JPS61291097A - Ozone treatment apparatus - Google Patents

Abstract

PURPOSE:To efficiently remove an ozone reactive substance within a short time, by enhancing the concn. of dissolved ozone of a water to be treated by providing a pressure adjusting means to the piping of a reaction tank and an exhaust ozone treatment part. CONSTITUTION:A pressure control valve 8 is provided on the way of the piping reaching an ozone decomposition furnace 9 from a reaction tank 6 so as to be present outside the reaction tank 6. A part of the piping communicating the reaction tank and the ozone decomposition furnace 9 is formed of a pipe of which the flow passage cross-sectional area is small to increase pressure loss and the pressure in the reaction tank 6 is enhanced and the dissolved ozone of water to be treated comes to high concn. to perform gas-liquid contact. By this method, strong oxidizing force possessed by ozone can be sufficiently developed and high treatment efficiency can be obtained within a short time.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention utilizes the powerful oxidizing effect of ozone.

This invention relates to ozone treatment equipment that sterilizes, deodorizes, and oxidizes organic substances in water.

[Prior art and its problems]

Taking advantage of the fact that ozone has the second strongest oxidizing power after fluorine, water treatment is widely used to perform sterilization, deodorization, decolorization, and oxidation removal of organic and inorganic substances by diffusing ozone into water. .

The following ozone treatment apparatuses are known, for example, for causing a reaction between such ozone and water to be treated by ozone (hereinafter referred to as water to be treated). In other words, there is an ejector method in which ozone is blown into the reaction tank using an ejector, or a bubble column method in which ozone is blown out as bubbles from the bottom of the reaction tank.In both cases, ozone is dissolved in the water to be treated, and ozone such as organic substances in the water to be treated is removed. This is a device that reacts with the reactant and discharges it without dissolving into the water to be treated.

FIG. 3 shows an overview of the configuration of an apparatus for batchwise ozonation of water to be treated using a bubble column method, as well as a conceptual diagram for explaining the l-co effect. In Fig. 3, the ozone treatment device includes a blower pump 1. Dehumidifier 2. Ozone regeneration unit equipped with ozonizer 3, liquid feeding pump 4. A treated water supply section equipped with a check valve 5.

Reaction tank 6 with a diffuser plate 7. It consists of an ozone decomposition furnace 9 and a liquid discharge valve 10, which form a gas and liquid flow path through piping. Ozone treatment in this device is performed as follows. First, a certain amount of water to be treated is sent into the reaction tank 6 using the liquid sending pump 4. Next, ozone was aerated into the water to be treated in the reaction tank 6, and the ozone raw material was sent to the dehumidifier 2 by the blower pump 1 using air to remove moisture in the air that would cause a decrease in ozone generation efficiency. After that, ozonized air is passed through the ozonizer 3, and further this ozonized air is sent to the aeration pipe 7 provided at the lower part of the reaction tank 6, and the aeration is diffused from the aeration pipe 7 into the water to be treated. The water to be treated comes into contact and both react.

At this time, ozone that is not dissolved in the water to be treated reaches the ozone decomposition furnace 91 from above the reaction tank 6, where it is decomposed into oxygen and then released into the atmosphere. Note that air is normally used as the raw material for ozone, but when it is desired to obtain ozone at a higher concentration, oxygen may be used instead of air. Further, in FIG. 3, the direction of flow of the oil body is shown by solid line arrows, and the direction of flow of air is shown by dotted line arrows. After the ozone and the water to be treated are brought into gas-liquid contact for a predetermined period of time, the liquid discharge valve 10 can be opened to take out the treated water from the bottom of the reaction tank 6.

Next, we will discuss the problems in this water treatment process. The rate at which the ozone-reactive substances in the water to be treated are removed varies depending on the concentration of ozone dissolved in the water to be treated, and the higher the dissolved ozone concentration, the faster the removal rate of the ozone-reactive substances. On the other hand, even if the pressure in the reaction tank 6 of the ozone treatment equipment is higher than atmospheric pressure by the pressure loss due to the pyrolysis furnace 9 for exhaust ozone treatment and the piping leading to it, this pressure loss is insignificant. It is almost equal to atmospheric pressure. The concentration of ozone dissolved in the water to be treated is the same as when a normal gas is dissolved in a liquid, and is proportional to the partial pressure of ozone. Therefore, the dissolved ozone magnetism in the reaction tank 6 is It is proportional to the ozone concentration sent in from the generator.

However, the concentration of ozone that can be generated by a normal ozonizer is very dilute, about 1.0 mg/l, even when oxygen is used as a raw material. In actual water treatment, using oxygen as a raw material poses problems in terms of transportation, storage, etc., so air is often used as the raw material for ozone generation. Generally, the ozone concentration of the gas obtained from an ozonizer is approximately proportional to the square root of the oxygen concentration of the raw material, so when air is used as the raw material, the ozone concentration is only about half that when oxygen is used as the raw material. When the ozone concentration of the ozonized air generated from the ozonizer 3 is low, the ozone concentration dissolved in the water to be treated in the reaction tank 6 is also low, and therefore the speed at which ozone reactants in the water to be treated is removed is slow, and the treatment time is reduced. There is a problem that the process takes a long time and is inefficient, and as a result, it cannot be said that ozone's strong oxidizing ability is fully utilized.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to eliminate ozone-reactive substances in the water to be treated even if the concentration of ozone in the ozonized air or oxygen diffused into the water to be treated is low. An object of the present invention is to provide an ozone treatment device that can remove ozone efficiently in a short time.

[Key points of the invention]

The present invention makes it possible to maintain the pressure inside the reaction tank above atmospheric pressure by providing a pressure adjustment means in the piping that communicates with the reaction tank of the ozone treatment equipment and the ozone treatment section, and to prevent the dissolution of the water to be treated. This is designed to increase the ozone concentration.

[Embodiments of the invention] The present invention will be explained below based on examples.

FIG. 1 is a conceptual diagram showing the structure and treatment system of a water treatment apparatus according to the present invention, and parts common to those in FIG. 3 are given the same reference numerals. The difference between Figure 1 and Figure 3 is the reaction tank 6.
A pressure regulating valve 8 is provided outside the reaction tank 6 in the middle of the piping from the ozone decomposition furnace 9 to the ozone decomposition furnace 9. Since the operation of this apparatus for ozone treatment is basically the same as that shown in FIG. 3, the explanation will be omitted and only the main points will be described. In Figure 1, reaction tank 6
The ozone that is not dissolved in the water to be treated is removed from the pressure regulating valve 8.
The ozone gas passes through the ozone decomposition furnace 9 and is decomposed into rV. The pressure regulating valve 8 serves to maintain the pressure inside the reaction tank 6 at a set pressure higher than atmospheric pressure and to increase the dissolved ozone concentration in the water to be treated, and a spring-type safety valve is suitable, for example.

In the present invention, instead of the pressure regulating valve 8, other pressure regulating means are used, for example, a part of the piping communicating with the reaction tank 6 and the ozone decomposition furnace 9 is made into a pipe with a small flow passage cross-sectional area to increase the pressure loss. Alternatively, a method may be used in which the pressure inside the reaction tank 6 is increased by increasing the pressure in the reaction tank 6. Accordingly, in the present invention, the pressure within the reaction tank 6 can be maintained at a level higher than atmospheric pressure by such a pressure regulating means, so that dissolved ozone in the water to be treated becomes uniform and gas-liquid contact is performed. From the above, when ozone treatment is performed using the apparatus of the present invention, the ozone treatment time is shortened.

Next, experimental results using the apparatus of the present invention will be explained as to how the processing time for the ozone reactant in the rose-treated water is shortened by increasing the pressure inside the reaction tank 6.

For the water to be treated, a standard solution of 3Q mg/IJ of ammonium ions (NH4+) adjusted to have a pH of about 12 was used as nitrogen. Mv is nitrate ion (NO,
-), but since this reaction progresses faster as the pH is higher, the pH was adjusted to about 12 and the water to be treated was used. Pour 300 ml of this treated water into reaction tank 6,
After changing the pressure inside the reaction tank 6 by adjusting the pressure regulating valve 8 and starting the aeration of ozone into the water to be treated,
The treated water was sampled every 10 minutes to measure the decrease in NH4+. In this experiment, acid accumulation was used as the raw material for ozone, and the voltage of the ozonizer 3 was kept constant. Ozone acidity is 23 mg/l (atmospheric pressure standard)9 ventilation rate is o, 41 (
(atmospheric pressure standard) 10. The experimental results are shown in Figure 2.

Figure 2 shows the pressure inside the reaction tank at 0.65 gauge pressure.
This is a diagram showing the relationship between the ozone ventilation time and the N1° C. residual rate when the pressure is 7 crt and 1.90 KP/d, and for comparison, the case where the pressure inside the reaction tank is atmospheric pressure is also shown. In Fig. 2, curve A is 0.654/d, and one curve is 1.90 Kv/c' *Curve C represents the state of atmospheric pressure. As you can see by comparing the three curves in Figure 2, this is a curved helix that keeps the inside of the reaction tank under pressure.

In the case of the mouth, the residual rate of Mv decreases rapidly, and in the case of the tube under atmospheric pressure, even if ozone is aerated for 60 minutes, 42"lo of MI4+ still remains in the water to be treated, whereas only a small amount of MI4+ remains in the water to be treated. By applying pressure to 65Y4/7, Nu,+ is almost completely oxidized to N0j-.

Furthermore, when the pressure is maintained at 1.90 Kp/cd, the oxidation rate of NH4+ becomes even steeper as shown in the curved line.

From the above, by keeping the reaction chamber under pressure and increasing the dissolved ozone concentration in the water to be treated, the strong oxidizing power of ozone can be fully utilized, resulting in extremely high treatment efficiency in a short period of time. is obtained.

In addition, the present invention can obtain the same effect even if an activated carbon adsorption tower is used instead of a pyrolysis furnace in the exhaust ozone treatment section, and the same effect can be obtained by providing a pressure adjustment means. It is possible to produce the same effect by using a continuous type device consisting of a level meter, a flow rate regulating valve, etc., and providing pressure regulating means.

In addition, the pressure regulating means for increasing the dissolved ozone concentration according to the present invention only needs to be provided in the piping between the reaction tank and the exhaust ozone treatment section, which has a sealed structure against harmful ozone.
The scale of the ozonizer is such that it can be attached to a Dutch school without any special considerations, and that the ozonizer can be treated at the level of ozone treatment at atmospheric pressure using the device invented by the believer. It also has the advantage that it can be made smaller.

〔Effect of the invention〕

Fiffi, a water treatment system that uses ozone, has a low ozone concentration in the gas generated from conventional ozonizers, so when aeration is diffused into the water to be treated in the reaction tank at atmospheric pressure, the concentration of dissolved ozone in the water to be treated is also low. Therefore, there was a problem that the rate of oxidation and removal of the ozone reactant was slow and the treatment efficiency was poor.In contrast, in the present invention, as explained in the embodiment, pressure is applied to the piping between the reaction tank and the square ozone treatment section. By providing adjustment means, the pressure inside the reaction tank could be maintained above atmospheric pressure, lowering the curable ozone concentration in the treated water, making it impossible to fully utilize the strong oxidizing power of ozone. However, extremely high ozone treatment efficiency cannot be obtained in a short period of time.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing the device configuration and processing system of the present invention.
Figure 2 is a diagram showing the relationship between the ozone ventilation time and the N■V residual rate in ozone treatment using this apparatus, and Figure 3 is a conceptual diagram showing the configuration and treatment system of the conventional apparatus. 1...Blower pump, 2...Dehumidifier, 3...Ozonizer-14...Liquid feed pump, 5...Check valve, 6...
・Reaction tank, 7...Scatter plate, 8...Pressure adjustment valve, 9.
Ozone splitting furnace, (if)

Claims (1)

[Claims] 1) A reaction tank having a diffuser plate and containing a certain amount of water to be treated, an ozone generation section having an ozonizer that generates ozone to be injected into the reaction tank, and an injection of water to be treated to be sent to the reaction tank. It is characterized by being equipped with a sending section, an exhaust ozone treatment section that detoxifies unreacted ozone in the reaction tank and releases it to the outside, and a pressure adjustment means provided in a part of the piping that communicates with the reaction tank and the exhaust ozone treatment section. ozone treatment equipment. 2) An ozone treatment apparatus according to claim 1, wherein the pressure regulating means uses a spring-type safety valve. 3) An ozone treatment apparatus according to claim 1, wherein the pressure regulating means uses a pipe having a smaller cross-sectional area than the pipe.