JP2001149973A - Water cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize and maintain a treatment capacity over a long period irrespective of the quality of water to be cleaned and to provide an excellent water purifier. SOLUTION: A means for detecting the organic matter concentration in the water to be treated is provided to adjust the flow rate of the water so that the amount of the organic matter introduced into a treating part is fixed. Namely, the product of the organic matter concentration in the water to be treated and the water flow rate is kept constant. Consequently, the amount of the organic matter matches the treatment capacity of the treating part, and the water is excellently cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to, for example, lakes, marshes, ponds,
The present invention relates to a water purification device for purifying water to be treated in water bodies to be purified, such as dams, reservoirs, reservoirs, rivers, irrigation canals, moats, canals, and aquariums.

[0002]

2. Description of the Related Art Lakes, ponds, dams, reservoirs, reservoirs, rivers,
As a countermeasure against water pollution in water purification systems such as irrigation canals, moats, canals, water tanks, etc., a treatment unit that purifies treated water passing through, and a pump that generates water flow through the treated water so as to pass through the treatment unit ) Is installed.

In such a water purification apparatus, microorganisms are allowed to survive in a treatment section for purifying the water to be treated, and the microorganisms decompose organic substances such as water worms, algae, organic suspended matters, and soluble organic substances in the water to be treated. It purifies the water to be treated.

In this water purification apparatus, the flow rate of water to be treated to the treatment section has been constant.

[0005]

In the water purification apparatus as described above, there is an upper limit to the amount of microorganisms that can live in the treatment section. For this reason, assuming that the maximum amount of microorganisms that can inhabit the treatment section is in the treatment section, if the water to be treated contains a large amount of organic matter, There is a problem in that the degree of purification of the water to be treated which has passed through the purification treatment in the treatment section exceeds the treatment capacity of the water to be treated by microorganisms, and becomes insufficient.

On the other hand, when the water to be purified contains only a small amount of organic matter, the purification ability of the microorganisms in the treatment section is higher than the amount of organic matter in the water to be treated. Since only the amount of organic matter in the water to be treated is purified, the maximum purification ability of the water purification device itself cannot be sufficiently exhibited, and therefore, there is a problem that the purification efficiency of the water purification device itself decreases.

It is an object of the present invention to sufficiently exhibit the purification ability of the water to be treated by changing the flow rate of the water to be treated to the treatment section in accordance with the concentration of organic substances in the water to be treated. It is to provide a water purification device that can be used.

[0008]

According to a first aspect of the present invention, there is provided a water purification apparatus, comprising: a treatment section for purifying treated water passing therethrough; and a water purification apparatus for passing the treated water through the treatment section. It consists of a water flow means for generating a water flow in the treated water,
In a water purification device for purifying the water to be treated using microorganisms living in the treatment section, an organic matter concentration detecting means for detecting an organic matter concentration of the water to be treated, and an organic matter concentration detected by the organic matter concentration detecting means, A water flow control means is provided for controlling the flow rate of the water to be treated by the water flowing means so as to increase or decrease the flow rate of the water to be treated passing through the processing section in accordance with the level of the organic matter concentration. I have.

Thus, when the concentration of organic matter in the water to be treated is high, the flow rate of water passing through the treatment section is reduced, and when the concentration of organic matter in the water to be treated is low, the flow rate of water passing through the treatment section is reduced. By increasing the flow rate, the purification treatment by the microorganisms in the processing section can be favorably performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the water purification apparatus of the present invention will be described below with reference to FIGS.

A water purification apparatus 1 according to the present invention comprises a purification unit 3 fixed to a water bottom 2b while sinking below a water surface 2a of a water area 2 to be purified in a closed system such as a pond or lake.
(See FIG. 1) and a drive device 30 (see FIG. 3) installed on the land side.

FIG. 2 is an enlarged view of a section AA 'of the purification processing unit 3 in FIG.

Next, the purification processing unit 3 will be described.

The purification unit 3 has an outer body 4 formed of a non-corrosive member such as vinyl chloride or stainless steel, a non-corrosive steel plate or the like, and formed in a cube. The upper plate 4a and the lower plate 4b of the outer body 4 have a large number of inflow holes 5 formed therein.
Are formed. The outer body 4 is fixed to the water bottom 2b via a support frame 6 fixed to the outer peripheral side of the lower surface of the lower plate portion 4b.

The outer body 4 is provided with a substantially L-shaped cylindrical water collecting pipe body 9 composed of an outer body first pipe part 7 and an outer body second pipe part 8.

The first tube portion 7 of the outer body has a flange portion 1 at one end.
0, the side plates 4c, 4d, 4
e, 4f attached to a specific side plate.

In this mounting state, the first tube portion 7 of the outer body extends horizontally in parallel with the lower plate portion 4b of the outer body 4, and the lower plate portion 4b
Extends to a substantially central position. In the attached state, the outer body second pipe section 8 extends upward from the opposite side to the flange section 10 of the outer body first pipe section 7 to a substantially central position in the height direction of the outer body 4. And the water collecting part 12 is connected vertically.

The water collecting section 12 has a plurality of branch pipes 12b connected to a main pipe 12a so that the insides thereof communicate with each other.
2b, a plurality of water collecting holes 13 are formed on the upper surface and the lower surface so that the water to be treated can flow. The main pipe 12 of this water collecting part 12
a is provided so as to contact the inside of the side plates 4d and 4f of the outer body 4, and the branch pipe 12b is provided so as to contact the inside of the side plates 4c and 4e of the outer body 4.

Here, one end of the water collecting pipe 9 is connected to the vicinity of the axial center of the main pipe 12a of the water collecting part 12 so that the inside thereof communicates with each other, so that water to be treated is uniformly collected from each branch pipe 12b. As the distance from the connection between the water collecting part 12 and the water collecting pipe 9 to the branch pipe 12b increases, the branch pipe 1
It is set so that the area of the water collecting hole 13 formed in 2b becomes large (so that the fluid resistance becomes small).

The inner space of the outer body 4 is filled with a charcoal 14 as a purifying material having a diameter larger than that of the inflow hole 5 and the water collecting hole 13, and also carries aerobic microorganisms for decomposing organic substances. 15 are formed.

Outside the outer body 4, a substantially L-shaped cylindrical water pumping pipe 18 comprising an outer first pipe section 16 and an outer second pipe section 17 is provided.

The first external pipe portion 16 of the pumping pipe body 18 has a flange portion 19 at an end, and the flange portion 19 is aligned with the through hole 11 with the inner peripheral surface thereof. Of the side plate portions 4c, 4d, 4e, and 4f. The flange portion 19 is attached to the side plate portion by being connected to the flange portion 10 of the water collecting pipe 9 with bolts or the like with the side plate portion interposed therebetween.
In such an attached state, the outer first pipe section 16
Is connected to the water collecting pipe 9.

The outer external second pipe section 17 is moved from the outer end position of the outer external first pipe section 16 with the outer external first pipe section 16 attached to the outer body 4 in this manner. First pipe part 16
The upper opening 18a extends upward at a position above the outer body 4 at right angles to the outer body 4.

The pumping pipe 18 is formed with a through hole 20 perpendicular to the central axis of the outer second pipe section 17, and a cylindrical air jet pipe 21 is fitted and fixed in the through hole 20. ing. At one end of the air ejection pipe 21 protruding into the pumping pipe 18, a large number of air ejection ports 26 having air ejection holes (not shown) for ejecting air into the second external pipe section 17 are formed. The other side is bent upward and connected to the connecting pipe 22 outside the second external pipe portion 17, and is connected to the driving device 30 installed on the land side.

On the lower side of the outer body 4, a cylindrical washing nozzle 23 having a closed end is provided while being fixedly supported by the support frame 6. In a fixed state, the cleaning nozzle 23 has one side thereof along the lower plate portion 4b.
This part has an air outlet 2 that connects the inside to the outside.
4 are formed over a substantially entire length at predetermined intervals. The other end of the cleaning nozzle 23 is connected to the side plate portions 4c, 4c.
d, 4e, 4f, and outside the side plate portion 4c,
It is bent so as to be parallel to any one of 4d, 4e, and 4f and is connected to the connection pipe 25. The cleaning nozzle 23 is
The driving device 3 installed on the land side via the connecting pipe 25
Connected to 0.

The cleaning nozzle 23 may be formed in one or a plurality of rings below the lower plate portion 4b, and a plurality of air ejection holes 24 may be formed in the circumferential direction.

Next, the driving device 30 will be described.

The drive unit 30 is a housing 3 installed on the land side.
As shown in FIG. 3, the connecting pipe 22 on the air ejection pipe 21 side and the connecting pipe 25 on the cleaning nozzle 23 side
It is connected to an electromagnetic switching valve 34 in the housing 31. The switching valve 34 is provided with the compressor 3 disposed in the housing 31.
5 is also connected to the air discharge side.

The switching valve 34 is in a state in which the discharge side of the compressor 35 is connected to the connecting pipe 22 without being connected to the connecting pipe 25, and the switching valve 34 is connected to the connecting pipe 2 without being connected to the connecting pipe 22.
5 can be switched.

The connecting pipe 22 is provided with a flow control valve 36 capable of changing the flow rate of air passing through the connecting pipe 22.

The switching valve 34, the compressor 35 and the flow control valve 36 are electrically connected to a controller 37 provided in the housing 31. The controller 37 is connected to an external power supply 38,
The power supply to the compressor 35 and the switching valve 34 is controlled.

Here, the compressor 35 and the air ejection pipe 2
1. The pumping pipe 18 constitutes an air lift pump (water passing means) that generates water flow in the processing unit 15 by sucking water from inside the processing unit 15.

The compressor 35, the switching valve 34, the connecting pipe 25, and the washing nozzle 23 constitute a washing device for washing the processing section 15.

In this embodiment, an organic substance concentration detecting sensor 40 for detecting the concentration of organic substances in the water area 2 is provided at a predetermined position in the water area 2 to be purified. The organic matter concentration detection sensor 40 measures the concentration of organic matter contained in the water to be treated in the water area 2 to be purified.

The organic substance concentration detection sensor 40 is electrically connected to a controller 37 by a cable 41. A signal from the organic substance concentration detection sensor 40 is sent to the controller 37, processed by the controller 37, and processed by the compressor 35 and the switching valve. 34, controlling the operation of the flow regulating valve 36, and the like.

The organic substance concentration detection sensor 40 is
If the organic substance concentration in the water area 2 to be purified can be measured, the position is, for example, in the vicinity of any one of the upper plate portion 4a, the lower plate portion 4b, the side plate portions 4c, 4d, 4e, and 4f of the water purification device 1, or It may be provided at any position of a specific place where a representative water quality of the water area 2 to be purified away from the main body of the water purification device 1 can be obtained.

The organic matter concentration detection sensor 40 detects a biological oxygen demand (BOD) in the water to be treated by a microorganism electrode comprising an immobilized microorganism membrane and a dissolved oxygen electrode, which is specified in, for example, JIS K3602. The organic matter concentration in the water area 2 to be purified is measured.

Further, as the organic substance concentration detection sensor 40, a sensor for directly detecting the organic substance concentration (TOC) in the water area 2 to be purified, and water quality such as dissolved oxygen (DO) and hydrogen ion concentration (pH) are detected. A sensor that indirectly detects the concentration of organic matter by correlating the water quality with the concentration of organic matter may be used.

Next, the control configuration of the water purification apparatus 1 having the above configuration by the controller 37 will be described below together with the operation of the water purification apparatus 1 itself using the flowchart shown in FIG.

First, the controller 37 is supplied from the external power supply 38.
Is supplied to the controller 37, the controller 37 fully opens the flow control valve 36 (step S1) and sets the switching valve 34 to
The discharge side of the compressor 35 is communicated with the connecting pipe 22 on the purification side without communicating with the connecting pipe 25 (step S
2). Then, the compressor 35 is driven (step S3), and compressed air is supplied from the compressor 35 to the air ejection pipe 21 via the connection pipe 22. Then
The compressed air is jetted from the air jet port 26 of the air jet pipe 21 and moves from the bottom to the top as bubbles in the external external second pipe portion 17 of the water pumping pipe 18. An upward water flow, that is, an air lift, is generated in the outer external second pipe portion 17 of the pipe body 18, and the water near the center of the processing section 15 is sucked from the water collecting section 12, and the water flows upward through the water collecting pipe 9 and the pumping pipe 18. It is discharged from the opening 18a to the outside of the processing unit 15. Thereby, the water outside the outer body 4 is forcibly introduced into the processing unit 15 from the inflow hole 5 of the upper plate 4a and the inflow hole 5 of the lower plate 4b, and moves toward the processing unit 15 toward the center. To the central water collecting section 12, where the algae such as blue-green algae, organic suspended matter, and soluble organic substances are decomposed into aerobic microorganisms carried on the charcoal 14 constituting the processing section 15. Water is purified.

The water thus purified is sucked from the water collecting part 12 into the water collecting pipe 9, moves from the water collecting pipe 9 to the inside of the water pumping pipe 18, and protrudes upward.
Is discharged into the water area 2. Thereby, the water area 2 to be purified is purified.

Next, the controller 37, which has performed the processing in step S3, uses the organic substance concentration detection sensor 40 to measure the organic substance concentration in the water area 2 to be purified, that is, the organic substance concentration of the water to be treated flowing into the processing section 15 ( Step S
4).

Then, a water flow rate is calculated to make the amount of organic matter of the water to be treated flowing into the processing section 15 a predetermined amount of organic matter stored (or set) in the controller 37 in advance (step S5). That is, the amount of organic matter flowing into the processing section depends on the concentration of the organic substance in the water to be treated and the processing section 15.
It is the product of the flow rate of the to-be-processed water flowing into the inside. Therefore, as for the flow rate, the processing unit 15 stores (or sets) a predetermined amount of organic matter suitable for the purification process in the controller 37 in advance, and determines the predetermined amount of organic matter stored (or set) in the controller 37. , Calculated by dividing by the organic matter concentration in the water area 2 to be purified measured by the organic matter concentration detection sensor 40 in step S4.

The predetermined amount of organic matter suitable for the purification treatment stored (or set) in the controller 37 depends on the size of the treatment unit 15 of the water purification device 1 itself and the microorganism carrier ( Here, the amount of organic matter suitable for the purification treatment of each water purification device is determined in advance by experiments or the like, and is stored in the controller 37, since the amount differs depending on the particle size of the charcoal 14).

Next, the valve opening of the flow control valve 36 is adjusted so that the water flow rate obtained in step S5 is obtained (step S6). In step S6, the flow rate of the compressed air supplied to the connecting pipe 22 and the air ejection pipe 21, that is, the flow rate of the air supplied to the pumping pipe body 18, is adjusted, and the flow rate of the water to be treated collected by the air lift is increased or decreased. . In other words, if the water to be treated is extremely dirty (the concentration of organic matter is higher than a predetermined concentration), the flow rate is small. If the water to be treated is clean (the concentration of organic matter is lower than the predetermined concentration), the flow rate is low. Do more.

Here, how to adjust the flow rate of the water to be treated will be described. The relationship between the valve opening of the flow control valve 36 and the amount of water to be treated is the relationship between the valve opening of the flow control valve 36 and the flow rate of air ejected from the air outlet 26, and the relationship between the valve opening and the air outlet 26. The relationship between the flow rate of the supplied air and the amount of water to be treated to be pumped by the air lift is obtained in advance. Therefore, the relationship between the valve opening and the pumping amount of the water to be treated is stored in the controller 37, and the valve opening of the flow control valve 36 corresponding to the pumping amount corresponding to the flow rate calculated in step S5 described above. Is read, and the valve opening of the flow rate adjusting valve 36 is adjusted so as to have the valve opening.

Further, a cleaning process is performed for a long time,
The clogging of the processing unit 15 progresses due to the aerobic microorganisms grown in 5 or the substances generated by the decomposition of the aerobic microorganisms and the suspended matter contained in the water to be treated in the processing unit 15, and the target purification performance is reduced. If not obtained, the processing section 15 is washed. The cleaning (backwashing) time of the processing unit 15 is determined by, for example, the pumping pipe 18 detected by a pressure sensor provided separately.
When the suction pressure of the water to be treated within the chamber and upstream of the air outlet 26 is equal to or higher than a preset pressure value, or when a timer is provided to perform purification for a certain period by the timer. It is determined by the method described above.

It is determined whether or not it is time to clean the processing unit 15 by the above-described method (step S7). If it is determined that the processing unit 15 does not need to be cleaned yet, step S7 is performed.
Returning to step 4, the measurement of the organic matter concentration of the water to be treated and the adjustment of the flow rate of water determined thereby are repeated.

If it is determined in step S7 that the processing section 15 is to be cleaned, the switching valve 34 is switched so that the air supply passage of the compressor 35 is connected to the connecting pipe 25 (step S8). As a result, the compressed air supplied from the compressor 35 to the connection pipe 25 is ejected from the air ejection holes 24 of the washing nozzle 23 and becomes bubbles.
It enters the processing section 15 through the inflow hole 5 of the lower plate section 4b above the cleaning nozzle 23, and moves upward in the processing section 15. Vibration occurs in the charcoal 14 constituting the processing unit 15 due to an impact or the like due to the movement of the bubble. The aerobic microorganisms or the aerobic microorganisms decomposed and produced by the aerobic microorganisms proliferated in the processing unit 15 by performing the cleaning process by the vibration or the shock due to the cleaning process.
Floating substances and the like contained in the water to be treated in the water 5 are separated from the charcoal 14 and rise in the processing section 15 together with the air by the water flow generated by the movement of the bubbles. It passes through and is discharged outside the processing unit 15. Thus, the processing unit 15 is cleaned.

Next, the cleaning timer t is reset (step S9), and thereafter the cleaning timer t is started (step 10). It is determined whether or not a preset cleaning time t ₁ has elapsed, that is, whether or not t> t ₁ (step S11).

If t> t ₁ is not satisfied in step S11, the value of the timer t is added, and
And the cleaning of the processing unit 15 is continued.

If t> t ₁ is satisfied in step S11, the cleaning of the processing section 15 is terminated. That is, the switching valve 34 is switched so that the compressor 35 is connected to the connecting pipe 25 (step S12), and the process returns to step S4, where the concentration of the organic matter in the water to be treated is measured again, and the flow rate of the flow rate determined thereby is determined. Make adjustments.

By performing the above control, a certain amount of organic matter flows into the processing unit 15 irrespective of the concentration of organic matter in the water area 2 of the water to be treated for purification. The amount of organic substances can be adjusted to the purification ability. Therefore, there is no need to apply a load greater than the processing capacity of the processing unit 15 or conversely, it is not possible to secure an amount of organic substances necessary for the microorganisms to survive. As a result, the purification capacity of the purification device can be sufficiently exhibited, and the purification treatment of the water to be treated can be performed efficiently.

Further, since the amount of organic matter flowing into the processing unit 15 is always constant, the progress of the clogging of the processing unit 15 can be easily predicted, so that the processing unit 15 can be cleaned at an appropriate time.

Further, similarly, since the amount of organic matter flowing into the treatment section 15 is always constant, the amount of organic matter to be purified in the water purification device 1 (ie, the performance of the purification device)
It is also easy to predict the water quality of the treated water area 2 by combining it with data such as the state of inflow of organic pollutants.

In the above description, the organic matter concentration detected by the organic matter concentration detection sensor 40 uses the biochemical oxygen demand (BOD) of the water area 2 to be purified as an index of organic matter pollution. That is, as the organic substance concentration detection sensor 40, the concentration of organic substances decomposable by aerobic microorganisms inhabiting inside the processing unit 15 is measured using a microorganism electrode comprising an immobilized microorganism membrane and a dissolved oxygen electrode. However, for example, the following method may be used.

That is, the dissolved oxygen (DO) of the water to be treated is used as an index of the organic matter pollution. In this case, a polar measurement DO measurement electrode is used as the organic substance concentration detection sensor 40. In general, DO is low in very dirty water,
Higher for clean water. Therefore, when DO is low, the flow rate is small, and when DO is high, the flow rate is high.

Further, since the DO saturation value changes depending on the water temperature, as described above, in addition to using the DO measuring electrode as the organic substance concentration detecting sensor 40, a water temperature meter 42 is provided to measure the temperature of the water to be treated. As a result, the DO saturation percentage can be obtained, and this DO saturation percentage can be used as an index of organic matter pollution. In this case as well, similarly to the control in the case where DO is used as an indicator of organic matter pollution, the flow rate is reduced when the DO saturation percentage is low, and the flow rate is increased when the DO saturation percentage is high.

Further, a hydrogen ion concentration (pH) may be used as an index of organic matter contamination. In this case, a pH electrode is used as the organic substance concentration detection sensor 40. In general, the controller 37 determines the correlation between the pH and the concentration of organic substances such that the pH is large in water in which blue water and the like are generated (toward the alkaline side), and is about 7 in neutral water (neutral).
To be entered. Thus, when the pH is large and the water is alkaline, the flow rate is reduced, and when the water is neutral, the flow rate is increased.

In this embodiment, the driving device 30
Although the configuration shown in FIG. 3 adjusts the flow rate of the water to be treated flowing into the processing section 15 by the valve opening of the flow rate adjustment valve 36, the configuration shown in FIG. 5 may be used. That is, the flow rate of the water to be treated is adjusted by adjusting the voltage supplied to the compressor 35 by the controller 37 without providing the flow rate adjusting valve 36. Thus, the same effect as in the above embodiment can be obtained only by electrical control without providing the flow rate adjusting valve 36.

In this case, the relationship between the voltage supplied to the compressor 35 and the flow rate of the air jetted from the air jet port 26,
In addition, the relationship between the flow rate of the air ejected from the air ejection port 26 and the amount of the water to be treated pumped by the air lift is determined in advance, so that the voltage supplied to the compressor 35 and the amount of the water to be treated are determined. Can be By storing the relationship between the voltage supplied to the compressor 35 and the pumping amount of the water to be treated in the controller 37, the voltage supplied to the compressor 35 can be set to an arbitrary pumping amount.

In this embodiment, the flow rate of the water to be treated flowing into the processing section 15 is adjusted according to the concentration of the organic matter in the water to be treated. Until the organic substance concentration reaches a predetermined organic substance concentration, the control may be such that the flow rate of the water to be treated flowing into the processing section is set to be constant. That is, when the organic matter concentration of the water to be treated is lower than the threshold value, the flow rate of the water to be treated flowing into the processing section is set to a predetermined high flow rate. By setting the flow rate of the treated water to be lower than the predetermined high flow rate, the purification process may be effectively performed.

In this embodiment, an example has been described in which the water to be treated flows into the processing section 15 by the air lift pump using the compressor 35, the air ejection pipe 21, and the water pumping pipe 18. Any pump may be used as long as it can adjust the flow rate. For example, a pump such as a submersible pump may be used. In this case, the flow rate of the water to be treated is adjusted by means such as changing the voltage supplied from the controller 37 as described above.

Further, in this embodiment, the water purification device in which one cubic purification unit 3 is fixed to the water bottom 2b has been described. However, when the shape of the purification unit 3 is other than a cube, or when two or more It is needless to say that the present invention can be applied to a water purification apparatus of a type in which the purification processing unit 3 is provided and the purification processing unit 3 itself is floated in a water area by floating or the like.

[0065]

As described above in detail, according to the water purification apparatus of the present invention, when the organic matter concentration of the water to be purified is high, the flow rate of the water passing through the treatment section is reduced, On the other hand, when the concentration of organic matter in the water to be treated is low, the flow rate of water passing through the treatment section is increased so that the purification ability of microorganisms in the treatment section can be sufficiently exhibited, and the treatment of the treatment water can be efficiently performed. Can do it.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a purification processing unit 3 of a water purification apparatus 1 according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of the purification processing unit 3 of the water purification apparatus 1 according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a driving device and the like of the first embodiment of the water purification device of the present invention.

FIG. 4 is a flowchart showing control contents of a controller of the water purification apparatus according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a modified example of the driving device and the like of the first embodiment of the water purification device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water purification apparatus 3 Water purification unit 12 Water collecting part 15 Processing part 18 Pumping pipe 35 Compressor 36 Flow control valve 37 Controller 40 Organic substance concentration detection sensor

Claims (1)

[Claims] 1. A treatment section for purifying treated water passing therethrough, and a water passing means for generating a water flow in the treated water so as to pass through the treatment section, using microorganisms living in the treatment section. In the water purification device for purifying the water to be treated, an organic substance concentration detecting means for detecting an organic substance concentration of the water to be treated, and an organic substance concentration detected by the organic substance concentration detecting means, A water quality purifying apparatus, further comprising a water flow rate control means for controlling a flow rate of the water to be treated by the water flowing means so as to increase or decrease the flow rate of the water to be treated passing through the processing section.