD value of the sewage to be treated or the first water body is high, the diversion ratio can be reduced, so that the flow rate of the first water body is reduced and the flow rate of the second water body is relatively large. A large amount of COD can reduce the load of the aerobic MBR device 301; on the contrary, when the COD value is low, the split ratio can be increased. If the ammonia nitrogen and total nitrogen values of the sewage to be treated or the first water body are low, the reflux ratio can be reduced to speed up the sewage treatment efficiency; on the contrary, if the ammonia nitrogen and total nitrogen values of the sewage to be treated or the first water body are high, it can be increased Reflux ratio.

Experiments show that when the COD value of the sewage to be treated or the first water body in operation one is higher than 250mg/L, it is appropriate to set the diversion ratio to 50%-60%, so as to better utilize the anaerobic anaerobic nitrogen removal tank. Remove a lot of COD. In operation 1, when the COD value of the sewage to be treated or the first water body is lower than 250 mg/L, it is appropriate to set the diversion ratio to 60%-90%.

When the ammonia nitrogen value of the sewage to be treated or the first water body is lower than 25mg/L and the total nitrogen value is lower than 60mg/L, the reflux ratio is preferably 30%-60%, so as to achieve higher sewage treatment efficiency. When the ammonia nitrogen value of the sewage to be treated or the first water body is higher than 25mg/L or the total nitrogen value is higher than 60mg/L, the reflux ratio is generally 60%-90%.

The sewage treatment system shown in FIG. 2 includes a first pretreatment device 100 for removing solid impurities in sewage, a second pretreatment device 200 for removing total phosphorus in sewage, an aerobic nitrogen removal device 300, and an anaerobic denitrification device 300. A nitrogen removal device 400 , a disinfection treatment device 500 , a sewage diversion control device 700 to be treated, and an aerobic MBR device 600 .

Among them, the first pretreatment device 100 adopts the combined form of grid tank and sedimentation tank, the second pretreatment device 200 adopts a phosphorus removal tank for removing total phosphorus by chemical phosphorus removal method on sewage, and the aerobic nitrogen removal device 300 The aerobic MBR device 310 is used, the anaerobic nitrogen removal device 400 uses an anaerobic nitrogen removal tank, and the disinfection treatment device 500 uses an ultraviolet disinfection tank.

The above-mentioned shunt control device 700 includes pipes that are respectively connected with the water outlet of the phosphorus removal pond to introduce the sewage to be treated out of the phosphorus removal pond into the aerobic nitrogen removal device 300 and the anaerobic nitrogen removal device 400 respectively, and the pipes arranged on each pipeline. Control valve. Through the diversion control device 700 , the sewage to be treated from the phosphorus removal tank can be diverted into a first water body with controllable flow that is led to the aerobic nitrogen removal device 300 and a second water body that is led to the anaerobic nitrogen removal device 400 . The water body flows out from the first water body output port and the second water body output port of the diversion regulating device 700 respectively.

The above-mentioned aerobic MBR device 310 is provided with a first input port on the raw water side and a first output port on the purified water side; the anaerobic denitrification device 400 has a first input port for water to be treated, a second input for water to be treated The first output port of the water body; the aerobic MBR device 600 is provided with a first input port on the raw water side and a first output port on the purified water side.

The first water body output port of the diversion control device 700 is connected to the first input port of the raw water side of the aerobic MBR device 310, and the second water body output port of the diversion control device 700 is connected to the first water body to be treated of the anaerobic nitrogen removal device 400. The input port is connected; the first output port of the raw water side of the aerobic MBR device 310 is connected to the second input port of the water body to be treated of the anaerobic nitrogen removal device 400; the first output port of the treated water body of the anaerobic nitrogen removal device 400 is connected to the The first input port on the raw water side of the oxygen MBR device 600 is connected. In addition, the first output port on the water purification side of the aerobic MBR device 600 is connected to the ultraviolet disinfection tank.

Using the sewage treatment method of the sewage treatment system shown in Figure 1, the steps are:

1) carry out the first pretreatment operation of removing solid impurities in the sewage through the grid tank and the sedimentation tank;

2) The second pretreatment operation of removing the total phosphorus in the sewage is carried out by introducing the sewage from which the suspended solids are removed into the phosphorus removal tank. The phosphorus removal agent is evenly mixed in the sewage to carry out chemical reaction to remove phosphorus, which can achieve a higher phosphorus removal rate;

3) The sewage to be treated after the phosphorus removal treatment in the phosphorus removal tank is divided into a first water body and a second water body by the diversion control device 700, and the first water body output port and Outflow from the second water body outlet;

4) the first water body enters the raw water side of the aerobic MBR device 310 from the first input port of the raw water side, and effectively removes COD, BOD and ammonia nitrogen under aerobic conditions, wherein ammonia nitrogen is converted into nitrate nitrogen by nitrification and removed ( That is, the first denitrification treatment), and then the third water body containing nitrate nitrogen produced by the first denitrification treatment is drawn from the first output port of the raw water side of the aerobic MBR device 310;

5) The third water body enters the anaerobic nitrogen removal device 400 (anaerobic nitrogen removal tank) from the second input port of the water body to be treated. In addition, the first input port of the water body to be treated is also entered into the anaerobic nitrogen removal device 400. The inflowing second water body, because the second water body is derived from the sewage to be treated and retains a relatively high concentration of COD, the COD concentration of the second water body after mixing with the third water body is higher than that of the third water body. Therefore, In the anaerobic nitrogen removal device 400, the nitrate nitrogen in the water can be effectively removed by denitrification (ie, the second nitrogen removal treatment), and then the treated water is led out from the first output port of the anaerobic nitrogen removal device 400 through the second nitrogen removal process. The fourth water body after nitrogen removal treatment;

6) The fourth water body enters the raw water side of the aerobic MBR device 600, and the sewage on the raw water side of the aerobic MBR device 600 is processed by the aerobic MBR device 310, and finally flows from the water purification side of the aerobic MBR device 600. The first outlet flows out of the fifth body of water;

7) The target water body is obtained after the fifth water body is introduced into an ultraviolet disinfection tank for disinfection and sterilization.

Example 1

An urban domestic sewage treatment plant adopts the sewage treatment system shown in Figure 1. The factory's incoming water volume is 100 tons/h, water quality indicators COD: 200mg/L, BOD5: 80mg/L, ammonia nitrogen: 20mg/L, total nitrogen: 50mg/L, TP: 3mg/L, SS: 100mg/L. The sewage flows through the grille tank, and the grille machine intercepts the floating garbage. After removing the sediment in the sedimentation tank, the sewage is lifted into the phosphorus removal tank by the lift pump, and 50KG of dry powder phosphorus removal agent (using Jiangxi Huihai Environmental Protection JX-305 Phosphorus Removal Agent produced by Science and Technology Co., Ltd. The phosphorus removal agent is directly put into the phosphorus removal tank according to the ratio of dry powder to water. The water can be fully reacted to remove TP), the TP removal rate can reach more than 90%, and the effluent TP of the phosphorus removal tank is less than or equal to 0.3mg/L. % enters the anaerobic nitrogen removal tank, and the return flow from the aerobic MBR device to the anaerobic nitrogen removal tank can be controlled at 30 tons/h. The anaerobic nitrogen removal tank can anaerobic digestion of COD and denitrification to remove total nitrogen, and the anaerobic removal efficiency of COD can reach more than 60%. In the anaerobic nitrogen removal tank, nitrate nitrogen combines with organic matter under the action of denitrifying bacteria, which has a good removal effect on total nitrogen. The aerobic MBR device has a fan to provide aeration. Under the aerobic state, it has a good removal rate of COD, BOD and ammonia nitrogen, and the ammonia nitrogen is oxidized into nitrite and nitrate. The aerobic MBR device passes through the MBR membrane, the COD removal rate can reach more than 90%, the ammonia nitrogen removal rate can reach more than 93%, the BOD5 can reach below 6mg/L, and the effluent SS can reach below 3mg/L. After the sewage is systematically treated, the sewage indicators reaching the ultraviolet disinfection tank can reach COD≤30mg/L, BOD≤6mg/L, ammonia nitrogen≤1.5mg/L, total nitrogen≤10mg/L, TP≤0.3mg/L, SS≤3mg /L.

Claims (9)

1. sewage treatment method, is characterized in that, comprises the following operations: 1. Divide the sewage to be treated into the first water body and the second water body; 2. Introduce the first water body into the aerobic nitrogen removal device (300) to carry out the first nitrogen removal treatment whose target includes the removal of ammonia nitrogen, and then lead out the aerobic nitrogen removal device (300) from the aerobic nitrogen removal device (300). The third water body of nitrogen; 3. The second water body and the third water body are respectively introduced and mixed in the anaerobic nitrogen removal device (400) to carry out the second nitrogen removal treatment whose target includes removing nitrite nitrogen, and then the anaerobic nitrogen removal device (400) is led out The fourth water body after the second nitrogen removal treatment. 4. Introducing the fourth body of water back to the aerobic nitrogen removal device (300); and 5. The fifth water body, which is the source of the target water body, is drawn from the aerobic nitrogen removal device (300). 2. The sewage treatment method according to claim 1, wherein the aerobic denitrification device (300) is an aerobic MBR device, and the second operation is to extract the described aerobic MBR device from the raw water side of the aerobic MBR device. For the third water body, operation four is to lead the fourth water body back to the raw water side of the aerobic MBR device, and operation five is to lead the fifth water body from the water purification side of the aerobic MBR device. 3. The sewage treatment method according to claim 1, characterized in that: it comprises a pretreatment process, and the sewage treated by the pretreatment process is drawn out as the sewage to be treated in the first operation; the pretreatment The process includes a first pretreatment operation for removing solid impurities in the sewage. 4. The sewage treatment method according to claim 1, characterized in that: it comprises a pretreatment process, and the sewage treated by the pretreatment process is drawn out as the sewage to be treated in the first operation; the pretreatment The process includes a second pretreatment operation for removing total phosphorus from the sewage. 5 . The sewage treatment method according to claim 4 , wherein the second pretreatment operation at least removes the total phosphorus in the sewage by a chemical phosphorus removal method. 6 . 6. The sewage treatment method according to any one of claims 1 to 5, wherein in the first operation, the ratio of the flow rate of the first water body to the flow rate of the sewage to be treated is a split ratio, then the split flow The ratio is 50%-90%. 7. The sewage treatment method according to claim 6, wherein the ratio of the flow rate of the third water body to the flow rate of the first water body drawn in the second operation is a reflux ratio, then the reflux ratio is 30%- 100%. 8. The sewage treatment method according to claim 7, characterized in that: when the COD value of the sewage to be treated or the first water body is higher than 250 mg/L in operation one, the diversion ratio is 50%-60%; When the ammonia nitrogen value of the sewage or the first water body is lower than 25mg/L and the total nitrogen value is lower than 60mg/L, the reflux ratio is 30%-60%. 9. A sewage treatment system, characterized in that it comprises: a sewage diversion regulating device (700) to be treated, the diversion regulating device (700) having a first water body outlet and a second water body outlet; an aerobic MBR device (310) , the aerobic MBR device (310) is provided with a first input port on the raw water side, a second input port on the raw water side, a first output port on the raw water side and a first output port on the purified water side; and an anaerobic nitrogen removal device (400 ), the anaerobic nitrogen removal device (400) has a first input port for the water body to be treated, a second input port for the water body to be treated, and a first output port for the treated water body; wherein, the first water body output port and the raw water side No. An input port is connected, the second water body output port is connected with the first input port of the water body to be treated, the second input port on the raw water side is connected with the first output port of the treated water body, and the first output port on the raw water side is connected with the second input port of the water body to be treated In addition, the drainage channel formed between the first output port on the raw water side and the second input port of the water body to be treated is also provided with a flow regulating device.

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