JP2020146670A - Wastewater treatment apparatus - Google Patents

Abstract

To provide a wastewater treatment apparatus that does not require sorting according to the quality of wastewater and can efficiently process wastewater without excess or shortage of treatment.SOLUTION: Inorganic wastewater is coagulated and sedimented by a coagulation/sedimentation apparatus 1 and then sent to a confluence tank 5 via a fluidized bed type aerobic biological treatment apparatus 2. A bypass line 4 is provided so as to bypass the fluidized bed type aerobic biological treatment apparatus 2, and the coagulation-sedimentation treated water is switched by a valve 3 so as to selectively flow the treated water to the fluidized bed type aerobic biological treatment apparatus 2 or to the bypass line 4. Organic wastewater is nitrified and denitrified in a nitrification/denitrification apparatus 6, then sedimented in a sedimentation tank 7, and then sent to the confluence tank 5. If the TOC concentration in the coagulation/sedimentation treated water is lower than a predetermined concentration A, the coagulation/sedimentation treated water from the coagulation/sedimentation apparatus 1 is flowed into the bypass line 4, and if it is higher than A, the coagulation/sedimentation treated water is introduced into the fluidized bed aerobic biological treatment system 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wastewater treatment device for treating inorganic wastewater and organic wastewater. More specifically, the present invention relates to a wastewater treatment apparatus suitable for treating wastewater from a manufacturing process of electronic parts and the like.

In electronic component manufacturing factories, wastewater of various water qualities is discharged from each manufacturing process. Normally, inorganic wastewater and organic wastewater are mainly stored in different water tanks and treated separately, or inorganic wastewater and organic wastewater are treated respectively, then merged and mixed, and then treated in one system. There is also. The treatment from this confluence tank is greatly affected by TOC and the like, which are abundant in the treated water of organic wastewater. The TOC concentration in the inorganic wastewater is lower than that in the organic wastewater. The TOC of this inorganic wastewater may also be removed by biological treatment or the like, and even when the TOC to be removed is small, the biological treatment (aeration) is operated, so that the operating cost is high.

Patent Document 1 describes that wastewater from each process is separated according to water quality, the separated wastewater is collected by those having similar water quality, and each collected wastewater is treated according to each water quality. There is.

Japanese Unexamined Patent Publication No. 8-173951

An object of the present invention is to provide a wastewater treatment apparatus that does not require sorting according to the quality of wastewater and can efficiently treat wastewater without excess or deficiency of treatment.

The gist of the present invention is as follows.

[1] A biological treatment device for inorganic wastewater, which is obtained by biologically treating inorganic wastewater or its coagulation / sedimentation treated water to obtain inorganic biologically treated water, and an organic, which is obtained by biologically treating organic wastewater to obtain organic biologically treated water. In a wastewater treatment device including a biological treatment device for system wastewater and a confluence tank into which the inorganic biological treatment water and the organic biological treatment water flow in, a bypass line bypassing the inorganic biological treatment device and an inorganic system It is characterized by being provided with a control means for controlling the flow of inorganic wastewater or the agglomeration / precipitation treatment water thereof to the bypass line when the concentration of organic matter in the wastewater or the agglomeration / precipitation treatment water thereof is equal to or less than a predetermined value. Wastewater treatment equipment.

[2] The control means is characterized in that when the organic matter concentration of the inorganic wastewater or the coagulation / precipitation treated water thereof is equal to or less than the organic matter concentration of the merging tank, the inorganic wastewater is controlled to flow to the bypass line. [1] Wastewater treatment equipment.

[3] The wastewater treatment apparatus according to [2], wherein the organic matter concentration is a TOC concentration.

[4] The wastewater treatment device according to any one of [1] to [3], wherein the inorganic biological treatment device is a fluidized bed type aerobic biological treatment device.

[5] The wastewater treatment apparatus according to any one of [1] to [4], wherein a solid-liquid separation apparatus is provided in front of the inorganic wastewater biological treatment apparatus.

[6] The wastewater treatment device according to any one of [1] to [5], wherein the organic wastewater biological treatment device is a nitrification / denitrification device.

[7] The wastewater treatment apparatus according to any one of [1] to [6], wherein the solid-liquid separation apparatus is installed after the biological treatment apparatus for organic wastewater and in front of the confluence tank.

According to the wastewater treatment apparatus of the present invention, the entire wastewater treatment is operated by controlling the biological treatment (fluidized bed type carrier) or the like to bypass the part where the operation cost is high due to the aeration power according to the organic matter concentration of the inorganic wastewater. Cost reduction is possible.

In addition, by mixing biologically treated water with a low organic matter concentration, the organic matter load after merging can be reduced and stable operation becomes possible.

It is a flow chart of the wastewater treatment apparatus which concerns on embodiment.

Hereinafter, embodiments will be described with reference to the drawings.

This wastewater treatment device is for treating inorganic wastewater and organic wastewater generated from the manufacturing process of electronic parts and the like.

In this embodiment, the inorganic wastewater has a TOC concentration of less than 30 ppm, particularly 20 ppm or less.

When the electronic component is a liquid crystal or the like, the TOC component is often an organic acid such as acetic acid or a dilute amine or the like. Examples of the inorganic component include phosphoric acid and fluorine. Organic wastewater has a TOC concentration of 30 ppm or more, usually 80 ppm or more, and particularly 100 ppm or more.

When the electronic component is a liquid crystal or the like, the TOC component is mainly an organic substance discharged in an etching process or the like, and for example, an amine or ether-based chemical used in a stripping solution or the like is the main component. Inorganic wastewater also contains a small amount of inorganic components.

As shown in FIG. 1, the inorganic wastewater is coagulated and settled by the coagulation / settling device 1 and then sent to the confluence tank 5 via the fluidized bed type aerobic biological treatment device 2 (or the bypass line 4 described later).

A bypass line 4 is provided so as to bypass the fluidized bed type aerobic biological treatment device 2, and the coagulated sedimentation treated water is switched so as to selectively flow to the fluidized bed type aerobic biological treatment device 2 or the bypass line 4. A valve 3 is provided.

The organic wastewater is nitrified and denitrified by the nitrification / denitrification apparatus 6, then settled in the settling tank 7, and then sent to the confluence tank 5.

The water in the merging tank 5 is treated by the post-stage treatment device 8 to become treated water. Examples of the post-stage treatment device include, but are not limited to, a pressure flotation device, a device that undergoes gravity filtration, then activated carbon filtration, and then RO treatment.

A TOC sensor (not shown) is provided to measure the TOC concentration of the agglomerated / settled water, and a TOC sensor 10 is installed in the merging tank 5, and these detection signals are input to the control device 11 and the TOC sensor 10 is installed. The control device 11 controls the switching valve 3.

In this embodiment, when the TOC concentration of the coagulation / precipitation treated water is lower than the predetermined concentration A, the coagulation / precipitation treatment water from the coagulation / precipitation device 1 is flowed to the bypass line 4, and when it is higher than A, the coagulation / precipitation treatment water is agglomerated. The switching valve 3 is controlled so as to introduce the precipitated treated water into the fluidized bed type aerobic biological treatment apparatus 2. In one aspect of the present invention, the predetermined concentration A may be set to the TOC concentration of the confluence tank 5 or a range of ± 50% thereof.

According to the wastewater treatment apparatus configured in this way, when the TOC concentration in the inorganic wastewater is lower than the predetermined concentration A, the coagulated sedimentation treated water is biologically treated by the fluidized bed type aerobic biological treatment apparatus 2. Since it directly flows into the merging tank 5 through the bypass line 4, the aeration power cost in the fluidized bed type aerobic biological treatment device 2 can be reduced. Inorganic wastewater treated water having a low TOC concentration is merged with the organic wastewater treated water in the confluence tank 5, and the TOC concentration of the water in the confluence tank 5 is lowered, so that the load of the post-stage treatment is reduced and the treatment is stable. Will be done.

In the above embodiment, the bypass line 4 is provided so as to bypass the fluidized bed type aerobic biological treatment device 2, but may be provided so as to bypass the coagulation / precipitation device 1. In this case, when the TOC concentration of the inorganic wastewater is low, the inorganic wastewater is bypassed by the aggregating device 1.

In the present invention, when the TOC concentration in the merging tank 5 is lower than a predetermined value, the bypass is not performed, and control is performed so as to reduce the amount of the coagulant and the polymer coagulant added in the coagulation / precipitation device 1. Alternatively, the fluidized bed type aerobic biological treatment apparatus 2 may be operated to adjust the pH and the amount of aeration. This predetermined value is set to a value selected from between 3 to 10 ppm, particularly 4 to 8 ppm, for example, 5 ppm. The operation of reducing the load in the TOC reduction step may be performed.

1 Coagulation / sedimentation equipment 4 Bypass line 5 Confluence tank 6 Nitrification / denitrification equipment

In this embodiment, when the TOC concentration of the coagulation / precipitation treated water is lower than the predetermined concentration A, the coagulation / precipitation treatment water from the coagulation / precipitation device 1 is flowed to the bypass line 4, and when it is higher than A, the coagulation / precipitation treatment water is agglomerated. The switching valve 3 is controlled so as to introduce the precipitated treated water into the fluidized bed type aerobic biological treatment apparatus 2. In one aspect of the present invention, the predetermined concentration A may be set to the TOC concentration of the confluence tank 5 or a range of + 50% thereof.

Claims (7)

Inorganic wastewater biological treatment equipment for obtaining inorganic biological treatment water by biologically treating inorganic wastewater or its coagulation / precipitation treated water.
A biological treatment device for organic wastewater that biologically treats organic wastewater to obtain organic biologically treated water,
In a wastewater treatment apparatus provided with a confluence tank into which the inorganic biologically treated water and the organic biologically treated water flow in.
A bypass line that bypasses the inorganic wastewater biological treatment equipment,
It is characterized by being provided with a control means for controlling the flow of the inorganic wastewater or the agglomeration / precipitation treatment water thereof to the bypass line when the organic matter concentration in the inorganic wastewater or the agglomeration / precipitation treatment water thereof is equal to or less than a predetermined value. Wastewater treatment equipment. The control means is characterized in that when the organic matter concentration of the inorganic wastewater or the coagulation / precipitation treated water thereof is equal to or less than the organic matter concentration of the merging tank, the inorganic wastewater is controlled to flow to the bypass line. 1 wastewater treatment device. The wastewater treatment apparatus according to claim 2, wherein the organic matter concentration is a TOC concentration. The wastewater treatment device according to any one of claims 1 to 3, wherein the inorganic biological treatment device is a fluidized bed type aerobic biological treatment device. The wastewater treatment apparatus according to any one of claims 1 to 4, wherein a solid-liquid separation apparatus is provided in front of the biological treatment apparatus for inorganic wastewater. The wastewater treatment device according to any one of claims 1 to 5, wherein the organic wastewater biological treatment device is a nitrification / denitrification device. The wastewater treatment apparatus according to any one of claims 1 to 6, wherein a solid-liquid separation apparatus is installed after the biological treatment apparatus for organic wastewater and in front of the confluence tank.

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