JP2005144352A - High-speed ozone catalytic reaction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ozone catalytic reaction apparatus of a small size, with a high reaction efficiency, and easy in maintenance. <P>SOLUTION: This ozone catalytic reaction apparatus is provided with an ejector 1 disposed in midway of a water pipe of water to be treated and having a mechanism of sucking ozone-containing gas 3 and injecting it into the water 2 to be treated; and a mixer 5 having elements 4 of an inorganic material carrying a metal oxide catalyst 6 disposed or filled in a pipe of a rear stage of the ejector 1. The mixer 5 is provided with an electromotive means for rotating or vibrating the elements 4. The element 4 is provided with at least one of blade-like, three dimensional mesh-like, spiral-like, ring-like, particulate or pellet-like shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to organic substances, dioxins, or environmental hormones that cause coloring or odor contained in water and sewage, human waste, industrial wastewater, agricultural and livestock wastewater, river water, lake water, waste landfill leachate, etc. The present invention relates to an ozone contact reaction apparatus useful as a treatment method for removing harmful organic substances such as those with high efficiency.

Oxidation decomposition treatment using ozone is performed for the treatment of organic components that cause pollution load in the treated raw water. Generally, treatment is performed by blowing ozone-containing gas into the water to be treated.
In addition, as an effective removal treatment method for persistent organic substances such as environmental hormone substances including dioxins contained in industrial wastewater and landfill leachate, promotion of combined use of ozone and catalyst, ultraviolet rays or hydrogen peroxide Oxidation treatment is becoming widespread. This uses an active radical species having a stronger oxidizing power than ozone, and a hydroxyl radical is a typical radical species.
MnO ₂ is often used as the metal oxidation catalyst, and as an example, raw material water is supplied from above while the ozone-containing gas is diffused from below the MnO ₂ supported ceramic packed bed fixed inside the reaction tower. Then, it is passed through the MnO ₂ -supported ceramic packed layer and contacted and reacted with ozone. Thereafter, an apparatus has been proposed in which treated water is taken out from the bottom of the reaction tower (see, for example, Patent Document 1).
In addition, in order to eliminate the clogging of the catalyst while making the surface area in contact with the ozone-containing gas and the water to be treated as large as possible, there are some ideas such as processing the shape of the MnO ₂ supported ceramic packed layer into a comb-like shape or a lotus root Some have been made (see, for example, Patent Document 2).
It is known that hydroxy radicals are generated in the process of ozone decomposing at the time of contact with a metal oxidation catalyst, and the amount of hydroxy radicals generated is higher as the ozone concentration in water is higher. For this reason, raising the ozone concentration in water has become an important issue in performing accelerated oxidation treatment.
Japanese Patent Laid-Open No. 9-253672 JP 2001-29787 A

However, the conventional treatment method in which the conventional ozone-containing gas is diffused into the reaction tower and brought into contact with the water to be treated in the MnO ₂ -supported ceramic packed bed has the following problems.
Such a reaction tower secures a contact time by taking a water depth of about 4 to 6 m in order to efficiently dissolve ozone in water, and the ozone reaction time is usually set to 10 minutes or more. Furthermore, since a space for fixing the MnO ₂ -supporting ceramic packed layer is required, the structure is often a large structure.
Further, in such a reaction tower, since it takes a relatively long time to dissolve ozone, it is difficult to obtain a high ozone concentration in water when contacting the catalyst due to the influence of ozone consumption and attenuation due to self-decomposition. For this reason, the production | generation efficiency of a hydroxyl radical is not necessarily favorable, and high reaction efficiency is not obtained. From such a situation, there is a problem that a large amount of ozone must be added in order to increase the ozone concentration in water and the ability to generate hydroxy radicals when contacting the catalyst and to improve the treatment efficiency.
Further, when the catalyst is deteriorated or worn out, it is necessary to open the reaction tower and replace the entire catalyst packed bed with a new one. Therefore, there are concerns about maintenance problems such as cost and workability required for replacement.
Accordingly, an object of the present invention is to provide an ozone contact reaction apparatus that is small in size, has high reaction efficiency, and is easy to maintain.

In order to solve the above problems, the present invention is configured as follows.
The high-speed ozone contact reaction apparatus according to claim 1 includes an ejector having a mechanism for sucking and injecting an ozone-containing gas into the water to be treated, disposed in the middle of the water pipe to be treated, It comprises a mixer formed by arranging or filling elements made of an inorganic material carrying a metal oxide catalyst.
The high-speed ozone contact reaction apparatus according to claim 2 rotates or vibrates the element by electric means.
The high-speed ozone contact reaction apparatus according to claim 3, wherein the shape of the element is any one of a wing shape, a three-dimensional network shape, a spiral shape, a ring shape, a granular shape, and a pellet shape. They are arranged or filled in the same size or a combination of sizes.
The high-speed ozone contact reaction apparatus according to claim 4 forms the surface state of the element in a porous or rough surface.

According to the first aspect of the present invention, the ejector provided in the middle part of the water pipe and the mixer in which the elements made of the inorganic material carrying the metal oxide catalyst are arranged or filled in the subsequent pipe are provided. As with normal piping, it does not take up space and is compact and at the same time has a uniform extrusion flow with no stagnation. Further, the mixing and stirring efficiency of ozone and water to be treated is improved by the mixer, so that the reaction efficiency is further improved and the entire apparatus can be greatly reduced in size. Further, at the time of maintenance, it is possible to remove only the mixer portion from the pipe and replace it with a new one, so that the replacement work becomes easy.
According to the second aspect of the present invention, since the element is rotated or vibrated by the electric means, the sheared or stirred ozone-containing gas becomes fine bubbles, the contact area is increased, and the reaction efficiency is further improved.
According to the invention described in claim 3, since the shape of the element is specified, the optimum mixing / stirring structure can be selected according to the required flow rate of water to be treated, water quality, etc., and the reaction efficiency can be improved. can do.
According to the invention described in claim 4, since the surface of the element is made porous or rough, it is possible to prevent the metal oxide catalyst from being reduced from the inorganic base material of the element due to wear, peeling, etc., and the contact area. This also leads to improved reaction efficiency.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view of a high-speed ozone contact reaction apparatus showing Example 1 of the present invention. In the figure, 1 is an ejector, 2 is water to be treated, 3 is an ozone-containing gas, 4 is a mixer, and 5 is treated water. This ozone contact reaction apparatus is provided as a part of piping in the middle part of the mixer 4 through the water pipe. The structure of the mixer 4 includes a wing-like element 41 and a tube body 42 as shown in FIG. 2A is a front sectional view taken along line AA ′ in FIG. 1, and FIG. 2B is a side sectional view. As shown in the enlarged cross section of FIG. 3, the element 41 includes a base material 41a made of an inorganic material such as ceramics and a catalyst 41b supported on the surface thereof. The catalyst 41b is provided with a metal oxide of MnO ₂ by firing or vapor deposition.

Next, the operation will be described.
When the water to be treated 2 containing harmful organic substances is introduced into the ejector 1, the ozone-containing gas 3 is sucked into the interior and mixed with the water to be treated 2. At this stage, ozone water having a concentration almost reaching vapor-liquid equilibrium is obtained. Note that an optimum amount of ozone can be set according to the water quality of the object to be removed such as COD and chromaticity.
The gas-liquid mixed fluid is delivered into the mixer 4 after passing through the ejector 1. Here, the water to be treated 2 is efficiently mixed, stirred or sheared with the gas-liquid mixed fluid by the element 41 formed in a wing shape. The hydroxyl radical is expressed by the contact between the ozone water and the metal oxide catalyst 41b on the surface of the element 41, and contributes to the decomposition reaction of the organic matter. In addition, the catalyst 41b continuously removes harmful organic substances by a reaction mechanism in which a reduction reaction with organic substances and a regeneration reaction with ozone are repeated. The purified treated water 7 is subjected to gas-liquid separation, exhaust gas treatment, and the like at a later stage, and then used as various kinds of discharged water or recycled water.
According to the present embodiment, the following effects can be obtained.
The ejector can be installed as a part of the water pipe, and since ozone is injected from the middle of the pipe and instantly dissolves in the treated water, it is affected by ozone consumption and ozone concentration attenuation due to self-decomposition. It is difficult to produce high-concentration ozone water. Also, the mixer disposed immediately after that can be disposed in-line like the ejector, and has a compact structure.
In addition to the effect of increasing ozone contact efficiency by dispersing the gas of the original line mixer into fine bubbles to increase the contact interface area, it dissolves in the water to be treated and water on the metal oxidation catalyst surface of the element. Hydroxy radicals are generated by contact with the ozone, and the reaction is strongly promoted.
As a result, not only the catalytic reaction apparatus becomes compact, but also the amount of ozone added can be reduced, and the cost can be reduced as the whole apparatus is downsized.
Further, a plurality of mixers provided with arbitrary elements can be connected in accordance with the degree of contamination of the water to be treated, the treatment conditions, and the scale of treatment. Furthermore, since it is possible to easily provide a switching valve to branch in a plurality of directions, it is possible to easily replace the catalyst and the mixer without stopping them even when the catalyst or the mixer is deteriorated or worn out.
Furthermore, if the shape of the element is configured so as to increase the contact area with the residual ozone gas, the residual ozone gas is also brought into contact with the metal catalyst to be reduced in concentration, so that the ozone in the exhaust gas can be easily decomposed.
Note that the object to be treated is not limited to liquids such as water, but the same treatment can be performed on a contaminated gas or a fluid obtained by mixing a contaminated gas and water vapor.
In this embodiment, a wing-shaped element 41 is used as the element 41, but a three-dimensional mesh-shaped element as shown in FIG. 4 may be used. Further, the metal oxide of the catalyst 41b is not limited to manganese, but at least selected from titanium, iron, cobalt, nickel, cerium, tungsten, copper, silver, gold, platinum, palladium, rhodium, ruthenium and iridium. You may choose one.

5A and 5B are schematic views of a high-speed ozone catalytic reactor showing Example 2 of the present invention, where FIG. 5A is a side sectional view and FIG. 5B is a front sectional view taken along line BB ′. In the figure, 6 is an electric motor and 7 is a rotating shaft. Description of the same parts as those in the first embodiment is omitted. The difference from the first embodiment is that a wing-like element 41 is attached to the rotating shaft 7 of the electric motor 6 so as to rotate at high speed.
The operation of this embodiment is the same as that of Embodiment 1, but by rotating the element 41 at a high speed of 500 rpm or more, the mixing / stirring efficiency of the water to be treated 2 and ozone is improved, and the reaction efficiency is further improved. Is possible. Further, the mixing / stirring / shearing performance of the combination of the ejector 1 and the mixer 4 in Example 1 depends on the flow rate of water, but even when the flow rate for sufficiently satisfying these performances cannot be secured due to a decrease in the amount of water. Stable performance can be obtained. Other effects of the present embodiment are the same as those of the first embodiment.

FIG. 6 is a side cross-sectional view of a high-speed ozone catalytic reactor showing Example 3 of the present invention.
In the present embodiment, the shape of the element 41 is the same as that of the first embodiment, but the diameter of the tube body 42 is larger than the diameter of the ejector 1. The outer diameter of the element 41 of the first embodiment may be simply increased according to the quality of the water to be treated, the shape or characteristics of the element, or elements having different shapes may be combined. This has the effect of further increasing the efficiency of the ozone treatment. Other effects of the present embodiment are the same as those of the first embodiment.
In this embodiment, the wing-shaped element and the three-dimensional mesh-shaped element are used as the element. However, the element is not limited to this, and elements such as a spiral shape, a ring shape, a granular shape, and a pellet shape may be used alone or in combination. Also good.

  The high-speed ozone contact reaction apparatus of the present invention can perform the same treatment not only on a liquid such as water as an object to be treated but also on a contaminated gas or a fluid in which a contaminated gas and water vapor are mixed.

It is a sectional side view of the high-speed ozone contact reaction apparatus which shows Example 1 of this invention. It is an enlarged view of the mixer of FIG. 1, (a) is a front sectional view in FIG. 1A-A 'line, (b) is a side sectional view. It is an expanded sectional view of the element of FIG. It is an enlarged view of the other mixer of FIG. 1, (a) is a front sectional view in the BB 'line of FIG. 1, (b) is a sectional side view. It is the schematic of the high-speed ozone contact reaction apparatus which shows Example 2 of this invention, (a) is a sectional side view, (b) is a front sectional view in the B-B 'line. It is a sectional side view of the high-speed ozone contact reaction apparatus which shows Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ejector 2 Water to be treated 3 Ozone-containing gas 4 Mixer 41 Element 41a Base material (ceramics)
41b Catalyst (metal oxide)
42 Tube 5 Treated water 6 Electric motor 7 Rotating shaft

Claims (4)

  An ejector having a mechanism for sucking and injecting an ozone-containing gas into the water to be treated, disposed in the middle of the water pipe of the water to be treated, and an inorganic material carrying a metal oxide catalyst in the tube at the subsequent stage A high-speed ozone contact reaction apparatus comprising a mixer in which elements are arranged or packed.   The high-speed ozone contact reaction apparatus according to claim 1, wherein the mixer includes electric means for rotating or vibrating the element.   3. The high-speed ozone contact reaction according to claim 1, wherein the element has at least one of a wing shape, a three-dimensional network shape, a spiral shape, a ring shape, a granular shape, and a pellet shape. apparatus.   The high-speed ozone contact reaction apparatus according to any one of claims 1 to 3, wherein the element has a surface state formed in a porous or rough surface.

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