KR100434639B1 - inner flow control system of apparatus for treating water - Google Patents

Abstract

The present invention relates to an internal return flow control system of a wastewater treatment apparatus. More specifically, in the waste water treatment apparatus comprising an anaerobic tank, a dissolved oxygen low tank, an anoxic tank, an aerobic tank, a settling tank, an internal transport line connecting the aerobic tank and the dissolved oxygen low tank and an internal transport line connecting the anoxic tank and the anaerobic tank, Controlling the flow rate inside the anaerobic tank and F / M ratio in the anaerobic tank to create an optimal environment for the PAOs, which are phosphorus-removing microorganisms that contribute to dephosphorization in the anaerobic tank, by returning the treated water with low concentration of nitrate nitrogen to the anaerobic tank. to keep the ^- - nitrate nitrogen (NO ₃ -N) and the mixture ratio of suspended solids (MLSS)] best possible effective control of a waste water treatment apparatus by a flow rate control possible anoxic tank internal high denitration ratio (SNDR) secured year The present invention relates to an internal transport flow control system of a wastewater treatment system that can be remotely controlled from a central control room.

Description

Inner flow control system of apparatus for treating water

The present invention relates to an internal return flow control system of a wastewater treatment apparatus. More specifically, in the waste water treatment apparatus comprising an anaerobic tank, a dissolved oxygen low tank, an anoxic tank, an aerobic tank, a settling tank, an internal transport line connecting the aerobic tank and the dissolved oxygen low tank and an internal transport line connecting the anoxic tank and the anaerobic tank, Controlling the flow rate inside the anaerobic tank and F / M ratio in the anaerobic tank to create an optimal environment for the PAOs, which are phosphorus-removing microorganisms that contribute to dephosphorization in the anaerobic tank, by returning the treated water with low concentration of nitrate nitrogen to the anaerobic tank. Efficient control of the wastewater treatment system is possible by controlling the internal flow rate of the anaerobic tank, which can maintain the ratio of nitrogen-nitrogen nitrogen (NO3-N) and mixed liquid suspended solids (MLSS) optimally to ensure high denitrification rate (SNDR) throughout the year. The present invention relates to an internal transport flow control system of a wastewater treatment system that can be remotely controlled from a central control room.

The present invention is for the efficient control of the internal transport flow rate of the wastewater treatment apparatus (patent application No. 10-2000-0011595) filed by the applicant of the present invention.

First, a representative embodiment of the wastewater treatment apparatus to which the present invention is applied will be described. As shown in FIG. 1, the wastewater treatment apparatus includes an anaerobic tank (1), an anaerobic tank (2), an aerobic tank (3), and a dissolved oxygen lowering tank (4) and a precipitation tank (5). ), And the configuration is the same as the conventional A ² / O wastewater treatment apparatus, while the conventional A ² / O wastewater treatment apparatus returns the sludge precipitated in the settling tank (5) to the anaerobic tank, The wastewater treatment apparatus to which the invention is applied has a difference in returning the sludge deposited in the settling tank 5 to the aerobic tank 3. The influent for wastewater treatment is introduced into the anaerobic tank (1), and is mixed by the mixer in the anaerobic tank (1) and at the same time organic matter is removed by the phosphorus-removing microorganisms (Phosphours Accumulating Organisms) and phosphorus (PO₄￣-P) Released, the concentration of phosphorus in the bath increases.

The treated water treated in the anaerobic tank 1 is transferred to the anoxic tank 2, and in the anoxic tank 2 is mixed by a mixer to remove nitrogen and organics by denitrification bacteria.

The treated water treated in the anaerobic tank (2) is transferred to the aerobic tank (3), and part of the treated water is returned to the anaerobic tank through the anaerobic tank internal transfer line (9), and the treated water from which the NOx is removed from the anaerobic tank is returned to the anaerobic tank (1). As a result, NOx suppression of phosphorus emission from the anaerobic tank does not occur, resulting in an improved efficiency of final phosphorus removal.

In the aeration tank (3), the compressed air is blown from the bottom to supply oxygen to remove residual organic matter and ammonia nitrogen. The treated water treated in the aerobic tank 3 is transferred to the settling tank 5 and a part of it is returned to the anoxic tank through the internal transfer line 7 for the removal of nitrogen. In the settling tank 5, the sludge is settled and the purified water is discharged to the outside, and a part of the sludge is supplied to the aeration tank 3 through the inner conveying line 6 again. By passing the dissolved oxygen reduction tank 4 in the middle of passing the returned water from the aerobic tank 3 to the anoxic tank 2, the treatment efficiency in the anoxic tank 2 is improved by removing the dissolved oxygen in the returned water. The dissolved oxygen reducing tank 4 may be installed inside the anaerobic tank 1 or the anaerobic tank 2 or may be provided between the anaerobic tank 1 and the anoxic tank 2.

For efficient operation of the wastewater treatment system as described above, the amount of treated water having low concentration of nitrate nitrogen in the anoxic tank (2) is optimized and returned to the anaerobic tank (1) to create an environment in which PAOs can predominate in the anaerobic tank. And the F / M ratio (the ratio of nitrate nitrogen (NO3-N) and mixed liquor suspended solids (MLSS)) indicating the optimal amount of denitrification bacteria in the anoxic tank (2). It is very important to adjust the return flow rate of the treated water returned to the dissolved oxygen reduction tank (4).

That is, since it is very important in the wastewater treatment apparatus described above to maintain the optimum amount of microorganisms (PAOs, denitrification bacteria, etc.) that function in the purification of wastewater in anaerobic and anaerobic tanks in the biological treatment process, such wastewater treatment apparatus There is an urgent need for the development of technology that can control the amount of treated water returned internally and further remotely control this control.

The present invention has been devised by the necessity of the above technical development,

An object of the present invention is to operate the wastewater treatment system more efficiently through the optimal control of the amount of water transported inside the wastewater treatment apparatus.

Another object of the present invention is to provide a system consisting of a measuring means, a control means for processing the value measured by the measuring means to adjust the amount of the internal transport water and a control monitoring means capable of automatically remotely controlling the control means. To provide optimum control of the wastewater treatment system.

1 is a specific example of the installation configuration of the wastewater treatment apparatus to which the present invention is applied.

Figure 2 is an embodiment of the installation configuration of the wastewater treatment apparatus to which the system of the present invention is applied.

3 is a specific example of an algorithm related to the control of an oxygen-free tank internal transfer flow rate in the internal operation circuit of the process control equipment (PCS) of the present invention.

4 is a specific example of an algorithm relating to the control of the internal conveyance flow rate of the anaerobic tank in the internal operation circuit of the process control equipment (PCS) of the present invention.

<Short description of the symbols in the drawings>

10: anaerobic tank 20: dissolved oxygen reduction

30: anoxic tank 40: angi group

50: sedimentation tank 100: anoxic tank flow transfer device 110, 210: internal transfer pump 120, 220: internal transfer pump adjusting means (inverter)

200: anaerobic tank flow transfer device 300: flow transfer control device

310: process control equipment (PCS) 311: nitrate nitrogen concentration meter

312: dissolved oxygen concentration meter 313: internal oxygen flow meter 314: influent flow meter 315: influent chemical oxygen demand meter

316: mixed liquid suspended solids concentration meter 317: anaerobic tank internal conveyance flowmeter 400: on-computer monitoring operation equipment

The present invention, in order to achieve the above object, in order to control the amount of treated water conveyed from the aerobic tank and the anaerobic tank of the waste water treatment apparatus, an oxygen-free tank flow transfer device, anaerobic tank flow transfer device and flow rate transfer control device and remote automatic control thereof A computer monitoring operation facility capable of being installed in the wastewater treatment apparatus will be described in detail with reference to FIGS. 2 to 4.

The internal conveyance flow control system of the wastewater treatment apparatus of the present invention,

An internal conveying line 70 connected between the aerobic tank 40 and the anoxic tank 30 via the dissolved oxygen reducing tank 20, the internal conveying line 60 and the settling tank 50 of the anaerobic tank 30 and the anaerobic tank 10. In the wastewater treatment apparatus (80) comprising:

An oxygen-free tank flow conveying apparatus 100 is installed in the exhalation tank, including an internal conveying pump 110 for conveying the treated water treated in the exhalation tank to the dissolved oxygen reduction tank 20 and a pump operation control means 120 such as an inverter. ; The anaerobic tank flow conveying apparatus 200, which is installed in the anoxic tank 30, includes an internal conveying pump 210 for conveying the treated water treated in the anaerobic tank 10 to the anaerobic tank 10 and a pump operation control means 220 such as an inverter. ; And a flow measuring device 300 including a measuring device for measuring control factors of the anaerobic tank and anoxic tank flow conveying device, and a process control facility 310 for controlling an internal conveying flow process by the measured value of the measuring device. In addition, the wastewater purification apparatus 80 is an anaerobic tank flow conveying apparatus 100, an anaerobic tank flow conveying apparatus 200 and a flow conveying control device 300 and a computer controlled monitoring operation equipment 400 is shown an installation diagram installed 2 is shown.

First of all, the wastewater treatment apparatus 80 to which the present invention is applied will be described first, and the oxygen-free tank flow conveyance apparatus 100 and the oxygen-free tank for conveying the treated water treated in the aerobic tank 40 to the dissolved oxygen lowering tank 20 in the anoxic tank ( Anaerobic tank flow conveying apparatus 200 for returning the treated water treated in 30) to the anaerobic tank 10, and a flow conveyance control device 300 for automatically controlling the anaerobic tank flow conveying apparatus and the anaerobic tank flow conveying apparatus, the flow rate conveying The computer monitoring and operating facility 400 for remotely controlling the adjusting device 300 will be described in order.

<Waste water treatment device>

Looking at the wastewater treatment apparatus 80 to which the present invention is applied, the wastewater treatment apparatus 80 is composed of an anaerobic tank 10, dissolved oxygen reduction tank 20, anoxic tank 30, an aerobic tank 40 and a settling tank 50. .

Influent for treating wastewater is introduced into the anaerobic tank (10), and mixed with the mixer in the anaerobic tank (10) and at the same time organic matter is removed by the phosphorus removal microorganisms (Phosphours Accumulating Organisms), phosphorus (PO ₄￣-P) It is released, increasing the concentration of phosphorus in the anaerobic tank. The treated water treated in the anaerobic tank 10 is transferred to the anoxic tank 30, and the nitrogen and organics are removed by the denitrification bacteria while being mixed by the mixer in the anoxic tank 30 as well.

The treated water treated in the anaerobic tank 30 is transferred to the aerobic tank 40, and part of the treated water is returned to the anaerobic tank 10 through the anaerobic tank internal return line 60, and the treated water from which the NOx is removed from the anaerobic tank 10 is anaerobic tank 10. As it is transported inside the furnace, the suppression of phosphorus emission by NOx does not occur in the anaerobic tank, so that the final phosphorus removal efficiency is improved.

In the aerobic tank (30) by blowing compressed air from the bottom to supply oxygen to remove the residual organic matter and ammonia nitrogen. The treated water treated in the aerobic tank 30 is transferred to the settling tank 50 and part of the treated water is returned to the anoxic tank 30 via the dissolved oxygen reduction tank 20 through the inner transfer line 70 to remove nitrogen. In the settling tank 50, the sludge is precipitated and the purified water is discharged to the outside, and a part of the sludge is supplied to the aeration tank 40 through the inner conveying line again.

By passing the dissolved oxygen reduction tank 20 in the middle of the conveyed water returned from the aerobic tank 40 to the anoxic tank 30, the dissolved oxygen in the conveyed water is removed to improve the treatment efficiency in the anoxic tank 30. Dissolved oxygen reduction tank 20 is installed in the anaerobic tank 10 or the anaerobic tank 30, or is installed between the anaerobic tank 10 and the anaerobic tank 30.

<Anoxic tank flow transfer device>

The oxygen-free tank flow conveying apparatus 100 is a device for conveying the treated water treated in the aerobic tank 30 to the dissolved oxygen-low tank 20 of the oxygen-free tank, the inverter for adjusting the rotational speed of the internal transport pump 110 and the internal transport pump Pump operation control means such as 120.

The internal conveying pump 110 is used to operate the pump inside the aerobic tank, it is installed in the bottom of the aerobic tank in Figure 2, may be installed in accordance with the size of the waste water purification treatment apparatus and the capacity of the aerobic tank. The amount of conveyance of the treated water processed in an aerobic tank to the anoxic tank is adjusted according to the magnitude | size of the rotation speed of the internal conveyance pump 110.

Pump operation control means 120 is for adjusting the rotational speed of the motor (M) of the internal transfer pump 110, to convert the rotational speed of the motor according to the control operation result of the process control equipment 310 to be described later It is preferable that an inverter can be used, but is not limited thereto. It is also possible to use another apparatus capable of controlling the rotational speed of the motor of the internal transfer pump. The means for controlling the adjustment of the rotational speed is a process control facility (PCS, 310) to be described later, this process control facility also controls the anaerobic tank flow transfer device 200 described later.

<Aerobic tank flow conveying device>

Anaerobic tank flow conveying apparatus 200 is a device for conveying the treated water treated in the anaerobic tank 30 to the anaerobic tank 10, the pump operation control such as the inverter to control the rotational speed of the inner conveying pump 210 and the inner conveying pump Means 220.

The internal conveying pump 210 is the same as the above-described aerobic flow rate conveying apparatus, and the conveying amount of the treated water treated in the anoxic tank is adjusted according to the magnitude of the rotation speed of the inner conveying pump 210.

The pump operation control means 220 is to adjust the rotational speed of the motor (M) of the internal transfer pump 210, and also to convert the rotational speed of the motor according to the control operation result of the process control equipment 320, which will be described later It is preferable that an inverter 220 can be used, and a means for controlling the adjustment of the rotation speed is a process control facility (PCS, 310) described below.

<Flow transfer control device>

The flow transfer control device 300 has a function of adjusting the rotation speed of the internal transfer pumps 110 and 120 which are commonly used in the above-described anoxic tank flow transfer device 100 and the anaerobic tank flow transfer device 200, for automatic control. Programmable Logic Control (PLC), which is a control operation device of a PCS (Process Control Station), is used. That is, the result of control operation according to the internal program of the PLC is output as an operation amount, and accordingly, the rotation speed of the internal transfer pump is adjusted. The input value required to obtain the control operation result is measured by a plurality of measuring devices installed in the wastewater treatment apparatus. The value is used. That is, the manipulated value (control operation result), which is a target value to be adjusted, is generated by the measured value (input value) measured by the measuring instrument and the internal program (control operation) of the PLC, and the manipulated value (control operation result) It is transmitted to the inverter of the internal transfer pump of the anaerobic tank, and the rotation speed of the internal transfer pump is controlled by the frequency generated by the inverter.

The measuring device can be divided into a measuring device for the control of the anaerobic flow rate transport apparatus and a measuring device for the control of the anaerobic flow rate transport apparatus, which is used to control the anaerobic flow rate transport apparatus 100 and the anaerobic flow rate transport apparatus 200. This is because there is a difference in the input value required for the control operation.

In other words, the input value required for the control operation of the oxygen-free tank flow transfer device 100 is the nitric acid concentration of the oxygen-free tank, the dissolved oxygen concentration of the dissolved oxygen-lowering tank 20 installed in the oxygen-free tank (or aerobic tank), and the internal transport flow value of the oxygen-free tank. The measuring instrument for measuring these values is a conventional densitometer and a flow meter, but is shown in Figure 2 as a nitrate nitrogen concentration meter 311, dissolved oxygen concentration meter 312, anoxic tank internal return flow meter (313), respectively The converted value is converted into an electrical signal and transmitted to the PLC, and these converters are indicated as NO ₃ T, DOT, and FT 1 in FIG.

In addition, input values required for the control operation of the anaerobic tank flow conveying apparatus 200 are inflow wastewater flowing into the anaerobic tank, chemical required oxygen content of the influent wastewater, concentration of the mixed liquid suspended solids (MLSS) of the anaerobic tank, and internal transport flow of the anaerobic tank. Measuring equipment for measuring these values also uses a conventional concentration meter and flow meter, but Figure 2 shows the influent flow meter 314, influent chemical oxygen demand meter 315, mixed liquid suspended solids concentration meter 316 and anaerobic tank internal flow meter (317) The measured values are also converted into electrical signals and transferred to the PLC, and these converters are indicated as FT2, CODT, and MLSST FT3 in FIG.

The apparatus for converting the input values measured from the measuring instruments installed in the aerobic tank, the dissolved oxygen lowering tank, the anoxic tank, and the anaerobic tank to the desired manipulated value is the process control facility (PCS) 310 of FIG. The PCS adopts a PLC as an internal computing device, and the PLC is a device for automatically calculating a target manipulated value according to an internal program based on an input value input from a measuring device. The means is called an input circuit, the means for converting the input value into the manipulated variable is called an internal operation circuit, and the means for forming the frequency at which the converted manipulated variable is capable of adjusting the inverter of the internal transfer pump is called a pump adjusting circuit. Function as internal program of PLC.

Since the input circuit and the pump adjusting circuit function as input circuits and output circuits adopted by ordinary PLCs, a separate description is omitted.

The internal operation circuit of the PLC serves to adjust the rotation speed of the internal transfer pumps 110 and 210 installed in the final wastewater treatment device according to the internal logic using the measured value transmitted from the measuring device as an input value.

First, FIG. 3 shows an algorithm of an internal operation circuit of a PLC for adjusting the rotation speed of the internal transfer pump 210 installed in the aerobic tank 40.

That is, as described above, the input value required for the control value of the oxygen-free tank flow conveyance apparatus 100 includes the nitrate-nitrogen concentration of the oxygen-free tank, the dissolved oxygen concentration of the dissolved oxygen-lowering tank 20 installed in the oxygen-free tank (or aerobic tank), and the oxygen-free tank. It is an internal conveyance flow rate value, and a final operation amount is the rotation speed of the inverter of the internal conveyance pump 210.

The control operation consists of the cascade operation circuit, which is the main operation circuit, and the dissolved oxygen concentration control PID operation circuit of the dissolved oxygen reduction modulation, which is the auxiliary operation circuit, and is dissolved by outputting each of these calculation results through a small value selector (LOW selector). When the dissolved oxygen concentration in the oxygen lowering tank exceeds the target value of 0.2 mg / L, the internal return flow rate can be reduced.

The deviation used for the master PID operation of the cascade operation circuit is the difference between the anoxic nitrogen nitrate (NO ₃ ^-- N) concentration and the target value, and the deviation used for the lower PID operation is the result of the upper PID operation. This is the difference from the internal return flow into the tank.

The upper and lower limit control circuit and the internal return flow driver circuit can be operated continuously by the manual setting value of the driver in case of failure of the measuring equipment.

As a result of the final control operation, that is, the inverter of the internal transfer pump converts the frequency of the motor power so as to be proportional to the output of the manipulated variable to adjust the rotation speed of the motor. By adjusting the rotational speed of the motor, the ratio between the nitrous nitrogen and the microbial mass (MLSS) in the anoxic tank in which the nitrate is removed by the microbial mechanism, that is, the maximum ratio is maintained by maintaining the above-described F / M ratio. An environment is created to enable SDNR.

4 shows an algorithm of the internal operation circuit of the PLC for adjusting the rotational speed of the internal transfer pump 110 installed in the oxygen-free tank 20.

That is, as described above, the input value required for the control operation of the anaerobic tank transfer device 100 includes the amount of wastewater flowing into the anaerobic tank, the chemical demand oxygen of the wastewater, the concentration of the mixed liquid suspended solids (MLSS) of the anaerobic tank, and the inside of the anaerobic tank. It is a conveyance flow volume and a final operation amount is the rotation speed of the inverter of the internal conveyance pump 110. FIG.

The control operation is a cascade operation method consisting of a master PID operation and a lower PID operation. Deviation used for higher PID operation is obtained by subtracting the anaerobic tank mixed liquor concentration from the target value obtained by multiplying the anaerobic tank waste and influent chemical oxygen demand by the set value conversion. The deviation used for the lower PID operation is obtained by subtracting the internal return flow of the anaerobic tank from the upper PID operation result. Can be operated continuously by the upper and lower limit circuit and the manual setting value of the internal return flow operator.

The process control equipment (PCS) is connected to a computer monitoring control system (OPS, CRT Operator's Station, 400) to remotely control the operation of the wastewater treatment system in a central control room. The central control room can be monitored in real time so that the PCS can be controlled without a separate manual operation.

The present invention is a system comprising a measuring device installed in a wastewater treatment device, a control means for processing the value measured by the measuring device to adjust the amount of the internal transport water and a control and monitoring means for automatically remotely controlling the control means. It is possible to increase the efficiency of the treatment of influent wastewater through the optimal control of the wastewater treatment system by providing a.

Claims (5)

In a wastewater treatment apparatus including an aerobic tank and an anoxic tank inner conveying line through a dissolved oxygen reducing tank, an inner conveying line of anoxic and anaerobic tanks and a settling tank, An oxygen-free tank flow conveyance device installed in the aerobic tank, the pump comprising an internal transport pump for conveying the treated water treated in the aerobic tank to the dissolved oxygen reduction tank and a pump operation control means such as an inverter; An anaerobic tank flow conveying apparatus installed in the anoxic tank and including a pump operation control means such as an internal conveying pump and an inverter for conveying the treated water treated in the anaerobic tank to the anaerobic tank; And, A flow conveyance adjusting apparatus including a measuring device for measuring a control value of the anoxic tank and an anaerobic tank flow conveying device, and a process control facility for controlling an internal conveying flow rate process by the measured value of the measuring device; Included, the internal flow rate control system of the wastewater treatment apparatus, characterized in that the dephosphorization action of the anaerobic tank and the non-nitrogen ratio of the anaerobic tank by the flow rate control device is automatically controlled and optimized. The method of claim 1, wherein the measuring device Installed in the inlet line in the wastewater treatment device, the measuring device for measuring the amount of wastewater introduced; A measuring device installed in an inlet line of the wastewater treatment device and measuring a chemical oxygen demand (COD) of the influent wastewater; A measuring device installed in the anaerobic tank and measuring the concentration of the mixed liquid suspended solids (MLSS) in the anaerobic tank; A measuring device installed in the anoxic tank and measuring the concentration of nitrate nitrogen in the anoxic tank; A measuring device for measuring the dissolved oxygen of the dissolved oxygen reducing tank installed in the anoxic tank or the aerobic tank; And A measuring device for measuring an internal conveying flow rate of the aerobic flow rate conveying apparatus and the anaerobic flow rate conveying apparatus; Included, the measured value of each measuring instrument is controlled in the process control equipment (PCS), the internal transport flow rate control system of the wastewater treatment apparatus, characterized in that the anaerobic tank and anoxic tank internal transport flow rate is automatically controlled. In claim 2, the automatic control of the flow rate of the inside of the anaerobic tank is An input circuit for receiving an input signal which is a measurement value of an inflow wastewater amount of an anaerobic tank, a chemical required oxygen amount of an inflow wastewater, a concentration of a mixed liquid floating material of an anaerobic tank, and an internal return flow rate of an anaerobic tank; An internal operation circuit adjusted to a driver input circuit capable of adding a manual setting value of a driver, and converting the input signal into upper and lower control values which are control target values; And, A pump adjusting circuit for adjusting the rotational speed of the internal conveying pump by a frequency adjusted by a pump operation adjusting means of an anaerobic tank so as to be proportional to the upper and lower control values; Internal conveyance flow control system of the wastewater treatment apparatus, characterized in that controlled by the plant control equipment comprising a. The automatic control of the oxygen-free tank internal transfer flow rate is An input circuit for receiving an input signal that is a measured value of the nitrate nitrogen concentration in the anoxic tank, the dissolved oxygen concentration in the dissolved oxygen low tank, and the internal return flow rate of the anoxic tank; An internal operation circuit adjusted to a driver input circuit capable of adding a manual setting value of a driver, and converting the input signal into upper and lower control values which are control target values; And, A pump adjusting circuit for adjusting the rotational speed of the internal conveying pump by the frequency adjusted by the pump operation adjusting means of the anoxic tank so as to be proportional to the upper and lower limit control values; Internal conveyance flow control system of the wastewater treatment apparatus, characterized in that controlled by the plant control equipment comprising a. The display apparatus according to any one of claims 1 to 4, wherein the flow conveyance control device is connected to a process control facility (PCS), and is provided by a display device and a display device capable of displaying the control of the process control facility in a promised figure. An internal conveyance flow control system of a wastewater treatment system, characterized in that the remote control is automatically controlled by a central control room equipped with an On-Site Monitoring System (OPS) for monitoring the visualized control process in real time.