JP2010194491A - Wastewater treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wastewater treatment apparatus capable of reducing a hydrogen sulfide concentration in a biomass decomposed gas generated from a reaction tank while retaining the generation amount of the biomass decomposed gas in the reaction tank. <P>SOLUTION: A control device 20 executes the control of operating a pump 44 for second treatment water when the pH of organic wastewater in an acid generation tank 12 is smaller than 5.5, stopps the pump 44 for the second treatment water when the pH of the organic wastewater in the acid generation tank 12 is larger than 6.5, operates a pump 43 for first treatment water when the pH of the organic wastewater in a pH adjustment tank 13 is smaller than 7.0, and stops the pump 43 for the first treatment water when the pH of the organic wastewater in the pH adjustment tank 13 is larger than 8.0. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technology of a wastewater treatment apparatus, and more particularly to a technology of a wastewater treatment apparatus including a raw material water tank, an acid generation tank, a pH adjustment tank, a reaction tank, and a control device.

  Conventionally, a wastewater treatment method using cell granules, such as UASB, which has the characteristics of maintaining a high concentration of granulated methane-fermenting bacteria with a high sedimentation rate and treating effluent with high-efficiency methane fermentation. The (Upflow Anaerobic Sludge Blanket) method and the like are widely applied and used in wastewater treatment equipment.

  This wastewater treatment apparatus has a wastewater supply unit at the bottom and a granule filling unit filled with anaerobic granules of methane fermentation bacteria at the bottom. In this way, the sludge having bacteria is granulated without using an adherent carrier, and a high concentration of microorganisms is ensured in the reaction tank (see, for example, Patent Document 1).

  In addition, waste water to be introduced into the waste water treatment apparatus is first decomposed into amino acids, sugars, alcohols and the like by hydrolyzing bacteria in the acid generation tank, and then charged into the reaction tank (for example, patents). Reference 2).

JP-A-11-128979 JP 11-347588 A

In the acid generation tank, an alkali chemical was introduced in order to adjust the pH lowered by the acid generation, and the pH was raised to near neutrality by the neutralizing action of the alkaline chemical.
However, increasing the pH to near neutral in the acid generation tank results in a pH environment higher than pH 4.0 to 6.5, which is an environment suitable for acid-producing bacteria in the acid generation tank. There was a problem that the generation amount decreased.

  Moreover, the waste water thrown into the reaction tank contains sulfate ions, and the sulfate-reducing bacteria present in the reaction tank use the sulfate ions to generate hydrogen sulfide. The produced hydrogen sulfide was mixed into the biomass decomposition gas and caused corrosion of the equipment.

  Then, this invention provides the waste water treatment apparatus which can reduce the hydrogen sulfide density | concentration in the biomass decomposition gas generated from a reaction tank, keeping the generation amount of the biomass decomposition gas in a reaction tank in view of the subject which concerns.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, in a wastewater treatment apparatus comprising a raw material water tank, an acid generation tank, a pH adjustment tank, a reaction tank, and a control device, the wastewater treatment apparatus is a treatment generated in the reaction tank. A plurality of treated water passages for refluxing water to the pH adjustment tank and the acid generation tank, and a plurality of switchable pumps for treated water provided in the treated water passage, When the pH of the organic waste water in the acid generation tank is less than 5.5, the control for operating the pump for the treated water, and when the pH of the organic waste water in the acid generation tank is higher than 6.5, Control for stopping the pump, control for operating the pump for treated water when the pH of the organic wastewater in the pH adjustment tank is less than 7.0, and pH of the organic wastewater in the pH adjustment tank being 8. Previous when greater than 0 A control to stop the process water pump, and performs.

  In Claim 2, the said waste water treatment apparatus is for recirculating | refluxing a regulator from the said regulator tank to a pH adjustment tank and an acid production tank for the regulator tank for storing the regulator for adjusting pH. A plurality of adjuster passages, and a plurality of switchable adjuster pumps provided in the adjuster passage, and when the pH of the organic waste water in the acid generation tank is less than 5.5, The control for operating the pump for treated water, the control for operating the pump for adjusting agent when the flow rate of the pump for treated water becomes larger than the upper limit flow rate, and the pH of the organic waste water in the acid generation tank A control for stopping the treated water pump when greater than 6.5, a control for operating the treated water pump when the pH of the organic wastewater in the pH adjusting tank is less than 7.0, and the treated water. Pump A control for operating the adjusting agent pump when the flow rate exceeds the upper limit flow rate, and a control for stopping the treated water pump when the pH of the organic waste water in the pH adjusting tank is higher than 8.0. .

  In Claim 3, the air pump which blows air from the lower part of the said reaction tank is provided.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, while maintaining the amount of biomass decomposition gas generated in the reaction tank, the concentration of hydrogen sulfide in the biomass decomposition gas generated from the reaction tank is reduced, and the amount of desulfurization agent used in the high-cost dry desulfurization apparatus is reduced. be able to.

  In Claim 2, pH adjustment can be performed by reducing the usage-amount of a pH adjuster.

  According to the third aspect, the amount of hydrogen sulfide produced in the reaction vessel can be reduced.

The block diagram which showed the whole structure of the waste water treatment apparatus which concerns on one Example of this invention. The block diagram which showed the control structure of the control apparatus. The flowchart figure which showed pH adjustment control of an acid production tank. The flowchart figure which showed pH adjustment control of the pH adjustment tank.

First, the whole structure of the waste water treatment apparatus 1 which is an Example of this invention is demonstrated using FIG.
The wastewater treatment apparatus 1 includes a raw material water tank 11, an acid generation tank 12, a pH adjustment tank 13, a reaction tank 14, and a control device 20.
The raw material water tank 11 is a tank for retaining the organic waste water to be treated, and the organic waste water in the raw material water tank 11 is introduced into the acid generation tank 12 by a water pump 31 by a certain amount.
The acid production tank 12 is a tank that holds anaerobic acid producing bacteria that perform an acid fermentation reaction of the input organic waste water in a floating state in the liquid tank. Large organic substances in the organic waste water charged into the acid generation tank 12 are first reduced to monosaccharides, aromatic compounds, amino acids, long chain fatty acids, etc. by hydrolyzing bacteria, and further volatilized by acid generating bacteria. It is broken down to fatty acids. Furthermore, it is decomposed into acetic acid by acid-producing bacteria, hydrogen-utilizing acetic acid-producing bacteria and hydrogen-utilizing bacteria.

The acid generation tank 12 is provided with a stirring blade 12a for promoting acid generation of organic wastewater. The rotation of the stirring blade 12a increases the chance that the organic waste water in the acid generation tank 12 comes into contact with the hydrolyzing bacteria, and promotes acid generation. The acid generation tank 12 is provided with an acid generation tank pH sensor 12b for detecting the pH of the organic waste water.
When a certain amount of the organic waste water from the raw water tank 11 is introduced, the organic waste water overflowing from the acid generation tank 12 flows into the pH adjustment tank 13.

  The pH adjusting tank 13 is a tank for raising the pH by introducing treated water or a pH adjusting agent into the organic waste water whose pH has been lowered in the acid generating tank 12. Further, the pH adjusting tank 13 is provided with a stirring blade 13a for promoting the pH adjustment of the organic waste water. By rotating the stirring blade 13a, the organic waste water in the pH adjusting tank 13 is stirred to promote pH adjustment. The pH adjustment tank 13 is provided with a pH sensor 13b for pH adjustment tank for detecting the pH of the organic waste water.

  The reaction tank 14 is a UASB type reaction tank, and a waste water supply unit for supplying organic waste water to the lower part of the reaction tank 14 is disposed at the bottom thereof. In addition, granule cells, which are aggregates of methane fermentation bacteria, are introduced into the reaction tank 14, and the acetic acid in the organic waste water is decomposed into methane and carbon dioxide by the granule cells, and methane fermentation is performed. As it progresses, biomass decomposition gas is generated. Further, the organic waste water staying in the reaction tank 14 for a certain period of time is treated water having a pH of 7.4 to 8.0 because the acetic acid is decomposed to greatly reduce the organic acid content.

  The wastewater treatment apparatus 1 includes a treatment water tank 15 for storing the treatment water generated in the reaction tank 14, and a plurality of treatment water for returning the treatment water to the pH adjustment tank 13 and the acid generation tank 12. The treated water passages 41 and 42 and a plurality of switchable treated water pumps 43 and 44 provided in the treated water passages 41 and 42 are provided.

The treated water passages 41 and 42 are formed by the first treated water passage 41 for returning the treated water generated in the reaction tank 14 from the treated water tank 15 to the pH adjusting tank 13 and the reaction tank 14. It comprises a second treated water passage 42 for returning the generated treated water to the acid generation tank 12. The first treated water passage 41 and the second treated water passage 42 are formed of cylindrical pipes and have a diameter that does not clog the treated water.
A first treated water pump 43 is provided in the middle of the first treated water passage 41 to adjust the amount of treated water to be recirculated by switching between operation and stop. A second treated water pump 44 is provided in the middle of the second treated water passage 42 to adjust the amount of treated water to be returned by switching between operation and stop.

Further, the wastewater treatment apparatus 1 is configured to recirculate the adjusting agent from the adjusting agent tank 45 to the pH adjusting tank 13 and the acid generating tank 12 for storing the adjusting agent for adjusting the pH. And a plurality of switchable adjustment agent pumps 53 and 54 provided in the adjustment agent passages 51 and 52.
The adjusting agent tank 45 is a container provided for storing the adjusting agent, and the adjusting agent is made of, for example, sodium hydroxide (NaOH).
The adjusting agent tank 45 includes a first adjusting agent passage 51 for supplying the adjusting agent from the adjusting agent tank 45 to the pH adjusting tank 13 and a second adjusting agent passage 52 for returning to the acid generating tank 12. It is connected.
A first adjusting agent pump 53 provided in the middle part of the first adjusting agent passage 51 so as to be able to switch between operation and stop is provided in a middle part of the second adjusting agent passage 52 so as to be able to switch between operation and stop. The second adjusting agent pump 54 is provided.

Further, the wastewater treatment apparatus 1 is provided with a control device 20 for controlling the pH of the acid generation tank 12 and the pH adjustment tank 13.
As shown in FIG. 2, the control device 20 includes a storage unit 21 configured with a RAM, a ROM, and the like, and a calculation unit 22 configured with a CPU, and the first treated water pump 43, It is connected to the second treated water pump 44, the first adjuster pump 53, the second adjuster pump 54, the acid generation tank pH sensor 12b, and the pH adjust tank pH sensor 13b.

  In addition, the wastewater treatment apparatus 1 includes a dry desulfurization apparatus 55 for removing sulfides such as hydrogen sulfide contained in the biomass decomposition gas discharged from the reaction tank 14. The dry desulfurization device 55 uses a desulfurization agent such as iron oxide, and removes hydrogen sulfide from biomass decomposition gas. That is, hydrogen sulfide is removed by reacting iron oxide and hydrogen sulfide to generate iron sulfide and water.

Next, control of pH adjustment by the control device 20 will be described.
First, pH control in the acid generation tank 12 will be described with reference to FIG.
In step S10, it is determined whether or not the pH of the organic waste water in the acid generation tank 12 is 5.5 or higher. Here, the pH of the organic waste water in the acid generation tank 12 is constantly detected by the acid generation tank pH sensor 12b, and information from the acid generation tank pH sensor 12b is input to the control device 20. . When the pH is 5.5 or higher, sulfate-reducing bacteria present in the organic wastewater are activated, and hydrogen sulfide is generated using sulfate ions in the organic wastewater. Thereby, the sulfate ion in the organic wastewater in the acid production tank 12 decreases, and the sulfate ion in the organic wastewater charged into the reaction tank 14 also decreases. Moreover, hydrogen sulfide generated in the reaction tank 14 can be reduced by reducing sulfate ions in the organic wastewater charged into the reaction tank 14. Therefore, it is desirable that the acid generation tank 12 has a pH of 5.5 or higher.
Therefore, in step S10, if the pH is 5.5 or higher, the process returns to step S10, and the pH is detected again to determine whether the pH is 5.5 or higher. When the pH is lower than 5.5, the second treated water pump 44 is operated in step S20 to recirculate treated water from the second treated water passage 42. As the acetic acid in the organic wastewater is decomposed in the reaction tank 14, the pH of the treated water is 7.4 to 8.0. By adding this treated water, the pH concentration of the organic waste water in the acid generation tank 12 is neutralized.

Next, after the set time T has elapsed (step S30), it is determined in step S40 whether or not the pH of the organic waste water in the acid generation tank 12 is 5.5 or higher. Here, if the pH is 5.5 or more, it is determined in step S110 whether the pH is smaller than 6.5. When the pH is 6.5 or more, anaerobic methane fermentation bacteria originally present in organic wastewater and treated water are actively activated, so that methane fermentation is promoted in the acid generation tank 12, resulting in a reaction. Methane fermentation does not proceed in the tank 14. Therefore, it is desirable that the pH in the acid generation tank 12 is smaller than 6.5.
Therefore, when the pH is smaller than 6.5, the treated water is continuously refluxed, and after a certain time T has elapsed (step S30), it is determined whether or not the pH is 5.5 or higher in step S40. On the other hand, when the pH is 6.5 or more, the reflux of the treated water is stopped in step S120 so that the pH becomes 6.5 or less.

  If the pH is smaller than 5.5 in step S40, then, in step S50, the flow rate Q2 returning to the acid generation tank 12 of the treated water and the flow rate Q1 returning to the pH adjustment tank 13 Is determined as to whether or not the sum is smaller than the upper limit flow Qmax. Here, the upper limit flow rate Qmax of the treated water is set so as not to exceed the upper limit of the linear velocity of the reaction tank 14. The linear velocity is obtained by dividing the flow rate (cubic meter / hour) by the cross-sectional area (square meter) of the reaction vessel 14, and the upper limit of the linear velocity is a value inherent to the reaction vessel 14 (for example, 1 meter / hour). In other words, the treated water is returned to the extent that the treated water quality does not deteriorate.

  If the sum of the flow rate Q2 returning to the acid generation tank 12 and the flow rate Q1 returning to the pH adjustment tank 13 is smaller than the upper limit flow rate Qmax, the second treated water pump 44 in step S60. Is increased by a certain amount. Then, after the set time T has elapsed (step S30), it is determined again in step 40 whether or not the pH is 5.5 or higher.

Further, in step S50, when the sum of the flow rate Q2 returning to the acid generation tank 12 and the flow rate Q1 returning to the pH adjustment tank 13 is equal to or higher than the upper limit flow rate Qmax, only the treated water is used. In step S70, the second adjusting agent pump 54 is operated and the pH adjusting agent is charged.
Then, after the set time T has elapsed (step S80), it is determined in step S90 whether or not the pH of the organic waste water is 5.5 or more. The input amount of the pH adjusting agent in the dual adjusting agent pump 54 is increased by a certain amount. And after setting time T progress (step S80), it is judged in step S90 whether the pH of organic waste water is 5.5 or more.

In step S90, if the pH of the organic waste water is 5.5 or higher, it is determined in step S130 whether the pH of the organic waste water is smaller than 6.5. In step S130, when the pH of the organic waste water is smaller than 6.5, it is determined whether or not the pH of the organic waste water is 5.5 or higher after the set time T has elapsed (step S80). To do.
In step S130, when the pH is 6.5 or more, the pH adjusting agent is stopped to be brought to 6.5 or less. Then, after the set time T has elapsed (step S30), it is determined in step 40 whether or not the pH is 5.5 or higher.

Next, pH control in the pH adjustment tank 13 will be described with reference to FIG.
First, in step S310, it is determined whether or not the pH of the organic waste water in the pH adjustment tank 13 is 7.0 or higher. Here, the pH of the organic waste water in the pH adjustment tank 13 is constantly detected by the pH sensor 13b for the pH adjustment tank, and information from the pH sensor 13b for the pH adjustment tank is input to the control device 20. . When the pH is 6.5 or more, anaerobic methane fermentation bacteria originally present in organic wastewater or treated water are actively activated. Therefore, it is desirable that the pH adjustment tank 13 has a pH of 7.0 or more as a preparation for charging into the reaction tank 14.
Therefore, if the pH is 7.0 or higher, the process returns to step S310, and the pH is detected again to determine whether the pH is 7.0 or higher. When the pH is less than 7.0, the first treated water pump 43 is operated in step S320 to recirculate treated water from the first treated water passage 41. As the acetic acid in the organic wastewater is decomposed in the reaction tank 14, the pH of the treated water is 7.4 to 8.0. By adding this treated water, the pH concentration of the organic waste water in the pH adjusting tank 13 is neutralized.

Next, after the set time T has elapsed (step S330), it is determined in step S340 whether or not the pH of the organic waste water in the pH adjustment tank 13 is 7.0 or higher. Here, if the pH is 7.0 or higher, it is determined in step S410 whether the pH is smaller than 8.0. When the pH is 8.0 or higher, the activity conditions of sulfate-reducing bacteria that are originally present in organic wastewater and treated water are exceeded, so hydrogen sulfate is used in the pH adjustment tank 13 using sulfate ions. As a result, the amount of hydrogen sulfide generated in the reaction vessel 14 increases. Therefore, in the pH adjusting tank 13, it is desirable that the pH is smaller than 8.0.
Therefore, when the pH is smaller than 8.0, the treated water is continuously refluxed, and after the set time T has elapsed (step S330), it is determined whether or not the pH is 7.0 or higher in step S340. On the other hand, when the pH is 8.0 or more, the reflux of the treated water is stopped in step S420 so that the pH becomes 8.0 or less.

If the pH is smaller than 7.0 in step S340, then, in step S350, the flow rate Q2 returning to the acid generation tank 12 of the treated water and the flow rate Q1 returning to the pH adjustment tank 13 Is determined as to whether or not the sum is smaller than the upper limit flow rate Qmax. Here, the upper limit flow rate Qmax of the treated water is set so as not to exceed the upper limit of the linear velocity of the reaction tank. The linear velocity is obtained by dividing the flow rate (cubic meter / hour) by the cross-sectional area (square meter) of the reaction vessel 14, and the upper limit of the linear velocity is an upper limit specific to the reaction vessel 14 (for example, 1 meter / hour). In other words, the treated water is returned to the extent that the treated water quality does not deteriorate.
If the sum of the flow rate Q2 flowing back to the acid generating tank 12 and the flow rate Q1 returning to the pH adjusting tank 13 is smaller than the upper limit flow rate Qmax, the first treated water pump 43 in step S360. Is increased by a certain amount. Then, after the set time T has elapsed (step S330), it is determined again in step 340 whether or not the pH is 7.0 or higher.

In step S350, when the sum of the flow rate Q2 refluxing to the acid generation tank 12 and the flow rate Q1 refluxing to the pH adjustment tank 13 is equal to or higher than the upper limit flow rate Qmax, only the treated water is used. In step S370, the first adjusting agent pump 53 is operated and the pH adjusting agent is charged.
Then, after the set time T has elapsed (step S380), it is determined whether or not the pH of the organic waste water is 7.0 or higher in step S390. If the pH is lower than 7.0, the first time is determined in step S400. The input amount of the pH adjusting agent in the one adjusting agent pump 53 is increased by a certain amount. Then, after the set time T has elapsed (step S380), it is determined in step S390 whether or not the pH of the organic waste water is 7.0 or higher.

If the pH of the organic waste water is 7.0 or higher in step S390, it is determined in step S430 whether or not the pH of the organic waste water is smaller than 8.0. In step S430, if the pH of the organic wastewater is smaller than 8.0, it is determined whether or not the pH of the organic wastewater is 7.0 or higher in step S390 after the set time T has elapsed (step S380). To do.
In step S430, when the pH is 8.0 or more, the pH adjusting agent is stopped and the pH is adjusted to 8.0 or less. Then, after the set time T has elapsed (step S330), it is determined in step S340 whether or not the pH is 7.0 or higher.

  Further, as shown in FIG. 1, an air pump 61 for sending air to the organic waste water in the reaction tank 14 is provided at the lower part of the reaction tank 14. The air pump 61 compresses external air and sends it into the reaction vessel 14. The air sent into the reaction vessel 14 increases the chance that the granule carrier in the reaction vessel 14 comes into contact with oxygen in the air. In this case, it becomes possible to inactivate the anaerobic sulfate-reducing bacteria attached to the outermost part of the granule carrier and to generate hydrogen sulfide from sulfate ions. Similarly, anaerobic methane-fermenting bacteria adhere to the inside of the granule carrier, and thus are difficult to inactivate with this air.

As described above, in the wastewater treatment apparatus 1 including the raw material water tank 11, the acid generation tank 12, the pH adjustment tank 13, the reaction tank 14, and the control device 20, the wastewater treatment apparatus 1 is connected to the reaction tank 14. The treated water passages 41 and 42 for returning the treated water generated to the pH adjusting tank 13 and the acid generation tank 12 and a plurality of switchable pumps for treating water provided in the treated water passages 41 and 42 43, 44, and the control device 20 controls the operation of the second treated water pump 44 when the pH of the organic waste water in the acid generation tank 12 is less than 5.5, and When the pH of the organic wastewater in the acid generation tank 12 is higher than 6.5, the control for stopping the second treated water pump 44 and the pH of the organic wastewater in the pH adjustment tank 13 are smaller than 7.0. For the first treated water A control for operating the flop 43, and performs a control to stop the pH of the organic waste water and is greater than 8.0 the first processing water pump 43 in the pH adjusting tank 13.
By comprising in this way, the anaerobic methane-fermenting bacteria which are pH 5.5 or more which the sulfate reduction bacteria which exist in the said organic wastewater activate, and which exist in organic wastewater and treated water are The pH of the organic waste water in the acid generation tank 12 can be adjusted to less than pH 6.5, which is the lower limit pH at which it does not act actively.
Moreover, the pH of the organic waste water in the pH adjustment tank 13 can be adjusted to pH 7.0 or more and less than pH 8.0 where the anaerobic methane fermentation bacteria present in the reaction tank 14 are active.
For this reason, the hydrogen sulfide concentration in the biomass decomposition gas generated from the reaction tank 14 is reduced while the amount of biomass decomposition gas generated in the reaction tank 14 is maintained, and the amount of desulfurization agent used in the high-cost dry desulfurization device 55 is reduced. be able to.

Further, the wastewater treatment apparatus 1 is configured to recirculate the adjusting agent from the adjusting agent tank 45 to the pH adjusting tank 13 and the acid generating tank 12 for storing the adjusting agent for adjusting the pH. And a plurality of switchable pumps 53 and 54 for switching provided in the regulator passages 51 and 52, and the organic waste water in the acid generation tank 12. When the pH is less than 5.5, the control for operating the second treated water pump 44, the flow rate Q2 returning to the acid generation tank 12 of the treated water of the treated water pump 44, and the pH adjusting tank 13 are provided. When the sum of the flow rate Q1 recirculating to the flow rate is larger than the upper limit flow rate Qmax, the control of operating the second regulator pump 54 and the pH of the organic wastewater in the acid generation tank 12 are 6. Above 5 A control for stopping the treated water pump 44, a control for operating the first treated water pump 43 when the pH of the organic waste water in the pH adjusting tank 13 is smaller than 7.0, and the first treated water. When the sum of the flow rate Q2 returning to the acid generation tank 12 of the treated water of the pump 43 and the flow rate Q1 returning to the pH adjustment tank 13 is greater than the upper limit flow rate Qmax, the first adjusting agent And control for stopping the first treated water pump 43 when the pH of the organic waste water in the pH adjusting tank 13 is higher than 8.0.
By comprising in this way, in pH adjustment control, when the sum of the flow volume Q2 recirculated to the acid generation tank 12 of treated water and the flow volume Q1 recirculating to the pH adjustment tank 13 is smaller than the upper limit flow volume Qmax Since pH adjustment control can be performed only with treated water, pH adjustment can be performed by reducing the amount of the pH adjuster used.

In addition, an air pump 61 for blowing air from the lower part of the reaction tank 14 is provided.
By comprising in this way, the production amount of hydrogen sulfide in the reaction vessel 14 can be reduced.

DESCRIPTION OF SYMBOLS 1 Waste water treatment apparatus 12 Acid production tank 12b Acid production tank pH sensor 13 pH adjustment tank 13b pH adjustment tank pH sensor 14 Reaction tank 20 Controller 41 First treated water path 42 Second treated water path 43 For first treated water Pump 44 Second treated water pump 51 First adjusting agent passage 52 Second adjusting agent passage 53 First adjusting agent pump 54 Second adjusting agent pump

Claims (3)

In a wastewater treatment apparatus comprising a raw material water tank, an acid generation tank, a pH adjustment tank, a reaction tank, and a control device,
The wastewater treatment apparatus includes a plurality of treated water passages for returning treated water generated in a reaction tank to a pH adjusting tank and an acid generation tank, and a plurality of switchable treated water provided in the treated water passage. A pump,
The control device includes:
When the pH of the organic wastewater in the acid generation tank is less than 5.5, the process water pump is operated, and when the pH of the organic wastewater in the acid generation tank is higher than 6.5, the treatment water A control to stop the pump,
When the pH of the organic wastewater in the pH adjustment tank is less than 7.0, the control for operating the pump for treated water, and when the pH of the organic wastewater in the pH adjustment tank is higher than 8.0, the treated water A control to stop the pump,
A wastewater treatment apparatus characterized by The wastewater treatment apparatus includes a regulator tank for storing a regulator for adjusting pH, and a plurality of regulator passages for returning the regulator from the regulator tank to a pH adjustment tank and an acid generation tank. A plurality of switchable regulator pumps provided in the regulator passage,
When the pH of the organic wastewater in the acid generation tank is smaller than 5.5, the control for operating the pump for treated water, and the adjustment when the flow rate of the treated water pump exceeds the upper limit flow rate Control for operating the agent pump, and control for stopping the treated water pump when the pH of the organic wastewater in the acid generation tank is greater than 6.5,
When the pH of the organic waste water in the pH adjusting tank is less than 7.0, the control for operating the pump for treated water, and the adjustment when the flow rate of the treated water pump exceeds the upper limit flow rate A control for operating the agent pump, and a control for stopping the treated water pump when the pH of the organic wastewater in the pH adjustment tank is greater than 8.0,
The wastewater treatment apparatus according to claim 1, wherein: The wastewater treatment apparatus according to claim 1 or 2, further comprising an air pump that blows air from a lower portion of the reaction tank.

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