JPH07275843A - Operation control method for drainage treatment facility and central control system for more than one drainage treatment facility - Google Patents

Abstract

PURPOSE:To prevent treated water with inferior quality from discharging in a process in which raw water to be purified is passed through a treatment tank, and the treated water is discharged from the treatment tank. CONSTITUTION:The quality of treated water discharged from a treatment tank 10 is monitored by a water quality measuring instrument 13. When the water quality exceeds or is going to exceed a set value, the amount of raw water to be supplied to the treatment tank 10 is reduced or stopped.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention monitors the quality of treated water discharged from drainage facilities such as sewage treatment facilities and rural village wastewater treatment facilities, and when the water quality exceeds or exceeds a certain set value. In this case, the present invention relates to a method for controlling the operation of the wastewater treatment facility for lowering the water quality below the set value, and a centralized management method for a plurality of wastewater treatment facilities.

[0002]

2. Description of the Related Art FIG. 10 shows a control state of a conventional operation of a wastewater treatment facility using activated sludge. Raw water flowing into a raw water tank is pumped by one of two pumps (the other one is a spare). )
Is supplied to the metering tank by two of the three pumps (the other one is a spare), and then flows from the metering tank to the aeration tank at a constant flow rate. Excess raw water supplied to the measuring tank returns to the flow rate adjusting tank. In the flow path of the raw water from the raw water tank to the flow rate adjustment tank, a flow rate indicator integration meter (FIQR)
To record the total inflow of raw water. Air is supplied from the blower to the aeration tank, and the raw water that has flowed into the aeration tank is purified by activated sludge that grows in the tank, becomes treated water and flows into the sedimentation tank in the subsequent stage, and sludge is separated by this. After that, it flows into the disinfection tank, is sterilized, and is discharged.

A dissolved oxygen meter (DO meter) is installed in the aeration tank, and the rotation speed of the blower is changed according to the indicated value (dissolved oxygen amount), and the number of blowers to be operated is one or two. However, if the dissolved oxygen amount is high, the air amount supplied by the blower is decreased, and if the dissolved oxygen amount is low, the supplied air amount is increased to keep the dissolved oxygen amount within a predetermined range.

A sludge densitometer (MLSS) is attached to the return line for returning sludge from the bottom of the settling tank to the aeration tank, and the operation of the return pump is controlled by the concentration of the sludge. In this case, return it to the other side and keep the concentration of activated sludge in the aeration tank within a predetermined range.

In order to measure the sludge concentration in the aeration tank, a sludge concentration meter is installed in the tank, and the operation of the return pump is similarly controlled according to the sludge concentration in the tank. Then, when the sludge concentration in the tank becomes high and exceeds a certain value, the sludge valve in the middle of the return line is opened and the returned sludge is discharged to the sludge storage tank. Also, the return pump of the sludge return line is controlled by the amount of raw water inflow by the above-mentioned raw water inflow meter, and the amount of returned sludge is increased when the amount of inflow of raw water is large, and the amount of returned sludge is decreased when the amount of inflow of raw water is small. .

[0006]

As described above, in the conventional wastewater treatment facility, the amount of dissolved oxygen in the treatment tank which is an aeration tank,
A measuring instrument that controls the sludge concentration of activated sludge to match the treatment conditions and measures the quality of treated water in a disinfection tank, such as C
In some cases, an OD measuring device is installed to measure the COD value, but the operation is not controlled based on the quality of treated water. Therefore, even if the amount of dissolved oxygen and the sludge concentration in the treatment tank are controlled, the treated water is not always sufficiently treated, and the treated water such as a high COD value is discharged. The current situation is that there are some cases.

[0007]

The present invention is for solving the above-mentioned problems, and the operation control method for a wastewater treatment facility according to claim 1 is one in which raw water is passed through the treatment tank, In the operation method of the wastewater treatment facility where the raw water is purified by the treatment method and the treated water is discharged from the treatment tank, the quality of the treated water discharged from the treatment tank is monitored with a water quality measuring device, and the water quality exceeds a certain set value. In the case of or when trying to exceed, it is characterized in that the amount of raw water flowing into the treatment tank is reduced or stopped. Then, the treatment tank may be provided with a sedimentation tank at the latter stage, and the treated water purified by the treatment tank may be discharged through the sedimentation tank. Further, the centralized management system for a plurality of wastewater treatment facilities according to claim 2 is one in which a plurality of wastewater treatment facilities pass raw water through a treatment tank, purify the raw water in the treatment tank, and discharge the treated water from the treatment tank. A water quality measuring instrument that monitors the quality of the treated water discharged from the treatment tank is installed in the plant, and the water quality signal output from the water quality measuring instrument of each wastewater treatment facility is input to the central management unit, and discharged from each wastewater treatment facility. When the quality of the treated water exceeds or exceeds a certain set value, the central management unit reduces the amount of raw water flowing to the treatment tank of the wastewater treatment facility.
Alternatively, it is characterized by stopping. Further, some or all of the wastewater treatment facilities may be provided with a settling tank at the latter stage of the processing tank, and the treated water purified by the processing tank may be discharged through the settling tank.

[0008]

EXAMPLE FIG. 1 is a wastewater treatment facility of the activated sludge method similar to the conventional example of FIG. 10 described above, and the dissolved oxygen amount and sludge concentration in the treatment tank (aeration tank) 10 by a dissolved oxygen meter and a sludge concentration meter. Is being controlled. In order to measure the water quality of the treated water that has flowed from the treatment tank 10 to the disinfection tank 12 through the settling tank 11, the disinfection tank is provided with a COD measuring device 13 such as a COD meter and a UV meter, and the COD measuring device 13 disinfects. The COD value of the treated water discharged from the tank is momentarily output to the computing unit (personal computer) 15 via the control panel 14. When the COD measuring device detects, for example, a COD value of the treated water of 10 mg / stand, the calculator 15 controls the operation of the pump P for pumping the raw water from the flow rate adjusting tank 16 to the measuring tank 17 through the control panel to process the raw water. Reduce the amount of raw water flowing to the tank or stop water flow.

The arithmetic unit 15 controls the operation of the pump in such a manner that the inverter is controlled to reduce the rotational speed of the pump even if the pump is continuously stopped, or the pump is not stopped continuously for 30 minutes or for 1 hour. Program control may also be used to select a program for performing intermittent operation for the destination.

Selection of how much the number of revolutions is reduced by inverter control of the number of revolutions and selection of whether the pump is continuously stopped by program control or intermittent operation for 30 minutes or one hour is performed. The arithmetic unit determines and determines the rising curve of the COD value within a predetermined time before the COD value of the treated water reaches 10 mg / stand. The operation of the pump may be returned to the normal state by the COD measuring device detecting that the COD value of the treated water has dropped to 5 mg / stand and outputting it to the computing unit. COD value of treated water is 1
The calculator may determine the time from the rising curve of the COD value before reaching 0 mg / stand.

When the amount of raw water flowing into the treatment tank 10 is reduced or stopped in this way, the retention time of the raw water in the tank is extended, and the contact time with the microorganisms in the tank is lengthened and the raw water is increased. Will be treated more and the water quality will be improved. Then, when the amount of raw water passing through the treatment tank decreases or stops,
The amount of treated water flowing from the treatment tank to the sedimentation tank is also reduced. As a result, the retention time of the treated water in the settling tank is extended, sludge can be sufficiently settled and separated, and SS can be prevented from being mixed with the treated water and leaking to the disinfection tank. As a result, the quality of treated water such as BOD and COD that flows into the disinfection tank is improved,
For example, the COD value decreases. Incidentally, the amount of raw water passing through the treatment tank is reduced, or the amount of raw water is temporarily stopped, so that the treatment time required to treat the same amount of raw water becomes longer.

The chart of FIG. 2 shows that when the COD value of the treated water rises to 10 mg / stand at 12 o'clock, the raw water continues to flow to the treatment tank as it is, and the instruction from the arithmetic unit indicates 12 to 15 The change in the COD value of the treated water when the pump is stopped and the passage of the raw water is stopped for 3 hours until the time. In the case of the broken line where water continues to flow as it is, the COD value rises to 15 mg / stand at 18:00, the processing of the raw water for the day ends at 21:00, and the
The treated water did not flow out for 3 hours at 24:00. On the other hand, in the case of the solid line in which the passage of the raw water was stopped for 3 hours from 12:00 to 15:00, the COD value gradually decreased from 10 mg / stand after 15:00. Then, because the water flow through the raw water was stopped for 3 hours, the water flow through the raw water for the day ended and the outflow of the treated water disappeared at 24:00, and the COD value at that time was 5 mg /
It was standing.

The chart of FIG. 3 shows that when the COD value of the treated water rises to 10 mg / stand at 12 o'clock, the raw water to the treatment tank is kept as it is, and at 12:00 and 16:00 according to the instruction from the arithmetic unit. Two
The change in COD value of treated water when the pump is stopped and the supply of raw water to the treatment tank is stopped is shown for each hour from 0:00. In the case of the broken line that continues water flow, CO
The D value increased to 15 mg / stand, the raw water treatment for the day was completed at 21:00, and the treated water did not flow out for 3 hours from 21 to 24:00. In the case of a solid line that stops water flow three times for one hour, 13:00 to 16:00, 17:00 to 20:00, 2
The COD value gradually decreased from 1 o'clock to 24:00, and the COD value at 24:00 when the inflow of raw water for the day ended and the outflow of the treated water disappeared was 5 mg / stand.

In the chart of FIG. 4, the COD value of the treated water gradually increases from 5 mg / stand at about 7 o'clock, and even if the COD value rises to 8 mg / stand at 11 o'clock, the raw water flow to the treatment tank is kept at that level. The change in the COD value of the treated water is shown in the case of continuing and in the case of lowering the rotation speed of the pump by the inverter control after 11:00 according to the instruction from the arithmetic unit. If the raw water is continuously pumped into the treatment tank at a flow rate of 1 m ³ / hour from midnight, the COD value will be 8 at 11:00.
After becoming mg / stand, the COD value is 1 as shown by the broken line.
The COD value increased to 13 mg / stand at 5 o'clock, and the COD value at 20 o'clock at the end of the inflow of the daily treatment amount of 20 m ³ was 15 mg / stand.
On the other hand, at 11:00 when the COD value reached 8 mg / stand,
When the rotational speed of the pump was reduced by a command from the computing unit and the flow rate up to that point of 1 m ³ / hour was 0.6 m ³ / hour, the COD value gradually decreased to 5 mg / stand at 19:00. Therefore,
The rotation speed of the pump was increased by a command from the computing unit, and the flow rate of raw water to the treatment tank was increased to 0.8 m ³ / hour, but the COD value was 5
It was kept below mg / till. The raw water that flowed into the treatment tank from 0 o'clock to 23 o'clock was found to be 19 m ³ by the flow rate integrating meter, so to achieve the daily treatment amount of 20 m ³ Raise it further, 2
Raw water was supplied to the treatment tank at a flow rate of 1 m ³ / hour for one hour from 3:00 to 24:00, and the inflow of raw water was terminated, but still 2
The COD value at 4 o'clock was kept below 5 mg / stand. Of course, 19
Since then, the flow rate of raw water has been increased to 0.8 m ³ / hour, and as a result,
When the COD value exceeds 5 mg / stand, at that time, the rotational speed of the pump is lowered again by a command from the arithmetic unit. In this case, the daily throughput of the day will be shifted to the next day.

The water quality of the discharged treated water is measured, and when the water quality exceeds or is about to exceed a certain set value, the amount of raw water passing through the treatment tank is reduced or stopped. The quality of water can be improved by using the biofilm method of FIG. 5 in which the aeration tank, which is a treatment tank, is replaced by an anaerobic filter bed tank and a contact aeration tank in addition to the wastewater treatment facility using activated sludge in FIG. Even in the processing facility, No. No. 1 batch tank, Even in the batch type wastewater treatment facility of FIG.
The same applies to the oxidation ditch type wastewater treatment equipment that uses the circulating water channel as the treatment tank. The COD measuring device 13 detects the COD value of the treated water and outputs it to the calculator 15, which then passes the raw water to the treatment tank. The same can be done by controlling the amount of water. In addition, the oxidation ditch drainage treatment facility often does not have a flow rate adjusting tank, and the raw water is supplied from the raw water tank 18 directly to the ditch 10 by a pump. Therefore, the calculator 15 controls this pump to control the ditch. Either reduce the amount of raw water supplied or stop the supply of raw water.

In the above description, in order to detect the COD value of the treated water, a COD measuring instrument such as a COD meter and a UV meter was installed in the disinfection tank. However, an SS meter and a pH meter were installed for water quality measurement, It can also improve other water quality.

In FIG. 9, reference numeral 20 denotes various wastewater treatment facilities such as the activated sludge method, the biofilm batch method, and the oxidation ditch method described above.
-1, 20-2 ... When the quality of the treated water discharged by 20-N exceeds or is about to exceed a certain set value, a reduction in the amount of raw water passing to the treatment tank of the wastewater treatment facility. , Or that the water flow is stopped by one central management device. Each wastewater treatment facility receives the output of the COD measuring device 13 or is provided with a control panel 14 connected to two pumps to eliminate the computing unit 15, and the control panel 14 of each wastewater treatment facility is connected to the telephone line network 31. To the computing unit 33 in the central monitoring center 32. As a result, the COD of the treated water discharged from one of the wastewater treatment facilities increases, and the C
The OD measuring instrument inputs the COD value to the computing unit 33 via the control panel, and when the computing unit determines that the COD value exceeds or is about to exceed a certain set value, the computing unit passes through the control panel of the facility. Control the operation of the two pumps to reduce the amount of raw water flowing to the treatment tank of the facility or stop the water flow. The mode in which the computing unit 33 of the monitoring center controls the operation of the two pumps of each wastewater treatment facility may be the above-mentioned inverter control or program control. In this way, the water quality of the treated water discharged by each of the plurality of wastewater treatment facilities can be monitored by one computing unit in the monitoring center, and the deterioration of the water quality can be prevented in advance.

Conventionally, an arithmetic unit is provided for each wastewater treatment device,
Since each computing unit was connected to the computing unit in the monitoring center by a telephone line network, if there were 10 wastewater treatment facilities, 10 computing units and 1 computing unit in the monitoring center totaled 11 units. A computing unit was required, and the equipment cost was very high. However, since only one computing unit needs to be installed in the monitoring center by the above method, the facility cost becomes very low.

[0019]

According to the first aspect of the present invention, it is possible to prevent deterioration of the quality of treated water discharged from various wastewater treatment facilities. According to claim 2, it is possible to prevent deterioration of the quality of the treated water individually discharged by a plurality of various wastewater treatment facilities with one arithmetic unit in the central monitoring center. Moreover, the equipment cost will be significantly reduced because there is no computing unit in each wastewater treatment facility.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a state in which the present invention is carried out in a wastewater treatment facility using an activated sludge method.

FIG. 2 is a chart showing changes in the quality of treated water when the raw water is temporarily stopped from flowing into the treatment tank and when it is not.

FIG. 3 is a chart showing changes in the quality of treated water when the raw water flow to the treatment tank is intermittently stopped and when it is not.

FIG. 4 is a chart showing changes in the quality of treated water when the pump operation is inverter-controlled and when it is not.

FIG. 5 is an explanatory diagram showing a state where the present invention is carried out in a wastewater treatment facility of the biofilm method.

FIG. 6 is an explanatory diagram showing a state in which the present invention is implemented in a batch-type wastewater treatment facility.

FIG. 7 is an explanatory diagram showing a state in which the present invention is carried out in an oxidation ditch type wastewater treatment facility.

FIG. 8 is an elevational view of an oxidation ditch type wastewater treatment facility.

FIG. 9 is an explanatory diagram of a centralized management state of a plurality of wastewater treatment facilities.

FIG. 10 is an explanatory diagram showing an operation control state in a conventional wastewater treatment facility.

[Explanation of symbols]

 10 treatment tank 11 settling tank 12 disinfection tank 13 COD measuring device (water quality measuring device of control water) 14 control panel 15 calculator 16 flow rate adjusting tank 17 measuring tank 18 raw water tank 20 wastewater treatment facility 31 telephone network 32 monitoring center 33 monitoring Center calculator

Claims (4)

[Claims] 1. A method of operating a wastewater treatment facility, wherein raw water is passed through a treatment tank, the raw water is purified by the treatment tank, and the treated water is discharged from the treatment tank. The quality of the treated water discharged from the treatment tank. The operation of the wastewater treatment facility is characterized in that when the water quality exceeds or exceeds a certain set value, the flow rate of raw water to the treatment tank is reduced or stopped. Control method. 2. The operation control method for a wastewater treatment facility according to claim 1, wherein the treatment tank is provided with a sedimentation tank at the latter stage, and the treated water purified by the treatment tank is discharged through the sedimentation tank. Operation control method for wastewater treatment facilities. 3. The quality of the treated water discharged from each treatment tank of a plurality of wastewater treatment facilities in which the raw water is passed through the treatment tank, the raw water is purified in the treatment tank, and the treated water is discharged from the treatment tank. A water quality measuring device for monitoring is installed, and the water quality signal output from the water quality measuring device of each wastewater treatment facility is input to the central control unit, and the quality of the treated water discharged from each wastewater treatment facility exceeds a certain set value. Central control system for a plurality of wastewater treatment facilities, characterized in that the central control unit reduces or stops the flow of raw water to the treatment tank of the wastewater treatment facility in the event of or in the case of overcoming. 4. The centralized management system for a plurality of wastewater treatment facilities according to claim 3, wherein some or all of the wastewater treatment facilities have a settling tank attached to the latter stage of the treatment tank and purification treatment is carried out in the treatment tank. A centralized management method for multiple wastewater treatment facilities where water is discharged through a settling tank.