JPH07284782A - Method for computing required amount of ozone and controlling ozone injection - Google Patents

Abstract

PURPOSE:To compute easily and precisely the amount of ozone necessary for the reaction with an ozone consuming component by a method in which ozone is injected respectively to water from which an ozone consuming component was removed and water to be treated and the dissolved ozone concentrations are measured to obtain the difference in the measurement results. CONSTITUTION:Dissolved ozone concentration CW1 in treated water TW1 which was obtained by injecting ozone G into water W to be treated in an ozone catalytic reaction vessel 1 (reaction vessel) is measured with a dissolved ozone concentration meter 13, and the results are inputted in a computer 24. The treated water TW1 from which an ozone consuming component was removed in the reaction vessel 1 is introduced into an ozone catalytic comparative reaction vessel 16 as comparative water TW2, and ozone is injected. The dissolved ozone concentration CW2 in the comparative water TW2 is measured with a dissolved ozone concentration meter 21, and the results are inputted in the computer 24. The computer 24 calculates CW2-CW1 to determine the required amount of ozone for the water W. The amounts of ozone G to be injected into the treated water TW1 and the comparative water TW2 are controlled so that the concentration of dissolved ozone in the water W becomes a specified value or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an ozone injection control method for calculating an ozone injection amount when ozone-treating treated water in a water purification plant or a sewage treatment plant.

[0002]

2. Description of the Related Art Due to water pollution of intake sources such as river water and lake water, at water purification plants, etc., instead of the current rapid filtration method, the precipitated water after coagulation and sedimentation is treated with ozone and then treated with biological activated carbon. There is a tendency to adopt advanced water treatment methods. This type of advanced water purification method is disclosed in JP-A-58-174288 and JP-A-2-2.
No. 33197 and Japanese Unexamined Patent Publication No. 4-281893.

In this method, raw water from a river or the like that has been taken in is subjected to coagulation-precipitation treatment, and then the precipitation water to be treated is introduced into an ozone contact tank to decolorize, deodorize, oxidize or modify organic matter in the water. It is what makes me. After that, the treated water that has been subjected to ozone treatment is introduced into a biological activated carbon tank, and by the action of the microorganisms that propagate on or inside the activated carbon, ammonia nitrogen that cannot be removed by ozone treatment is removed by nitrification and dissolved organic matter is metabolically removed. .

[0004]

In the ozone treatment, it is required that a high removal rate of organic substances be maintained and the water quality after the ozone injection treatment be stable. In addition, it is required to efficiently treat the water to be treated with the minimum required ozone injection amount.

On the other hand, the concentration and composition of organic matter in raw water taken from river water, lakes and the like greatly change under the influence of external factors such as seasonal factors, meteorological conditions and discharge of dam water.

When the treated water is treated with ozone by using the raw water whose water quality is relatively small as a water source, generally, the water amount proportional control for injecting ozone at a constant injection rate proportional to the water amount is performed.

However, if the water quality of the water to be treated which is the object of ozone treatment changes due to the factors mentioned above, in the above-mentioned water amount proportional control method, ozone is injected in an excessive amount or in excess, and the water quality after ozone injection treatment becomes stable. do not do. Exhaust ozone discharged from the ozone contact tank is treated by an ozone decomposition catalyst as disclosed in, for example, Japanese Patent Laid-Open No. 15738/1993. However, when ozone is excessively injected, the amount of exhausted ozone increases, so that the load on the exhausted ozone treatment by the catalyst increases and the amount of ozone treated decreases. Although the reaction temperature of the catalyst is raised as a means for suppressing the emission of exhausted ozone to the atmosphere due to the decrease in the amount of ozone treated, it causes an increase in running cost.

For this reason, for example, in ozone treatment in a water purification plant, the concentration of exhaust ozone discharged from the ozone contact tank to the gas phase after ozone injection is detected, and the ozone concentration is adjusted to a constant value. Exhaust ozone concentration constant control is performed to control the injection amount. Further, the residual ozone concentration constant control is performed in which the dissolved ozone concentration remaining in the liquid phase in the ozone contact tank is detected and the ozone injection amount is controlled so that the dissolved ozone concentration becomes a constant value.

However, the solubility of ozone in water and the amount of self-decomposition in water change depending on the water temperature, pH and contact time of the water to be treated. For example, when the ozone-containing gas is brought into contact with water, the ozone concentration in the liquid can be expressed by the generally known empirical formula (1), but when the water temperature changes, the ozone concentration in the liquid also changes, and The solubility of ozone changes depending on the water temperature.

C = K · Y (1) K = {0.604 × (1 + t / 273)} / 1 + 0.06
3t where C: ozone concentration in liquid (g / m ³ ), K: constant,
t: Water temperature (° C.) Y: Ozone concentration in air (g / m ³ ) The constant K is based on a generally known empirical formula based on the relationship with the water temperature under atmospheric pressure.

On the other hand, the self-decomposition of ozone in a liquid largely depends on pH, and at low pH, the self-decomposition of ozone is slow,
It becomes faster at high pH (alkaline side). Therefore, if the pH of the water to be treated changes, the concentration of dissolved ozone in the liquid will differ even if ozone is injected at the same injection rate. As a result, even if the organic matter concentration and composition in the water to be treated do not change and the ozone injection rate is constant, the exhaust ozone concentration or dissolved ozone concentration changes due to changes in water temperature, pH, etc.
The appearance is also perceived as a change in the concentration of organic matter.

Therefore, it is difficult to efficiently and stably treat the water to be treated by the feedback control based on the detected value of the exhaust ozone concentration or the dissolved ozone concentration.

Originally, the ozone injection control may be performed by injecting an amount of ozone required by the water to be treated based on the required ozone amount obtained from the concentration of organic substances in the water to be treated. However, at present, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-277596 or "Ozone treatment for widespread clean water" (Electronic Journal, Vol. 113, March issue, p228, 1993), etc.,
There is no suitable measuring instrument that can directly detect the amount of ozone injection required by the water to be treated online in a short time. As a result, it is difficult to control ozone injection with high control accuracy in response to the water quality of the water to be treated and its changes, and because ozone is injected excessively in consideration of safety in operation, running cost can also be reduced. Have difficulty.

From the above, for example, JP-A-60-16
As disclosed in Japanese Patent No. 1797, it has been proposed to correct the ozone injection rate according to the factor and the degree of disturbance to the ozone consumption amount. In many cases, it will be newly installed due to deterioration, and it will take a lot of time and labor to understand the fluctuation characteristics of the water quality of the intake source and the reaction characteristics in the ozone contact reaction tank, which will cause disturbances.

The present invention has been made in view of the above-mentioned inconveniences, and its main object is to provide an amount of ozone necessary to react with ozone consuming components in the water to be treated (hereinafter, the water to be treated may be used as necessary). The optimum ozone demand amount calculation method is suitable for easily and appropriately calculating the ozone demand amount).

Another object of the present invention is to provide an ozone injection control method with high control accuracy.

[0017]

In order to achieve the above-mentioned object, as a result of studying a method for measuring the ozone demand amount of the water to be treated with high accuracy, as a result, an oxidizable component of ozone in the water to be treated, a so-called By injecting ozone into the ozone-consuming component-removed water after removing the ozone-consuming component (hereinafter referred to as comparative water, if necessary) and the treated water, the difference between the dissolved ozone concentrations of both after the ozone injection is calculated. It was clarified that the ozone demand of the water to be treated can be measured if required.

The ozone consumption amount Dg of the water to be treated is calculated by the following equation (2).
As shown in, the difference can be obtained by subtracting the dissolved ozone concentration in the water to be treated from the difference between the amount of ozone injected into the water to be treated and the amount of ozone discharged to the gas phase.

Dg = [{Qg (Cg1-Cg2)} / Qw] -Cw (2) Here, water amount: Qw (l / h), injected ozone gas amount: Q
g (l / h), injected ozone gas concentration: Cg1 (mg /
l), concentration of ozone-containing exhaust gas Cg2: (mg / l),
Dissolved ozone concentration: Cw: (mg / l), ozone consumption:
Dg (mg / l) However, if the oxidizable components that are ozone consuming components in the water to be treated are, for example, Fe ions and Mn ions, the target components represented by the following formulas (3), (4) and (5) are given. Along with the progress of the reaction due to the ozone consuming component in the treated water, the reaction due to the self-decomposition of ozone proceeds.

[0020]

[Equation 1]

[0021]

[Equation 2]

[0022]

[Equation 3]

The mechanism of the autolysis reaction of ozone in water is complicated, but as shown in the following equations (6) to (12), hydroperoxy radicals (HO _2. ) And hydroxyl radicals (OH. ) Is generated, which is considered to decompose ozone in a chain as shown in the equations (8) and (9). On the other hand, the generated OH and HO ₂ radicals disappear as shown in the equations (10) to (12).

O ₃ + H ₂ O → HO ₃ ⁻ + OH ⁻ (6) HO ₃ ⁻ + OH · → 2HO ₂ ··· (7) O ₃ + HO ₂ · → OH · + 2O ₂ ··· (8) O ₃ + OH · → HO ₂ · + O ₂ (9) HO ₂ · + HO ₂ · → H ₂ O ₂ + O ₂ … (10) OH · + HO ₂ · → H ₂ O + O ₂ … (11) OH · + OH · → H ₂ O ₂ … (12) In the water to be treated, the reaction due to ozone consuming components {(3),
Reaction of (4), (5)} with ozone self-decomposition {(6)
→ (12)} progresses in parallel. For this reason, it is not possible to distinguish between ozone consumption due to organic substances or inorganic substances, which are ozone consuming components in the water to be treated, and ozone consumption due to self-decomposition. It is difficult to measure the ozone demand of the water to be treated only by using.

As a means for distinguishing both ozone consumption,
If water that does not contain organic substances such as distilled water is used as comparison water and ozone is injected into this comparison water, the consumption amount due only to self-decomposition of ozone can be obtained. And in comparison with the amount of ozone consumption on the side of the treated water into which ozone was injected separately,
It is possible to measure the ozone demand amount due to the ozone consuming component in the water to be treated excluding the effect of self-decomposition of ozone.

As a result, if the ozone consumption amount due to organic substances in the water to be treated accompanying ozone injection is CR1 and the ozone consumption amount due to self-decomposition is CR2, the dissolved amount after ozone injection including both oxidation reaction and self-decomposition will be described. The ozone concentration K1 is represented by the following equation (13) from the above equation (2).

K1 = [{Qg (Cg1-Cg2)} / Qw]-(CR1 + CR2) (13) On the other hand, distilled water containing no organic matter or the like is used as comparison water.
When ozone is injected into this comparative water, since ozone consuming components are not contained in this comparative water, there is no ozone consumption required for oxidation of organic substances, etc., and ozone is consumed mainly by self-decomposition of ozone. It Here, assuming that the ozone consumption amount due to self-decomposition accompanying ozone injection is CR2 ′, the dissolved ozone concentration K2 after ozone injection is expressed by the following expression (14) from the above expression (2).

K2 = [{Qg (Cg1-Cg2)} / Qw] -CR2 '(14) Therefore, if the reaction conditions such as the amount of injected ozone and the amount of water are kept equal, the ozone consumption due to self-decomposition is CR2.
= CR2 ', and the difference (K2-K1) between the dissolved ozone concentrations of the comparative water and the water to be treated is the ozone demand amount due to the ozone consuming component in the water to be treated excluding the self-decomposition of ozone, as shown in the following equation (15). Is required as.

CR1 = K2-K1 (15) As described above, the solubility of ozone in water and the self-decomposition in liquid are affected by water temperature, pH and the like. Therefore, it is necessary to match the water temperature, pH, etc. on the comparative water side and the treated water side. Specifically, the water temperature of the treated water side is detected and the comparative water side is heated or cooled to maintain the same water temperature, or the pH of the treated water side is detected and the comparative water side is detected. Control such as addition of acid or alkali as a pH adjuster is required. However, if the water temperature or pH of the comparative water is matched based on the detection result of the water temperature, pH, etc. of the water to be treated, there will be a time delay. As a result, when the water temperature or pH of the water to be treated fluctuates greatly, it becomes difficult to maintain the same reaction conditions in a short time, and there is the inconvenience that the water temperature or pH cannot be matched with the water to be treated side. Among them, the controllability of pH is affected by the buffering capacity (buffer index) of water that requires ozone self-decomposition, and the pH of water with a large buffering capacity is relatively easy to adjust, but the pH buffering capacity of distilled water or the like is It is difficult to adjust the pH of small water, and the pH cannot be adjusted to the side of the water to be treated in a short time. Further, when an alkali or an acid is used as the pH adjusting agent, if these adjusting agents and ozone react with each other, it becomes difficult to accurately obtain the consumption amount due to self-decomposition of ozone.

Based on the above-mentioned matters, the inventors of the present invention examined a method of simply and accurately obtaining the consumption amount of ozone by self-decomposition, and as a result, compared the treated water after removing the ozone consuming components in the treated water. As water, it has been found that if ozone is injected into this comparative water, adjustment for matching with the water temperature or pH of the treated water can be eliminated. When the treated water after removing the ozone consuming component in the treated water is used as the comparative water for determining the consumption amount due to the self-decomposition of ozone, the water temperature, pH or the like substantially matches the treated water side water temperature or pH. As a result, it becomes unnecessary to adjust the water temperature or pH, and there is no disturbing factor of ozone consumption accompanying the pH adjustment, and the ozone demand amount by the oxidizable component in the water to be treated can be measured easily and accurately. .

Therefore, a feature of the present invention is that in the water to be treated containing the ozone consuming component that reacts with ozone, the amount of ozone that reacts with the ozone consuming component and ozone due to self-decomposition of ozone in the water to be treated. To find the consumption.

Further, a feature of the present invention is that ozone is injected into the comparative water and the treated water after the ozone consuming component due to ozone in the treated water is removed, and the comparative water and the treated water are dissolved. This is to obtain the ozone demand amount of the water to be treated from the difference in ozone concentration.

When the ozone demand amount of the water to be treated is calculated as described above, as a means for obtaining the comparative water, the treated water obtained by injecting ozone into the water to be treated to remove the oxidizable component is used as the comparative water. Method, method of absorbing and removing the oxidizable components in the treated water with activated carbon to obtain comparative water, and injecting ozone into the treated water, and removing residual oxidizable components with activated carbon to obtain the comparative water The method and the like are preferred embodiments.

In each of these embodiments, the method of injecting ozone into the water to be treated to remove the oxidizable component is to oxidize the oxidizable component which is an ozone consuming component efficiently by the strong oxidizing power of ozone. Although it can be removed, the comparative water side, which obtains the ozone consumption amount due to the self-decomposition of ozone, cannot obtain the accurate ozone demand amount simply by not containing the oxidizable component. In other words, when ozone is injected into the water to be treated to remove the ozone consuming component, and this is used as comparison water, the ozone is injected again in order to obtain the amount of self-decomposition, and in the comparison water it is used in the previous step. Part of the injected ozone remains as dissolved ozone. The concentration of the remaining dissolved ozone is not always constant. Therefore, when ozone is injected into the comparative water in order to determine the self-decomposition of ozone, the dissolved ozone concentration after the ozone injection changes under the influence of the above-mentioned residual dissolved ozone concentration. As a result, when the required ozone amount is calculated from the difference in the dissolved ozone concentration between the treated water after ozone injection and the comparative water, the fluctuation of the residual dissolved ozone causes an error in determining the required amount, and the required ozone amount can be calculated accurately. I can't ask.

Therefore, in the present invention, ozone is injected into the water to be treated and the comparative water that does not contain the oxidizable component and dissolved ozone after the ozone is injected into the water to be treated, and the ozone after the ozone injection is injected. It was decided to determine the ozone demand of the water to be treated from the difference in dissolved ozone concentration between the comparative water and the water to be treated. In this preferred embodiment, the dissolved ozone in the treated water after injecting ozone into the water to be treated is released to the gas phase by a removal means such as aeration, and then ozone is again injected as comparative water for determining the amount of self-decomposition of ozone. To do.

Next, in determining the ozone demand of the water to be treated, a method can be obtained with a high degree of accuracy to obtain the ozone demand of the water to be treated, even if the organic matter concentration in the water to be treated and its composition greatly fluctuate. investigated. The feature of the present invention for this is that ozone is injected into the comparative water after removal of the oxidizable components in the treated water and the treated water, and the comparative water after the ozone injection and the treated water are treated. Obtain the ozone required amount of the water to be treated from the difference in the dissolved ozone concentration with water, further to the treated water and the comparative water so that the measured value of the dissolved ozone concentration of the treated water is maintained at a predetermined value or more. It is to control the ozone injection amount. In this preferred embodiment, the dissolved ozone concentration in the treated water after ozone injection is measured, and the amount of ozone injected into the treated water and the comparative water is controlled according to the deviation from the target value of the dissolved ozone concentration.

In the present invention, when constructing an ozone demand meter for measuring the ozone demand of the water to be treated, a measuring method for simplifying the apparatus constitution was also examined. As a device configuration for measuring the ozone demand amount of the water to be treated, from the viewpoint of installation space of the measurement device, handleability, rationality in manufacturing the device, etc., the device configuration is simple and downsizing is required. In addition, in order to accurately and reasonably measure the ozone demand of the water to be treated, ozone is injected into the water to be treated to remove the oxidizable components as described above, and then this is used as comparison water for water temperature and pH. It is necessary to adjust the water quality conditions such as the above to the treated water side. Further, it is necessary to inject ozone into the comparative water and the water to be treated, which have the same water quality. In this case, an increase in the number of operations leads to an increase in reaction tanks for contacting water and ozone, which goes against the simplification of the device configuration. Therefore, it is an important factor in constructing an ozone demand meter to minimize the number of operations and to rationally combine the operations.

Therefore, in the present invention, the treated water obtained by injecting ozone into the ozone contact reaction tank into which the water to be treated is introduced to remove the oxidizable components is treated to remove the dissolved ozone located on the downstream side of the ozone contact reaction tank. Introduced into the tank, the treated water from which dissolved ozone has been removed is introduced as a comparative water into the ozone contact comparison reaction tank located on the downstream side of the dissolved ozone removing tank, and the treated water after the ozone injection and the comparative water are introduced. It was decided to determine the required ozone amount of the water to be treated from the difference in the dissolved ozone concentration.

Furthermore, in the present invention, when measuring the ozone demand amount of the water to be treated, a method of measuring the ozone demand amount having excellent responsiveness was examined. The ozone demand of the water to be treated is obtained from the difference in the dissolved ozone concentration between the water to be treated after ozone injection and the comparative water, but the responsiveness of measuring the ozone demand is to obtain comparative water that does not contain ozone consuming components. It depends on time. Therefore, in order to obtain the comparative water after removing the oxidizable components in the treated water in a short time, in addition to the system that measures the dissolved ozone concentration in the treated water after ozone injection It was decided to arrange the water system for removing the components in parallel. When the treated water system and the comparative water system are arranged in parallel, in order to remove the oxidizable component in the treated water, for example, the ozone injection amount can be increased to accelerate the removal of the oxidizable component. You can improve your sex.

Ozone injected into the water to be treated and the comparative water is
Rather than all being dissolved in the liquid phase, some ozone is released from the liquid phase into the gas phase. Since ozone has a strong oxidizing power, prevention of ozone leakage is also necessary for environmental protection.

Therefore, in order to prevent the injected ozone from being discharged out of the system of the ozone demand meter, the exhaust ozone gas discharged from the water to be treated and the comparative water to the gas phase through the ozone decomposition treatment means. I decided to discharge it outside.

Further, with respect to the ozone-containing water discharged after measuring the required ozone amount, the ozone discharged from the liquid phase to the gas phase is discharged to the outside of the system through the ozone decomposition treatment means.

When the raw water taken from a river or the like is subjected to ozone injection treatment as treated water, the ozone injection treatment of the treated water in the plant depends on the contact time between the treated water and ozone or the number and structure of ozone contact reaction tanks. It changes depending on the conditions such as.
From this, it is important to measure the ozone demand amount of the water to be treated that reflects the result of the actual ozone injection treatment.

In the present invention, when determining the ozone demand amount of the water to be treated, the ozone injecting treatment apparatus into which the water to be treated which is the object of ozone treatment is introduced is regarded as a large scale ozone demand meter. The ozone demand amount of the treated water to be treated was calculated.

This type of ozone injection treatment device is disposed downstream of the ozone contact tank into which the water to be treated is introduced, the ozonizer for supplying ozone to this ozone contact tank, and the ozone contact tank, and after the ozone injection. It is composed of a biological activated carbon tank into which treated water is introduced. In this case, the oxidizable component, which is an ozone consuming component in the water to be treated, is subjected to ozone injection treatment in the ozone contact reaction tank, and then the residual content is removed in the biological activated carbon tank. As a result, the treated water obtained from the biological activated carbon tank does not contain an oxidizable component that becomes an ozone consuming component, and this treated water can be used as comparative water for determining the ozone demand amount of the treated water. Therefore, a part of the treated water from the biological activated carbon tank is sampled, and the difference between the dissolved ozone concentration after injecting ozone into this treated water and the dissolved ozone concentration after injecting ozone into the water to be treated is obtained. For example, it is possible to measure the ozone demand amount of the treated water with high accuracy that reflects the actual ozone treatment.

The features of the present invention are that the ozone contact reaction tank into which the water to be treated is introduced, the ozonizer for injecting ozone into the ozone contact reaction tank, and the dissolved ozone concentration after the ozone is injected into the water to be treated. A biological activated carbon tank equipped with a dissolved ozone concentration meter for measurement, further disposed on the downstream side of the ozone contact reaction tank, into which the treated water after the ozone injection is introduced, and the treated water from the biological activated carbon tank are sampled. Then, a dissolved ozone concentration meter for measuring the dissolved ozone concentration after injecting ozone into the sampling water is provided, and the ozone required amount of the water to be treated is obtained from the difference between the dissolved ozone concentrations.

Another feature of the present invention is that
An ozone contact reaction tank into which water to be treated is introduced, an ozonizer for injecting ozone into the ozone contact reaction tank, and biological activated carbon disposed downstream of the ozone contact reaction tank and into which treated water after the ozone injection is introduced. A tank is provided, and ozone is injected into the comparative water in which the treated water from the biological activated carbon tank is sampled and the treated water, and the treated ozone is injected from the difference in the dissolved ozone concentration between the comparative water after the ozone injection and the treated water. This is because the ozone demand of treated water is calculated.

As described above, the ozone injection control method of the present invention obtains the ozone required amount of the treated water from the difference in the dissolved ozone concentration between the comparative water and the treated water, and according to this required amount, the ozone contact reaction tank It is to control the ozone injection amount.

In the ozone treatment, it is necessary to calculate the ozone injection amount by compensating not only the ozone amount necessary for reacting with the ozone consuming component but also the consumption amount due to self-decomposition of ozone. Then, the preferable aspect of the measuring method of the ozone injection amount including the self-decomposition of ozone was examined.

Then, ozone is injected into the water to be treated and the ozone consuming component-removed water after the ozone consuming component in the water to be treated is respectively injected, and the amount of ozone which reacts with the ozone consuming component in the water to be treated and By adding the ozone consumption amount due to the self-decomposition of ozone in the ozone consuming component-removed water,
It has been found that the amount of ozone to be injected into the water to be treated, which is the target of the ozone injection treatment, is determined.

In the present invention, when ozone is injected into the water to be treated, it is prevented that the ozone injection amount becomes too small and the dissolved ozone concentration (or the exhaust ozone gas concentration) in the treated water after the ozone injection becomes undetected. ing. If the ozone injection amount is calculated and ozone is injected into the water to be treated as described above, the minimum necessary amount of ozone will be injected. However, depending on the time until the ozone injection amount is obtained and the injection amount. There is a time lag such as the time until ozone is injected. Further, if the water quality fluctuation of the water to be treated is greater than the time lag, ozone is injected too little, which may lead to deterioration of the water quality of the treated water. Therefore,
In order to respond to the effects of water quality fluctuations, a supplemental ozone injection amount is required to maintain the dissolved ozone concentration (or exhaust ozone gas concentration) after ozone injection into the water to be treated that is the target of ozone injection treatment above a prescribed value. In addition to the injection amount, it is desirable to prevent the ozone injection amount from becoming too small.

Further, a preferable mode for obtaining the ozone consumption amount due to the self-decomposition of ozone on the water side from which the ozone consuming component has been removed was examined. When ozone is injected into a liquid, a part of the injected ozone is discharged to the gas phase as exhaust ozone gas.Therefore, in order to obtain the ozone consumption due to the self-decomposition of ozone on the water side where ozone-consuming components are removed, It is necessary to consider the amount of ozone emitted into the gas phase regardless of the self-decomposition in the gas. The ozone consumption of the ozone-consuming component-removed water is determined from the difference in the vapor-phase ozone concentration before and after the ozone-consuming component-removed water is injected, and the dissolved ozone between the ozone-consuming component and the ozone-consuming component-removed water after the ozone injection is obtained. The ozone consumption due to self-decomposition of ozone is calculated from the difference in concentration. By doing so, it is possible to accurately calculate the ozone consumption amount due to the self-decomposition of ozone in the ozone-consumption-component-removed water in consideration of the exhaust ozone.

Therefore, the feature of the present invention resides in that ozone is injected into the water to be treated and the ozone-consuming component-removed water after the ozone-consuming component is removed from the water to be treated, and the ozone after the ozone injection is injected. Obtain the amount of ozone necessary to react with the ozone consuming component of the water to be treated from the difference in dissolved ozone concentration between the ozone consuming component removed water and the water to be treated, and further before and after the injection of ozone into the ozone consuming component removed water. The ozone consumption of the ozone consuming component-removed water is obtained from the difference in the vapor phase ozone concentration, and the ozone consumption and the dissolved ozone concentration difference of the ozone consuming component-removed water after ozone injection are self-decomposed in the ozone consuming component-removed water. The amount of ozone consumed by water is calculated, and the amount of ozone necessary to react with the ozone consuming component of the water to be treated and the ozone consumption due to the self-decomposition of ozone in the ozone consuming component-removed water By adding the bets is to to obtain the required ozone injection amount into the treatment water to be ozone injection process.

As described above, when the ozone consumption due to the self-decomposition of ozone in the ozone consuming component-removed water is obtained, the amount of ozone injected into the ozone consuming component-removing water and the amount of ozone discharged into the gas phase and the removed water are removed. It may be obtained by subtracting the amount of dissolved ozone.

[0055]

[Operation] When measuring the ozone demand amount of the water to be treated, ozone is injected into the water to be treated and the comparative water after removal of the oxidizable component which is an ozone consuming component in the water to be treated, and then ozone is injected. Since the ozone required amount of the treated water is obtained from the difference in the dissolved ozone concentration between the comparative water and the treated water, the ozone required amount of the treated water can be simply and highly accurately measured. That is, the oxidizable component in the water to be treated is removed and this is used as the comparative water. This comparative water is the same water as the water to be treated for which the ozone demand amount is obtained regardless of the presence or absence of ozone consuming components, and is less likely to be affected by disturbance factors.
The water temperature, pH, etc. substantially match the water temperature, pH, etc. on the treated water side.

As a result, in order to make the ozone reaction conditions uniform, there is no need to attach any means for matching the water temperature and pH of the comparative water with the treated water.

Further, in the present invention, ozone is injected into the water to be treated to remove the oxidizable component as a means for obtaining comparative water containing no oxidizable component due to ozone in the water to be treated. . Ozone is inevitably used when measuring the ozone demand of the water to be treated, but this ozone, which has a strong oxidizing power, can efficiently remove oxidizable components, and the ozone demand Ozone can be commonly used for removing the oxidizable component together with ozone for measurement. Therefore, there is an advantage of easily removing the oxidizable component due to ozone in the water to be treated.

Further, in the present invention, the oxidizable component is adsorbed and removed as another means for obtaining comparative water by removing the oxidizable component in the water to be treated. There is no factor to change the water temperature and pH by removing the oxidizable component by adsorption by means of obtaining comparative water from the treated water, and the oxidizable component can be easily removed to remove the oxidizable component and the water temperature and pH on the treated water side. It is possible to match the comparison water side with the above.

Further, as another means for obtaining comparative water, if ozone is injected into the water to be treated and then the oxidizable component is removed by adsorption, the oxidizable component is added to the water to be treated at the ozone injection stage. Even if it remains, it is possible to remove the residual oxidizable component by adsorption in the latter stage. As a result, it becomes possible to measure the ozone demand amount of the water to be treated, which corresponds to the variation in the concentration of organic substances in the water to be treated.

In the present invention, it is also intended to prevent the dissolved ozone remaining in the comparative water from causing an error in the ozone required amount of the water to be treated. If dissolved ozone remains in the comparative water, the amount of consumption due to self-decomposition of ozone is small even if ozone is injected later due to the residual ozone.

For this reason, in the present invention, the dissolved ozone in the water to be treated is discharged to the gas phase by means of aeration or the like before the ozone for self-decomposition is injected into the water to be treated. As a result, at the pre-injection stage of ozone for self-decomposition, the dissolved ozone is not contained in the comparative water. It will not be expensive to receive. Therefore, if the dissolved ozone is removed before the self-decomposition is obtained, the ozone required amount of the water to be treated can be obtained without error.

In a preferred embodiment of the present invention, when ozone is injected into the water to be treated and the comparative water and the ozone demand amount of the water to be treated is determined from the difference in dissolved ozone concentration between the two, the water to be treated after the ozone injection is treated. The dissolved ozone concentration of is maintained above a predetermined value. When the concentration of organic substances in the water to be treated becomes high and all of the injected ozone is consumed, the dissolved ozone thereafter becomes undetectable, and even if oxidizable components remain, the residual oxidizable components will remain due to the injected ozone. It is not consumed (oxidized) and the required ozone amount corresponding to the residue is not required. But,
By ensuring that dissolved ozone is always detected in the water to be treated, sufficient ozone to oxidize the oxidizable components may be injected into the water to be treated, and oxidizable components that are not oxidized by ozone may remain. Disappear.

In the present invention, in order to simplify the device constituting the ozone demand meter, ozone is injected into the water to be treated to measure the concentration of dissolved ozone, and then the dissolved ozone in the treated water is removed to remove the ozone. We propose a method to measure the dissolved ozone concentration of this comparative water by injecting ozone as the comparative water.

Further, in order to remove the oxidizable components in the treated water and obtain comparative water in a short time, in addition to the water system for measuring the dissolved ozone concentration in the treated water after ozone injection, An aqueous system for removing oxidizable components was arranged in parallel. By doing so, the dissolved ozone concentration after ozone injection into the water to be treated is measured in a separate system, and it is not necessary to set it equal to the amount of ozone injected into the comparative water. At the time of removing, the ozone injection amount can be set to be large, and the removal of the oxidizable component can be accelerated. Therefore, the comparative water that does not contain the oxidizable component can be obtained in a short time, and the required ozone amount can be measured with good responsiveness.

Further, according to the present invention, when the ozone is injected into the comparative water and the treated water from which the oxidizable components in the treated water have been removed, the exhausted ozone gas discharged from the comparative water and the treated water into the gas phase. Is discharged to the outside of the system through the ozone decomposing process means, it is possible to prevent ozone leakage to the measurement environment or the like when measuring the required ozone amount of the water to be treated.

Separately from the above, the ozone dissolved in the water to be treated and the comparative water after the ozone demand measurement is released from the liquid phase to the gas phase. In the present invention, the ozone released to this gas phase is released. Is discharged to the outside of the system through the ozone decomposition treatment means. Therefore, ozone becomes harmless oxygen and is discharged to the outside of the system, so that ozone is prevented from leaking to the measurement environment.

Further, in the present invention, when the ozone demand amount of the treated water is determined, the ozone demand amount of the treated water is determined based on the result of the actual ozone injection treatment of the treated water. It is possible to measure the ozone demand amount that reflects the plant characteristics of the ozone injecting and treating apparatus for the water to be treated. That is, ozone is injected into the ozone contact reaction tank into which the water to be treated is introduced, and the dissolved ozone concentration in the water to be treated after the ozone injection is measured. Then, a part of the treated water is sampled from the biological activated carbon tank into which the treated water after ozone injection is introduced, and this sampled water is treated as comparative water containing no oxidizable component, and ozone is injected into this comparative water. Measure the dissolved ozone concentration. Therefore, if the difference between the dissolved ozone concentrations described above is obtained, it is possible to measure the ozone demand amount of the water to be treated that reflects the actual ozone injecting treatment of the water to be treated.

Further, in the present invention, as a method of obtaining the comparative water containing no oxidizable component in the treated water, the treated water from the actual ozone injecting treatment apparatus is used as the comparative water. That is, a part of the treated water from the biological activated carbon tank in the ozone injection treatment device described above was sampled and used as comparative water. And
Ozone is injected into the comparative water and the water to be treated, and the required ozone amount of the water to be treated is obtained from the difference in the dissolved ozone concentration between the water to be treated after the ozone injection and the comparative water. In this way, by using the comparative water that does not contain the oxidizable component after the treated water is actually subjected to the ozone injection treatment, the ozone injection treatment characteristics of the actual plant can be reflected, and the treated water with high accuracy can be reflected. The ozone demand can be measured.

In the present invention, the ozone injection amount into the water to be treated is controlled based on the ozone demand amount thus obtained, so that the ozone injection control with high control accuracy can be performed. Further, in the present invention, the amount of ozone that reacts with the ozone consuming component in the water to be treated and the ozone consuming component due to the self-decomposition of ozone in the water to be treated are determined, and the amount of ozone that reacts with the ozone consuming component and the self-decomposition The amount of ozone required for the water to be treated which is the object of the ozone injection treatment is calculated by adding the amount of ozone consumed by
Obtaining the amount of ozone that reacts with the ozone consuming component in the water to be treated is an important factor in measuring the amount of ozone consumption due to the water quality of the water to be treated. However, when the water to be treated is injected with ozone, ozone is consumed in parallel by self-decomposition of ozone at an injection amount corresponding to the amount of ozone consumed by organic substances in the water to be treated. Injecting the amount of ozone consumed by is too much. That is, when ozone is injected into the liquid, the ozone is consumed by self-decomposition, so if the component for compensating the self-decomposition of ozone is not injected further, the ozone-consuming component in the water to be treated can be effectively treated. Can not. In the present invention, the amount of ozone that reacts with the ozone consuming component in the water to be treated is further compensated by adding the amount of ozone consumption due to self-decomposition of ozone to obtain the required amount of ozone to be injected into the water to be treated.
Therefore, during the ozone injection treatment of the water to be treated, the ozone consuming component in the water to be treated can be treated without being affected by the ozone consumption due to the self-decomposition of ozone.

Further, in the present invention, the supplementary ozone injection amount is further added to the required ozone injection amount obtained by adding the ozone amount due to the ozone consumption component in the water to be treated and the ozone consumption amount due to the self-decomposition of ozone in the ozone consumption component-removed water. Is added to obtain the ozone injection amount. Then, according to the ozone injection amount, ozone is injected into the water to be treated which is the object of the ozone injection process. In this case, there is a time lag between obtaining the required ozone injection amount, etc., and even if the water quality on the treated water side fluctuates during that time, the dissolved ozone concentration after the ozone injection treatment should be kept above the specified value. Since supplemental ozone to be secured is injected, it is possible to cope with an increase in ozone consumption due to water quality fluctuations. Therefore, the dissolved ozone concentration of the treated water does not become undetectable as the ozone consumption increases due to the water quality fluctuation, and the treated water quality does not deteriorate.

In the present invention, as a mode of determining the consumption amount of ozone due to self-decomposition, ozone is injected into the ozone-consuming component-removed water to determine the ozone consumption amount due to self-decomposition. If the ozone consumption due to the self-decomposition of ozone is obtained using the ozone-consumption-component-removed water, it is not affected by the ozone consumption due to other factors. Therefore, the ozone consumption due to the self-decomposition of ozone can be accurately obtained. . Therefore, the required ozone injection amount into the water to be treated, which is obtained from the ozone consumption due to self-decomposition obtained by the means and the amount of ozone that reacts with the ozone consuming component in the water to be treated, is highly accurate. In addition, if ozone is injected into the water to be treated according to the required ozone injection amount, ozone can be injected in response to changes in the water quality of the water to be treated, and it is stable even if the water quality of the water to be treated changes. The ozone injection process described above can be performed, and the water quality after ozone injection can be stabilized.

As another preferred embodiment for obtaining the ozone consumption amount due to self-decomposition of ozone, in the present invention, the ozone consumption in the removed water is calculated from the difference in the ozone concentration in the gas phase before and after the ozone injection into the ozone-consuming component removed water. The amount of ozone is calculated, and the amount of ozone consumed by self-decomposition of ozone is calculated from the difference between the amount of ozone consumed and the concentration of dissolved ozone in the removed water.
If the ozone consumption amount due to the self-decomposition of ozone is obtained in this way, it is possible to exclude the ozone discharged into the gas phase without participating in the self-decomposition in the liquid.

[0073]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. In the system flow of the ozone demand measuring device 1A for water to be treated shown in FIG. 1, the water W to be treated is introduced into the ozone contact reaction tank 1, and the reaction tank has a concentration set to a predetermined concentration by the ozonizer 2. Ozone gas OG is injected. In this embodiment, the ozone generation amount is, for example, 1
The ozonizer 2 having a small capacity of about g / h to 20 g / h is used.

A dehumidifier 3 is disposed on the inlet side of the ozonizer 2 to remove moisture in the raw material gas G (air or oxygen) supplied to the ozonizer 2 and to use the dry raw material gas G having a low dew point as an ozonizer. Supply to 2. In this embodiment, air as a raw material gas G is supplied to the ozonizer 2 by the air pump 5 via the filter 4. In this case, oxygen or oxygen-enriched air may be used as the source gas and is not specified. The ozone concentration from the ozonizer 2 is measured by the ozone concentration meter 6 by, for example, a diaphragm polarographic electrode method or an ultraviolet absorption method. The principle of the measurement method of the ozone concentration meter is not particularly limited.

The ozone generation concentration from the ozonizer 2 is controlled by the controller 7. In this embodiment, the concentration of ozone generated is controlled by adjusting the voltage applied to the discharge section (not shown) that constitutes the ozonizer 2. In this case, when a large amount of ozone generation (for example, about 10 kg / h to 20 kg / h) at the plant scale level is required as in other embodiments described later, the frequency during high voltage application is adjusted. A method of controlling the generated ozone concentration is adopted, but the method of controlling the generated ozone concentration is not particularly limited.

The flow rate of ozone OG injected into the ozone contact reaction tank 1 is adjusted by the constant flow valve 8, and the ozone OG set to a predetermined flow rate is injected into the ozone contact reaction tank 1 through the flow meter 9. To be done.

The sampling pump 10 for supplying the water W to be treated into the ozone contact reaction tank 1 samples the water W to be measured and introduces it into the reaction tank 1. The flow rate of the water to be treated W is adjusted to a predetermined flow rate by the constant flow rate control valve 11, and the ozone contact reaction tank 1 is passed through the flow meter 12.
Will be introduced in. The water W to be treated, which is introduced into the ozone contact reaction tank 1, becomes a counterflow to the gas flow of the ozone OG which is simultaneously introduced, and comes into contact with ozone and flows down.

As the dissolved ozone concentration meter 13 for measuring the dissolved ozone concentration CW1 in the water W to be treated after the ozone is injected, the diaphragm type polarographic electrode method or the ozone concentration meter by the ultraviolet absorption method or the like is used as described above. be able to.
The gas-liquid separator 14 disposed on the inlet side of the dissolved ozone concentration meter 13 gas-liquid separates the ozone gas contained in the treated water TW1 from the ozone contact reaction tank 1, and the dissolved ozone concentration meter 13
Prevents ozone gas from mixing in. Then, the treated water TW1 from which ozone has been separated is introduced into the dissolved ozone concentration meter 13. In this example, when measuring the dissolved ozone concentration CW1 in the water to be treated W into which ozone has been injected, the dissolved ozone concentration CW1 in the treated water TW1 exiting the ozone contact reaction tank 1 is measured. The dissolved ozone concentration meter 13 may be provided in the contact reaction tank 1 to measure the dissolved ozone concentration CW1. Alternatively, the sample water may be sampled from the ozone contact reaction tank 1 with a sampling pump (not shown) or the like, and the sampled water may be measured, and the measurement location and the water sampling method are not particularly limited. Further, although the dissolved ozone concentration meter 13 is arranged in the water conduit 15 in the present invention, the treated water TW1 may be sampled by, for example, a sampling pump (not shown) and measured.

The ozone contact reaction tank 16 has the same function as the ozone contact reaction tank 1 described above. Then, water from which the oxidizable component which is the ozone consuming component in the treated water is removed is introduced into the ozone contact comparison reaction tank 16. In this embodiment, the treated water after the ozone is injected into the water to be treated in the ozone contact reaction tank 1 to oxidize the oxidizable component is introduced as the comparative water TW2. Further, the comparative water TW2 introduced into the ozone contact comparison reaction tank 16 is dissolved as in Example 3 described later when the oxidizable component is oxidized and removed by the ozone injection in the previous stage as in this example. Ozone is removed and introduced. As a means for removing the oxidizable component that becomes an ozone consuming component in the water to be treated, there are, for example, adsorption by activated carbon, a removal means by a ceramic membrane or a hollow fiber membrane, or a combination thereof, and there is a means for obtaining comparative water. In particular, the present invention is not limited to the embodiments.

Further, ozone gas OG is introduced from the ozonizer 2 into the ozone contact comparison reaction tank 16. The flow rate and the ozone concentration of this ozone gas OG are set to be equal to those of the introduction of ozone into the ozone contact reaction tank 1, and the constant flow valve 17
The ozone gas flow rate is adjusted and controlled at. Also, comparison water T
The flow rate of W2 is also set equal to the flow rate of the water W to be treated to the ozone contact reaction tank 1.

On the outlet side of the constant flow valve 17, the flow meter 1
8 are provided. When the ozone gas OG is introduced into the tanks 1 and 16, one ozonizer 2 is used in one embodiment of the present invention in order to avoid fluctuations in ozone concentration, and from the viewpoint of economy, the outlet side of this ozonizer 2 is used. The ozone introducing pipe 19 is branched in the middle. Furthermore, treated water W
In order to make the reaction conditions such as the contact time of ozone OG and the retention time of each water W, TW2 with respect to the reference water TW2 and the comparison water TW2, the shapes and volumes of the ozone contact reaction tank 1 and the ozone contact comparison reaction tank 16 and the material of the inner wall of the tank, etc. Are equal.

In the gas-liquid separator 20 disposed on the outlet side of the ozone contact comparison reaction tank 16, the comparison water T into which ozone was injected was used.
Ozone in W2 is separated into gas and liquid. Dissolved ozone concentration meter 21
Then, the dissolved ozone concentration CW2 in the comparative water TW2 into which ozone is injected is measured. Then, the comparative water TW2 from which ozone has been separated by the gas-liquid separator 20 is introduced into the ozone concentration meter 21 and the dissolved ozone concentration CW2 is measured. In addition,
In this embodiment, the dissolved ozone concentration CW2 of the comparative water TW2 discharged from the ozone contact comparative reaction tank 16 is measured, but the dissolved ozone concentration CW2 of the comparative water TW2 in the comparative reaction tank 16 may be measured, and particularly, The measurement location and water sampling method are not limited. As described above, each dissolved ozone concentration meter 13, 2
When the dissolved ozone concentrations CW1 and CW2 are measured in 1,
The time from the injection of ozone to the measurement is set to be equal. As described above, each dissolved ozone concentration meter 13, 21
When the dissolved ozone concentrations CW1 and CW2 are measured in, the time from injection of ozone to the measurement is set to be equal.

The inlet side of the exhaust ozone discharge pipe 23 is connected to the gas phase portions of the tanks 1 and 16 described above, and further to the gas phase portions of the gas liquid separators 14 and 20. Then, the ozone-containing exhaust gas EG discharged from the liquid phase of each tank to the gas phase or the exhaust ozone from each gas-liquid separator is discharged to the outside of the system through the discharge pipe 23.

In the calculator 24 for calculating the ozone demand amount of the water to be treated which is the object of ozone injection, the dissolved ozone concentration C of the water to be treated W after the ozone is injected in the ozone contact reaction tank 1
W1 is input as an output value from the dissolved ozone concentration meter 13. The dissolved ozone concentration CW2 of the comparative water TW2 after ozone is injected in the ozone contact comparison reaction tank 16 is input to the calculator 24 as an output value from another dissolved ozone concentration meter 21. In addition, in one Example of this invention, when measuring the dissolved ozone concentration of the to-be-processed water W and the dissolved ozone concentration of the comparative water TW2, it measures independently using two ozone concentration meters. On the other hand, one ozone concentration meter may be used to alternately measure the ozone concentration of the water to be measured, and the number of ozone concentration meters and measuring means are not limited. In the calculator 24, each dissolved ozone concentration CW2,
The difference from CW1 is obtained according to the following equation (16), and the difference is output as the ozone demand amount DK of the water to be treated.

DK = CW2-CW1 (16) Next, the operation of this configuration will be described.

First, the water to be treated W containing the ozone consuming component to be measured of the required amount of ozone is introduced into the ozone contact reaction tank 1 by the sampling pump 10, and the water to be treated W has a predetermined amount set. be introduced. Treated water W
The composition and concentration of the ozone consuming component that becomes an oxidizable component in the inside vary depending on the water to be measured, but for example, humic substances that are factors of chromaticity as an organic substance, and geosmin that becomes an odor component (Geosmin, C ₁₂ H ₂₂ O), 2- methyl-isoborneol (2-Methylisoborneol, C ₁₁ H
₂₀ O), Fe ions, Mn ions and SS (S uspended S olids), and the like as further inorganic material.

Into the ozone contact reaction tank 1, ozone gas OG having a predetermined concentration is injected from the ozonizer 2 separately from the water to be treated W, and the ozone injection rate for the water to be treated W is set to a predetermined value. By supplying the water W to be treated and the ozone into the ozone contact reaction tank 1, the oxidizable components in the water W to be treated are oxidized by the injected ozone in the reaction tank 1 and the ozone injected at the same time. Is conversely consumed.
On the other hand, apart from the consumption of ozone by the oxidizable components in the water W to be treated, part of the injected ozone is converted to oxygen by self-decomposition and consumed by self-decomposition of ozone itself. Here, since the dissolved ozone concentration K1 after ozone injection including both oxidation reaction and self-decomposition is represented by the above equation (13), the dissolved ozone concentration CW1 of the water to be treated W corresponding to this dissolved ozone concentration K1 is It is measured by the dissolved ozone concentration meter 13 and input to the calculator 24.

When ozone is injected into the water to be treated W as described above, in the other ozone contact comparison reaction tank 16, after the ozone is injected into the water to be treated, the comparative water TW2 containing no oxidizable component is introduced. It That is, the ozone contact reaction layer 1
Comparative water TW2 from which the oxidizable component has been removed is introduced. Then, this comparative water amount is set to be equal to the above-mentioned treated water amount. Further, ozone having the same concentration and injection amount as the ozone injected into the ozone contact reaction tank 1 described above is injected into the ozone contact comparison reaction tank 16.

Here, in the ozone contact comparison reaction tank 16, since the ozone consuming component is not contained in the comparison water TW2, there is no ozone consumption required for the oxidation of the organic matter and the consumption (reduction) of the injected ozone. Ozone is consumed by being controlled only by self-decomposition of ozone.

As a result, the dissolved ozone concentration K2 after the ozone injection is expressed by the above equation (14), and therefore the dissolved ozone concentration C of the comparative water TW2 corresponding to this dissolved ozone concentration K2.
W2 is measured by the dissolved ozone concentration meter 21, and the calculator 24
Entered in.

Incidentally, by injecting ozone into the comparative water TW2 containing no oxidizable component after injecting ozone into the water to be treated W and the treated water W containing an oxidizable component separately from this. When comparing the dissolved ozone concentrations of the two TW2 and W, the injected ozone is only consumed by the self-decomposition of ozone on the side of the comparative water TW2. Therefore, the dissolved ozone concentration meter 1
The relationship between the dissolved ozone concentrations CW1 and CW2 measured at 3, 21 is CW1 <CW2.

As described above, the dissolved ozone concentration CW1 on the treated water W side and the dissolved ozone concentration CW on the comparative water TW2 side are measured.
When 2 is measured and input to the calculator 24, and the difference is obtained based on the above equation (16), the ozone demand amount of the water W to be measured becomes a value excluding the amount of self-decomposition of ozone. This difference is obtained as the ozone demand amount DK of the water to be treated.

More specifically, the treated water W and the comparative water T
The difference DR between the dissolved ozone concentrations K1 and K2 of W2 and W2 is expressed by the following equation (17) from the above equations (13) and (14), but if the ozone reaction conditions such as the amount of injected ozone are the same, Since the ozone consumption amounts CR2 and CR2 'due to the decomposition are offset, this difference DR is equal to the ozone consumption amount CR1 of the water W to be treated excluding the ozone consumption amount CR2 due to self-decomposition, as shown in the following equation (18). It becomes a value.

DR = (CR1 + CR2) −CR2 ′ (17) DR = CR1 (18) Then, this difference DR corresponds to the difference DK of the dissolved ozone concentration measured by the dissolved ozone concentration meters 13 and 21. Therefore, the dissolved ozone concentration CW1 of the water W to be treated and the comparative water T
If the dissolved ozone concentration CW2 of W2 is measured and the difference DK between the dissolved ozone concentrations CW2 and CW1 is obtained, the ozone demand amount DK of the treated water excluding the ozone consumption amount due to self-decomposition on the treated water W side is Desired.

When the ozone demand amount of the water to be treated is obtained as described above, if the pH, water temperature and the like change along with changes in the concentration and composition of the organic matter in the water to be measured, the solubility of ozone and the ozone in the liquid. The self-decomposition amount of will also change. Therefore, it is necessary to match the pH and water temperature of the comparative water TW2 with those of the water to be treated W so that the reaction conditions of the two are the same. Therefore, in the present invention, when obtaining the comparative water containing no oxidizable component, the oxidizable component due to ozone in the treated water is removed based on the treated water W to contain the oxidizable component. Not trying to get comparative water. For this reason, this comparative water is not affected by the disturbance that changes the water temperature or pH, and is the same as the original water to be treated W regardless of the presence or absence of the oxidizable component. The reaction conditions will match the treated water W side.

Therefore, an adjusting means for matching the water temperature and pH on the comparative water side for obtaining the ozone consumption due to self-decomposition with the water to be treated becomes unnecessary, and disturbance factors of ozone consumption due to pH adjustment and the like are also caused. Since it can be eliminated, the ozone demand amount of the water to be treated can be obtained simply and accurately from the ozone consumption by the oxidizable components of the water to be treated.

(Embodiment 2) FIG. 2 shows another embodiment of the present invention. An adsorption tank 30 for adsorbing and removing an oxidizable component due to ozone in the water W to be treated is disposed upstream of the ozone contact comparison reaction tank 16, and the sampling pump 1 is provided in this adsorption tank.
The water W to be treated is introduced by being branched on the discharge side of 0. Then, the flow rate of the treated water W measured by the flow meter 31 is adjusted by the flow rate control valve 32, and is set to be equal to the flow rate of the treated water W to the ozone contact reaction tank 1. Here, the oxidizable component in the water W to be treated is adsorbed and removed in the adsorption tank 30. In this embodiment, the adsorbent 3 such as activated carbon is placed in the adsorption tank 30.
3 is filled. It should be noted that ozone may be injected on the upstream side of the adsorption tank 30 to oxidize the oxidizable component in the water to be treated, and then the oxidizable component may be removed in the adsorption tank 30.

The water pipe 34 disposed on the outlet side of the ozone contact reaction tank is the water pipe 3 from the ozone contact reaction tank 16.
5 and the drainage water from the tanks 1 and 16 is connected to the pipes 34 and 35.
Is discharged to the outside of the system via.

The treated water from which the oxidizable components have been removed in the adsorption tank 30 is the ozone contact comparison reaction tank 16 as the comparison water TW2.
Will be introduced to. Ozone OG is injected into the ozone contact comparison reaction tank 16. Therefore, here, since the oxidizable component does not exist in the comparative water, ozone consumption due to self-decomposition of ozone proceeds, and the dissolved ozone concentration CW2 in the comparative water is measured by the dissolved ozone concentration meter 21. on the other hand,
Into the ozone contact reaction tank 1, water to be treated containing an oxidizable component is introduced and ozone is also injected. Then, the dissolved ozone concentration CW1 after ozone injection is measured by the dissolved ozone concentration meter 13.

The dissolved ozone concentrations CW1 and CW2 of each water after the ozone injection are input to the calculator 24 for obtaining the ozone demand amount of the water W to be treated, where the dissolved ozone concentrations CW are
The required ozone amount DK of the water W to be treated is calculated from the difference between 1 and CW2 and output.

When the ozone demand amount DK of the water to be treated W is obtained as described above, as a means for obtaining comparative water containing no oxidizable component, the oxidizable component in the water to be treated can be removed by adsorption. Since there is no major factor that changes the water temperature, pH, etc. of the comparative water, the water temperature, pH of the treated water matches the comparative water side, and comparative water containing no oxidizable component can be easily obtained.

(Embodiment 3) FIG. 3 shows another embodiment of the present invention. The dissolved ozone removal tank 36 is arranged on the upstream side of the ozone contact comparison reaction tank 16 into which the comparison water TW2 is introduced. In one embodiment of the present invention, ozone contact comparison reactor 16
Is provided on the upstream side of the ozone contact reaction tank 1 and on the downstream side of the ozone contact reaction tank 1.

Inorganic gas such as N ₂ or air is introduced into the dissolved ozone removing tank 36 through the air diffuser 37 having innumerable pores, and the ozone contact reaction tank 1 enters the dissolved ozone removing tank 36. Bubbling is performed in the introduced treated water TW1.

More specifically, air is discharged into the dissolved ozone removing tank 31 from the discharge side of the air pump 5 for supplying air to the ozonizer 2 through the ventilation pipe 39. As a result, the dissolved ozone in the treated water TW1 is released from the liquid phase to the gas phase as the partial pressure decreases, and the dissolved ozone remaining in the treated water TW1 after the ozone has been injected into the water to be treated W remains. To be removed.

In this embodiment, bubbling (aeration) is performed by using air from the viewpoint of economy to accelerate the removal of dissolved ozone, but the retention time of the treated water TW1 in the dissolved ozone removal tank 36 is Dissolved ozone may be removed by self-decomposition of ozone after securing it for a long time. That is, the ozone in the liquid is self-decomposed and converted into oxygen over time.
Although the self-decomposition rate of ozone differs depending on the water temperature, pH, etc., self-decomposition of ozone progresses in a short time and dissolved ozone disappears.

With the flow rate control valve 39A, the dissolved ozone removing tank 3
The flow rate of the gas (air in this embodiment) introduced into No. 6 is adjusted to a predetermined flow rate. The introduced gas is introduced into the dissolved ozone removing tank 36 via the flow meter 39B.

The operation of the apparatus having the following structure will be described. The treated water TW1 in which ozone has been injected into the treated water W to remove the oxidizable components in the treated water is the comparative water TW.
2 is introduced into the ozone contact comparison reaction tank 16, but is introduced into the dissolved ozone removal tank 36 before being introduced into the reaction tank 16.

Here, air is introduced into the dissolved ozone removing tank 36 to be bubbled, and the dissolved ozone remaining in the treated water TW1 after the ozone is injected is released from the liquid phase to the gas phase. Next, the treated water from which the dissolved ozone remaining in the liquid phase has been removed by the above-mentioned operation is introduced into the ozone contact comparison reaction tank 16 as comparison water TW2 for obtaining ozone consumption due to self-decomposition, and the ozone is stored in the tank 16. Is injected and then the dissolved ozone concentration CW2 in the comparative water is measured.
Then, the ozone demand amount DK of the water to be treated is obtained from the difference DR between the dissolved ozone concentration CW2 and the dissolved ozone concentration CW1 in the water to be treated W after the ozone injection.

When the required ozone amount of the water to be treated is obtained as described above, the comparison water T for obtaining the self decomposition of ozone is obtained.
The W2 side does not contain dissolved ozone before the ozone injection. Therefore, even if ozone is injected after that, the dissolved ozone concentration in the comparative water is not affected by the residual ozone injected in the previous step, and when measuring the ozone requirement of the water to be treated, a highly accurate ozone requirement is required. be able to.

(Embodiment 4) FIG. 4 shows another embodiment of the present invention.

In the comparator 40, the measured value CW1 from the dissolved ozone concentration meter 13 for measuring the dissolved ozone concentration in the water to be treated after the ozone OG is injected, and the dissolved value after the ozone is injected into the water to be treated W. The target value K ₀ of the ozone concentration is input.

The target value K ₀ is a target value for keeping the dissolved ozone concentration in the water to be treated after ozone injection at a predetermined value or more, and is arbitrarily set. This target value can be changed, and is set in consideration of the concentration of the oxidizable component in the water to be treated, its composition, fluctuation range, and the like. In this comparator 40,
The deviation ± ΔKn (hereinafter simply referred to as deviation ΔKn) between the dissolved ozone concentration CW1 and the target value is obtained, and this deviation Δ
Kn is input to the calculator 41.

When the deviation ΔKn obtained by the comparator 40 is a negative deviation −ΔKn, the deviation 41 is calculated by the calculator 41.
The corrected ozone injection rate ΔF corresponding to Kn is obtained, and the corrected ozone injection rate ΔF is input to the next calculator 42.

The relationship between the deviation ΔKn and the corrected ozone injection rate ΔF is set in advance in accordance with the relationship between the ozone injection treatment characteristics of the water to be treated as shown in FIG. The calculator 42 has
Further, the reference ozone injection rate Fn is input in advance, and the following equation (1
According to 9), the ozone injection rate Fm to be injected into the water to be treated W is obtained.

Fm = Fn + ΔF (19) The reference ozone injection rate Fn is arbitrarily set in consideration of ozone absorption characteristics and the like, and the setting can be changed in advance. Required according to.

The ozone injection rate Fm into the water to be treated obtained as described above is the ozone injection amount F into the water to be treated.
It is input to the computing unit 43 for obtaining j. Further, the calculator 43 is provided with a flow rate Q1 of the water to be treated to the ozone contact reaction tank 1.
The output value from the flow meter 12 for measuring
Is entered as.

As a result, the calculator 43 calculates the ozone injection amount Fj from the relationship between the ozone injection rate m and the treated water flow rate Q1 according to the following equation (20).

Fj = Fm × Q1 (20) The controller 44 controls the ozone generation amount Sj of the ozonizer 2 according to the ozone injection amount Fj. When the supply flow rate of the source gas (air or oxygen) to the ozonizer 2 is constant, the ozone generation amount Sj can be controlled by changing the voltage applied to the discharge part (not shown) of the ozonizer 2. When the frequency is constant, the ozone generation concentration increases and the ozone generation amount increases as the applied voltage increases. On the other hand, when the applied voltage is constant, the ozone generation concentration increases and the ozone generation amount increases as the frequency increases. If the applied voltage or frequency is lowered,
The amount of ozone generated will decrease. In this embodiment, the controller 44 changes the voltage applied to the ozonizer 2 in accordance with the ozone injection amount Fj to control the ozone generation amount Sj. However, if it does not depend on the applied voltage, the frequency is controlled. The control method is not particularly limited.

When controlled as described above, the ozonizer 2 causes the controller 44 to generate an ozone amount corresponding to the ozone injection amount Fj. Then, the treated water W has an ozonizer 2
From the above, ozone corresponding to the ozone injection amount Fj is injected. Note that the same amount of ozone as the water to be treated W is injected into the comparative water TW2.

The operation of the above arrangement will be described. The dissolved ozone concentration CW1 in the water to be treated W after ozone injection is
It is measured by the dissolved ozone concentration meter 13. The measured value is input to the comparator 40 as an output value, and the dissolved ozone concentration C
The deviation ΔKn from the target value K ₀ input separately from W1 is obtained.

This deviation ΔKn is input to the calculator 41. Here, the dissolved ozone concentration CW1 in the water to be treated W after ozone injection is lower than the target value K ₀ , and the negative deviation −ΔKn
In this case, the calculator 41 obtains the corrected ozone injection rate ΔF corresponding to the deviation −Kn, and the corrected ozone injection rate ΔF is input to the calculator 42. Then, the ozone injection rate Fj into the water to be treated is calculated based on the corrected ozone injection rate ΔF and the reference ozone injection rate ΔF, and the ozone injection amount Fj obtained according to the ozone injection rate Fj is the treated water W.
Is injected into.

On the other hand, the dissolved ozone concentration CW in the water W to be treated
If 1 exceeds the target value K _0, the deviation DerutaKn target value K ₀ and dissolved ozone concentration CW1 is input from the comparator 40 as a positive deviation + DerutaKn to the calculator 41. In this case, since the dissolved ozone concentration CW1 is maintained above the predetermined value (target value) here, the corrected ozone injection rate ΔF for supplementing the ozone injection amount is not added to the next calculator 42. Therefore, the ozonizer 2 injects ozone into the water to be treated W in accordance with the ozone injection amount Fj obtained based on the reference ozone injection rate Fn.

When the ozone injection rate or the ozone injection amount into the water to be treated W is controlled as described above, the dissolved ozone concentration in the water to be treated W after the ozone injection has a predetermined value in accordance with the deviation from the target value. Since the above is maintained, the dissolved ozone concentration in the water W to be treated after ozone injection will not be undetected.

Therefore, sufficient ozone to oxidize the oxidizable components in the water to be treated is injected into the water to be treated W, and there is no residual unreacted oxidizable component due to insufficient ozone injection amount. It is possible to measure the ozone demand amount of the water to be treated with high accuracy.

On the other hand, in addition to the control of the dissolved ozone concentration after the ozone injection described above, in one embodiment of the present invention, when measuring the ozone demand amount of the water to be treated, the structure of the device is simplified. .

Explaining with reference to FIG. 3 (or FIG. 4) of the above-mentioned embodiment, the dissolved ozone in the treated water TW1 after ozone injection is provided on the downstream side of the ozone contact reaction tank 1 into which the treated water W is introduced. A dissolved ozone removing tank 36 for removing the above is provided. An ozone contact comparison reaction tank 16 is disposed on the downstream side of the dissolved ozone removal tank 36.
And 16 are arranged in series with the flow of water. On the outlet side of the ozone contact reaction tank 1, a dissolved ozone concentration meter 13 for measuring the dissolved ozone concentration CW1 after injection of ozone OG is disposed, and on the outlet side of the ozone contact comparison reaction tank 16, after ozone OG injection. The dissolved ozone concentration meter 21 for measuring the dissolved ozone concentration CW2 in the comparative water TW2 of FIG.

As described above, each tank 1, 36 and 1
In the case where No. 6 is provided, first, the water to be treated W, which is the object of measuring the required ozone amount, is introduced into the ozone contact reaction tank 1. Then, here, ozone OG is injected from the ozonizer 2 into the tank 1 to oxidize the oxidizable component that is an ozone consuming component in the water W to be treated, and the dissolved ozone concentration CW1 after ozone injection is measured. The measured value CW1 is calculated by the calculator 24.
Entered in.

The treated water TW1 after the ozone injection, for which the dissolved ozone concentration CW1 has been measured, is then introduced into the dissolved ozone removing tank 36 arranged on the downstream side. Here, the dissolved ozone in the treated water TW1 injected in the previous stage and remaining in the liquid phase is released to the gas phase by aeration and removed.

The treated water from which the dissolved ozone had been removed was then treated with a comparative water T containing no oxidizable component and dissolved ozone.
As W2, it is introduced into the ozone contact comparison reaction tank 16 arranged on the downstream side of the dissolved ozone removal tank 36. here,
By injecting ozone OG into the comparative water TW2 containing no oxidizable component, ozone consumption due to self-decomposition of ozone is obtained, and the dissolved ozone concentration CW2 in the comparative water TW2 after ozone injection is measured by the dissolved ozone concentration meter 21. To do. The measured value CW2 is input to the calculator 24 as an output value. The calculator 24 obtains the ozone demand amount DR of the water to be treated from the input dissolved ozone concentrations CW1 and CW2 based on the equation (16).

When the ozone demand amount of the water W to be treated is measured as described above, the water tanks 1, 36 and 16 for carrying out the respective operations are carried out.
Are arranged in series, it is possible to inject ozone into the water to be treated W, measure the dissolved ozone CW1 of the water, and then remove the dissolved ozone, and use this as the comparative water TW2. Become. Therefore, the operation for obtaining the comparative water containing no oxidizable component can be combined with the operation for injecting ozone into the water to be treated W to obtain the ozone consumption by the organic matter and the like.

Therefore, the operation of separately injecting ozone to obtain the comparative water to remove the oxidizable component and the operation makes the water tank unnecessary and simplifies the instrument structure for measuring the ozone required amount of the treated water. It

(Embodiment 5) FIG. 6 shows another embodiment of the present invention. Ozone-consuming component removal tank 5 into which treated water W is introduced
An ozone contact comparison reaction tank 16 is disposed on the downstream side of 0. The water W to be treated is passed through the sampling pump 10, the constant flow rate control valve 51, and the flow meter 52 to remove the ozone consuming component removal tank 5.
Introduced to zero. Reference numeral 53 is a constant flow valve for adjusting the flow rate of ozone injected into the ozone consuming component removal tank 50, and 54 is a flow meter.

The ozone contact reaction tank 1 into which the water W to be treated is divided and introduced is arranged in parallel with the water system of the removal tank 50. That is, water is separated on the discharge side of the sampling pump 10 and introduced into each tank 1, 50.

In the case of the above configuration, in the ozone consuming component removing tank 50 into which the water W to be treated is divided and introduced, ozone OG is injected into the tank 50 to remove the water in the water W to be treated. Oxidizing component is oxidized, and then dissolved ozone removal tank 3
After the dissolved ozone is removed via 6, the ozone contact comparison reaction tank 16 is used as comparison water TW2 containing no oxidizable component.
Will be introduced to. At the same time, ozone O
G is injected, and the dissolved ozone concentration CW2 of the comparative water after ozone injection is measured by the dissolved ozone concentration meter 21.

On the other hand, the water W to be treated, which has been divided into water and introduced into the ozone contact reaction tank 1, is injected with ozone OG to oxidize the oxidizable component which is an ozone consuming component in the water W to be treated. As a result, the injected ozone is consumed along with the self-decomposition of ozone, and then the dissolved ozone concentration CW after ozone injection
1 is measured by the dissolved ozone concentration meter 13.

The dissolved ozone concentrations CW1 and CW2 measured as described above are input to the calculator 24 for determining the ozone demand amount of the water to be treated, where the concentrations CW1 and CW1 are calculated on the basis of the equation (16). The ozone demand amount DR of the water to be treated is obtained from the CW2 difference.

When the ozone demand amount of the water to be treated is measured as described above, in this example, the water to be treated is divided to obtain a comparative water containing no oxidizable component. It is introduced into the removal tank 50, and the oxidizable component in the water to be treated W is removed here. Here, since the operation is to remove the oxidizable component, there is no restriction to set the ozone injection amount equal to the ozone injection amount injected into the ozone contact reaction tank 1 and the ozone contact comparison reaction tank 16, so that the ozone injection amount is set to be large. Can accelerate the removal of oxidizable components,
Comparative water containing no oxidizable component can be obtained in a short time.

Therefore, even if the water quality of the water to be treated varies greatly, it is possible to reduce the time constraint for obtaining the comparative water. Therefore, when measuring the ozone demand of the water to be treated, it is possible to measure the ozone demand with excellent responsiveness. .

(Embodiment 6) FIG. 7 shows another embodiment of the present invention. The dissolved ozone treatment tank 60 is disposed on the downstream side of the ozone contact comparison reaction tank 16, and when the comparison water TW2 after ozone injection from the reaction tank 16 is discharged to the outside of the system, It has the function of removing the dissolved ozone without discharging it and then discharging it.

More specifically, the dissolved ozone treatment tank 60.
Comparative water from the ozone contacting / comparing reaction tank 16 is introduced into the processing tank 60, and the dissolved ozone removing tank 36 is provided in the processing tank 60.
The air is introduced from the air pump 5 and bubbled (aerated) like the air introduced into the. As a result, the ozone injected in the ozone contact comparison reaction tank 16 and remaining in the comparison water, that is, the dissolved ozone, is released from the liquid phase to the gas phase as the partial pressure decreases. Of course, the dissolved ozone may be removed by other means.

On the other hand, as described in the third embodiment, the dissolved ozone removing tank 36 is disposed downstream of the ozone contact reaction tank 1, and the ozone contact comparison reaction tank is provided downstream of the dissolved ozone removing tank 36. 16 are provided. Then, the treated water TW1 containing no oxidizable component after the ozone has been injected into the treated water W is introduced into the dissolved ozone removal tank 36. Further, air is introduced into the dissolved ozone removing tank 36 from the air pump 5 through the ventilation pipe 39. As a result, dissolved ozone is released from the liquid phase to the gas phase. The dissolved ozone removing tank 36 has both the function of releasing dissolved ozone after ozone injection into the gas phase and the two functions of obtaining comparative water containing no dissolved ozone as a result.

The flow rate adjusting valve 61 adjusts and sets the flow rate of the air introduced into the dissolved ozone treatment tank 60 via the filter 4 and the air pump 5 to a predetermined value. Reference numeral 62 represents the flow rate control valve, and 61 represents a flow meter.

On the other hand, the inlet side of the exhaust ozone discharge pipe 23 is connected to the gas phase portions of the respective tanks 1, 16, 36 and 60 described above. Furthermore, the gas-liquid separators 14 and 20 are communicated with the gas phase portions. On the other hand, this exhaust ozone discharge pipe 23
The outlet side of is connected to the ozone decomposition treatment means 66 through the mist separator 65.

The ozone-containing exhaust gas E discharged from the liquid phase to the gas phase into each of the tanks 1, 16, 36 and 60 described above.
The exhaust ozone from G or each of the gas-liquid separators 14 and 20 is introduced into the ozone decomposition treatment means 66 after the water is removed by the mist separator 65 through the exhaust ozone exhaust pipe 23.

The ozone decomposing means 66 comprises an exhaust ozone decomposing tank 67 and an ozone decomposing catalyst 63 filled in the exhaust ozone decomposing tank 67. In the embodiment of the present invention, MnO ₂ catalyst is filled as an ozone decomposition catalyst. However, activated carbon, at least one element such as Fe or Ni, an oxide or a composite oxide, and a noble metal catalyst such as Pt or Pd are used. May be used.

When the ozone-containing exhaust gas EG passes through the ozone decomposition processing means 66, the ozone in the gas is converted into oxygen and is discharged out of the system as exhaust gas containing no ozone. In this embodiment, the exhaust ozone decomposing tank 6
Although the catalyst 63 is filled in 7 to decompose ozone, ozone may be treated by thermal decomposition, and the exhaust ozone treatment method is not particularly limited to the catalytic method.

One end of the drain pipe 68 is connected to the dissolved ozone treatment tank 6
It is connected to 0, and the other end faces the outside of the system. Then, the water treated in the dissolved ozone treatment tank 60 is discharged out of the system as drainage through the drainage pipe 68. Mist separator 6
The wastewater from No. 5 is also discharged to the outside of the system through the drain pipe 68, but it may be discharged after being introduced into the dissolved ozone treatment tank 60. Further, in the embodiment of the present invention, the ozone-containing exhaust gas discharged from each tank 1, 16, 31, and 60 is processed by the common ozone decomposition processing means 66, but it may be processed independently. . For example, ozone contact reaction tank 1
And ozone decomposition processing means (not shown) for processing the exhaust gas containing ozone discharged from the ozone contact comparison reaction tank 16
And the ozone decomposing means (not shown) for treating the ozone-containing exhaust gas discharged from the dissolved ozone removing tank 36 and the dissolved ozone treating tank 60.

In the case of the above configuration, the ozone-containing exhaust gas EG released from the ozone contact reaction tank 1 and the ozone contact comparison reaction tank 16 to the gas phase is discharged to the outside of the system via the ozone decomposition treatment means 66. Since it is discharged, it is possible to protect the measurement environment and prevent ozone leakage to the environment when measuring the ozone demand amount of the water to be treated. That is, when measuring the ozone demand amount of the water to be treated, all of the ozone injected into the ozone contact reaction tank 1 and the ozone contact comparison reaction tank 16 is not dissolved in the liquid phase, and some ozone is released from the liquid phase to the gas phase. However, the exhaust gas EG containing ozone is released into the gas phase.
Is not discharged directly to the outside of the system after the contained ozone is converted to oxygen by the ozone decomposition processing means 66 and then discharged to the outside of the system.

Therefore, it is possible to provide a method for measuring the ozone demand amount of the water to be treated which can maintain the measurement environment and prevent ozone leakage.

On the other hand, in addition to the ozone-containing exhaust gas EG from each of the reaction tanks 1 and 16 described above, in order to prevent ozone leakage to the environment from ozone-containing water discharged after the ozone demand is measured, In the embodiment of the present invention, dissolved ozone in the water to be treated and the comparative water after ozone injection is released from the liquid phase to the gas phase, and the ozone-containing exhaust gas EG is discharged to the outside of the system through the ozone decomposition treatment means 66. ing.

That is, the ozone injected in the previous stage remains as dissolved ozone in the water to be treated and the comparative water after the measurement of the required ozone amount. Therefore, treated water T after ozone injection
W1 is introduced into the dissolved ozone removing tank 36, and similarly, comparative water TW2 after ozone injection is introduced into the dissolved ozone treatment tank 60. Then, dissolved ozone is released from the liquid phase to the gas phase by means of aeration or the like to remove the dissolved ozone, and the discharged ozone-containing exhaust gas is discharged to the outside of the system through the ozone decomposition treatment means 66. It is the one. As a result, when measuring the ozone demand of the water to be treated, wastewater containing no dissolved ozone is discharged outside the system,
In addition, the ozone-containing exhaust gas released into the gas phase after the removal of dissolved ozone is converted into oxygen by the ozone decomposition processing means and discharged.

Therefore, similarly to the above, it is possible to provide a method for measuring the ozone demand amount of the water to be treated which can preserve the measurement environment and prevent ozone leakage.

(Embodiment 7) FIG. 8 shows another embodiment of the present invention. An example of ozone injection will be explained using a water purification plant as an example. Raw water RW taken from a water intake source such as a river through an intake port reaches a sand basin (not shown) through a water conduit (not shown), and after sand having a large particle size is removed, It is led to the landing well 70.

The raw water RW is then introduced into a chemical mixing basin 71, where it is mixed with a coagulant 72 such as a sulfuric acid band or PAC (polyaluminum chloride), and further with an alkaline agent 73 serving as a coagulant auxiliary agent. It is sent to the floc formation pond 74.

In the floc formation pond 74, the growth of micro flocs in which fine particles in the raw water are aggregated is promoted. After that, the condensed water containing the flocs that have grown greatly is guided to the sedimentation tank 75, where the sedimentation and separation of the flocs is performed.

The settling water SW from which flocs have been settled and separated through the above-described process is then introduced into the ozone injection treatment device 76 as water to be treated which is the object of ozone injection treatment. The ozone injecting and treating apparatus 76 is an ozonizer 77 for generating ozone and ozone O from the ozonizer 77.
The ozone contact reaction tank 78 into which Z is introduced and the ozone decomposition processing means 79 for processing the ozone-containing exhaust gas EG discharged from this ozone contact reaction tank 78 are mainly constituted.

More specifically, the source gas RA (air or oxygen) is supplied to the ozonizer 77 after the moisture is removed by the dehumidifier 80. The raw material gas RA is supplied by the blower B. Here, the oxygen is ozonized, and the ozone-containing gas passes through the ventilation pipe 81 and has many small holes (not shown).
Is introduced into the ozone contact reaction tank 78 from the air diffusing pipe 82. Most of the ozone introduced into the ozone contact reaction tank 78 is dissolved in the liquid, but some ozone is not dissolved and is discharged from the upper portion of the contact tank 78 into the gas phase G as ozone-containing exhaust gas EG. .

The ozonizer 77, which is an ozone generating means,
Controller 83, high frequency inverter 84, and high voltage transformer 8
5 Further, a main part is composed of a discharge part (not shown). Then, a high frequency high voltage is applied from the power source 86 to the discharge unit via the high frequency inverter 84 and the high voltage transformer 85.

More specifically, a high frequency high voltage is applied to a dielectric (not shown) forming the discharge part and an electrode (not shown) facing the dielectric.

As a means for generating ozone, there are a silent discharge method, an electrolysis method, a photochemical reaction method, and a high frequency electrolysis method, and the silent discharge method is generally adopted from the viewpoint of ozone generation efficiency. Then, it is classified into direct current corona, alternating current corona discharge, etc. according to the type of voltage to be applied, but ozone is generated by alternating current corona discharge in terms of efficiency. In one embodiment of the present invention, an ozonizer by AC corona discharge is used, but the ozone generating means is not particularly limited.

The amount of ozone generated by the ozonizer 77 is the power consumption W in the discharge section when the flow rate of the raw material gas is constant.
(Discharge power), and the generated ozone concentration increases as the power consumption increases. Then, the following equation (2
As shown in 1), the power consumption is determined by the applied voltage and the power supply frequency, when the conditions such as the material of the dielectric material of the discharge part constituting the ozonizer 77, the effective area of discharge, the discharge gap, etc. are determined.

W = f · (εd / 4πd _d ) · S · γ · dg [2√2E _eff − {1+ (εg · d _d ) / (εd · dg)} γ · dg] × 1/9 × 10 ^-11 (21) where f: power supply frequency, εd: dielectric constant of dielectric, ε
g: dielectric constant of reaction gas, dg: discharge gap (cm),
d _d : thickness of dielectric (cm), S: effective area of discharge (cm ² ), E
_eff : Applied voltage, γ: Seaside breakdown electric field (γ = (Vs + Ve) /
dg), Vs: discharge start voltage, Ve: extinguishing voltage.

Therefore, in order to increase the power consumption and increase the ozone generation amount, the applied voltage or the power supply frequency may be controlled. In one embodiment of the present invention, the applied voltage is kept constant and the frequency is controlled by the high-frequency inverter to change the ozone generation amount, but both or the applied voltage may be controlled to change the ozone generation amount.

Ozone decomposition treatment means 79 is disposed downstream of the mist separator 87 for removing water in the ozone-containing exhaust gas EG from the ozone contact reaction tank 78. Examples of the ozone decomposition catalyst 88 include the catalyst described in the above-described sixth embodiment. Further, as described above, the treatment may be performed by thermal decomposition or the like, and the catalyst used and the ozone decomposition method are not particularly limited.

The blower 89 sucks the ozone-containing exhaust gas EG from the ozone contact reaction tank 78 and discharges it to the outside of the system.

A biological activated carbon tank 90 disposed on the downstream side of the ozone contact reaction tank 78 is filled with activated carbon 91, and treated water TW from the ozone contact reaction tank 78 is introduced. At the beginning of filling with activated carbon 91 and passing water, there are few microorganisms on the surface or inside of this activated carbon, but with the passage of time, microorganisms that have acclimatized and propagated on the surface or inside of this activated carbon (not shown). Exists. Pseudomonas etc. are mentioned as the dominant species of microorganisms.

Treated water TW from the ozone contact reaction tank 78
Ammonia nitrogen that cannot be removed by ozone treatment is nitrified and removed by the action of microorganisms, and dissolved organic matter whose molecular weight has been lowered by ozone treatment is also metabolically removed. The water from the biological activated carbon tank 90 treated as described above is then sent to a distribution reservoir (not shown) or the like. Although not shown in the embodiment of the present invention, the biological activated carbon tank 90
Is back-washed with the treated water that has flowed out of the tank 90 as needed, and the microorganisms excessively attached to the activated carbon 91 are removed.

The dissolved ozone concentration meter 92 disposed on the downstream side of the ozone contact reaction tank 78 measures the dissolved ozone concentration CW1 on the actual plant side after being introduced into the ozone contact reaction tank 78 and injected with ozone OG. To do. Sampling pump 9
At 3, a part of the treated water BL from the biological activated carbon tank 90 is sampled.

The treated water BL sampled from the biological activated carbon tank 90 is introduced into the ozone contact comparison reaction tank 94 which constitutes the ozone demand measuring device 1B, and ozone OG is injected into the tank 94 from the ozonizer 2 side. It The ozone contact comparison reaction tank 94 has the same function and configuration as the ozone demand amount measuring apparatus 1A of the water to be treated described in the above-mentioned first embodiment, and is composed of the ozone contact reaction tank 78 and the biological activated carbon tank 90. It is provided separately from the process. The ozone injection rate for the sampling water S is set to be equal to the ozone injection rate for the water W to be treated. Further, as shown in detail in the ozone demand measuring device 1B in FIG. 9, the flow rate of the sampling water S to the ozone contact comparison reaction tank 94 is adjusted by the flow rate adjusting valve 95, and the sampling water in the ozone contact comparison reaction tank 94 is adjusted. The residence time of S or the contact time with ozone is adjusted. Reference numeral 96 denotes a flow meter arranged on the outlet side of the control valve 95. On the other hand, the residence time or contact time in the tank 94 is set to be equal to the condition in the ozone contact reaction tank 78 on the plant side where the water W to be treated is introduced separately from the tank 94.

A dissolved ozone concentration meter 21 is provided on the outlet side of the ozone contact comparison reaction tank 94 to measure the dissolved ozone concentration CW2 in the sampling water S after ozone injection. Each dissolved ozone concentration CW1 and C measured as described above
W2 is a calculator 24 for calculating the ozone demand amount of the water W to be treated.
Is input as an output value to. As a result, this computing unit obtains and outputs the ozone demand amount DK of the water to be treated according to the above equation (16).

When the ozone demand amount of the water to be treated is obtained as described above, in the ozone contact reaction tank 78 on the plant side into which the water to be treated W is introduced, the ozone consumption and self-oxidation due to oxidizable components such as organic substances The reaction of ozone consumption including both ozone consumption due to decomposition progresses, and the dissolved water concentration CW1 after ozone injection is obtained on the treated water W side as a result of reflecting the characteristics of the actual ozone injection treatment. On the other hand, the comparative water used to calculate ozone consumption due to self-decomposition is treated water W
Since ozone is injected into the water, and then water of the same system as the water to be treated that has passed through the biological activated carbon tank 90, there is no disturbance effect that changes the water temperature, pH, etc. in the pretreatment step for obtaining this comparative water, Maintains water temperature, pH, etc. that does not contain oxidizable components and that matches the treated water side. Then, this comparative water also reflects the treatment characteristics in the actual plant, like the above-mentioned treated water.

Therefore, when the ozone demand amount of the water to be treated is obtained, the ozone demand amount of the water to be treated can be obtained based on the result of the actual ozone injection treatment of the water to be treated. The ozone demand of water can be measured.

(Embodiment 8) FIG. 10 shows another embodiment of the present invention. In this embodiment, when measuring the ozone demand amount of the water W to be treated, a biological activated carbon tank 90 disposed downstream of the ozone contact reaction tank 78 constituting the ozone injection treatment device 76.
A part of the treated water BL from No. 1 was sampled, and this sampled water was used as comparative water.

With the sampling pump 100, the settling water SW from the settling tank 75 after the completion of the coagulation and settling is sampled as the water W to be treated. The sampled water W is
As shown in detail in FIG. 11, it is introduced into the ozone contact reaction tank 1 which constitutes the ozone demand amount measuring device 1A.

The other sampling pump 93 samples a part of the treated water BL from the biological activated carbon tank 90 arranged on the downstream side of the ozone contact reaction tank 78 constituting the ozone injection processing device 76. The sampled treated water BL is used as a comparative water, and the ozone demand amount measuring device 1A is used.
Flow control valve 10 in ozone contact comparison reaction tank 16
1 and the flow meter 102.

Each tank 1, into which the water to be treated and the comparative water are introduced
Ozone OG is injected from 16 from the ozonizer 2.
Then, the flow rates of the water to be treated and the comparative water to the respective tanks 1 and 16 are set to be equal, and the ozone injection amount to each water is also set to be equal.

As described above, the water to be treated whose ozone demand is to be measured is introduced into the ozone contact reaction tank 1, and the treated water BL from the biological activated carbon tank 90 is introduced into the ozone contact comparison reaction tank 16 as comparison water. In this case, since the comparative water does not contain an oxidizable component that becomes an ozone consuming component, a means for removing the oxidizable component is not necessary to obtain comparative water for obtaining ozone consumption by self-decomposition. Therefore,
It is possible to measure the ozone demand amount of the water to be treated by simplifying the device configuration.

(Embodiment 9) FIG. 12 shows another embodiment of the present invention.

The controller 110 controls the amount of ozone injected into the water to be treated, and the arithmetic unit 11 which constitutes this controller.
In 1, the ozone demand amount DK of the water to be treated from the ozone demand amount measuring device 1A is input.

More specifically, ozone is injected into the water to be treated and the comparative water from which the oxidizable component to be the ozone consuming component in the water to be treated has been injected, and the comparative water after the ozone injection and the to-be-treated water are treated. The ozone demand amount DK of the water to be treated obtained from the difference between the dissolved ozone concentrations CW1 and CW2 with water is input. The ozone demand amount is input from the calculator 24 that constitutes the ozone demand amount measuring device 1A.

The calculator 11 into which the requested ozone amount DK is input.
1 further includes the ozone contact reaction tank 78 from the settling tank 55.
The flow rate F of the water to be treated flowing into is measured by the flow meter 112 and input.

As a result, in this computing unit 111, the required ozone injection amount Nj based on the measurement result of the ozone demand amount DK of the water to be treated is calculated from the following equation (22) based on the ozone demand amount DK and the flow rate F of the water to be treated. Calculate according to.

Nj = DK × F (22) 113 is a computing unit, to which the required ozone injection amount Nj obtained by the computing unit 111 is input, and further the flow meter 1
The flow rate F of the treated water from 12 is input. As a result,
The calculator 113 calculates the required ozone injection rate Dj based on the measurement result of the ozone demand amount DK of the treated water based on the required ozone injection amount Nj and the flow rate F of the treated water according to the following equation (23).

Dj = Nj / F (23) 114 is also an arithmetic unit, and the required ozone injection rate Dj obtained by the arithmetic unit 113 is input. Furthermore, this computing unit 114
Is input with the reference ozone injection rate Sj, and the ozone injection rate Pj to be injected into the water to be treated in the ozone contact reaction tank 78 is calculated according to the following equation (24).

Pj = Sj + Dj (24) The basic ozone injection rate Sj input to the computing unit 114 can be arbitrarily set in consideration of ozone absorption characteristics and the like and can be changed. The basic ozone injection rate Sj is input and set by an operator or the like.

Further, in this embodiment, as described above, the basic ozone injection rate Sj is input to the calculator 114 in consideration of the ozone absorption characteristics and the like. However, instead of the basic ozone injection rate Sj, ozone is self-decomposed. You may enter the self-decomposition consumption of ozone. That is, the self-decomposition consumption amount due to self-decomposition of ozone on the comparison water side is obtained and input from the relationship between the injection amount of ozone injected into the comparison water, the concentration of dissolved ozone and the concentration of ozone-containing exhaust gas into the gas phase, It is also possible to add ozone to the amount of ozone required of water and inject ozone into the water to be treated to be ozone-treated. By doing so, the ozone injection into the water to be treated takes into account ozone demand and ozone consumption due to self-decomposition, so that the ozone injection is suppressed from becoming insufficient.

Reference numeral 115 denotes a calculator, to which the ozone injection rate Pj from the calculator 114 is input.
Further, the flow rate F of the water to be treated flowing from the settling tank 55 into the ozone contact reaction tank 78 is supplied to the calculator 115.
Input from 2.

As a result, the calculator 115 calculates the ozone injection amount Oj according to the following equation (25) based on the ozone injection rate Pj and the flow rate F of the water to be treated.

Oj = Pj × F (25) The ozone injection amount Oj obtained as described above is the controller 8 for controlling the ozone generation amount Gs of the ozonizer 77 next.
3, the controller 83 controls the ozone generation amount Gs of the ozonizer 77.

More specifically, the controller 83 controls the high frequency inverter 84 based on the input ozone injection amount Oj.
Of the ozone injection amount Oj is controlled to control the ozone generation amount Gs according to the ozone injection amount Oj. Then, ozone corresponding to the ozone injection amount Oj is injected from the ozonizer 77 into the water to be treated.

In the embodiment of the present invention, when the ozone injection amount Oj into the water to be treated is controlled according to the ozone demand amount DK, the required ozone injection amount Nj is calculated by the calculator 111, and the required ozone injection rate Dj is then calculated. Although calculated by the calculator 113 and added to the basic ozone injection rate Sj, another method may be used as shown in FIG. That is, the basic ozone injection rate Sj is input to the calculator 116, and the flow rate F of the water to be treated to the ozone contact reaction tank 78 is also input to the calculator 11
In step 6, the basic ozone injection amount St is calculated according to the following equation (26).

St = Sj × F (26) Then, the basic ozone injection amount S obtained by the calculator 116
t is input to the calculator 117, and the calculator 11
The required ozone injection amount Nj obtained in 1 may be input and the ozone injection amount Oj may be calculated according to the following equation (27).

Oj = St + Nj (27) Next, the operation of the above configuration will be described. The ozone demand amount DK of the water to be treated is the dissolved ozone concentration CW after ozone injection.
This ozone demand amount DK is calculated from the difference between 1 and CW2.
Is input to the calculator 111 that controls the amount of ozone injected into the water to be treated. Then, in this computing unit 111, the required ozone injection amount Nj based on the ozone demand amount DK of the water to be treated is obtained from the relationship with the flow rate F of the water to be treated that is input to the other, and according to this required ozone injection amount Nj. Ozone is injected into the water to be treated.

As described above, when ozone is injected into the water to be treated, the amount of ozone injected into the water to be treated is to be injected according to the measurement result of the ozone demand amount DK of the water to be treated. As a result, even if the concentration of organic substances in the water to be treated fluctuates and the ozone consumption component increases or decreases, the ozone demand amount DK of the water to be treated is measured so as to correspond to it, and ozone corresponding to this ozone demand amount DK is generated. Since it is injected, the amount of ozone injected into the water to be treated does not become too small or excessive, and ozone injection control with high control accuracy becomes possible.

Therefore, it is possible to suppress the deterioration of water quality due to the excessive amount of ozone injection into the water to be treated, while preventing the increase of running cost due to the excessive injection, and the control accuracy corresponding to the water quality of the water to be treated and its fluctuation. It is possible to provide a high ozone injection control method.

In the embodiment of the present invention, when the amount of ozone injected into the ozone reaction contact tank 78 into which the water to be treated is introduced is controlled according to the ozone demand amount DK of the water to be treated, the measurement described in the first embodiment is carried out. Although the ozone demand amount DK obtained by the means is input to the calculator 111 and the ozone injection amount is controlled thereafter, other means may be used. For example, the ozone demand amount DK obtained according to the ozone demand amount measuring means of the treated water described in the seventh or eighth embodiment is input to the calculator 111, and based on this, the ozone demand amount DK is calculated. The ozone injection amount may be controlled, and the present invention is not limited to this embodiment.

(Embodiment 10) FIG. 14 shows another embodiment of the present invention. The ozone concentration meter 6 for measuring the ozone gas concentration G1 injected from the ozonizer 2 into the ozone contact comparison reaction tank 16 (or ozone contact reaction tank 1) is provided in the calculator 120.
Output value, that is, the ozone concentration G1 is input. In the ozone concentration meter 123, the ozone contact comparison reaction tank 1
The concentration of the exhaust ozone gas discharged from No. 6 is measured. The exhaust ozone gas concentration G2 measured by the ozone concentration meter is input to the calculator 120. Since the ozone gas concentrations G1 and G2 are input to the calculator 120, the following equation (28)
According to the above, the ozone consumption amount G3 by the ozone consuming component removed water (comparative water) in the ozone contact comparison reaction tank 16 is obtained.

G3 = G1-G2 (28) The ozone consumption amount G3 includes the ozone consumption amount due to self-decomposition of ozone and the dissolved ozone amount dissolved in the ozone consumption component-removed water.

To the calculator 121, the ozone consumption G4 obtained by the calculator 120 and the dissolved ozone concentration CW2 from the dissolved ozone concentration meter 21 are input. Then, the following equation (2
According to 9), ozone consumption DB due to self-decomposition of ozone
Is required. In the embodiment of the present invention, the ozone consumption DB due to the self-decomposition of ozone injected into the ozone consuming component-removed water is calculated.

DB = G3-CW2 (29) The ozone consumption amount DB due to self-decomposition of ozone in the liquid phase obtained by the calculator 121 is input to the calculator 122. The ozone demand amount of the water to be treated, that is, the ozone amount DK consumed by the ozone consuming component in the water to be treated is also input to the calculator 122. More specifically, the dissolved ozone concentration CW1 in the water to be treated after ozone was injected
Is input to the calculator 24, and the dissolved ozone concentration CW2 after the ozone is injected into the ozone consuming component-removed water is input, and the ozone demand amount DK (consumed by the ozone consuming component is calculated according to the above equation (16). Amount of ozone)
Is entered.

The ozone consumption DB due to the self-decomposition of ozone is input to the calculator 122, and the ozone demand amount DK is further input.
By inputting the
According to 0), the required ozone injection amount FG to be injected into the water to be treated which is the object of ozone injection treatment is obtained.

FG = DB + DK (30) As described above, when the amount of ozone injected into the water to be treated which is the object of the ozone injection treatment is obtained, the amount of ozone consumed by the ozone consuming component in the water to be treated is Further, the ozone injection amount FG required for actual ozone injection is obtained by taking into consideration the ozone consumption amount consumed by self-decomposition of ozone in addition to the ozone consumption.

If ozone is injected according to the required ozone injection amount FG, the ozone injection amount will not become too small due to self-decomposition.

(Embodiment 11) FIG. 15 shows another embodiment of the present invention. The necessary ozone injection amount FG obtained by the calculator 122 described in the tenth embodiment is injected into the calculator 124. Further, the supplemental ozone injection amount Tj for maintaining the dissolved ozone concentration (or exhaust ozone concentration) after the ozone injection of the water to be treated which is the object of the ozone injection processing at a predetermined value or more is input to the calculator 124. It Calculator 12
In 4, the ozone injection amount Jk is calculated according to the following equation (31).

Jk = FG + Tj (31) The supplemental ozone injection amount Tj is set in advance in consideration of ozone absorption characteristics and the like.

The ozone injection amount Jk obtained by the calculator 124 is input to the calculator 125. Further, a flow meter 1 for measuring the flow rate F of the water to be treated which is the target of the ozone injection treatment.
The measured value F from 12 is input. In the calculator 125,
The ozone amount Gj based on the ozone injection amount Jk is obtained according to the following equation (32) based on the ozone injection amount Jk and the flow rate F.

Gj = Jk × F (32) The calculator 126 receives the ozone amount Gj and the flow rate F of the water to be treated, which are calculated by the calculator 125. Then, the ozone injection rate Gr to be injected into the water to be treated flowing into the ozone contact reaction tank 78 is obtained according to the following equation (33).

Gr = Gj / F (33) The calculator 127 has an ozone injection rate Gr from the calculator 126.
Is input, and the flow rate F of the water to be treated flowing into the ozone contact reaction tank is also input from the flow meter 112. Then, based on the ozone injection rate Gr and the flow rate F of the water to be treated, the injected ozone amount Hg that becomes a gas is obtained according to the following equation (34).

Hg = Gr × F (34) The injected ozone amount Hg obtained as described above is the controller 83 for controlling the ozone generation amount Gs of the ozonizer 77 next.
The controller 83 controls the ozone generation amount Gs of the ozonizer 77. More specifically, the frequency of the high-frequency inverter 84 is controlled based on the injected ozone amount Hg input to the controller 83, and the ozone generation amount Gs according to the injected ozone Hg is controlled. Then, ozone corresponding to the injected ozone amount Hg is injected from the ozonizer 77 into the water to be treated.

As described above, when ozone is injected into the water to be treated for control, both the required ozone amount of the water to be treated and the ozone consumption amount due to self-decomposition of ozone are added. Become. Therefore, even if ozone is consumed by self-decomposition of ozone, the amount of injected ozone does not become too small, and deterioration of treated water quality can be prevented.

[0211]

According to the present invention, the amount of ozone required to react with the ozone consuming component in the water to be treated can be easily and accurately determined. Further, since the ozone injection amount is controlled on the basis of the ozone amount necessary for reacting with the ozone consuming component upon ozone injection of the water to be treated, it is possible to provide an ozone injection control method with high control accuracy.

[Brief description of drawings]

FIG. 1 is a system flow diagram of an ozone demand amount measuring method showing an embodiment of the present invention.

FIG. 2 is a system flow chart of an ozone demand amount measuring method showing another embodiment of the present invention.

FIG. 3 is a system flow chart of an ozone demand amount measuring method according to another embodiment of the present invention.

FIG. 4 is a system flow chart of an ozone demand amount measuring method showing another embodiment of the present invention.

5 is a partial functional diagram of FIG. 4.

FIG. 6 is a system flow diagram of an ozone required amount measuring method showing another embodiment of the present invention.

FIG. 7 is a system flow diagram of an ozone demand amount measuring method showing another embodiment of the present invention.

FIG. 8 is a water treatment process flow chart of a water purification plant to which the ozone demand measurement method according to one embodiment of the present invention is applied.

FIG. 9 is a partial detailed view of FIG.

FIG. 10 is a water treatment process flow chart of a water purification plant showing another embodiment of the present invention.

FIG. 11 is a partial detailed view of FIG.

FIG. 12 is a system flow diagram of an ozone injection control method showing an embodiment of the present invention.

FIG. 13 is a system flow chart of an ozone injection control method showing another embodiment of the present invention.

FIG. 14 is a system flow chart of an ozone injection control method showing another embodiment of the present invention.

FIG. 15 is a system flow chart of an ozone injection control method showing another embodiment of the present invention.

[Explanation of symbols]

1 ... Ozone contact reaction tank, 2, 77 ... Ozonizer, 5 ... Air pump, 6 ... Ozone concentration meter, 13, 21, 92 ... Dissolved ozone concentration meter, 16, 94 ... Ozone contact comparison reaction tank,
24, 42, 43, 111, 113, 114, 115,
116, 117 ... Arithmetic unit, 30 ... Adsorption tank, 36 ... Dissolved ozone removal tank, 40 ... Comparator, 44, 110 ... Controller, 50
… Ozone-consuming component removal tank, 60… Dissolved ozone treatment tank, 6
6 ... Ozone decomposition processing means, 67 ... Waste ozone decomposition tank, 70
... water landing well, 71 ... chemical mixing pond, 74 ... floc formation pond,
75 ... Settling tank, 78 ... Ozone contact reaction tank, 84 ... High frequency inverter, 85 ... High voltage transformer, 89 ... Blower, 9
0 ... Bioactive carbon tank.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Watanabe 7-1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Minoru Suzuki 1-chome, Kokubun-cho, Hitachi-shi, Ibaraki No. 1 inside the Kokubun Plant of Hitachi, Ltd. (72) Naoto Komatsu 1-1-1 Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Kokubun Plant of Hitachi, Ltd. (72) Naoki Hara Five Omika-cho, Hitachi City, Ibaraki Prefecture 2-2-1, Hitachi Ltd. Omika Plant (72) Inventor Nobuyoshi Yamakoshi 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Omika Plant

Claims (24)

[Claims] 1. A treated water containing an ozone consuming component,
Obtaining the amount of ozone that reacts with the ozone consuming component and the amount of ozone consumed by self-decomposition of ozone in the water to be treated,
A method for calculating a required ozone amount, comprising adding the amount of ozone that reacts with the ozone consuming component and the amount of ozone consumed by self-decomposition to obtain the required amount of ozone for the water to be treated. 2. A method for ozone treatment by bringing ozone-containing gas into contact with water to be treated containing ozone-consuming components, wherein the ozone demand amount of the water to be treated is calculated by the method according to claim 1, and ozone-containing gas is obtained. A method for controlling ozone injection, which comprises controlling the injection amount of ozone. 3. An amount of ozone that reacts with the ozone consuming component in the treated water by injecting ozone into the treated water and the ozone consuming component-removed water after removing the ozone consuming component in the treated water, respectively. And an ozone consumption amount due to self-decomposition of ozone in the ozone consuming component-removed water to obtain an ozone demand amount of the water to be treated. 4. In a method of ozone treatment by bringing ozone-containing gas into contact with water to be treated containing ozone-consuming components, the ozone demand amount of the water to be treated is calculated by the method according to claim 3, and ozone-containing gas is obtained. A method for controlling ozone injection, which comprises controlling the injection amount of ozone. 5. The amount of ozone that reacts with the ozone consuming component in the treated water by injecting ozone into the treated water and the ozone consuming component-removed water after removing the ozone consuming component in the treated water, respectively. And the ozone consumption amount due to the self-decomposition of ozone in the ozone consuming component-removed water, and adding them to obtain the ozone demand amount, and further, the dissolved ozone concentration or the exhaust ozone gas concentration after the ozone injection of the water to be treated. Is added to the required ozone amount to obtain a supplemental ozone injection amount for maintaining the above value above a predetermined value, and an ozone-containing gas is injected into the water to be treated so as to satisfy the ozone injection amount. Control method for ozone injection. 6. Ozone is injected into the water to be treated and the ozone-consuming component-removed water after the ozone-consuming component is removed from the water to be treated, and the ozone-consuming component-removed water after the ozone injection and the ozone-consumable component-removed water after the ozone are injected. Obtain the amount of ozone necessary to react with the ozone consuming component in the treated water from the difference in the dissolved ozone concentration with the water to be treated, further, from the difference in the gas phase ozone concentration before and after the ozone injection into the ozone consuming component removal water The ozone consumption of the ozone consuming component-removed water is determined, and the ozone consumption of the ozone consuming component-removed water due to self-decomposition of ozone is determined from the difference between the ozone consumption and the dissolved ozone concentration. A method for calculating an amount of injected ozone, wherein the amount of injected ozone is determined by adding the amount of ozone required to react with the components and the amount of ozone consumed by self-decomposition of ozone. 7. An ozone treatment method in which ozone-containing gas is brought into contact with water to be treated containing ozone-consuming components.
An ozone treatment method comprising injecting an ozone-containing gas satisfying the ozone injection amount calculated in step 1 into the water to be treated. 8. Ozone is injected into the water to be treated and the ozone-consuming component-removed water after the ozone-consuming component is removed from the water to be treated, and the ozone-consuming component-removed water after the ozone is injected and the ozone-consumed component-removed water. The amount of ozone required to react with the ozone consuming component in the treated water is determined from the difference in the dissolved ozone concentration with the water to be treated, and the dissolved ozone concentration of the removed water is calculated from the amount of ozone injected into the ozone consuming component removed water. And the ozone consumption amount due to the self-decomposition of ozone in the ozone consumption component-removed water is obtained by subtracting the amount of ozone exhausted from the removed water to the gas phase, and it is necessary to react with the ozone consumption component of the treated water. A method for calculating an amount of injected ozone, wherein the amount of injected ozone is determined by adding the amount of ozone and the amount of ozone consumed by self-decomposition of ozone. 9. An ozone treatment method in which an ozone-containing gas is brought into contact with water to be treated containing an ozone-consuming component, and the ozone injection amount is determined by the method according to claim 10, and the ozone-containing gas is injected into the water to be treated. An ozone treatment method characterized by the above. 10. When performing ozone treatment by injecting an ozone-containing gas into water to be treated containing ozone consuming components, the amount of ozone that reacts with ozone consuming components in the water to be treated and the amount of ozone in the water to be treated An ozone treatment method, wherein an ozone injection amount is determined by obtaining an ozone consumption amount due to self-decomposition. 11. Ozone is injected into each of the water to be treated and the ozone-consuming component-removed water after removing the ozone-consuming component from the water-to-be-treated, and the ozone-consuming component-removed water after the ozone injection and the A method for calculating an ozone reaction amount, which comprises obtaining an ozone amount necessary for reacting with an ozone consuming component in the water to be treated from a difference in concentration of dissolved ozone with respect to the water to be treated. 12. The method for calculating an ozone reaction amount according to claim 11, wherein the ozone-consuming component-removed water is produced by injecting ozone into the water to be treated. 13. The ozone reaction amount calculating method according to claim 11, wherein the ozone consuming component-removed water is produced by adsorbing and removing the ozone consuming component in the water to be treated. 14. The method according to claim 11, wherein the ozone consuming component-removed water is produced by injecting ozone into the water to be treated and adsorbing and removing the ozone consuming component in the water to be treated. Ozone reaction amount calculation method. 15. Water to be treated, and ozone-consumed component-removed water after injecting ozone into the water to be treated to remove ozone-consuming components in the water to be treated and after removing dissolved ozone by aeration. Inject ozone into
Calculation of required ozone amount, characterized in that the amount of ozone required to react with the ozone consuming component in the water to be treated is calculated from the difference in dissolved ozone concentration between the water for removing the ozone consuming component after the ozone injection and the water to be treated. Method. 16. Injecting ozone into the water to be treated and the ozone consuming component-removed water after removing the ozone consuming component in the water to be treated, respectively, and then the water to be treated after the ozone injection and the ozone consuming component The amount of ozone required to react with the ozone consuming component in the water to be treated is calculated from the difference in the concentration of dissolved ozone with the removed water, and the amount of ozone is further ozone for making the concentration of dissolved ozone in the water to be treated above a predetermined value. A method for injecting ozone, wherein an amount of ozone is added to the water to be treated. 17. The ozone-consumption-component-removed water after the ozone-consumption component in the water-to-be-treated is removed by injecting ozone into the ozone-contact reaction chamber into which the water-to-be-treated is introduced, Introduced into the dissolved ozone removal tank located at
Further, the ozone-consumed component-removed water from which dissolved ozone has been removed is introduced into an ozone contact comparison reaction tank located on the downstream side of the dissolved ozone-removal tank, and ozone is added to the treated water and the ozone-consumed component-removed water, respectively. And the ozone amount required to react with the ozone consuming component in the treated water from the difference in the dissolved ozone concentration between the treated water and the ozone consuming component-removed water after the ozone injection. Quantity calculation method. 18. An ozone contact reaction tank into which water to be treated is introduced, and an ozone consuming component removal tank in which the water to be treated is introduced to remove ozone consuming components in the water to be treated are provided. Dissolved ozone concentration of the water to be treated and the ozone-consuming component-removed water after the ozone injection by injecting ozone into the ozone-consuming component-removed water from which the ozone-consuming component has been removed in the component removing tank and the treated water. A method for calculating a required ozone amount, which comprises obtaining the amount of ozone required to react with an ozone consuming component in the water to be treated from the difference. 19. The ozone reaction amount according to claim 11, wherein the exhaust ozone gas discharged from the water to be treated and the ozone consuming component-removed water to the gas phase is discharged to the outside of the system through the ozone decomposition treatment means. Calculation method. 20. Dissolved ozone in the water to be treated and the ozone consuming component-removed water after injecting ozone into the water to be treated and the ozone consuming component-removed water is released from a liquid phase to a gas phase, A method for calculating an ozone reaction amount, characterized in that the ozone released to the gas phase is discharged to the outside of the system through an ozone decomposition treatment means. 21. An ozone contact reaction tank into which water to be treated is introduced, an ozonizer for injecting ozone into the ozone contact reaction tank, and a dissolved ozone concentration meter for measuring the dissolved ozone concentration after ozone injection into the water to be treated. Further, the biological activated carbon tank, which is provided downstream of the ozone contact reaction tank and into which the treated water after the ozone injection is introduced, and the treated water from the biological activated carbon tank are sampled, and ozone to the sampling water is sampled. In an ozone treatment characterized by comprising a dissolved ozone concentration meter for measuring the dissolved ozone concentration after injection, determining the amount of ozone necessary to react with the ozone consuming component in the water to be treated from the difference of each dissolved ozone concentration Ozone demand calculation method. 22. An ozone contact reaction tank into which water to be treated is introduced, an ozonizer for injecting ozone into the ozone contact reaction tank, and treated water after the ozone injection is disposed downstream of the ozone contact reaction tank. Equipped with a biological activated carbon tank to be introduced,
Injecting ozone into the treated water from the biological activated carbon tank and the treated water, and reacting with ozone consuming components in the treated water from the difference in dissolved ozone concentration between the treated water and the treated water after the ozone injection A method for calculating an ozone reaction amount, characterized in that the ozone amount required to do so is obtained. 23. When performing ozone treatment by injecting an ozone-containing gas into water to be treated containing ozone consuming components, according to the amount of ozone calculated in claim 11, the ozone contact reaction tank into which the water to be treated is introduced An ozone injection control method comprising controlling an ozone injection amount. 24. An ozone contact reaction tank into which treated water is introduced, and a biological activated carbon tank into which treated water from this ozone contact reaction tank is introduced, further comprising the treated water and ozone consumption in the treated water. Means for injecting ozone into the ozone-consuming component-removed water after the components are removed, and ozone in the treated water from the difference in dissolved ozone concentration between the ozone-consuming component-removed water after the ozone injection and the treated water An ozone treatment apparatus comprising: means for determining an amount of ozone required to react with a consumption component.