CN111960531A - Process and automatic control coupled sewage treatment system and aeration control method thereof - Google Patents

Abstract

The invention provides a sewage treatment system coupled with automatic control and an aeration control method thereof. The system includes an aerobic tank with a mechanical stirring device and a blower arranged outside the aerobic tank. The blower is communicated with the aerobic tank through the air main pipe, the air main pipe and the air branch pipe, and a valve is arranged on the air branch pipe; an aerator is arranged at the bottom of the aerobic tank, and the aerator is arranged on the air branch pipe. Dissolved oxygen meter and ammonia nitrogen meter are set in the aerobic tank, and a central controller is set outside the pool. The central controller is connected with the dissolved oxygen meter, ammonia nitrogen meter and blower. According to the real-time value of ammonia nitrogen and dissolved oxygen, the aeration volume of the blower is adjusted. The concentration of dissolved oxygen and ammonia nitrogen in the water in the sewage treatment tank is almost the same, avoiding excessive local dissolved oxygen, minimizing the waste of carbon sources by endogenous respiration, and helping to increase the proportion of carbon sources used for denitrification and phosphorus removal. The effect of biological nitrogen and phosphorus removal reduces the dosage of carbon sources and phosphorus removal agents. At the same time, the aeration energy consumption is also reduced.

Description

A sewage treatment system coupled with process and automatic control and its aeration control method

technical field

The invention relates to the technical field of sewage treatment, in particular to a sewage treatment system coupled with automatic control and an aeration control method thereof.

Background technique

The existing aeration control technologies include precise aeration technology and model control technology based on the kinetic model of activated sludge reaction. The method adopted by the precise aeration technology is mainly based on feedforward and feedback control based on the water quality and quantity parameters of the influent water and the online dissolved oxygen parameters of the biological pool. The impact of influent water quality and quantity often leads to unsatisfactory aeration control, resulting in excessive or insufficient aeration. The aeration control method based on the kinetic model of the activated sludge reaction requires more input parameters than the precise aeration technology. In addition to the parameters of water quality and quantity, and the parameters of online dissolved oxygen, it also needs online nitrate, sludge concentration, volatile sludge Concentration, water temperature and other parameters, use a large amount of real-time data to calculate the aeration amount required by the current system. The theoretical basis of this control method is relatively mature, but in practical applications, because too much data needs to be provided, too many real-time instruments are used. On the one hand, it is difficult for the meter itself to support the detection frequency required for its calculation. On the other hand, the failure of a single meter often brings about a butterfly effect, which leads to the deviation of the entire calculation result. When the water quality and quantity of the influent have a large impact, the control is stable. In particular, it is difficult to guarantee the performance, so this method cannot achieve on-demand aeration according to the ammonia nitrogen situation.

The biggest problem that the existing method cannot achieve on-demand aeration is that the existing aeration control technology does not combine the control technology and the process pool type together, and it is difficult to realize the aeration control with the effluent ammonia nitrogen as the target value.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to propose a sewage treatment system coupled with automatic control and an aeration control method thereof, so as to solve the problem that on-demand aeration cannot be realized in the prior art.

Based on the above object, a first aspect of the present invention provides a sewage treatment system coupled with a process and automatic control, the sewage treatment system coupled with a process and automatic control includes an aerobic tank with a mechanical stirring device inside and a A blower outside the pool, the blower is communicated with the aerobic pool through an air main pipe, an air main pipe and an air branch pipe, and a valve is provided on the air branch pipe; an aerator is provided at the bottom of the aerobic tank, and the The aerator is arranged on the air branch pipe; the inside of the aerobic tank is also provided with a dissolved oxygen meter and an ammonia nitrogen meter, and a central controller is arranged outside the aerobic tank, and the central controller is respectively connected with the dissolved oxygen meter. The oxygen meter, the ammonia nitrogen meter and the blower are connected.

Optionally, the aerobic tank is further provided with a group of U-shaped guide walls located at both ends of the aerobic tank.

Optionally, the number of the aerobic pools is one or more; when the number of the aerobic pools is multiple, a water passage is provided between the adjacent aerobic pools.

Optionally, the central controller is respectively connected with the dissolved oxygen meter, the ammonia nitrogen meter and the blower through signal lines.

Optionally, the mechanical stirring device is one or more of a flow propeller or a vertical stirrer.

Optionally, when the mechanical stirring device is working, the air volume of the blower can be reduced to a minimum value or the blower can be turned off.

Optionally, the sewage treatment system coupled with the process and self-control further includes an anaerobic tank and an anoxic tank, one side of the anoxic tank is connected to the anaerobic tank, and the other side is connected to the aerobic tank.

Based on the same purpose, a second aspect of the present invention provides an aeration control method for a sewage treatment system coupled with a process and an automatic control, the method comprising:

Monitoring the ammonia nitrogen value in the aerobic tank, and judging whether the real-time ammonia nitrogen value in the aerobic tank exceeds the first threshold range;

If it is determined that the real-time ammonia nitrogen value in the aerobic tank is higher than the first threshold value range, increase the aeration amount of the blower;

If it is determined that the real-time ammonia nitrogen value in the aerobic tank is lower than the first threshold value range, reducing the aeration amount of the blower;

or,

Monitoring the real-time dissolved oxygen value in the aerobic tank, and judging whether the real-time dissolved oxygen value in the aerobic tank exceeds the second threshold range;

If it is determined that the real-time dissolved oxygen value in the aerobic tank is higher than the second threshold range, the aeration amount of the blower is reduced;

If it is determined that the real-time dissolved oxygen value in the aerobic tank is lower than the second threshold range, the aeration amount of the blower is increased.

Based on the same purpose, a third aspect of the present invention provides an aeration control method for a sewage treatment system coupled with process and automatic control, the method comprising:

Monitoring the real-time ammonia nitrogen value in the aerobic tank, and judging whether the real-time ammonia nitrogen value exceeds the first threshold range;

If so, adjusting the target dissolved oxygen value and determining a second threshold range based on the adjusted target dissolved oxygen value;

Monitoring the real-time dissolved oxygen value in the aerobic tank, and judging whether the real-time dissolved oxygen value exceeds the second threshold range;

If so, adjust the blower air volume so that the real-time dissolved oxygen value is within the second threshold range.

As can be seen from the above, in the sewage treatment system and its aeration control method provided by the present invention, the process and the automatic control are coupled, by arranging an aerator at the bottom of the aerobic tank and a mechanical stirring device in the aerobic tank to ensure At the same time of aeration, the mixed liquid circulates in the aerobic tank to achieve the effect of full mixing, and the influent water of the aerobic tank is rapidly diluted and mixed, so that the water in the aerobic tank can be completely mixed, and the dissolved oxygen concentration in the water is almost In the same way, it avoids the occurrence of high local dissolved oxygen, enhances the operation stability of the sewage treatment system coupled with the process and automatic control, and solves the problems of uneven aeration and lag in aeration control. The control of low dissolved oxygen in the aerobic tank not only reduces the energy consumption of aeration, but more importantly, it can create conditions for simultaneous nitrification and denitrification, improve the denitrification rate in the aerobic zone, and reduce the cost of additional carbon sources; on the other hand, The concentration of nitrate nitrogen in the effluent of the aerobic tank decreases, so the concentration of nitrate nitrogen in the return sludge outside the secondary sedimentation tank will also decrease, and it will flow back to the anaerobic zone, weakening the effect of nitrate nitrogen on anaerobic phosphorus release, which is conducive to the accumulation of nitrogen. Phosphorus bacteria absorb small molecular organic matter to promote phosphorus release, thereby improving the efficiency of biological phosphorus removal, and saving the cost of phosphorus removal agent.

Description of drawings

In order to more clearly illustrate one or more embodiments of the present specification or the technical solutions in the prior art, the following briefly introduces the accompanying drawings used in the description of the embodiments or the prior art. Obviously, in the following description The accompanying drawings are only one or more embodiments of the present specification, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the structural schematic diagram of the aerobic tank in the sewage treatment system of the process and automatic control coupling provided by this specification;

FIG. 2 is a schematic structural diagram of a sewage treatment system with process and automatic control coupling provided in this specification;

Figure 3 is a schematic diagram of the arrangement of the air branch pipe provided in this specification in the aerobic tank;

Fig. 4 provides the schematic diagram of logic control based on real-time ammonia nitrogen value for this specification;

Fig. 5 provides the schematic diagram of logic control based on real-time dissolved oxygen value for this specification;

Detailed ways

In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the present disclosure will be further described in detail below with reference to the specific embodiments and the accompanying drawings.

It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of the present specification shall have the usual meanings understood by those with ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and similar terms used in one or more embodiments of this specification do not denote any order, quantity, or importance, but are merely used to distinguish the various components. "Comprises" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

At present, in the process of sewage treatment by activated sludge method, aeration is an important part of the sewage treatment process. Dissolved oxygen is provided to the water through aeration to maintain the needs of microbial life activities, and at the same time, reducing pollutants such as COD and ammonia nitrogen are removed. With the improvement of national sewage treatment discharge standards, the standards for total nitrogen, ammonia nitrogen, total phosphorus and COD in effluent are relatively strict. The amount of aeration has an important impact on the compliance of various indicators. If the aeration is insufficient, the ammonia nitrogen or even the COD may not meet the standard, and the excessive aeration may lead to poor removal of total nitrogen and total phosphorus, thereby increasing the dosage of chemical agents such as carbon sources and phosphorus removal agents, increasing operating costs and increasing the amount of chemicals. Pollution in the production process, and the power consumption of the system is also higher when the aeration is excessive. Therefore, it is of great significance to find a method to control the aeration amount according to the needs in order to achieve the compliance of various indicators and reduce the consumption of chemicals and electricity in operation.

According to the principle of microbial ecology, in the aeration link of the activated sludge system, the bacteria that remove COD are heterotrophic bacteria, and the bacteria that remove ammonia nitrogen are autotrophic bacteria. Significantly different, the population density of heterotrophic bacteria is much larger than that of autotrophic bacteria, and the reaction rate is also much larger than that of autotrophic bacteria. Therefore, when the ammonia nitrogen reaches the standard in the aeration link, the easily degradable COD has already reached the standard. According to this principle, it can be seen that the limiting factor of the aeration link is the residual concentration of ammonia nitrogen in the aeration tank. When the ammonia nitrogen reaches the standard, it can be considered that the aeration amount is sufficient, so the required residual ammonia nitrogen concentration is aeration on demand. need.

Conventional aeration tanks, such as the typical AAO process, the aerobic tank (O section) is generally a plug-flow reaction tank. The ammonia nitrogen concentration of this type of reaction tank is constantly changing along the process, and the demand for aeration is also Constantly changing, with the change of the water quality and quantity of the influent, the point at which the ammonia nitrogen reaches the standard is also constantly changing along the process. Therefore, the push-flow reaction tank needs to measure dissolved oxygen and ammonia nitrogen at multiple points to achieve on-demand aeration, which requires a large number of instruments and equipment. Complex control logic is very difficult to implement. Many aeration rate control technologies or methods based on push-flow biological pools show weak shock resistance when encountering fluctuations in influent water quality and quantity, and often fail to control.

The existing aeration control technologies include precise aeration technology and model control technology based on the kinetic model of activated sludge reaction. The method adopted by the precise aeration technology is mainly based on feedforward and feedback control based on the water quality and quantity parameters of the influent water and the online dissolved oxygen parameters of the biological pool. The impact of influent water quality and quantity often leads to unsatisfactory aeration control, resulting in excessive or insufficient aeration. The aeration control method based on the kinetic model of the activated sludge reaction requires more input parameters than the precise aeration technology. In addition to the parameters of water quality and quantity, and the parameters of online dissolved oxygen, it also needs online nitrate, sludge concentration, volatile sludge Concentration, water temperature and other parameters, use a large amount of real-time data to calculate the aeration amount required by the current system. The theoretical basis of this control method is relatively mature, but in practical applications, because too much data needs to be provided, too many real-time instruments are used. On the one hand, it is difficult for the meter itself to support the detection frequency required for its calculation. On the other hand, the failure of a single meter often brings about a butterfly effect, which leads to the deviation of the entire calculation result. When the water quality and quantity of the influent have a large impact, the control is stable. In particular, it is difficult to guarantee the performance, so this method cannot achieve on-demand aeration according to the ammonia nitrogen situation.

The biggest problem that the existing method cannot achieve on-demand aeration is that the existing aeration control technology does not combine the control technology and the process pool type together, and it is difficult to realize the aeration control with the effluent ammonia nitrogen as the target value.

Therefore, the main problems existing in the existing sewage treatment technology are:

(1) Unstable operation: the water quality and quantity of the incoming water are constantly changing, and the required aeration amount is also different, which is reflected in the dissolved oxygen, that is, the front end dissolved oxygen may be low or even insufficient, while the back end dissolved oxygen may be high , and even aeration has occurred. After over-aeration, it will cause problems such as loose sludge and small flocs.

(2) High energy consumption and high drug consumption: the existing technology is difficult to achieve on-demand aeration, and excessive aeration will waste aeration energy consumption, resulting in high energy consumption. Excessive aeration will increase the endogenous respiration of microorganisms, waste carbon sources, increase the consumption of chemicals for denitrification and phosphorus removal, and cause secondary pollution in the production of chemicals.

(3) Low control accuracy: Since it is impossible to accurately control the effluent ammonia nitrogen value, dissolved oxygen is used as the main control target. The ammonia nitrogen value is either too low or too high, and the control accuracy is low. In order to ensure compliance, the ammonia nitrogen value is often controlled at a lower level range, resulting in excessive aeration.

(4) Control hysteresis: The method adopted by the precise aeration technology is mainly based on the water quality and quantity parameters of the influent. Since the biological pool has a hydraulic retention time of several to dozens of hours, the online dissolved oxygen parameters of the biological pool are fed forward and fed back. There is a large hysteresis in the control of aeration volume. The nonlinear characteristics of aeration volume and the impact of influent water quality and quantity often lead to unsatisfactory aeration control, resulting in excessive or insufficient aeration.

In order to solve the above-mentioned technical problems, this specification provides a sewage treatment tank and an aeration control method thereof. The sewage treatment tank includes an aerobic tank with a mechanical stirring device inside and a blower arranged outside the aerobic tank. The blower passes the air The main pipe, the air main pipe and the air branch pipe are connected with the aerobic tank, the control branch pipe is provided with a valve, the aerator is provided at the bottom of the aerobic tank, the aerator is arranged on the air branch pipe, and the inside of the aerobic tank is also provided with There are dissolved oxygen meter and ammonia nitrogen meter. A central controller is arranged outside the aerobic tank, and the central controller is respectively connected with the dissolved oxygen meter, ammonia nitrogen meter and blower.

When performing aeration control on the sewage treatment system coupled with the process and automatic control, in one case, monitor whether the real-time ammonia nitrogen value in the aerobic tank is within the first threshold range; when the real-time ammonia nitrogen value in the aerobic tank exceeds the first threshold value range Adjust the air volume of the blower so that the real-time ammonia nitrogen value in the aerobic pool reaches the first threshold range.

When performing aeration control on the sewage treatment system coupled with the process and automatic control, in one case, monitor whether the real-time dissolved oxygen value in the aerobic tank is within the second threshold range; when the real-time dissolved oxygen value in the aerobic tank exceeds the second threshold When it is within the threshold range, adjust the air volume of the blower so that the real-time dissolved oxygen value in the aerobic pool reaches the second threshold range.

Therefore, the process and self-control coupling sewage treatment system and its aeration control method provided in this specification, by arranging an aerator at the bottom of the aerobic tank, and setting a mechanical stirring device in the aerobic tank, to ensure mixing at the same time of aeration The liquid circulates in the aerobic tank and is fully mixed, and the influent water of the aerobic tank is rapidly diluted and mixed, so that the water in the aerobic tank can be completely mixed, and the dissolved oxygen concentration in the water is almost the same, so as to avoid local high dissolved oxygen. It enhances the operation stability of the sewage treatment system coupled with the process and automatic control, and solves the problems of uneven aeration and lag in aeration control. The control of low dissolved oxygen in the aerobic tank not only reduces the energy consumption of aeration, but more importantly, it can create conditions for simultaneous nitrification and denitrification, improve the denitrification rate in the aerobic zone, and reduce the cost of additional carbon sources; on the other hand, The concentration of nitrate nitrogen in the effluent of the aerobic tank decreases, so the concentration of nitrate nitrogen in the return sludge outside the secondary sedimentation tank will also decrease, and it will flow back to the anaerobic zone, weakening the effect of nitrate nitrogen on anaerobic phosphorus release, which is conducive to the accumulation of nitrogen. Phosphorus bacteria absorb small molecular organic matter to promote phosphorus release, thereby improving the efficiency of biological phosphorus removal, and saving the cost of phosphorus removal agent.

The process and self-control coupling sewage treatment system and its aeration control method provided in this manual mainly have the following advantages:

(1) Stable operation: It can realize the stable operation of ammonia nitrogen in the effluent near the target value, and achieve just the right amount of aeration, which greatly improves the control accuracy.

(2) Timely control: in a fully mixed aerobic tank, based on one of the three control methods of real-time ammonia nitrogen value, real-time dissolved oxygen value, and real-time ammonia nitrogen value and real-time dissolved oxygen value in the aerobic tank, the aeration can be realized. The timely control of the amount solves the problems of uneven aeration and lag in aeration control.

(3) Energy saving: In a fully mixed tank, the dissolved oxygen is controlled at a reasonable level to avoid the local high dissolved oxygen situation, the aeration efficiency is higher, and the aeration energy consumption can be saved.

(4) Saving drug consumption: Due to the reasonable control of aeration volume, excessive aeration is prevented. On the one hand, the influence of dissolved oxygen entrainment in the internal and external reflux mixture on the anoxic tank and anaerobic tank is reduced, and on the other hand, it is prevented. Excessive aeration leads to waste of carbon source by endogenous respiration of activated sludge, which helps to increase the proportion of carbon source used for nitrogen and phosphorus removal, improve the effect of biological nitrogen and phosphorus removal, and reduce the dosage of carbon source and phosphorus removal agent quantity.

(5) Diversity of reactions: This aeration control method reduces the aeration as much as possible when the ammonia nitrogen reaches the standard, and the dissolved oxygen in the aerobic tank can be controlled at a low level, and it is easy to trigger synchronous or short-range nitrification reactions under low dissolved oxygen conditions. Nitrification, further reducing the system's demand for carbon sources and improving the ability of biological nitrogen removal.

The sewage treatment tank and the aeration control method thereof provided in this specification will be described in detail below with reference to the accompanying drawings.

Figure 1 is a schematic structural diagram of an aerobic tank in a sewage treatment system with a process and automatic control coupling provided by this specification; as shown in Figure 1, a mechanical stirring device 11 is provided inside the aerobic tank 1, and a The blower 12, the blower 12 is communicated with the aerobic pool 1 through the air main pipe 13, the air main pipe 131 and the air branch pipe 14, and the air branch pipe 14 is provided with a first valve 141; the mechanical stirring device 11 can promote the circulation of sewage in the aerobic tank 1 Flow; the aerobic tank equipped with the mechanical stirring device 11 can ensure that the sludge does not settle without aeration, and the mixing ratio of the raw water entering the aerobic tank is generally more than 20 times; the blower 12 has frequency conversion control, which can be flexibly Adjust the frequency to adjust the blowing volume. During sewage treatment, the blower 12 can deliver the outside air to the air main pipe 13, and the air main pipe 13 delivers the air to the air main pipe 131, and then the air main pipe 131 delivers the air to the air branch pipe 14, The air branch pipe 14 transports air to the aerobic tank 1 to aerate the sewage in the aerobic tank 1 .

The bottom of the aerobic pool 1 is provided with an aerator 15, the aerator 15 is arranged on the air branch pipe 14, the inside of the aerobic pool 1 is also provided with a dissolved oxygen meter 16, an ammonia nitrogen meter 17, and the outside of the aerobic pool 1 is also provided with There is a central controller 18, and the central controller 18 is respectively connected with the dissolved oxygen meter 16, the ammonia nitrogen meter 17 and the blower 12. The aerator 15 receives the air transmitted from the air branch pipe 14 to aerate the sewage in the aerobic tank 1 . The data of the blower 12, the dissolved oxygen meter 16, and the ammonia nitrogen meter 17 are respectively transmitted to the central controller 18, and the user obtains the above-mentioned data through the central controller 18, and based on the above-mentioned data, regulates and regulates the aeration amount of the blowing volume of the blower 12. The dissolved oxygen in the oxygen tank 1 is controlled to improve aeration efficiency and reduce aeration energy consumption.

Fig. 3 is a schematic diagram of the arrangement of the air branch pipe in the aerobic tank provided by this specification; as shown in Fig. 2, in practical application, the central elevation of the main pipe of the air branch pipe 14 is 1.0m higher than the liquid level, and the air branch pipe 14 penetrates well After the side wall of the oxygen tank 1 along the water flow direction, one of the branch pipes is turned down and communicated with the aerator 15 located in the aerobic tank 1; in the aerobic tank 1, the upper end of the vertical pipe of the air branch pipe 14 leads out the first thin pipe And connect the first horizontal pipe, the diameter of the first horizontal pipe is 15-20mm, the second valve 142 is installed on the first horizontal pipe, the second valve 142 is used to discharge the condensed water in the air pipeline, and close the drain valve in time.

In practical application, in one case, as shown in FIG. 1 , partition walls 19 are also arranged in the aerobic pool 1 along the water flow direction, and first U-shaped walls 19 are also arranged in the aerobic pool 1 respectively located at both ends of the partition walls 19 The guide wall 101 and the second U-shaped guide wall 102 . By arranging the partition wall 19, the first U-shaped guide wall 101 and the second U-shaped guide wall 102 in the aerobic tank 1, the sewage entering the aerobic tank 1 can be made to flow along the expected water flow direction, and the sewage entering the aerobic tank 1 can be well In the oxygen pool 1, the water flows from the first U-shaped guide wall 101 to the second U-shaped guide wall 102 along the water flow direction, and then flows in the reverse direction along the second U-shaped guide wall 102 to reach the first U-shaped guide wall 101 . The first U-shaped guide wall 101 and the second U-shaped guide wall 102 can prevent the sewage in the aerobic tank 1 from hitting the side wall of the aerobic tank, and promote the circulating flow of the sewage in the aerobic tank 1 .

In one case, the aerobic pool 1 may not be provided with a partition wall, and the aerobic pool 1 is provided with a first U-shaped guide wall 101 and a second U-shaped guide wall 102 respectively located at both ends of the aerobic pool 1 . The first U-shaped guide wall 101 and the second U-shaped guide wall 102 can prevent the sewage in the aerobic tank 1 from hitting the side wall of the aerobic tank, and promote the circulating flow of the sewage in the aerobic tank 1 .

In some possible implementations, in one case, the number of mechanical stirring devices 11 is even, the partition wall 19 is centrally arranged in the aerobic tank 1 , and the mechanical stirring devices 11 are evenly arranged on both sides of the partition wall 19 . Even-numbered mechanical stirring devices 11 are arranged in the aerobic pool 1, and the even-numbered mechanical stirring devices 11 are evenly arranged on both sides of the centrally arranged partition wall 19, so that the aerobic pool 1 can be operated without opening the first valve 141. It ensures that the sludge does not settle, and can promote the circulating flow of sewage in the aerobic tank 1, and quickly dilute and mix the influent water in the aerobic tank 1. The dissolved oxygen concentration in the sewage is almost the same, so as to avoid local dissolved oxygen excess. In the case of high temperature, the operation stability of the aerobic tank 1 is enhanced, and the problems of uneven aeration and lag in aeration control are solved. For example, in practical applications, two mechanical stirring devices or four mechanical stirring devices, etc. may be provided, which are not specifically limited.

In one case, the number of the mechanical stirring devices 11 is an odd number, and the mechanical stirring devices 11 are equally distributed in the aerobic tank 1 . For example, in practical applications, three mechanical stirring devices or five mechanical stirring devices, etc. may be provided, which are not specifically limited.

In some possible implementations, in one case, the number of aerators 15 is an even number, the number of aerators 15 is the same as the number of air branch pipes 14, and the partition wall 19 is centrally arranged in the aerobic tank 1 , the aerators 15 are evenly arranged on both sides of the partition wall 19 . An even number of aerators 15 are arranged in the aerobic tank 1, and the even number of aerators 15 are evenly arranged on both sides of the partition wall 19 set in the play, so that the sewage in the aerobic tank 1 can be fully aerated. The concentration of dissolved oxygen in the sewage is almost the same everywhere, which avoids the situation that the local dissolved oxygen is too high, and enhances the operation stability of the aerobic tank 1 . In practical applications, according to the size of the aerobic tank 1, the number of aerators 15 and the number of air branch pipes 14 used in the aerobic tank 1 are different, and different arrangements can be made according to the actual situation, which is not limited in detail. . For example, 6 aerators and air branch pipes or 8 aerators and air branch pipes can be provided, which is not specifically limited.

In one case, the number of the aerators 15 is an odd number, the number of the aerators 15 is the same as the number of the air branch pipes 14 , and the aerators 15 are evenly arranged in the aerobic tank 1 . In practical applications, according to the size of the aerobic tank 1, the number of aerators 15 and the number of air branch pipes 14 used in the aerobic tank 1 are different, and different arrangements can be made according to the actual situation, which is not limited in detail. . For example, 5 aerators and air branch pipes or 7 aerators and air branch pipes can be provided, which is not specifically limited.

In some possible implementations, the number of aerobic pools 1 is one or more; when the number of aerobic pools 1 is multiple, a water passage is provided between adjacent aerobic pools 1 . When there are multiple aerobic pools, an ammonia nitrogen meter and a dissolved oxygen meter are installed in each aerobic pool. The ammonia nitrogen value in each aerobic tank corresponds to a different control range, and each aerobic tank corresponds to its own dissolved oxygen target value; when multiple aerobic tanks are set up, the sewage can be fully aerated.

In some possible implementations, the central controller 18 is connected to the dissolved oxygen meter 16 , the ammonia nitrogen meter 17 and the blower 12 through signal lines, respectively.

In some possible embodiments, the mechanical stirring device 11 is one or more of a flow mover or a vertical stirrer. Different types of mechanical stirring devices can be selected according to the tank type. If the aerobic tank 1 is a rectangular tank type, a flow pusher can be used; if the aerobic tank 1 is a square tank type, a vertical agitator can be used. When the mechanical stirring device 11 is working, the air volume of the blower 12 can be reduced to the minimum value or the blower 12 can be turned off in a short time; the sludge is prevented from sinking, and the sewage and the sludge in the aerobic tank are completely mixed, and the uneven aeration is solved. And the problem of aeration control lag.

As shown in FIG. 1, the aerobic pool 1 is also provided with a first water inlet 103 and a water outlet 104, the first water inlet 103 is arranged on a side wall of the aerobic pool 1 perpendicular to the water flow direction, and the water outlet 104 is arranged in a good Oxygen pool 1 is on the other side wall perpendicular to the direction of water flow.

Figure 2 is a schematic structural diagram of a sewage treatment system with process and self-control coupling provided in this specification; as shown in Figure 2, the sewage treatment tank also includes an anaerobic tank 2 and an anoxic tank 3. Pool 2 is connected, and the other side is connected to aerobic pool 1. The side wall of the anoxic tank 3 is provided with a third water inlet 31, the side wall of the anaerobic tank 2 is provided with a second water inlet 21, and the sewage enters the anaerobic tank from the second water inlet 21 on the side wall of the anaerobic tank 2 Pool 2, after being treated by anaerobic pool 2, enters the anoxic pool 3 from the third water inlet 31 on the side wall of the anoxic pool 3, and after being treated by the anoxic pool 3, it enters the anoxic pool 3 from the first water inlet on the side wall of the aerobic pool 1 103 enters the aerobic tank 1, and is left by the water outlet 104 on the other side wall of the aerobic tank 1 after being processed by the aerobic tank 1. The mud-water mixture at the end of the aerobic tank is returned to the anoxic tank 3 through the inner return pipe 6, and the sludge precipitated in the secondary sedimentation tank is returned to the front of the anaerobic tank through the outer return pipe 7.

It should be noted that the aerobic tank type, mixing and aeration control methods provided in this manual are aimed at the aerobic link in the activated sludge process for sewage treatment, and are suitable for all treatment processes with aerobic sections. Figure 2 uses traditional AAO The process is used as an example to illustrate the implementation, but it is not limited to be applied to AAO and its modification process. This method can also be applied to the aerobic pool of multi-stage AO process, Bardenpho, oxidation ditch and other processes and the aerobic period of intermittent SBR process, It is also within the protection scope of the present invention.

Fig. 4 is a schematic diagram of logic control based on real-time ammonia nitrogen value provided by this specification, and Fig. 5 is a schematic diagram of logic control based on dissolved oxygen online value provided by this specification; as shown in Fig. 4 and Fig. 5, this specification also provides a process An aeration control method for a sewage treatment system coupled with automatic control, the method comprises: monitoring the ammonia nitrogen value in the aerobic tank, and judging whether the real-time ammonia nitrogen value in the aerobic tank exceeds a first threshold range; if determining the real-time ammonia nitrogen value in the aerobic tank If it is higher than the first threshold range, increase the aeration amount of the blower; if it is determined that the real-time ammonia nitrogen value in the aerobic pool is lower than the first threshold value range, reduce the aeration amount of the blower; or,

Monitor the real-time dissolved oxygen value in the aerobic tank, and judge whether the real-time dissolved oxygen value in the aerobic tank exceeds the second threshold range; if it is determined that the real-time dissolved oxygen value in the aerobic tank is higher than the second threshold range, reduce the blower aeration If it is determined that the real-time dissolved oxygen value in the aerobic pool is lower than the second threshold range, increase the aeration amount of the blower.

In practical applications, the main purpose of aeration is to use activated sludge to remove COD and ammonia nitrogen in sewage. According to the principle of microbial ecology, the population density and reaction rate of microorganisms that remove COD are much larger than those of microorganisms that remove ammonia nitrogen, so it can be considered that When the ammonia nitrogen in the sewage reaches the standard, the degradable COD has been degraded, so the real-time ammonia nitrogen value index becomes the limiting factor for the control of the aeration rate. When performing aeration control, it is possible to monitor whether the real-time ammonia nitrogen value in the aerobic tank is within the first threshold range; when the real-time ammonia nitrogen value in the aerobic tank exceeds the first threshold range, the blower aeration amount can be adjusted in a certain step to make The real-time ammonia nitrogen value in the aerobic tank reaches the first threshold value range; when the real-time ammonia nitrogen value in the aerobic tank is higher than the first threshold value range, the aeration amount of the blower can be increased in a certain step to reduce the real-time ammonia nitrogen value in the aerobic tank. ; When the real-time ammonia nitrogen value in the aerobic pool is lower than the first threshold range, the aeration amount of the blower is reduced to increase the real-time ammonia nitrogen value in the aerobic pool.

The monitoring and adjustment of the real-time ammonia nitrogen value is carried out according to a certain cycle, and the cycle is adjusted so that the real-time ammonia nitrogen value in the aerobic tank is constantly approaching the first threshold range. Determined by the adjustment performance of the blower, it can be a fixed period and a stride, or it can be adjusted with a variable period and a variable step. The basis of the variable period is the measurement period of the ammonia nitrogen meter and the actual hydraulic retention time of the aerobic tank. Deviation of real-time ammonia nitrogen value and big data analysis of historical operation.

For example, the period can be 30 to 120 minutes, and there is no specific limitation; when the execution period is reached, the real-time ammonia nitrogen value in the aerobic tank is detected. When the real-time ammonia nitrogen value in the aerobic tank reaches 90% to 110% of the target ammonia nitrogen value, no need Adjust the air volume of the blower, and the state of the blower remains unchanged; when the real-time ammonia nitrogen value in the aerobic pool is higher than 110% of the target ammonia nitrogen value, adjust the air volume of the blower upward in the range of 1%-5%; When the real-time ammonia nitrogen value is lower than 90% of the target ammonia nitrogen value, adjust the air volume of the blower downward in the range of 1%-5% until the real-time ammonia nitrogen value falls within 90% to 110% of the target ammonia nitrogen value.

In practical applications, it is also possible to adjust the aeration rate of the blower according to the real-time dissolved oxygen value in the aerobic tank, monitor the real-time dissolved oxygen value in the aerobic tank, and periodically compare the real-time dissolved oxygen value with the second threshold range. When the real-time dissolved oxygen value is higher than the second threshold range, the blower aeration amount is decreased in a certain step, and when the real-time dissolved oxygen value is lower than the second threshold range, the blower aeration amount is increased in a certain step.

The monitoring and adjustment of the real-time dissolved oxygen value is carried out according to a certain period, and the cycle is adjusted repeatedly, so as to reduce the real-time dissolved oxygen value as much as possible on the premise that the real-time ammonia nitrogen value reaches the first threshold range, so as to create conditions for simultaneous nitrification and denitrification. , and further reduce carbon consumption and energy consumption.

For example, the cycle can be 15 to 30 minutes, which is not limited in detail; when the real-time dissolved oxygen value in the aerobic tank reaches 80% to 120% of the target dissolved oxygen value, there is no need to adjust the air volume of the blower, and the state of the blower remains unchanged; when When the real-time dissolved oxygen value in the aerobic tank is higher than 120% of the target dissolved oxygen value, adjust the air volume of the blower downward in the range of 1%-5% until the real-time dissolved oxygen value falls within 80% of the target dissolved oxygen value. Within 120%; when the real-time dissolved oxygen value in the aerobic tank is lower than 80% of the target dissolved oxygen value, adjust the air volume of the blower upward in the range of 1%-5% until the real-time dissolved oxygen value falls within the target dissolved oxygen value within 80% to 120%.

In practical applications, when aeration control is performed on the sewage treatment system coupled with the process and automatic control, ammonia nitrogen value control and dissolved oxygen control aeration amount or both are used together. , The measurement period of the ammonia nitrogen meter is long, and the measurement period of the dissolved oxygen meter is real-time. Therefore, the use of the dissolved oxygen meter to control the blower aeration volume control cycle can be shortened, the response time is short, and the ability to withstand the impact of upstream water quality and water volume is also stronger. In the future, the use of ammonia nitrogen meter to directly control the aeration volume of the blower can also achieve rapid response after the technical progress of ammonia nitrogen meter, which is also within the protection scope of this patent.

This specification also provides an aeration control method for a sewage treatment system coupled with process and automatic control. The method includes: monitoring the real-time ammonia nitrogen value in the aerobic tank, and judging whether the real-time ammonia nitrogen value exceeds the first threshold range; if so, adjusting The target dissolved oxygen value and the second threshold range are determined based on the adjusted target dissolved oxygen value; the real-time dissolved oxygen value in the aerobic tank is monitored, and it is judged whether the real-time dissolved oxygen value exceeds the second threshold value range; The real-time dissolved oxygen value is within the second threshold range.

In practical applications, when performing aeration control, first monitor whether the real-time ammonia nitrogen value in the aerobic tank is within the first threshold range. If the real-time ammonia nitrogen value is within the first threshold range, there is no need to adjust the target dissolved oxygen value; If the value is higher than the first threshold range, the target dissolved oxygen value is adjusted upward in a certain step; if the real-time ammonia nitrogen value is lower than the first threshold range, the target dissolved oxygen value is adjusted downward in a certain step.

After determining the adjusted target dissolved oxygen value, determine a second threshold range for judging the real-time dissolved oxygen value based on the adjusted target dissolved oxygen value; monitor the real-time dissolved oxygen value, if the real-time dissolved oxygen value is within the second threshold value range, There is no need to adjust the air volume of the blower; if the real-time dissolved oxygen value is higher than the second threshold range, reduce the air volume of the blower in a certain step; if the real-time dissolved oxygen value is lower than the second threshold range, increase the air volume of the blower in a certain step .

For example, to detect the real-time ammonia nitrogen value in the aerobic tank, when the real-time ammonia nitrogen value in the aerobic tank reaches 90% to 110% of the target ammonia nitrogen value, there is no need to adjust the target dissolved oxygen value; when the real-time ammonia nitrogen value in the aerobic tank is higher than the target value When the ammonia nitrogen value is 110% of the target ammonia nitrogen value, the target dissolved oxygen value is adjusted upward in the range of 0.1-0.3mg/L; when the real-time ammonia nitrogen value in the aerobic tank is lower than 90% of the target ammonia nitrogen value, the Adjust the target dissolved oxygen value downward by the magnitude of .

After determining the adjusted target dissolved oxygen value, the second threshold range is determined based on the adjusted target dissolved oxygen value as 80% to 120% of the adjusted target dissolved oxygen value; If the value is within 80% to 120% of the adjusted target dissolved oxygen value, there is no need to adjust the air volume of the blower; if the real-time dissolved oxygen value is higher than 120% of the adjusted target dissolved oxygen value, the range of 1% to 5% will be used. Adjust the air volume of the blower downward; if the real-time dissolved oxygen value is lower than 80% of the adjusted target dissolved oxygen value, adjust the air volume of the blower upward by 1%-5%.

To sum up, the process and self-control coupling sewage treatment system provided in this specification, by setting an aerator at the bottom of the aerobic tank, and setting a mechanical stirring device in the aerobic tank, to ensure that the mixed liquid is in the aerobic tank during aeration. Circulating flow and fully mixing, the water in the aerobic tank is rapidly diluted and mixed, so that the water in the aerobic tank can be completely mixed, and the dissolved oxygen concentration in the water is almost the same, avoiding the situation of local high dissolved oxygen, enhancing the Operational stability of wastewater treatment systems coupled with process and automation.

When aeration control is performed on the sewage treatment system coupled with the process and automatic control, the low dissolved oxygen control in the aerobic tank not only reduces the energy consumption of aeration, but more importantly, it can create conditions for simultaneous nitrification and denitrification, and simultaneous nitrification, denitrification and denitrification. Nitrogen can account for more than 10% of the total nitrogen removal, which improves the denitrification rate in the aerobic zone and reduces the cost of external carbon sources; The concentration of nitrate nitrogen in the mud will also decrease, and it will flow back to the anaerobic zone, weakening the influence of nitrate nitrogen on anaerobic phosphorus release, helping phosphorus accumulating bacteria to absorb small molecules of organic matter to promote phosphorus release, thereby improving the efficiency of biological phosphorus removal and saving energy. cost of phosphorus removal agent.

It should be understood by those of ordinary skill in the art that the discussion of any of the above embodiments is only exemplary, and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples; under the spirit of the present disclosure, the above embodiments or Technical features in different embodiments may also be combined, steps may be carried out in any order, and there are many other variations of the different aspects of one or more embodiments of this specification as described above, which are not in detail for the sake of brevity supply.

Although the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations to these embodiments will be apparent to those of ordinary skill in the art from the foregoing description.

The embodiment or embodiments of this specification are intended to cover all such alternatives, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of the present specification should be included within the protection scope of the present disclosure.

Claims (8)

1. A sewage treatment system with coupled technology and automatic control is characterized in that the sewage treatment system with coupled technology and automatic control comprises an aerobic tank with a mechanical stirring device arranged inside and an air blower arranged outside the aerobic tank, wherein the air blower is communicated with the aerobic tank through an air main pipe, an air main pipe and an air branch pipe, and the air branch pipe is provided with a valve; an aerator is arranged at the bottom of the aerobic tank and is arranged on the air branch pipe; the inside of the aerobic tank is also provided with a dissolved oxygen instrument and an ammonia nitrogen instrument, the outside of the aerobic tank is provided with a central controller, and the central controller is respectively connected with the dissolved oxygen instrument, the ammonia nitrogen instrument and the blower.

2. The process and automatic control coupled sewage treatment system of claim 1 wherein a set of U-shaped guide walls are further disposed in the aerobic tank at both ends of the aerobic tank.

3. The process and autoregulation coupled wastewater treatment system of claim 1, wherein the number of the aerobic tanks is one or more; when the number of the aerobic tanks is multiple, a water passing opening is arranged between the adjacent aerobic tanks.

4. The process and integrated wastewater treatment system according to claim 1, wherein said central controller is connected to said dissolved oxygen meter, said ammonia nitrogen meter and said blower via signal lines, respectively.

5. The process and self-control coupled wastewater treatment system according to any of claims 1-4, wherein the mechanical stirring device is one or more of a flow impeller or a vertical stirrer.

6. The process and integrated wastewater treatment system of claim 1 wherein the mechanical agitator is operable to minimize or shut down the blower.

7. A process and aeration control method for an automatic control coupled sewage treatment system according to any one of claims 1 to 6, wherein the method comprises:

monitoring the ammonia nitrogen value in the aerobic tank, and judging whether the real-time ammonia nitrogen value in the aerobic tank exceeds a first threshold range;

if the real-time ammonia nitrogen value in the aerobic tank is judged to be higher than the first threshold range, increasing the aeration rate of a blower;

if the real-time ammonia nitrogen value in the aerobic tank is judged to be lower than the first threshold range, reducing the aeration rate of the blower;

or the like, or, alternatively,

monitoring a real-time dissolved oxygen value in the aerobic tank, and judging whether the real-time dissolved oxygen value in the aerobic tank exceeds a second threshold range;

if the real-time dissolved oxygen value in the aerobic tank is judged to be higher than the second threshold range, reducing the aeration rate of the blower;

and if the real-time dissolved oxygen value in the aerobic tank is judged to be lower than the second threshold range, increasing the aeration rate of the blower.

8. A process and aeration control method for an automatic control coupled sewage treatment system according to any one of claims 1 to 6, wherein the method comprises:

monitoring a real-time ammonia nitrogen value in an aerobic tank, and judging whether the real-time ammonia nitrogen value exceeds a first threshold range;

if so, adjusting the target dissolved oxygen value and determining a second threshold range based on the adjusted target dissolved oxygen value;

monitoring a real-time dissolved oxygen value in the aerobic tank, and judging whether the real-time dissolved oxygen value exceeds a second threshold range;

and if so, adjusting the air volume of the blower to enable the real-time dissolved oxygen value to be within the second threshold range.

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