JPS60206491A - Apparatus for treatment of waste water - Google Patents

Abstract

PURPOSE:To miniaturize a water quality control apparatus and to obtain stable treated water quality, by mounting a flow amount control apparatus of raw waste water, a waste water retraction tank for retracting waste water exceeding a controlled amount, a water quality measuring instrument of treated water and the control apparatus of the flow amount control apparatus. CONSTITUTION:Raw waste apparatus is sent to flow amount control apparatus 11 where a predetermined amount of waste water controlled by a control apparatus 22 is sent to an aeration tank 12. When the amount of inflow raw waste water exceeds the control amount of raw waste water sent to the aeration tank 12, the excessive raw waste water is sent to a retraction tank 13 and temporarily stored therein. The raw waste water sent to the aeration tank 12 receives biological treatment according to a usual method and treated water is sent to a precipitation tank 17 to separate activated sludge while supernatant treated water is discharged to the outside through a monitor tank 20. The variation in the inflow amount of waste water is controlled by the flow amount control apparatus 11 and the amount of waste water sent to the aeration tank 12 is determined so as to always obtain good quality treated water.

Description

[Detailed description of the invention] The present invention relates to a wastewater treatment device.

FIG. 1 shows a conventional general wastewater treatment device. In order to treat organic wastewater with this wastewater treatment device, raw wastewater is first sent to the flow rate adjustment tank 1 . A fixed amount of the raw wastewater once stored in the flow rate adjustment tank 1 is sent to the aeration tank 3 by the pump 2, where air from the blower 4 is passed through the aeration pipe 5.
Aeration is diffused into the aeration WI3, and the activated sludge in the tank 3 is used for biological treatment. The biologically treated wastewater is then aerated, drained from the aeration tank 3, and sent to a settling tank 6. The sludge is settled in the settling tank 6, and the supernatant treated water is discharged to the outside, and the settled sludge is returned to the aeration tank 3, where it is subjected to aeration treatment.

Incidentally, the flow rate and water quality of raw wastewater discharged from a discharge source generally vary significantly over time.

For this reason, in the conventional treatment equipment shown in FIG. 1, the flow rate adjustment tank 1 is installed, and raw wastewater is temporarily stored there.
A fixed amount of raw wastewater is sent to the subsequent aeration tank 3 so that treated water that always satisfies the standard value is obtained.

However, the processing capacity of the wastewater treatment equipment is installed so as to be able to handle the maximum load of the water quality of the inflow source wastewater, and therefore, on average, the equipment as a whole has excess capacity. In particular, even if the treatment system after the aeration tank 3 is downsized, the flow rate adjustment tank 1 inevitably becomes large in order to achieve the above objective of equalizing fluctuations in the amount of inflow raw wastewater, and it takes up more than half of the entire treatment equipment. This was a major cause of increased equipment costs.

This invention has been made in view of the above circumstances, and an object of the present invention is to provide a wastewater treatment device that can extremely downsize a tank for adjusting the flow rate and water quality of raw wastewater, and can always obtain stable treated water quality. The purpose is to

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an example of the wastewater treatment device of the present invention.
This is applied to activated sludge treatment of organic wastewater.

Reference numeral 11 in the figure is a flow rate adjustment device. This flow rate adjustment device 11 adjusts the amount of raw wastewater sent to the subsequent aeration tank 12 to a predetermined amount, and for example, it may consist of a small metering tank and an electric valve that adjusts the flow rate from this metering tank. , a small aquarium with a movable weir is used. The flow rate is adjusted by this flow rate adjustment device 11, and the excess raw wastewater is removed from the evacuation tank 13.
and is temporarily stored there. The evacuation tank 13 is a small-capacity storage tank, and a pump 14 is provided in the tank 13 to send the raw wastewater stored here to the flow rate adjustment device 11 or the aeration tank 12. The aeration tank 12 is a conventional aeration tank that is provided with an aeration pipe 16 that diffuses air from a blower 15 into the tank 12, and that uses activated sludge to biologically treat incoming raw wastewater. Moreover, the code|symbol 17 is a settling tank. This settling tank 1
7 is also a common type, and a drainage pipe 18 is provided at the bottom of the tank 17 to remove the settled sludge. The aeration tank 12 and settling tank 17 constitute the main body of the processing apparatus in this example. However, a special type such as one in which the aeration tank 12 and the settling tank 17 are integrated may also be used. In addition, settling tank 17
is equipped with a sludge interface meter 19 that constantly monitors the interface of settled sludge. Further, a monitoring tank 20 is installed downstream of the settling tank 17. The monitoring tank 20 is provided with one or more types of water quality measuring devices 21 for measuring the quality of the treated water flowing therein, such as a TOC meter, a COD meter, a Uv meter, and an H meter. Further, a control amount N22 is provided. This control device 22 includes a sludge interface H] 19 and a water quality measuring device 2.
1 and controls the flow rate regulator 11 based on this input signal to send raw wastewater to the aeration WJ 12.
It also controls the operation of the pump 14 of the evacuation tank 13 to send a predetermined amount of raw wastewater in the evacuation tank 13 to the flow rate adjustment device 11 or the aeration tank 12.

Next, the operating method and operation of the wastewater treatment apparatus will be explained.

The raw wastewater is first sent to the flow rate regulating device 11, where a predetermined amount of raw wastewater controlled by the control device 22 is immediately sent to the aeration tank 12. Then, the inflow source wastewater amount is
When the amount of raw wastewater sent to tank 2 exceeds the control amount, the surplus raw wastewater is sent to the evacuation tank 13 and temporarily stored. The raw wastewater sent to the aeration tank 12 is biologically treated by a conventional method,
The treated water is sent to a settling tank 17, where activated sludge is separated, and the supernatant treated water is discharged to the outside via a monitoring tank 20.

During this operation, if the amount of raw wastewater sent to the aeration tank 12 is too large, the sludge interface in the settling tank 17 will rise, making solid-liquid separation impossible here. Therefore, if the sludge interface rises above a predetermined level, the sludge interface meter 19 detects this and sends this signal to the control device 22. The control device 22 controls the flow rate adjustment device fi111 based on this signal to reduce the amount of raw wastewater sent to the aeration tank 12 and keep the sludge interface constant. By reducing the amount of liquid sent to the aeration tank 12 with the flow rate adjustment device 11, excess raw wastewater is transferred to the evacuation tank 1.
Sent to 3. Further, when the sludge interface becomes lower than a predetermined value, the control device 22 similarly operates to increase the amount of liquid sent to the aeration tank 12. At this time, when the amount of liquid sent exceeds the inflow amount of raw wastewater, the pump 14 of the evacuation tank 13 is operated to transfer the raw wastewater stored in the evacuation tank 13 to the flow rate adjustment device 11 or the aeration tank 12. A predetermined amount of raw wastewater is sent to the aeration tank 12.

At the same time, if the treated water quality measured by the water quality measuring device 21 of the monitoring tank 20 decreases and becomes equal to or higher than the reference value, the control device 22 controls the flow 1 adjustment device 11 based on this signal, The amount of raw wastewater sent to the aeration tank 12 is reduced, the residence time of the raw wastewater in the aeration tank 12 is increased, and treated water of water quality below a standard value is obtained. The remaining raw wastewater is sent to the evacuation tank 13 and temporarily stored in the same manner as before. In addition, when the treated water quality is below the standard value and there is a surplus in the treatment load, the pump 14 of the evacuation tank 13 is operated to transfer the raw wastewater stored in the evacuation tank 13 to the flow rate adjustment device 11 or the aeration tank 12. Send liquid to.

In this way, in the apparatus of this example, the amount of raw wastewater sent to the aeration tank 12 is simultaneously controlled from the viewpoint of both the amount of liquid sent and the quality of the treated water. However, in this example, the reason why the treated water quality is not below the standard value is not only due to the feeding capacity of the raw wastewater, but is also related to, for example, the degree of contamination of the raw wastewater, so the signal from the sludge interface meter 19 It is necessary to set a limit on the amount of liquid to be controlled so that the minimum amount of raw wastewater is supplied to the aeration tank 12.

In such a treatment device, fluctuations in the amount of inflowing wastewater are controlled by a flow rate regulator 11, the amount of liquid sent to the aeration tank 12 is determined so that good treated water quality is always obtained, and only excess raw wastewater is can be sent to the evacuation tank 13, the amount of raw wastewater temporarily stored in the evacuation tank 13 is reduced, and the evacuation tank 13 only needs to have a sufficiently small capacity, which can reduce equipment costs.

Furthermore, since the amount of liquid sent to the aeration tank 12 can be adjusted depending on the quality of the treated water, the quality of the treated water is stabilized and the quality of the discharged water can be monitored at the same time.

Note that the present invention is not limited to the above embodiments,
If the raw wastewater is, for example, nitrogen-containing organic wastewater, the main body of the treatment equipment used is a nitrification tank and a denitrification tank installed after the settling tank 17, and the type of wastewater to be treated and the type of the main body of the treatment equipment are Regardless of the flow rate adjustment device 11,
Evacuation 1113.

If the water quality meter 21 and the control device 22 are provided, similar effects can be obtained.

As explained above, the wastewater treatment device of the present invention includes a flow rate adjustment device that adjusts the amount of raw wastewater sent to the wastewater treatment device main body to a predetermined amount, and a flow rate adjustment device that adjusts the amount of liquid that exceeds the WI amount adjusted by the flow rate adjustment device. an evacuation tank for storing -B'y amount of raw wastewater; a water quality measuring device for measuring the quality of the treated water flowing out from the wastewater treatment equipment main body; and the above-mentioned flow rate adjustment device based on the water quality signal from this water quality measuring device. Since the system is equipped with a control device that controls the amount of liquid sent, the amount of raw wastewater that fluctuates over time can be adjusted using a flow rate adjustment device, and the raw wastewater can be treated in such a way that good treated water quality can always be obtained. Since the liquid can be sent to the equipment main body and only excess raw wastewater can be sent to the evacuation tank, the amount of raw wastewater stored in the evacuation tank is reduced, making the evacuation tank much smaller than a conventional flow rate adjustment tank. It is possible to reduce equipment costs. In addition, since the amount of raw wastewater sent to the treatment equipment can be adjusted depending on the quality of the treated water, the quality of the treated water is stabilized and the quality of the discharged water can be monitored at the same time. be.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of a conventional wastewater treatment device, and FIG. 2 is a schematic configuration diagram showing an example in which the wastewater treatment device of the present invention is applied to biological treatment using activated sludge of organic wastewater. . 11...Flow rate adjustment device, 12...Aeration tank, 13...Evacuation tank, 17...Sedimentation tank, 19...Sludge interface J1.20...Monitoring tank, 21...Water quality measuring instrument, 22...
Control device. Applicant: Shimizu Corporation

Claims (1)

[Scope of Claims] A flow rate adjustment device that adjusts the amount of raw wastewater sent to the wastewater treatment device main body to a predetermined amount, and an evacuation tank that temporarily stores the amount of raw wastewater that exceeds the amount regulated by the flow rate adjustment device. and a water quality measuring device for measuring the quality of treated water flowing out from the main body of the wastewater treatment device, and a control device for controlling the amount of liquid sent by the flow rate regulating device based on the water quality signal from the water quality measuring device. A wastewater treatment device featuring: