JPH07232190A - Batchwise waste water treatment device and its centralized control system - Google Patents

Abstract

PURPOSE:To make it possible to inexpensively obtain a COD discharge rate by abolishing a costly flow rate indicating integrator which is used so far in order to determine the COD discharge rate per 24 hours of the treated water released from a batchwise waste water treatment device. CONSTITUTION:This batchwise waste water treatment device is constituted by providing plural batch tanks No. 1, No. 2 with water level gates 15 for determining the inflow rates of the raw water supplied into these tanks to prescribed values. The raw water is supplied from a raw water tank 10 to the plural batch tanks by varying the time and the raw water is subjected to aerating, stirring and settling treatments in the respective batch tanks. The treated water treated in the respective batch tanks is released through a common disinfecting tank 17. This disinfecting tank 17 or the release path for the treated water is provided with a COD measuring instrument for measuring the COD value of the treated water. The device is provided with an arithmetic and logic unit 27 to which the outputs of the respective water level gages 15 of the plural batch tanks and the output from the COD measuring instrument 25 are inputted. The COD discharge rate per 24 hours of the treated water released through the disinfecting tank is calculated by this arithmetic and logic unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces the number of expensive flow rate integrating meters used in a conventional batch type waste water treatment device by half and obtains the COD emission amount of discharged treated water per 24 hours. Of multiple batch type waste water treatment devices and multiple batch type waste water treatment devices that manage the COD discharge amount per 24 hours of the treated water discharged from the multiple batch type waste water treatment devices with a central arithmetic unit It relates to a centralized management system for wastewater treatment equipment.

[0002]

2. Description of the Related Art A batch-type wastewater treatment system, together with a wastewater treatment system using an activated sludge method or a biofilm method, has a population of about 1,000.
It is widely used as a wastewater treatment device for agricultural settlements that treats 250 households of domestic wastewater. As is well known, this batch-type wastewater treatment device transfers the raw water that has passed through the coarse screen and the crusher from the raw water tank to the flow rate adjusting tank, and supplies it from the flow rate adjusting tank to a plurality of batch tanks at different times, Raw water is aerated, stirred, and settled in each batch tank, and the treated water treated in each batch tank is discharged through a common disinfection tank. In the conventional batch-type wastewater treatment device, an inflow-side flow indicator integrating meter is provided to measure the inflow amount of raw water in the flow path that transfers the raw water from the raw water tank to the flow rate adjusting tank. In addition, a COD measuring device in the disinfection tank,
A discharge-side flow-rate integrator is provided in the flow path of the treated water discharged from the disinfection tank, and COD discharge per 24 hours is released from the device by the output of the COD measuring device and the output of the discharge-side flow-rate integrator. The amount is calculated by inputting it into a dedicated COD calculator or a personal computer.

The reason for obtaining the COD emission amount per 24 hours of treated water is that the allowable value of the COD emission amount per 24 hours is set for each facility in a facility that discharges 50 m ³ or more of treated water per day depending on the region. It is required to prove that the COD emission amount per 24 hours is less than the allowable value, or because COD ≈ BOD × 1.6 to 2.0, the BOD can be estimated by calculation. It is not possible to continuously measure by the above method, and instead of obtaining the BOD that cannot be obtained without manual analysis, the COD is estimated to check the treatment status, and the amount of air for aeration and return sludge can be checked by the COD value. This is for adjusting the amount of the power consumption to maintain a good and normal driving condition.

[0004]

In the above-mentioned conventional wastewater treatment equipment, in addition to installing a flow-rate integrator on the inflow side for measuring the inflow water amount of raw water, another unit for calculating the COD emission amount is provided. A flow-rate indicator is installed on the discharge side of the treated water. Since this flow rate indicator integrating meter is a very expensive device, it causes an increase in the installation cost of the device, and there is a demand for cost reduction. Further, in the above-mentioned conventional wastewater treatment device, the output of the flow rate indicating integrating meter on the discharge side and the output of the COD measuring device are calculated by the personal computer, and the COD per 24 hours
We are looking for emissions. Therefore, for example, when centrally managing wastewater treatment equipment at 10 locations, one
In addition to 0 computing units, a central computer for recording and recording 1
Since a total of 11 computers are required, a large amount of investment is required, which is a hindrance to widespread use.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and the batch-type wastewater treatment apparatus according to claim 1 has a plurality of batch tanks, each of which is supplied with raw water supplied into the tank. Raw water is supplied from the raw water tank to the above batch tanks at different times from the raw water tank, and the raw water is aerated, stirred, and precipitated in each batch tank, and then treated in each batch tank. In a batch-type wastewater treatment device that discharges water through a common disinfection tank, a COD measuring device for measuring the COD value of the processed water is provided in the disinfection tank or the discharge path of the treated water, and each water level of the plurality of batch tanks is set. A calculator is provided for inputting the output of the meter and the output of the COD measuring device, and the calculator calculates the COD discharge amount per 24 hours of the treated water discharged through the disinfection tank. According to the centralized control method of a plurality of batch type waste water treatment devices of claim 2, each of a plurality of batch tanks is provided with a water level gauge that determines a predetermined inflow amount of raw water supplied into the tank, and the plurality of batch water tanks are connected to the plurality of batch water tanks. Raw water is supplied to the batch tank at different times, and the raw water is aerated, stirred, and precipitated in each batch tank.
The treated water treated in each batch tank is discharged through a common disinfecting tank, and a COD measuring device for measuring the COD value of the treated water is provided in the disinfecting tank or the treated water discharge passage. The output of each water level meter of the batch tank and the output of the COD measuring device are input to a plurality of batch type wastewater treatment devices provided with a control panel. It is characterized in that the calculator calculates the COD discharge amount of the treated water discharged through the disinfecting tank of each batch type wastewater treatment device per 24 hours.

[0006]

EXAMPLE FIG. 1 is a flow sheet of a typical example of a batch type waste water treatment apparatus. As described above, raw water that has passed through a crusher and a coarse screen and flowed into a raw water tank 10 is pumped to a flow rate adjusting tank 11. It is supplied and stored, and then pumped up from here, and after passing through the screen tank 12 and the measuring tank 13, two batch tank Nos. 1, No. Supply at 2 different times. The flow rate adjusting tank 11 and the measuring tank 13 may be omitted and the raw water tank may be supplied to the batch tank through the screen tank. The bottom of each batch tank can be aerated and agitated simultaneously or separately,
A stirrer 14 is provided. The amount of raw water that flows into each batch tank once is that the water level meter 15 attached to each tank has a flow rate of 100 m ³ or 150 m ³ into the tank. The on-off valve V ₁ provided in the pipe 16 is closed and controlled.

The capacity of the batch tank should be designed with a margin based on the population of the target agricultural settlement. For example, if the inflow rate of raw water is 100 m ³ , the capacity should be several times that of the aeration, stirring and precipitation. After the treatment, etc., the same amount of supernatant water as the inflow is discharged as treated water.

One cycle of the batch tank is usually 6 hours,
No. 1 and No. 2, as shown in FIG. 2, four cycles a day are alternately performed with a shift of 3 hours. FIG. 3 shows one cycle of each batch tank. In (a), a predetermined amount of raw water flows in in 2 hours, aeration is performed at the start of the inflow, the stirring device 14 performs aeration and stirring for 3 hours, and then left standing for 1 hour. Then, the supernatant treated water is drained to the disinfection tank 17 outside the tank in the next 1.5 hours,
The sludge in the tank is pulled out within the remaining 0.5 hours (drainage).
Also, as in (b), sedimentation, drainage, and sludge are the same as in (a), but because denitrification is actively performed, the total of 2 hours of raw water inflow and 1 hour until the subsequent sedimentation During 3 hours, stirring and aeration may be alternately performed for 30 minutes. Further, the raw water may be stirred for 2 hours and then aerated for the remaining 1 hour until precipitation.

Raw water pumped up from the raw water tank is a flow control tank 1
1 or a pipe 18 flowing toward the screen tank 12 is provided with a flow rate indicating integrator 19, which allows the total inflow amount of raw water flowing into both batch tanks per 24 hours to be known.

When the precipitation process is completed in each batch tank, the supernatant water draining device 20 attached to each tank discharges the supernatant treated water to the common disinfection tank 17. FIG. 1 shows a swirling type clear water drainage device, which is immersed and fixed near the lower limit level of clear water drainage on the inner wall of the tank, and an arm with a float 20 'attached at the tip is directed upward.ゞ Drainage is not performed when held vertically, so keep that state during stirring, aeration, and precipitation in the batch tank. When draining water, it is swung downward so that the float 20 'at the tip is positioned on the water surface. The flow rate of drainage to the disinfection tank is determined by the descending speed of the float 20 'or the liquid surface. Since the float descends at a constant speed, the amount of drainage is almost constant and it is set to complete in 1.5 hours. Once drained, hold the arm up vertically again. The treated water drained to the disinfecting tank 20 is disinfected by the chlorine disinfecting device 21, flows into the adjacent discharge tank 22, and is pumped up from here for discharge.

After the discharge of the treated water from each batch tank to the disinfection tank is completed, the sludge accumulated in the batch tank is discharged to the sludge thickening tank 23 by the drawing pump P ₁ , and the excess sludge concentrated in the tank is sludge storage tank. Then, the supernatant water is returned to the raw water tank 10.

The disinfection tank 17 is provided with a COD measuring device 25 such as a COD meter and a UV meter upstream of the disinfecting device 21 so as not to be affected by chlorine. It is possible to know the COD value of the treated water. The COD measuring device is not limited to being provided in the disinfecting tank, and may be provided at a point after the disinfecting tank where the influence of chlorine on the discharge channel of the treated water disappears.

Since the COD discharge amount (COD load) per 24 hours is calculated and obtained, each batch tank No. 1, No.
Output of two water gauges 15 attached to 2 and COD
An arithmetic unit for receiving the output of the measuring instrument 25 via the control panel 26, for example, a personal computer 27 is provided.

As described above, the drainage time for the supernatant water drainage device 20 to drain the treated water from each batch tank to the disinfection tank 17 is 90.
Since the water is drained at a constant flow rate in minutes, when the water level meter 15 sets the inflow rate of raw water flowing into the batch tank to 90 m ³ and inputs it to the calculator, the calculator is addressed to each 10 minutes of the discharge time of 90 minutes. The amount of treated water discharged is calculated as 10 m ³ .

Further, the withdrawal amount of the excess sludge discharged from the sludge thickening tank 23 to the sludge storage tank 24 per 24 hours can be calculated by the sludge accumulation condition in the sludge storage tank 24 and is almost constant. , This is also input to the arithmetic unit. As for the value of the amount of excess sludge drawn out, a numerical value that actually matches the actual situation is obtained, and the value input to the computing unit is corrected. The calculator calculates the input value of the sludge withdrawal amount per 24 hours as the batch tank N.
o. 1 and No. If 2 perform 4 cycles a day for a total of 8 cycles, it will be divided into 8 equal parts, and the amount of withdrawal per 1 cycle divided into 8 parts will be further divided into 9 parts for each 10 minutes in the 90-minute discharge time zone. Then, the withdrawal amount of the sludge, which is divided into 9 equal parts, is subtracted from the treated water discharge amount of 10 m ³ for each 10 minutes in the 90 min discharge time zone of the treated water, and the actual discharge amount of the treated water is calculated. For example, if you enter a withdrawal amount per day of excess sludge to 1.60 m ³ and calculator, the calculator is 0.2 m ³ withdrawal amount per cycle, the 9 equally divided values calculated as 0.022 m ³ 10 minutes ³ to 0.022m of treated water drainage
Wastewater of the actual processing water by subtracting ³ calculates a 9.978M ^3.

Batch tank No. 1, No. The COD measuring instrument 25 is set to 1 as shown in Table 1 in any one cycle that
When the average value (mg / stand) of the COD measurement values every 0 minutes is detected and output to the calculator 27,

[Table 1] The computing unit has a capacity of 9.978m ^{3 for} each 10 minutes of drainage of treated water.
Therefore, the COD emission amount every 10 minutes is calculated every 10 minutes as shown in Table 2, and the total amount thereof is calculated.

[Table 2] Finally, the computing unit is the batch tank No. No. 1 performed four cycles. The COD emission amount of the four cycles performed by 2 is summed up to calculate the COD emission amount per 24 hours. The batch tank No. As shown in FIG. 2, the batch tank No. 1 performs processing for 6 hours from midnight of the day. In the case where the processing is performed for 6 hours from 3:00 am on that day, the batch tank No. 2 starts processing at 9:00 pm on the previous day, adds COD discharge amount of treated water drained between 1:00 am and 2:30 pm on that day, and starts processing at 9:00 pm on that day The COD emission of the treated water discharged between 1 am and 2:30 am on the next day is added to the next day.

In the above description, the amount of excess sludge drawn out was subtracted from the amount of treated water drained to calculate the actual amount of treated water drained. However, since the amount of excess sludge withdrawn is overwhelmingly smaller than the amount of treated water drained. In the above case, the amount of waste sludge drawn out may be ignored, that is, the amount of waste sludge drawn out may be calculated to be 10 m ³ per 10 minutes without subtracting the amount of drawn off excess sludge. A calculator 27 can be used to switch whether the COD discharge amount is calculated by subtracting the excess sludge withdrawal amount from the treated water discharge amount or the COD discharge amount is calculated without subtracting the excess sludge withdrawal amount. It is preferable to set.

As is clear from the above, the COD discharge amount (C) per 24 hours of the treated water discharged from the batch-type wastewater treatment device (C
The OD load) can be accurately obtained. The starting point for 24 hours is not limited to midnight, and may be any time. Further, in the above example, the treated water discharge amount and the COD discharge amount are set to 1
The calculation was made for 0 minutes, but this may be 5 minutes, 15 minutes, 20 minutes, or the like.

In FIG. 4, reference numeral 30 denotes the above-mentioned batch type waste water treatment device, and a plurality of waste water treatment devices 30-1, 30-.
It is shown that the calculation of the COD discharge amount per 24 hours of the treated water discharged from each of 2 ... 30-N is performed by one calculator 32 in the monitoring center 31. Batch tank No. is provided for each wastewater treatment device. 1, No. The control panel 26 for receiving the outputs of the water level gauges 15 and 15, the flow rate indicating integrator 19, and the COD measuring device 25 of 2 is provided, and the computing unit 27 is abolished. The control panel 26 of each wastewater treatment device is connected to the telephone line network 33. Through monitoring center 3
1 is connected to the arithmetic unit 32. As a result, the COD discharge amount of the treated water of the plurality of wastewater treatment devices can be calculated by the single computing unit 32 in the monitoring center.

Conventionally, a computing unit for computing the COD emission amount is provided for each wastewater treatment device, and each computing unit is connected to the computing unit at the monitoring center by a telephone line network, so that there are 10 wastewater treatment devices. In the case, 10 computing units and 1 computing unit at the monitoring center are needed, totaling 11 computing units,
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.

[0021]

According to the first aspect of the present invention, the water level for obtaining the amount of raw water to be supplied to each batch tank is used without using an expensive flow rate indicator integrating meter for measuring the amount of treated water discharged for calculating the COD emission amount. The output of the meter and the output of an inexpensive COD measuring device that measures the COD of the discharged treated water can be input to the arithmetic unit to accurately obtain the COD discharge amount of the discharged treated water per 24 hours. Also, the use of expensive flow indicator integrated meters
The equipment cost will be lower because the platform is abolished. According to claim 2, the computing unit for computing the COD emission amount, which is provided for one unit in the wastewater treatment device, is abolished, and is discharged from a plurality of batch type wastewater treatment units by one computing unit in the central monitoring center. The COD emission amount of the treated water per 24 hours can be calculated and calculated for each batch type waste water treatment device, and can be centrally managed.
In addition, since each batch type waste water treatment device is not provided with a computing unit, the facility cost is significantly reduced.

[Brief description of drawings]

FIG. 1 is a flow sheet of an embodiment of a batch type waste water treatment device of the present invention.

Fig. 2 Batch tank No. for a certain 24 hours of the wastewater treatment device. 1
It is explanatory drawing which shows the operating condition of No. 2 and No.

FIG. 3A is an explanatory diagram of a processing pattern of a batch tank. (B) is an explanatory view of another processing pattern of the batch tank.

FIG. 4 is an explanatory diagram of a centralized management system for a plurality of batch type waste water treatment devices according to the present invention.

[Explanation of symbols]

 No. No. 1 batch tank 2 batch tanks 10 Raw water tanks 11 Flow rate adjusting tanks 12 Screen tanks 13 Measuring tanks 14 Aeration / stirring devices 15 Water level gauges 16 Raw water supply pipelines 17 Disinfecting tanks 18 Pipelines 19 Flow indicator accumulators 20 Clear water drainage equipment 21 Disinfectors 22 Discharge Tank 23 Sludge thickener tank 24 Sludge storage tank 25 COD measuring instrument 26 Control panel 27 Computing unit 30 Batch type wastewater treatment device 31 Monitoring center 32 Computing unit 33 Telephone network

Claims (2)

[Claims] 1. A plurality of batch tanks are respectively provided with water level gauges that determine the inflow amount of raw water supplied to the tanks, and raw water is supplied from the raw water tank to the batch tanks at different times. In a batch-type wastewater treatment device that aerates, stirs, and precipitates the raw water in the batch tank and discharges the treated water treated in each batch tank through a common disinfection tank, the treated water is discharged to the disinfection tank or the discharge path of the treated water. Is provided with a COD measuring device for measuring the COD value of each of the batch tanks, and an arithmetic unit for inputting the outputs of the water level gauges of the plurality of batch tanks and the output of the COD measuring device is provided. A batch-type wastewater treatment device, characterized in that the COD emission amount of the treated water per 24 hours is calculated. 2. A plurality of batch tanks are each provided with a water level gauge that determines a predetermined inflow amount of raw water supplied into the tank, and raw water is supplied from the raw water tank to the plurality of batch tanks at different times. The raw water is aerated, stirred, and precipitated in the batch tank, and the treated water treated in each batch tank is discharged through a common disinfection tank, and the treated water COD is discharged to the disinfection tank or the discharge path of the treated water. Each of a plurality of batch type wastewater treatment devices provided with a COD measuring device for measuring a value and a control panel to which the outputs of the water level gauges of the plurality of batch tanks and the output of the COD measuring device are input. The control panel is connected to a central arithmetic unit by a line, and the arithmetic unit calculates the COD discharge amount per 24 hours of the treated water discharged through the disinfection tank of each batch type wastewater treatment device. Centralized management system for batch type waste water treatment equipment.