JP5700735B1 - Water treatment apparatus and control method for water treatment apparatus - Google Patents

Abstract

A water treatment apparatus capable of being suitably treated is provided. SOLUTION: A circulation tank 20 into which water to be treated flows and stores liquid, an electrolytic treatment tank 30 having an electrode 30a and generating electrolytic treatment water by electrolysis, a circulation tank 20, and an electrolytic treatment tank 30 A circulation pump 32 that circulates the liquid between them, an electrode power supply device 35 that applies a current to the electrode 30a, and a discharge passage 21 that discharges the liquid overflowing from the circulation tank 20, and continuously treats the water to be treated. . [Selection] Figure 1

Description

  The present invention relates to a water treatment apparatus for removing ammonia nitrogen and organic substances and a method for controlling the water treatment apparatus.

  As a method for removing ammonia nitrogen and organic substances from wastewater, a method for water treatment using microorganisms is known. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2014-104416), in the nitrification process, ammonia ions are oxidized to nitrite ions by ammonia-oxidizing bacteria that are autotrophic bacteria under aerobic conditions. It is oxidized to nitrate ion by nitrite-oxidizing bacteria, which are vegetative bacteria. In the denitrification process, it is disclosed that these nitrite ions and nitrate ions are decomposed into nitrogen gas under anaerobic conditions by using denitrifying bacteria, which are heterotrophic bacteria, using organic substances as electron donors. ing.

JP 2014-104416 A

  However, a water treatment apparatus that performs denitrification treatment using microorganisms requires a water tank for each step, and there is a problem that it is difficult to reduce the size. Moreover, since it processes with microorganisms, there exists a subject that processing capacity falls in a cold region. Moreover, in order to maintain microorganisms, there exists a subject that the maintenance management of adding organic substance (for example, alcohol) as needed is required. Moreover, since sludge is generated during the treatment, there is a problem that the treatment is necessary.

  Then, this invention makes it a subject to provide the control method of the water treatment apparatus and water treatment apparatus which can be processed suitably.

In order to solve such a problem, the present invention provides a circulation tank into which water to be treated flows and stores a liquid, an electrolytic treatment tank having an electrode and generating electrolytic treatment water by electrolysis, and the circulation comprising a circulating pump for circulating the liquid between the electrolytic cell and a tank, and the electrode power supply for applying a current to the electrode, a continuous process the water to be treated, the circulation tank is generated by electrolysis A gas discharge path for exhausting the discharged gas to the outside, and a liquid discharge path that is disposed in the circulation tank and is an U-shaped pipe having an opening facing upward, and that discharges the overflowed liquid from the circulation tank. It is a water treatment apparatus characterized by having .

The present invention also includes a circulation tank into which treated water flows and stores liquid, an electrolytic treatment tank having an electrode and generating electrolytic treatment water by electrolysis, the circulation tank, and the electrolytic treatment tank. comprising a circulating pump for circulating the liquid between the electrode power source device for applying a current to the electrode, a continuous process the water to be treated, the circulation tank, to exhaust gas generated by electrolysis outside gas A method for controlling a water treatment apparatus , comprising: a discharge path; a liquid discharge path that is disposed in the circulation tank and has an U-shaped pipe with an opening facing upward, and that discharges the overflowed liquid from the circulation tank. The current applied to the electrodes is applied to the inlet concentration, which is the concentration of the target substance in the treated water flowing into the circulation tank, the flow rate of the treated water flowing into the circulation tank, and the treated water flowing out from the circulation tank. Oh And outlet required concentration is the concentration that is required of the target substance that is a control method of the water treatment apparatus, characterized in that it is determined based on.

The present invention also provides a circulation tank into which water to be treated flows and stores a liquid, an electrolytic treatment tank having a plurality of electrodes provided in parallel and having an electrode to generate electrolytic treatment water by electrolysis, and the circulation tank wherein comprising a circulation pump for circulating the liquid between the electrolytic cell, and the electrode power supply for applying a current to the electrodes, the a, continuous process water to be treated, the circulation tank, generated by electrolysis A gas discharge path for exhausting gas to the outside, and a liquid discharge path that is disposed in the circulation tank and is an U-shaped pipe having an opening facing upward, and that discharges the overflowed liquid from the circulation tank. In the method for controlling a water treatment apparatus, the number of operating electrolytic treatment tanks includes an inlet concentration that is a concentration of a target substance in water to be treated flowing into a circulation tank, a flow rate of water to be treated that flows into a circulation tank, Circulating tongue An outlet the required density is required concentrations of substances in the treated water flowing out of a method for controlling a water treatment device, characterized in that is determined based on.

  ADVANTAGE OF THE INVENTION According to this invention, the control method of the water treatment apparatus and water treatment apparatus which can be processed suitably can be provided.

It is a block diagram of the waste water treatment apparatus which concerns on 1st Embodiment. It is an expanded sectional schematic diagram of a connection part. It is a functional block diagram of the control apparatus with which the wastewater treatment apparatus which concerns on 1st Embodiment is provided. It is a graph explaining the principle of a calculation table. It is a block diagram of the waste water treatment apparatus which concerns on 2nd Embodiment.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

<< First Embodiment >>
A wastewater treatment apparatus (water treatment apparatus) according to the first embodiment will be described with reference to FIG. FIG. 1 is a configuration diagram of a wastewater treatment apparatus according to the first embodiment.

  The wastewater treatment apparatus according to the first embodiment is an apparatus that reduces (removes) water-soluble organic matter (for example, alcohol) and ammonia contained in wastewater to be treated by electrolysis treatment and discharges it as treated water. That is, the wastewater treatment apparatus according to the first embodiment electrolyzes water-soluble organic substances in the wastewater, so that biochemical oxygen demand (BOD) and chemical oxygen demand (BOD) in the treated water ( COD (Chemical Oxygen Demand) can be reduced below the target value. In addition, the wastewater treatment apparatus according to the first embodiment can reduce the ammonia nitrogen concentration in the treated water by electrolyzing ammonia in the wastewater. Incidentally, nitrogen (N) contained in the wastewater includes ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, etc., but ammonia nitrogen occupies most of it. For this reason, reducing ammonia nitrogen is effective in reducing (denitrifying) nitrogen (N) in wastewater to a target value or less.

  As shown in FIG. 1, the wastewater treatment apparatus includes a wastewater tank 10, an electrolyte tank 16, an antifoaming material tank 18, a circulation tank 20, an electrolytic treatment tank 30, an electrode power supply device 35, a blower 36, And a control device 50.

  The waste water tank 10 is a tank in which waste water to be treated is stored. A flow path 11 through which waste water flows from the waste water tank 10 toward the circulation tank 20 is provided. The flow path 11 is provided with a pump 12, an on-off valve 13, a strainer 14, and a flow meter 15. ing. The operation of the pump 12 and the opening / closing of the on-off valve 13 are controlled by the control device 50. The strainer 14 is a device that collects solid matter in the liquid, and the collection portion (not shown) of the strainer 14 has a network structure. The flow rate detected by the flow meter 15 is input to the control device 50.

  The electrolyte tank 16 is a tank in which an aqueous solution of an electrolyte used when performing electrolysis in the electrolytic treatment tank 30 is stored. For example, sodium chloride (NaCl) can be used as the electrolyte. A flow path through which the aqueous electrolyte solution flows from the electrolyte tank 16 toward the joining position 11a of the flow path 11 is provided, and a pump 17 is provided in this flow path. The operation of the pump 17 is controlled by the control device 50.

  The defoaming material tank 18 is a tank in which a defoaming material for suppressing generation of bubbles on the liquid surface in the circulation tank 20 is stored. As the electrolyte, for example, a silicone-based antifoaming agent can be used. A flow path through which the antifoaming agent flows from the defoaming material tank 18 toward the joining position 11a of the flow path 11 is provided, and a pump 19 is provided in this flow path. The operation of the pump 19 is controlled by the control device 50.

  In the circulation tank 20, the flow path 11 into which waste water from the waste water tank 10 (and the electrolyte aqueous solution from the electrolyte tank 16 and the defoaming material from the defoaming material tank 18) flows, and from the circulation tank 20 to the electrolytic treatment tank 30. A flow path 31 for sending waste water (waste water diluted in the circulation tank 20), a flow path 34 into which the electrolytic treatment water from the electrolytic treatment tank 30 flows, and a U-shaped pipe for discharging the treatment water from the circulation tank 20 21 and the flow path 22 which discharges | emits gas are connected.

  A flow path 31 through which waste water flows from the circulation tank 20 toward the electrolytic treatment tank 30 is provided, and a pump 32 is provided in the flow path 31. The operation of the pump 32 is controlled by the control device 50.

  In the electrolytic treatment tank 30, a pair of electrodes 30 a is provided on the flow path, and a current flows between the pair of electrodes 30 a by the electrode power supply device 35. The electrode power supply device 35 is controlled by the control device 50. Thereby, the electrolytic treatment tank 30 can decompose | disassemble the organic substance and ammonia in wastewater by an electrolysis process.

Here, when sodium chloride (NaCl) is used as the electrolyte, the reaction formula of electrolysis is as shown in the following reaction formulas (1) to (3).
Anode reaction: 2Cl ⁻ → Cl ₂ + 2e ⁻ (1)
Cathode reaction: 2Na ⁺ + 2H ₂ O + 2e ⁻ → 2NaOH + H ₂ (2)
Cl ₂ + 2NaOH → NaClO + NaCl + H ₂ O (3)
Thus, sodium hypochlorite (NaClO) is produced by electrolysis. In addition, since the produced | generated sodium hypochlorite is in aqueous solution, this production | generation is also generating hypochlorous acid (HClO) and a hypochlorite ion (ClO < ^- >).

And sodium hypochlorite (NaClO) produced | generated by electrolysis will become like Reaction formula (4)-(6) by reacting with ammonia (NH3).
NH ₃ + NaClO → NH ₂ Cl + NaOH (4)
NH ₂ Cl + NaClO → NHCl ₂ + NaOH (5)
NH ₂ Cl + NHCl ₂ → N ₂ + 3HCl (6)
In this way, ammonia nitrogen (N) derived from ammonia (NH ₃ ) in waste water is denitrified as nitrogen gas (N ₂ ) by sodium hypochlorite.

Although the reaction formula is omitted, the organic substance is converted into water (by the oxidation of hypochlorous acid (HClO) and hypochlorite ion (ClO ⁻ ) using the generated sodium hypochlorite (NaClO). Decomposes into H ₂ O) and carbon dioxide (CO ₂ ).

Thus, the electrolytic treatment tank 30 reduces ammonia nitrogen and organic matter in wastewater by electrolysis. Further, during the electrolysis treatment, chlorine gas (Cl ₂ ), hydrogen gas (H ₂ ), nitrogen gas (N ₂ ), carbon dioxide gas (CO ₂ ), and the like are generated.

  A flow path 33 extending substantially upward from the downstream side of the electrolytic treatment tank 30 toward the circulation tank 20 and a flow path 34 extending substantially in the lateral direction are provided. ), The flow path 37 from the blower 36 is joined. The blower 36 blows air for diluting the generated gas (especially combustible hydrogen gas) of the electrolytic treatment tank 30, and connects the flow path 33 and the flow path 34 via the flow path 37. To supply air.

  FIG. 2 is an enlarged schematic cross-sectional view of the connection part of the flow path 33, the flow path 34, and the flow path 37. As shown in FIG. 2, the electrolytically treated water W containing the generated gas G flows from the flow path 33 into the connection portion. Then, the electrolytically treated water W flows toward the circulation tank 20 using the flow path 34 as a liquid layer. On the other hand, the generated gas G is released into the gas layer, but is quickly diluted with the air A from the flow path 37. The diluted generated gas D flows toward the circulation tank 20 with the flow path 34 as an air layer.

  With such a configuration, the hydrogen gas generated in the electrolytic treatment tank 30 is quickly diluted to the explosion limit or less at the connection part of the flow path 33, the flow path 34 and the flow path 37. Thereby, the accident by hydrogen gas can be prevented.

  Returning to FIG. 1, the electrolytically treated water treated in the electrolytic treatment tank 30 and the diluted generated gas flow into the circulation tank 20 from the flow path 34. The diluted gas is exhausted to the outside through a scrubber 23 from a flow path 22 provided above the circulation tank 20. The electrolytically treated water treated in the electrolytic treatment tank 30 flows into the circulation tank 20, dilutes the wastewater flowing from the flow path 11, and unreacted sodium hypochlorite (NaClO) is contained inside the circulation tank 20. Reduce ammoniacal nitrogen (N) and organics.

  The treated water in the circulation tank 20 is discharged from the circulation tank 20 via the U-shaped pipe 21. The U-shaped pipe 21 is configured as a U-shaped pipe with the opening 21a facing upward. With such a configuration, when the treated water in the circulation tank 20 is discharged, only the treated water can be taken out without taking out the gas inside the circulation tank 20. Further, the height of the liquid level of the circulation tank 20 is usually the height of the opening 21 a of the U-shaped pipe 21.

  In addition, depending on the type of wastewater, bubbles may be generated by electrolysis. For this reason, a flow path 38 through which the electrolytic treatment water flows from the branch position of the flow path 31 (downstream of the pump 32) toward the defoaming nozzle 24 in the circulation tank 20 is provided. A valve 39 is provided. The opening / closing of the on-off valve 39 is controlled by the control device 50.

  The defoaming nozzle 24 quickly defoams the effect of active oxygen by spraying electrolytically treated water into the circulation tank 20 with mist. Here, the defoaming nozzle 24 is provided at a position lower than the discharge port of the flow path 34. With such a configuration, it is possible to prevent the mist from being scattered by the air flowing from the flow path 34 into the circulation tank 20 (air from the blower 36).

  Next, the electrode power supply device 35 and the control device 50 included in the wastewater treatment apparatus according to the first embodiment will be described with reference to FIG. FIG. 3 is a functional block diagram of the wastewater treatment apparatus according to the first embodiment.

  As illustrated in FIG. 3, the electrode power supply device 35 includes an applied current control unit 35 a, an electrode current detection unit 35 b, and an electrode voltage detection unit 35 c.

  The applied current control unit 35a applies a current to the pair of electrodes 30a by CC (Constant Current) control based on a command from the control device 50 (a current command unit 52 described later).

  The electrode current detection unit 35b detects a current between the pair of electrodes 30a. The detected current is input (feedback) to the applied current control unit 35a. The electrode voltage detector 35c detects a voltage between the pair of electrodes 30a.

  As shown in FIG. 3, the control device 50 includes an operation control unit 51, a current command unit 52, a storage unit 53, and an input unit 54.

  The operation control unit 51 can control the entire operation of the wastewater treatment apparatus by controlling various pumps, various on-off valves, the electrode power supply device 35, and the blower 36.

  The current command unit 52 determines a current to be applied to the pair of electrodes 30a and commands the applied current control unit 35a. Details will be described later.

  The storage unit 53 includes an inlet concentration storage unit 53a, an outlet concentration storage unit 53b, and a calculation table storage unit 53c.

The inlet concentration storage unit 53a stores the inlet concentration (for example, ammonia nitrogen concentration, COD, BOD) of waste water flowing into the circulation tank 20 (waste water of the waste water tank 10).
The outlet concentration storage 53b is an outlet concentration (for example, ammonia nitrogen concentration, COD, BOD) that is a reference value of the concentration required for the treated water flowing into the circulation tank 20 (treated water discharged from the U-shaped pipe 21). ) Is stored.
The calculation table storage unit 53c stores a calculation table used when the current command unit 52 calculates a current. Instead of the calculation table, it may be stored as a function.

  The input unit 54 can input the inlet concentration stored in the inlet concentration storage unit 53a and the outlet concentration stored in the outlet concentration storage unit 53b. For example, the administrator extracts a wastewater sample from the wastewater tank 10 and obtains the concentration (inlet concentration) of the wastewater by a reagent test or the like. Then, the administrator operates the input unit 54 to input the inlet concentration (stored in the inlet concentration storage unit 53a). The inlet concentration may be detected by a concentration detector (not shown) and the value may be stored in the inlet concentration storage unit 53a. In addition, the administrator operates the input unit 54 to input the outlet concentration that is the reference value of the treated water (stored in the outlet concentration storage unit 53b).

<Current calculation process>
Next, the current calculation process of the current command unit 52 will be described.
The current command unit 52 stores in the calculation table storage unit 53c based on the inlet concentration stored in the inlet concentration storage unit 53a, the outlet concentration stored in the outlet concentration storage unit 53b, and the flow rate detected by the flow meter 15. The current applied to the electrode 30a is determined with reference to the calculated table.

FIG. 4 is a graph for explaining the principle of the calculation table. Here, a graph a1 in FIG. 4A shows a case where waste water having an inlet concentration R _in1 is supplied to the waste water treatment apparatus according to the present embodiment at a flow rate L ₁ and a current indicated by a horizontal axis is applied to the electrode 30a (current). It is the graph which showed the value of the exit density | concentration at the time of changing (on the vertical axis | shaft). Similarly, the graph a2 has a wastewater inlet concentration R _in2 supplied at a flow rate L _1, is a graph showing the ratio of exit concentration when applying a current indicated by the horizontal axis to the electrode 30a on the vertical axis. Graph a3 is a waste water inlet concentration R _in3 supplied at a flow rate L _1, is a graph showing the ratio of exit concentration when applying a current indicated by the horizontal axis to the electrode 30a on the vertical axis. Graph a4 is a waste water inlet concentration R _in4 supplied at a flow rate L _1, is a graph showing the ratio of exit concentration when applying a current indicated by the horizontal axis to the electrode 30a on the vertical axis. FIG. 4B is a graph when the flow rate is L ₂ . Such a relationship is obtained in advance by experiment and stored in the calculation table storage unit 53c.

  The current command unit 52 determines a current to be applied to the electrode 30a based on such information stored in the calculation table storage unit 53c.

For example, _assuming that the flow rate L ₁ is the inlet concentration R _in3 and the outlet concentration R _out , the intersection of the graph a 3 and the graph b (a line drawn horizontally from the outlet concentration R _out shown by a broken line) from FIG. The current _Is1 , which is the value on the horizontal axis, is determined as the current applied to the electrode 30a. Similarly, at a flow rate of L _1, the inlet concentration R _in4, when the outlet concentration R _out, applied from FIG. 4 (a), a graph a4, the current I _s2 to the electrode 30a is the value of the horizontal axis at the intersection of the graph b The current to be determined. Further, at a flow rate of L _2, the inlet concentration R _in3, when the outlet concentration R _out, determining the current applied to current I _s3 to the electrode 30a from FIG. 4 (b). Similarly, at a flow rate of L _2, the inlet concentration R _in4, when the outlet concentration R _out, from FIG. 4 (b), determining the current applied to current I _s4 to the electrode 30a.

<Effect>
According to the wastewater treatment apparatus according to the first embodiment, wastewater can be treated with treated water by continuous treatment. Moreover, compared with the water treatment apparatus (for example, patent document 1) using the conventional microorganisms, an apparatus can be reduced in size. In addition, there is no reduction in treatment capacity due to temperature changes as occurs in conventional water treatment apparatuses using microorganisms (for example, Patent Document 1), and water treatment can be performed stably. Moreover, there is no generation of sludge as occurs in a conventional water treatment apparatus using microorganisms (for example, Patent Document 1), and sludge treatment can be reduced.

<< Second Embodiment >>
A wastewater treatment apparatus (water treatment apparatus) according to a second embodiment will be described with reference to FIG. FIG. 5 is a configuration diagram of a wastewater treatment apparatus according to the second embodiment.

  Compared with the wastewater treatment apparatus according to the first embodiment, the wastewater treatment apparatus according to the second embodiment includes a plurality (three in FIG. 5) of electrolytic treatment tanks 30 (30A to 30C) and an electrode power supply device 35 (35A). ~ 35C) are provided in parallel. Moreover, the on-off valve 40 (40A-40C) is arrange | positioned upstream of the electrolytic treatment tank 30 (30A-30C), and the on-off valve 41 (41A-41C) is each arrange | positioned downstream. The electrode power supply device 35 (35A to 35C), the on-off valve 40 (40A to 40C) and the on-off valve 41 (41A to 41C) are controlled by the control device 50.

  The current command unit 52 of the wastewater treatment apparatus according to the second embodiment refers to the calculation table stored in the calculation table storage unit 53c based on the inlet concentration, the outlet concentration, and the flow rate. Determine the number.

<Effect>
According to the wastewater treatment apparatus according to the second embodiment, an appropriate operation number can be determined according to the amount and concentration of wastewater, and the water treatment operation can be performed. In addition, by increasing the number of electrolytic treatment tanks 30 in parallel, water treatment can be performed even for high-concentration wastewater that is difficult to treat with a conventional water treatment apparatus using microorganisms (for example, Patent Document 1).

10 Wastewater tank (treated tank)
15 Flow meter 20 Circulation tank 21 U-shaped piping (discharge path)
21a Opening 24 Defoaming nozzle (nozzle)
30 Electrolytic treatment tank 30a Electrode 32 Pump (circulation pump)
33 channel (first channel)
34 channel (second channel)
35 Electrode power supply device 35a Applied current control unit 36 Blower 37 Flow path (third flow path)
50 control device 51 operation control unit 52 current command unit 53 storage unit 53a inlet concentration storage unit 53b outlet concentration storage unit 53c calculation table storage unit

Claims (7)

A circulation tank into which treated water flows and stores liquid;
An electrolytic treatment tank having electrodes and generating electrolytically treated water by electrolysis;
A circulation pump for circulating a liquid between the circulation tank and the electrolytic treatment tank;
And a electrode power supply for applying a current to the electrode, continuous process water to be treated,
The circulation tank is
A gas discharge passage for exhausting gas generated by electrolysis to the outside;
A water treatment comprising: a U-shaped pipe disposed in the circulation tank and having an opening facing upward, and a liquid discharge passage for discharging the overflowed liquid from the circulation tank. apparatus. The current applied to the electrode is
Inlet concentration, which is the concentration of the target substance in the treated water flowing into the circulation tank,
The flow rate of the treated water flowing into the circulation tank,
The required concentration at the outlet, which is the required concentration of the target substance in the treated water flowing out of the circulation tank,
The water treatment apparatus according to claim 1, wherein the water treatment apparatus is determined based on A plurality of the electrolytic treatment tanks are provided in parallel,
The number of operating electrolytic treatment tanks is
Inlet concentration, which is the concentration of the target substance in the treated water flowing into the circulation tank,
The flow rate of the treated water flowing into the circulation tank,
The required concentration at the outlet, which is the required concentration of the target substance in the treated water flowing out of the circulation tank,
The water treatment apparatus according to claim 1, wherein the water treatment apparatus is determined based on The flow path flowing from the electrolytic treatment tank to the circulation tank is:
A first flow path extending substantially upward;
A second flow path extending in a substantially lateral direction,
The water treatment apparatus according to claim 1, wherein a third flow path into which air from the blowing unit flows is connected to a connection portion between the first flow path and the second flow path. A part of the liquid circulated by the circulation pump is supplied, and includes a nozzle for spraying the liquid inside the circulation tank,
The nozzle is
The water treatment apparatus according to claim 1, wherein the water treatment apparatus is disposed at a position lower than a connection portion with the circulation tank in a flow path that flows from the electrolytic treatment tank to the circulation tank. A circulation tank into which treated water flows and stores liquid;
An electrolytic treatment tank having electrodes and generating electrolytically treated water by electrolysis;
A circulation pump for circulating a liquid between the circulation tank and the electrolytic treatment tank;
And a electrode power supply for applying a current to the electrode, continuous process water to be treated,
The circulation tank is
A gas discharge passage for exhausting gas generated by electrolysis to the outside;
A control method for a water treatment apparatus, which is disposed in the circulation tank and has a U-shaped pipe with an opening facing upward, and a liquid discharge path for discharging the overflowed liquid from the circulation tank ,
The current applied to the electrode is
Inlet concentration, which is the concentration of the target substance in the treated water flowing into the circulation tank,
The flow rate of the treated water flowing into the circulation tank,
The required concentration at the outlet, which is the required concentration of the target substance in the treated water flowing out of the circulation tank,
The control method of the water treatment apparatus characterized by determining based on this. A circulation tank into which treated water flows and stores liquid;
An electrolytic treatment tank provided with a plurality of electrodes in parallel to generate electrolytically treated water by electrolysis;
A circulation pump for circulating a liquid between the circulation tank and the electrolytic treatment tank;
And a electrode power supply for applying a current to the electrode, continuous process water to be treated,
The circulation tank is
A gas discharge passage for exhausting gas generated by electrolysis to the outside;
A control method for a water treatment apparatus, which is disposed in the circulation tank and has a U-shaped pipe with an opening facing upward, and a liquid discharge path for discharging the overflowed liquid from the circulation tank ,
The number of operating electrolytic treatment tanks is
Inlet concentration, which is the concentration of the target substance in the treated water flowing into the circulation tank,
The flow rate of the treated water flowing into the circulation tank,
The required concentration at the outlet, which is the required concentration of the target substance in the treated water flowing out of the circulation tank,
The control method of the water treatment apparatus characterized by determining based on this.

Images