JPH0873202A - Controller for amount of ozone to be generated for water treating facility - Google Patents

Abstract

PURPOSE: To adequately control the amt. of ozone to be generated with respect to a flow rate of inflow water by adding an arithmetic section for correcting the control target value on the flow rate of the inflow water to the fore stage of an existing control system for the ozone to be generated. CONSTITUTION: The raw water taken in from rivers, etc., is introduced to a flocculating and settling treatment 1, where a flocculating agent is injected into the raw water to remove sand and suspended materials. The raw water is automatically measured by a flow meter 3 and is introduced by a raw water pump 2 to an ozone contact basin 4. The gaseous raw material of an ozonizing gas is supplied by a blower 10 to an ozone generator 11 and the generated gaseous ozone is supplied as fine bubbles by a gas diffusion pipe 12 into the ozone contact basin 4, by which the dissolved org. materials in the water to be treated are oxidation decomposed. At this time, the ozone injection rate set by an ozone injection rate setter 6 is corrected by the measured value of the flowmeter 3 in the arithmetic section 7 for correcting the ozone injection rate and is transmitted to the arithmetic section 8 for the amt. of the ozone to be generated and the control section 9 for the amt. of the ozone to be generated. The effluent water from the ozone contact basin 4 enters a bioactive carbon treating device 5 where the dissolved org. materials are adsorbed away and the effluent water is subjected to the oxidation decomposition of microorganisms then to sterilization with chlorine. This water is distributed as city water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone generation amount control device for optimally controlling the amount of ozone generation injected into water to be treated in a water treatment facility using ozone treatment.

[0002]

2. Description of the Related Art In recent years, with the deterioration of water quality in lakes and rivers, which are the water sources, the offensive odor damage of water supply is reported every year in the suburbs of large cities. The offensive odor damage is caused by dissolved organic substances represented by geosmin and dimethylisoborneol (hereinafter referred to as 2-MIB). Therefore, it is required to remove these dissolved organic substances from tap water. However, water purification treatment by the conventional coagulation-sedimentation method mainly aims to remove the suspended matter,
It was difficult to remove dissolved organic substances sufficiently.

The advanced water purification treatment is installed after the coagulation-sedimentation method for the purpose of removing these dissolved organic substances. This type of advanced water purification method is disclosed in JP-A-58-174288, JP-A-2-233197 and JP-A-4-281893. The outline of the advanced water purification treatment will be described below.

Advanced water purification treatment is generally composed of ozone treatment and biological activated carbon treatment. In the ozone contact pond, fine bubbles of ozone gas are injected into the water to be treated. Ozone gas is dissolved by gas-liquid contact to become dissolved ozone. Due to the strong oxidizing power of dissolved ozone, dissolved organic substances in the water to be treated are oxidatively decomposed. After sufficiently removing the dissolved ozone, the ozone-treated water is introduced into the biological activated carbon treatment. In biological activated carbon treatment, adsorption of organic substances by the numerous pores on the surface of activated carbon, nitrification of ammonia nitrogen and the like by microorganisms propagated on and inside the activated carbon and metabolism of organic substances are removed. By the above treatment, the dissolved organic substances in the water to be treated are removed, and the off-flavor can be removed.

In the ozone treatment in the above-mentioned advanced water purification treatment, it is required that the high removal rate of dissolved organic substances be maintained and that the water quality after ozone treatment is always stable. Further, since the ozone generator has a low ozone generation efficiency and a high electric power cost, it is required to suppress the amount of ozone to be generated and injected to a necessary minimum and perform an efficient treatment. It is necessary to control so as to meet these requirements.

[0006]

As an ideal ozone generation amount control system for the ozone generator for optimizing the ozone injection amount, a system in which the concentration of the dissolved organic substance flowing out is a control target is ideal. To make this automatic control,
There is a need for a measuring instrument that measures the type and concentration of dissolved organic matter online. However, at present, there is no measuring instrument that can measure the kind and concentration of a trace amount of dissolved organic matter in the treated water in real time with sufficient accuracy, so this ozone generation control method cannot be realized.

As a general ozone generation control method which has been proposed and put into practical use, there are constant ozone injection rate control in which the ozone injection rate is constant (Japanese Patent Laid-Open No. 61-68195) and ozone concentration in exhaust gas. Exhaust ozone concentration constant control by applying feedback so that
-161894, JP-A-56-58583) and constant control of dissolved ozone concentration by feedback such that the dissolved ozone concentration in the effluent maintains a constant value (JP-A-59-39388).
And JP-A-62-176594). Hereinafter, these three types of control methods will be referred to as the current ozone generation control method.

With respect to the current ozone generation amount control system described above, the stability of each control system against disturbance was examined by computer experiments. In other words, a mathematical model of an ozone contact pond was constructed, and the states of constant injection rate control, constant dissolved ozone concentration control, and constant exhaust ozone concentration control were simulated and examined.

When actually performing ozone treatment in a water purification plant, parameters such as inflow water quality and inflow water amount vary. Therefore, the fluctuation of the inflow of water was assumed as a disturbance, and simulations were performed for each control method.

As a result, in any control method,
It was shown that when the inflow water quantity fluctuates as a disturbance, the outflow water quality also fluctuates almost in proportion. Since the water treatment facility is required to maintain stable outflow water quality regardless of any disturbance, it is inconvenient from the viewpoint of control that the outflow water quality fluctuates in response to the fluctuation of the inflow water amount. In other words, just using the current ozone generation control method,
It is not enough to achieve the purpose of keeping the runoff quality at the target value.

The present invention has been made in view of the above-mentioned inconvenience, and an object of the present invention is not to be affected by disturbance such as fluctuation of inflow water amount, to properly maintain the treated water quality, and to provide ozone without excess or deficiency. An object is to provide an ozone generation amount control device that achieves an injection amount.

[0012]

The present invention has the above-mentioned problems,
That is, to solve the problem that the outflow water quality changes due to changes in the inflow water amount, to stabilize the outflow water quality, an ozone contact pond, an ozone generator that generates ozone blown into the ozone contact pond, and the ozone contact pond. In an ozone contact pond including an inflow water amount measuring means for measuring the inflow amount of inflow and an ozone generation amount control unit for controlling the ozone generation amount of the ozone generator, the ozone generation amount used in the ozone generation amount control unit In order to obtain the control calculation value, (1) the ratio of the inflow water amount measured by the inflow water amount measuring means and the inflow water amount at a predetermined reference time is set to the ozone injection rate set by the ozone injection rate setting device. An ozone injection rate correction calculation unit that corrects the ozone injection rate by multiplication, an ozone injection rate corrected by the ozone injection rate correction calculation unit, and the inflow water meter And a ozone generation amount calculating unit for obtaining the amount of ozone generated control calculation value of the ozone generator from the product of the measured inflow water amount by means. Alternatively,
(2) Exhaust ozone concentration measuring means for measuring the ozone concentration in the exhaust gas of the ozone contact pond, and an exhaust ozone concentration target value setting device for presetting a constant exhaust ozone concentration target value,
By multiplying the ratio of the inflow water amount measured by the inflow water amount measuring means and the inflow water amount at a predetermined reference time to the exhaust ozone concentration target value set by the exhaust ozone concentration target value setting device, the exhaust ozone Exhaust ozone concentration target value correction calculator for correcting the target concentration value, and exhaust ozone concentration target value correction calculated by the exhaust ozone concentration target value correction calculator for the exhaust ozone concentration measured by the exhaust ozone concentration measuring means. And an ozone generation amount calculation unit that obtains an ozone generation amount control calculation value that is equal to the amount. Alternatively,
(3) Measured by the dissolved ozone concentration measuring means for measuring the dissolved ozone concentration in the ozone contact pond water, the dissolved ozone concentration target value setting device for presetting a constant dissolved ozone concentration target value, and the inflow water amount measuring means Dissolved ozone for correcting the dissolved ozone concentration target value by multiplying the dissolved ozone concentration target value set by the dissolved ozone concentration target value setter by the ratio of the inflow water amount thus determined and the inflow water amount at a predetermined reference time Generation of ozone such that the dissolved ozone concentration measured by the concentration target value correction calculation unit and the dissolved ozone concentration measurement unit becomes equal to the dissolved ozone concentration target value correction amount calculated by the dissolved ozone concentration target value correction calculation unit. An ozone generation amount calculation unit for obtaining the amount control calculation value;
Is provided.

[0013]

The reason why stable control can be realized against fluctuations in the amount of inflow water by using the ozone generation amount control method described in the present invention will be described below.

By changing the amount of inflow water, (1) amount of inflowing dissolved organic substances per unit time (2) residence time of treated water in the ozone contact pond (3) gas-liquid contact time between treated water and ozone gas bubbles The three elements of are constantly changing.

However, since the current ozone generation control method only considers (1), the amount of injected ozone is insufficient or excessive. The present invention is a control system considering all of the above (1), (2), and (3).

The present invention is based on the current ozone injection rate constant control, exhaust gas ozone concentration constant control and dissolved ozone concentration constant control, and controls the amount of inflow water having the effect of canceling the influence of (3) as a control target value. I added a part to add to. The calculation of the inflow water amount correction is performed by multiplying the control target value of each control method by the ratio of the current inflow water amount and the reference time inflow water amount.

As a result, the quality of outflow water can be stabilized, and ideal ozone generation amount control can be realized.

[0018]

Embodiments of the present invention will be described below.

FIG. 1 is a block diagram of an inflow water amount correction injection rate control system. In FIG. 1, 1 is a coagulation sedimentation treatment, 2 is a raw water pump, 3 is a flow meter, 4 is an ozone contact basin, 5 is a biological activated carbon treatment device, 6 is an ozone injection rate setting device, 7 is an ozone injection rate correction calculation unit, 8 is an ozone generation amount calculation unit, 9 is an ozone generation amount control unit, 10 is a blower, 11 is an ozone generator, 12
Is an air diffuser.

Raw water taken from a river or the like through a water pipe (not shown) is guided to a coagulating sedimentation treatment 1.

In the coagulation-precipitation treatment 1, sand and suspended matter in the inflowing raw water are removed by injecting a coagulant.

Outflow water from the coagulating sedimentation treatment 1 is introduced into an ozone contact basin 4 by a raw water pump 2.

The amount of water flowing into the ozone contact pond 4 is automatically measured by the flow meter 3.

The ozonized gas generated in the ozone generator 11 is supplied to the ozone contact basin 4 as fine bubbles by the air diffuser 12.

The blower 10 supplies a raw material gas of ozonized gas to the ozone generator 11.

The ozone of the ozonized gas supplied from the air diffuser 12 into the ozone contact basin 4 dissolves in the water to be treated and oxidizes and decomposes the dissolved organic substances in the water to be treated.

Outflow water from the ozone contact pond 4 flows into the biological activated carbon treatment apparatus 5.

The low-molecular-weight dissolved organic substance is adsorbed and removed on the surface of the activated carbon in the biological activated carbon treatment apparatus 5. Further, the adsorbed low molecular weight dissolved organic matter is oxidatively decomposed by the microorganisms attached to the surface of the activated carbon.

Through the above treatment process, the raw water becomes purified treated water, which is sterilized with chlorine and then distributed as tap water.

(1) Inflow Water Quantity Corrected Injection Rate Control Method FIG. 1 is a block diagram of an inflow water quantity corrected injection rate control method. In the water purification process shown in FIG. 1, the ozone injection rate set by the ozone injection rate setter 6 is corrected by the ozone injection rate correction calculator 7 by the measurement value of the flow meter 3. The ozone injection rate is input to the ozone injection rate setting device 6 in advance by an operator or the like and can be arbitrarily changed.

The ozone injection rate correction calculation unit 7 calculates the ozone injection rate by multiplying the ratio of the current measured value of the flow meter 3 and the inflow water amount at a predetermined reference time. However, the reference time is when the effect of ozone treatment is ideally achieved. When this operation is written as an expression, it becomes as follows.

(Corrected ozone injection rate) = (Ozone injection rate set value) × (Current inflow water amount) / (Reference inflow water amount) The corrected ozone injection rate should be multiplied by the measured value of the flow meter 3. Is converted into an ozone generation amount control calculation value by the ozone generation amount calculation unit 8. When this operation is written as an expression, it becomes as follows.

(Ozone generation amount control calculation value) = (corrected ozone injection rate) × (current inflow water amount) The ozone generation amount control unit 9 uses the ozone generation amount control calculation value to generate the ozone generator 11 and the blower. Control the operation amount of 10.

(2) Inflow water amount correction exhaust gas ozone concentration control system FIG. 2 is a block diagram of an inflow water amount correction ozone gas concentration control system. In the water purification process shown in FIG. 2, the exhaust ozone concentration target value target value set by the exhaust ozone concentration target value setting unit 14 is corrected by the exhaust ozone concentration target value correction calculation unit 15 by the measurement value of the flow meter 3. This correction is achieved by multiplying the exhaust ozone concentration target value by the ratio of the current measured value of the flow meter 3 and the inflow water amount at a predetermined reference time. That is, (corrected exhaust ozone concentration target value) = (exhaust ozone concentration target value) × (current inflow water amount) / (reference water inflow amount) However, with reference time, the effect of ozone treatment is ideally achieved. That is the case. As the ozone concentration target value in exhaust gas, the ozone concentration in exhaust gas at the standard time is used.

In the ozone generation amount calculator 16, the corrected exhaust ozone concentration target value and the value measured by the exhaust ozone concentration measuring means 13 provided in the gas phase portion of the ozone contact basin 4 become equal. Calculate the ozone generation control value.

Using this ozone generation amount control calculation value, the ozone generation amount control unit 9 causes the ozone generator 11 and the blower 1 to operate.
Control 0.

(3) Inflow water amount correction dissolved ozone concentration control method FIG. 3 is a block diagram of the inflow water amount correction dissolved ozone concentration control system. In the purified water treatment shown in FIG. 3, the dissolved ozone concentration target value set by the dissolved ozone concentration target value setting device 18 is
The dissolved ozone concentration target value correction calculation unit 19 corrects the measured value of the flow meter 3. This correction is achieved by multiplying the dissolved ozone concentration target value by the ratio of the current measured value of the flow meter 3 and the inflow water amount at a predetermined reference time. That is, (corrected dissolved ozone concentration target value) = (dissolved ozone concentration target value) × (current inflow water amount) / (reference water inflow amount) However, the ozone treatment is ideally performed in the reference time. This is the case, and the dissolved ozone concentration target value uses the dissolved ozone concentration at the reference time.

In the ozone generation amount calculation unit 16, the corrected dissolved ozone concentration target value and the value measured by the dissolved ozone concentration measuring means 17 provided in the liquid phase portion of the ozone contact pond 4 become equal. Calculate the ozone generation control value.

The ozone generation amount control unit 9 controls the ozone generator 11 and the blower 10 using the value of the ozone generation amount control calculation value.

Next, an example in which the effects of the present invention are verified by simulation will be described.

As a mathematical ozone contact pond model for simulation, a complete mixing tank array model was used. As typical ozone contact pond models, there are a fully mixed model and an extruded flow model, but the actual ozone contact pond model is usually in an intermediate state between them. Therefore, we adopted a complete mixing tank row model that can express the intermediate state,
A simulation was performed.

FIG. 4 shows a conceptual diagram of the complete mixing tank row model. The complete mixing tank array model is a model in which the entire ozone contact tank is conceptually composed of N small virtual tanks, and the inside of each virtual tank is assumed to be in a completely mixed state. Equations (1) to (3) show the model equations of the complete mixing vessel array for the [i] th vessel. However, Vl is the total volume of the liquid inside the virtual tank, Vg is the total volume of the air bubbles existing inside the virtual tank, Ql is the inflow water amount (flow rate), Qg is the inflow gas amount, C
l is the dissolved ozone concentration, Cg is the vapor ozone concentration, Cs is the dissolved organic matter concentration, KLa is the overall mass transfer coefficient, S is the distribution coefficient, Kde is the self-decomposition reaction coefficient, Kox is the organic matter oxidative decomposition reaction coefficient, and Kr is the organic matter 1g. Represents the amount of ozone consumed for the oxidative decomposition of. The numerical value i in [] represents the number of each tank.

Vl × dCl [i] / dt = Ql × (Cl [i−1] −Cl [i]) + KLa × (S × Cg [i] −Cl [i]) − Kde × Cl [i] − Kox × Kr × Cl [i] × Cs [i] Formula (1) Vg × dCg [i−1] / dt = Qg × (Cg [i] −Cg [i−1]) − Vl × KLa × (S XCg [i] -Cl [i]) Formula (2) VlxdCs [i] / dt = Qlx (Cs [i-1] -Cs [i])-Kox xCl [i] xCs [i [Equation (3)] This model equation is composed of simultaneous ozone differential equations related to the material balance for dissolved ozone concentration: equation (1), gas-phase ozone concentration: equation (2), dissolved organic substance concentration: equation (3). ,
The ozone dissolution reaction, the self-decomposition reaction of dissolved ozone, and the oxidative decomposition reaction of dissolved organic substances are considered.

The self-decomposition reaction of dissolved ozone was a primary reaction with respect to the dissolved ozone concentration, and the oxidative decomposition reaction of a dissolved organic substance was a primary reaction with each of the dissolved ozone concentration and the dissolved organic substance concentration.

However, Vl and Vg are expressed by the following equations using the ozone contact cell volume V and the gas holdup φ, respectively.

Vl = V × (1−φ) Formula (4) Vg = V × φ Formula (5) Further, Table 1 shows the setting values of the coefficients used in the model formulas (1) to (5). Shown in.

Table 2 shows the calculation conditions used for the verification. 2-M, which is one of the causes of offensive odor damage, as an inflowing organic substance
IB was used.

The amount of inflowing gas was kept constant, and the ozone concentration in the gas was changed when the amount of ozone generated was changed.

[0049]

[Table 1]

[0050]

[Table 2]

Under the above conditions, verification by simulation was performed.

With respect to the current ozone generation amount control method, the change in the concentration of outflowing organic substances when the amount of inflowing water was changed was obtained by a simulation using the above-mentioned complete mixing tank array model.

The control method studied is ozone injection rate control,
There are three types: exhaust ozone concentration control and dissolved ozone concentration control.

In this example, the ozone contact time was 5 (mi
n) inflow rate of 0.06 (m ³ / min), ozone injection rate 2
The case of (g / m ³ ) was assumed to be the reference time when the ideal treatment was achieved. Then, the set value was determined so that the control target value of each control method becomes equal to the ozone injection rate, the exhaust ozone concentration, and the dissolved ozone concentration at this reference time. That is, if the control target is the ozone injection rate, 2 (g / m ³ ), the exhaust ozone concentration is 4.58 (g / Nm ³ ), and the dissolved ozone concentration is 1.41 (g / m ³ ) as the standard set value. did.

The Runge-Kutta method was used as the numerical solution, and the numerical solutions of the equations (1), (2) and (3) were calculated.

(Verification example 1) (Current ozone generation amount control system) Ozone injection rate constant control, exhaust gas ozone concentration constant control,
FIG. 5 shows the water quality simulation results of the ozone contact pond effluent in the case where the constant value control is performed for the three types of the dissolved ozone concentration constant control.

This is the relationship between the inflow water amount and the outflow odorant concentration in a steady state after a sufficient time has passed.

In the figure, the circles show the simulation result of ozone constant injection rate control, the triangles show the simulation result of exhaust gas ozone concentration constant control, and the squares show the simulation result of dissolved ozone concentration constant control. When the inflow water amount which is the reference time is 0.06 (m ³ / min), the outflow odorant concentration is about 25 (ng / L).

The amount of inflowing water is 0.12 (m ³ / m)
in), the outflow odor concentration is 45 (ng / L) in the constant injection rate control and 50 in the exhaust ozone constant control.
(Ng / L), 62 (ng
/ L) was calculated.

On the contrary, the amount of inflow water is 0.03 which is half of the standard time.
When it becomes (m ³ / min), the outflow odor concentration is 11 (ng / L) in the constant injection rate control, 4 (ng / L) in the exhaust ozone constant control, and 8 in the dissolved ozone concentration constant control.
The calculation result was (ng / L).

As described above, when the above-mentioned current ozone generation amount control method is used, the water quality of the outflow water greatly changes with the change of the inflow water amount, and stable treated water cannot be obtained. This is an inconvenient point when the purpose of ozone treatment control is to constantly maintain the outflow water quality at a predetermined target value.

(Verification Example 2) (Control System of the Present Invention) The ozone generation control system for correcting the control target value described in the present invention was verified by simulation. This is a control method in which the value of the ozone injection rate, the exhaust ozone concentration, or the dissolved ozone concentration, which is the control target of each control method described above, is corrected by the amount of inflowing water and the corrected control target value is used.

Here, the control target value corrected by the calculation of the following equation was obtained.

(Corrected control target value) = (control target value) × (current inflow water amount) / (reference inflow water amount) Equation (6) Simulation using the control method with the correction shown in Equation (6). Results are shown in FIG.

As in the case of the current control method described in (Verification example 1), the contact time was 5 (min) and the inflow water amount was 0.06 (m).
³ / min) was used as the reference time for the simulation. The simulation conditions used the values in Table 2.

In FIG. 6, black circles represent simulation results of injection rate control with correction, black triangles represent simulation results of exhaust ozone concentration control with correction, and black squares represent dissolved ozone concentration control with correction. It is a simulation result.

The amount of inflow water which is the standard time is 0.06 (m ³ / mi)
In the case of n), the outflow odor concentration is about 25 (ng / L).

The amount of inflowing water was 0.12 (m ³ / m)
The inflow odorous substance concentration in the case of becoming in) is 22 (ng / L) in the injection rate control with the inflow water amount correction, 40 (ng / L) in the exhaust ozone concentration control with the inflow water amount correction,
25 for dissolved ozone concentration control with inflow correction
The calculation result was (ng / L).

On the contrary, the amount of inflow water is 0.03 which is half of the standard time.
The effluent odorous substance concentration when it becomes (m ³ / min) is 29 (ng / L) in the corrected injection rate control and 17 (ng / L) in the corrected exhaust ozone concentration control. With the added dissolved ozone concentration control, the calculation result was 21 (ng / L).

In all the calculation results, the difference from the outflow odorant concentration of 25 (ng / L) at the reference time is smaller than that of the result calculated in (Verification example 1). Three
Among the various control methods, the combination of dissolved ozone concentration control and inflow water amount correction shows the best result in terms of stability. This is considered to be a result of the dissolved ozone concentration control method and the correction equation of the equation (6) being properly matched.

As described above, by adding the correction based on the inflow water amount to each of the existing control methods, it becomes possible to control the ozone generation amount capable of maintaining the stable water quality against the variation of the inflow water amount. The correction value this time was calculated by a simple equation like the equation (6), but the control accuracy can be improved by matching and developing this equation for each control method.

[0072]

As described above, according to the present invention, by adding the control target value correction calculation unit for the inflow water amount to the preceding stage of the current ozone generation amount control system, the ozone generation amount can be compared with the inflow water amount. It becomes possible to control appropriately.

[Brief description of drawings]

FIG. 1 is a block diagram showing an ozone injection rate control system to which an inflow water amount correction calculation unit is added.

FIG. 2 is a block diagram showing an exhaust ozone concentration control system in which an inflow water correction calculation unit is added.

FIG. 3 is a block diagram showing an exhaust ozone concentration control system to which an inflow water amount correction calculation unit is added.

FIG. 4 is an explanatory view showing the concept of a complete mixing tank row model.

FIG. 5 is a diagram showing a simulation result using a current ozone generation amount control method.

FIG. 6 is a diagram showing a simulation result using the corrected ozone generation amount control method of the present invention.

[Explanation of symbols]

1 ... Coagulation sedimentation treatment, 2 ... Raw water pump, 3 ... Flowmeter, 4 ...
Ozone contact pond, 5 ... Biological activated carbon treatment device, 6 ... Ozone injection rate setting device, 7 ... Ozone injection rate correction calculation section, 8 ... Ozone generation rate calculation section, 9 ... Ozone generation rate control section, 10 ... Blower, 11 ... Ozone generator, 12 ... Air diffuser, 13 ... Exhaust ozone concentration measuring means, 14 ... Exhaust ozone concentration target value setting device, 1
5 ... Exhaust ozone concentration target value correction calculation unit, 16 ... Ozone generation amount calculation unit, 17 ... Dissolved ozone concentration measurement means, 18 ... Dissolved ozone concentration target value setting device, 19 ... Dissolved ozone concentration target value correction calculation unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyoshi Yamakoshi 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Omika Plant, Ltd. (72) Inventor Shoji Watanabe 7-chome, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Ltd., Hitachi Research Laboratory (72) Inventor Kenji Baba 7-11 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. (72) Inventor Tetsuro Haga Omi Mika, Hitachi City, Ibaraki Prefecture 7-1-1, Machi, Hitachi Co., Ltd. Hitachi Research Laboratory

Claims (3)

[Claims] 1. A water treatment facility including an ozone treatment step, which comprises an ozone contact pond and an ozone generator for generating ozone to be blown into the ozone contact pond, and an ozone injection rate setting device for setting an ozone injection rate, The ozone injection rate is obtained by multiplying the inflow water amount measuring means for measuring the inflow water amount flowing into the ozone contact pond and the ratio of the inflow water amount measured by the inflow water amount measuring means to the inflow water amount at a predetermined reference time. An ozone injection rate correction calculation unit for correcting the ozone injection rate of the setter, and an ozone injection rate corrected by the ozone injection rate correction calculation unit and an inflow water amount measured by the inflow water amount measuring means, The ozone generation amount calculation unit for calculating the ozone generation amount control calculation value, and the ozone generation amount control calculation value obtained by the ozone generation amount calculation unit, Ozone generation amount control device of the water treatment facility, characterized in that it comprises an ozone generation amount control unit for controlling the amount of ozone generated Zon generator, a. 2. A water purification treatment facility including an ozone treatment step, which comprises an ozone contact pond and an ozone generator for generating ozone to be blown into the ozone contact pond, and an inflow for measuring the amount of inflow water flowing into the ozone contact pond. A water amount measuring means, an exhaust ozone concentration measuring means for measuring the ozone concentration in the exhaust gas of the ozone contact pond, an exhaust ozone concentration target value setting device for presetting an exhaust ozone concentration target value of the ozone contact pond, and the inflow Exhaust ozone concentration target value correction calculation for correcting the exhaust ozone concentration target value of the exhaust ozone concentration target value setting device by multiplying the ratio of the inflow water amount measured by the water amount measuring means and the inflow water amount at a predetermined reference time And the exhaust ozone concentration measured by the exhaust ozone concentration measuring means, the exhaust ozone concentration calculated by the exhaust ozone concentration target value correction calculation unit. The ozone generation amount calculation unit for obtaining the ozone generation amount control calculation value so as to be equal to the concentration target value correction amount, and the ozone generation amount of the ozone generator by the ozone generation amount control calculation value obtained by the ozone generation amount calculation unit An ozone generation amount control device for a water treatment facility, comprising: an ozone generation amount control unit for controlling the amount. 3. A water purification treatment facility including an ozone treatment step, which comprises an ozone contact pond and an ozone generator for generating ozone to be blown into the ozone contact pond, and an inflow for measuring the amount of inflow water flowing into the ozone contact pond. A water amount measuring means, a dissolved ozone concentration measuring means for measuring a dissolved ozone concentration in the ozone contact pond water, and a dissolved ozone concentration target value setting device for presetting a dissolved ozone concentration target value in the ozone contact pond water, A dissolved ozone concentration target value for correcting the dissolved ozone concentration target value of the dissolved ozone concentration target value setting device by multiplying the ratio of the inflow water amount measured by the inflow water amount measuring means and the inflow water amount at a predetermined reference time A correction calculator, and the dissolved ozone concentration measured by the dissolved ozone concentration measuring means is calculated by the dissolved ozone concentration target value correction calculator. Therefore, the ozone generation amount calculation unit for obtaining the ozone generation amount control calculation value so as to be equal to the calculated dissolved ozone concentration target value correction amount, and the ozone generation amount control calculation value calculated by the ozone generation amount calculation unit, An ozone generation amount control device for a water treatment facility, comprising: an ozone generation amount control unit for controlling an ozone generation amount of an ozone generator.