JP2000167543A - Device and process for decomposition of underwater trace hazardous organic compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decomposition technology for an organic hazardous matter contained as a trace underwater. SOLUTION: A raw water containing a hazardous organic compound is picked, and the picked raw water is introduced into a high pressure pump 11 and pressurized therein, and the pressurized raw water is introduced into a nozzle 9 provided on an inlet of a reactor 22 and jetted with high pressure into the interior of the reactor, and the hazardous organic compound is decomposed by the action of the cavitation of underwater jet flows 10 in the reactor and turned to be harmless. Water to be treated drained from the reactor is circulated in the picked raw water, and the interior of the reactor is jetted repeatedly by the underwater jet flows thus formed. Gas is formed into the very fine foam shapes 30 by the aeration and blown into the picked raw water, and foam cores of the cavitation are introduced forcibly into the raw water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet technology used in water, and more particularly to a technology for decomposing organic harmful substances contained in a trace amount of water.

[0002]

2. Description of the Related Art The water environment surrounding daily life is threatened by contamination with organochlorine compounds. One is the problem of dioxins. Dioxin is concentrated in the incineration ash discharged from the refuse incinerator. If the incineration ash is not properly managed, dioxin is eluted from the ash by rainwater and seeps into the soil to follow the path of groundwater, or to flow down the surface of the ground, and to run into small and medium-sized rivers, ponds or It is flowing into the swamp.

[0003] In many cases, the disposal process of industrial waste is not thoroughly controlled as an environmental measure. Harmful components eluted from the ashes of the open fire may flow into the pond for agricultural use. The problem is that the water in agricultural ponds is used for paddy fields and upland fields, and enters the body of organisms in a chain.

In so-called "high-tech" factories handling semiconductor electronic components, jet engines, and the like, the outflow of chemicals such as trichloroethane used for cleaning is also a problem. In addition, endocrine disorders (so-called environmental hormones) also pollute the waters, although they have spread considerably in the living environment. In rivers in metropolitan areas, there is a problem that nonylphenol and the like are detected at a high concentration, and the problem may be more serious than dioxin.

[0005] With respect to such water-based pollution, regulations on the sources of the pollution have been strengthened. For example, in state-of-the-art refuse incinerators, thorough control of catalyst bag filters and combustion gas / exhaust gas temperatures is performed. However, existing aging furnaces, small and medium-sized furnaces, etc. are considered to be inadequate in terms of cost and water pollution is continuing.

Various methods have been proposed for such pollution of the water environment, but a method which is currently decisively effective is a method for treating harmful substances diffused at a low concentration in a wide area of water. It seems that there is no situation.

Although harmful substances can be decomposed by a supercritical fluid method, an ultrasonic method, or a method using a catalyst, they are not suitable for treating a large amount of contaminated water. Certain drug-based methods have the potential for cross-contamination.

When cavitation is used, harmful substances can be decomposed by an oxidizing action and a thermal decomposition action in a high-temperature and high-pressure field generated when the bubbles burst, but the present invention is a technique utilizing this cavitation. The problem in the prior art of using cavitation will be described.

[0009]

FIG. 11 and FIG. 12 show a conventional ultrasonic method. It is possible to decompose or break harmful substances by cavitation generated by the ultrasonic method. It is possible. Here, 1 is a reaction vessel, 2 is a processing liquid supply, 3 is a processing liquid discharge,
4 represents an ultrasonic vibration device, 5 represents cavitation, 6 represents ultrasonic vibration, and 7 represents a horn-type vibration member. However, since the generation region of the cavitation 5 is limited to the vicinity of the vibrating member, in other words, these ultrasonic methods are methods for concentrating energy at a high density and locally,
Not suitable for treating large quantities of pollutants. The cavitation 5 generated at the tip of the vibrator has no function of stirring or mixing the surrounding liquid. In order to cause the contaminated water to flow through the reaction section by the cavitation 5, a pump for supplying the processing liquid 2 is required.

[0010]

In order to solve the above problems, the present invention mainly employs the following configuration.

[0011] Raw water containing harmful organic compounds is collected, the collected raw water is fed to a high-pressure pump to be pressurized, the pressurized raw water is fed to a nozzle, and jetted from the nozzle into the raw water at high pressure, A device for decomposing trace amounts of harmful organic compounds in water that decomposes and detoxifies harmful organic compounds by the action of cavitation in underwater water jets.

Further, raw water containing harmful organic compounds is collected, the collected raw water is fed to a high-pressure pump to be pressurized, and the pressurized raw water is fed to a nozzle provided at an inlet of a reactor. A device for decomposing trace amounts of harmful organic compounds in water that injects raw water into the reactor at a high pressure and decomposes and detoxifies harmful organic compounds by the action of cavitation of a water jet in the reactor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus and a method for decomposing trace harmful organic compounds in water according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 13 is an embodiment of the present invention and shows an entire system of a decomposition processing apparatus by a method of blowing a high-speed jet of raw water into contaminated raw water. Here, 8 is a purification target area, 9 is a nozzle, 10 is a submerged water jet with cavitation, 11 is a plunger pump, 1
2 denotes a high-pressure hose, 13 denotes a pumping line, 14 denotes a circulation pump, 15 denotes a water storage tank, 16 denotes high-pressure water, 20 denotes a three-way switching valve, and 21 denotes a return line. The nozzle 9 is submerged in the contaminated water area 8 to be purified, and the underwater water jet 10 with cavitation is jetted into the contaminated water area 8 to be purified. In order to treat pollution in a wide area of water by this method, it is necessary to move the nozzle 9 or the sampling position over a wide range.

FIG. 1 shows another embodiment of the present invention, which shows an overall system of a device for decomposing trace amounts of harmful organic compounds in water. Here, reference numeral 22 denotes a tubular reactor, 23 denotes a return line, 24 denotes a valve, and 25 denotes a foreign matter removal filter, and other components are common to those in FIG. Raw water is pumped up from a water body 8 to be purified, which is contaminated with harmful organic compounds, by a circulation pump, and the water is stored in a water storage tank 15.
to go into. In order to prevent foreign matter from entering, a foreign matter removing filter 25 is interposed in front of the circulation pump.

The raw water in the water storage tank 15 enters the plunger pump 11 and is pressurized to a predetermined pressure, which will be described later.
6 and is blown into the inside of the tubular reactor 22 from the nozzle 9 attached to the upstream end of the tubular reactor 22 through the high-pressure hose 12. The raw water containing harmful substances blows out from the nozzle 9 to form a high-speed jet, but the inside of the tubular reactor 22
Because of the fullness of the treated water, this high velocity jet becomes an underwater jet 10 with severe cavitation.

The harmful substances are decomposed by the action of the severe cavitation. The water treated by the water jet method in this manner is returned to the purification target water area 8 so as to overflow from the tubular reactor 22. When returning to the water area to be purified, the water may be forcibly fed by a pump. In this embodiment, the throughput is about 20 × 10 ³
In the case of kg / day, the inner diameter of the tubular reactor 22 is 160 mm and its length is 1.5 × 10 ³ mm.

FIG. 2 also shows the overall system of still another embodiment of the present invention. Basically, it is the same as the embodiment of FIG. 1, but the raw water in the middle of the process that overflows from the tubular reactor 22 is once stored in the water storage tank 26 through the return line 23, and the raw water is fed to the raw water feed tank by the circulation pump 27. This is a method of returning to a certain water storage tank 15. In short, this embodiment is a so-called circulation system in which raw water is repeatedly passed through the tubular reactor 22 and repeatedly subjected to severe cavitation to increase the decomposition rate. This method is suitable for decomposition treatment of relatively hardly decomposable substances.

FIG. 3 shows an embodiment in which a submerged water jet 10 with cavitation is caused to collide with a target which is a collision plate in a tubular reactor 22. The target 31 is supported by a control rod 32 from the rear end of the tubular reactor 22. The control rod 32 is also used for positioning the target 31. As described above, when the jet 10 collides with the target 31, the impact of the collision triggers the immature nuclei that are innumerable floating in the water in a countless manner, cavitation is promoted, and the decomposition of harmful substances proceeds.

When the impact pressure is measured in the axial direction of the submerged water jet 10 with cavitation, a distribution having two peaks appears as shown in the lower part of FIG.
FIG. 3 shows an example in which the target 31 is installed at a position corresponding to the “first peak” close to the nozzle. Xs represents the standoff distance. When the collision occurs at the first peak in this way,
Although the power of the collision is severe and cavitation is remarkably promoted, the target 31 is likely to be eroded and dug, so it is necessary to treat the target 31 as a consumable and replace it before performance degradation occurs.

FIG. 4 shows an embodiment in which a target 31 is provided in a region corresponding to the downstream "second peak". When the "second peak" is used, erosion of the target 31 hardly occurs, and there is no need to use a special super-hard material.
Normal stainless steel is sufficient.

FIG. 5 shows an example of a nozzle for producing a jet, and its structure is drawn as a longitudinal sectional view.
The high-pressure water 16 is supplied through a high-pressure water supply channel 17,
In the small-diameter orifice 18, the pressure is rapidly reduced and accelerated.
Is jetted into the dome-shaped enlarged hollow portion 19 attached to the tip of the water, and becomes an underwater high-speed water jet with cavitation.
Inside the enlarged cavity 19, strong shear vortices are created around the jet, so that cavitation is promoted.

FIG. 6 shows a nozzle according to another embodiment. The high-pressure water 16 is supplied through the high-pressure water supply channel 17, and the inlet of the small-diameter jet hole 18 is formed on the protrusion 20 that projects to the upstream side, that is, the inside (upstream side) of the high-pressure water supply channel 17. Has become. The ejection holes 1 are formed by the projections 20.
Since a strong contraction is created inside the nozzle hole 8,
Intense cavitation is generated in the jet blown out of the jet. At the outlet end of the ejection hole 18, a conical enlarged cavity 1
Although 9 ′ is provided, the volume of the hollow body of this nozzle is smaller than that of the hollow body of the nozzle of FIG. The enlarged hollow portion 19 'is like a large "counterbore", and is provided for the purpose of preventing the outlet end of the ejection hole 18 from being eroded by cavitation and deteriorated in performance.

FIG. 8 shows the water jet injection conditions according to the embodiment of the present invention. By the pressurization of the plunger pump, the injection pressure Pj of the nozzle becomes 6
The pressure is adjusted to 50 kgf / cm ² (65 MPa).
When the nozzle diameter Dj is 1 mm, the amount of jetted water Qw from the nozzle is about 12.5 L / min. This spouted water quantity Qw
Varies little by little depending on the shape of the nozzle. For example, FIG.
In the nozzle, when the same injection pressure is used as compared with the nozzle in FIG. 5, the injection water amount is smaller by about 4%.

The target was provided at a position corresponding to a stand-off distance Xs = 100 mm corresponding to the second peak. The stand-off distance Xs corresponding to the second peak is determined by the structure of the nozzle, the injection pressure Pj, the nozzle diameter Dj, and the like. The same applies to the stand-off distance corresponding to the first peak as determined by the injection conditions.

The raw water to be treated is under direct sunlight in summer,
Approximately 30 degrees Celsius because we pumped from the position near the water surface
Met. This water temperature is not particularly disadvantageous for the production of cavitation. The air blowing amount for aeration described later (implemented for supplying bubble nuclei) is 18
L / min.

Next, functions and effects of the decomposition processing method according to the embodiment of the present invention will be described.

Also in the embodiment shown in FIG. 13, the decomposition rate can be increased by colliding the jet with the target plate. According to this method, the impinging jet spreads radially and diffuses into the wide water area 8 to be purified. But,
According to the embodiment shown in FIG. 1, since the entire amount of the jet colliding with the target 31 also passes through the inside of the tubular reactor 22, the efficiency is high when the reaction is repeatedly performed. Therefore,
If the treatment is performed by the method shown in FIG. 1, it is easy to carry out the system without returning to the first water area.

FIG. 9 shows a case where the same power consumption is used, in which the embodiment of the present invention is compared with a conventional technique (FIG. 11) which is an ultrasonic method for treated water. The flow rate Q on the vertical axis is the treated water quantity Q in the prior art (ultrasonic method).
Dimensionless by dividing by ^* . In the case of the water jet method according to the present invention, it can be seen that the treated water could be increased three times or more.

FIG. 10 compares the decomposition rate of harmful organic substances between the embodiment of FIG. 13 in which a water jet is directly blown into a water area and the embodiment of FIG. 1 in which a water jet is blown into a tubular reactor. Although the comparison is made with the concentration C of the organic matter in the water area after the treatment over a predetermined time, C on the vertical axis is obtained as a relative value by dividing by the concentration C ^* after the treatment in the technique of FIG. expressed. According to the embodiment of FIG.
It can be seen that the concentration of harmful organic substances has been significantly reduced. This is because the method of FIG. 1 is a method of surely passing through the inside of the reaction tube, and thus the decomposition has proceeded efficiently. The harmful substance in this embodiment is dibutyl phthalate, which is known as an endocrine disrupting substance (so-called environmental hormone), and provides raw water (initial concentration C = about 8 ppm) dissolved in water before diffusing into an environment such as a river. did. This is the result of passing about four times in the reaction tube. The above demonstrates the superiority of implementing the embodiment of FIG.

FIG. 7 shows another embodiment of the present invention. Here, 28 is an air pump, 29 is an air nozzle, 3
0 represents a bubble group. Basically, the configuration is the same as that shown in FIG.
It is characterized in that aeration is performed. A multi-element air nozzle 29 is submerged at the bottom of the water storage tank 15, and an air pump 28
Supply air with a hose. Fine air bubbles are generated in the air nozzle 29 and diffuse into the water storage tank.

The aeration includes (1) an oxidizing action,
There are three actions: (2) mixing and stirring action and (3) supply of cavitation bubble nuclei (Nuclei). When the amount of dissolved oxygen in the water to be treated is small, the effect of decomposition is slightly reduced, but (1) compensates for this. The concentration of harmful substances contained in the water bodies to be treated is not always uniform in water. By changing the pumping position, various concentrations of contaminated water are handled. The action (2) is to make the concentration uniform and stabilize the decomposition rate.

The function of supplying the bubble nuclei of the cavitation of the above (3) is the most important in the present invention. When the amount of dissolved air in the water is small, not only the oxidizing action becomes poor, but also the number of bubble nuclei decreases. Most of the air supplied by aeration floats and is released from the water surface only by the action of the above (3), but the remaining air is dissolved in the sewage and becomes cavitation bubble nuclei. When the number of bubble nuclei increases, the power of cavitation increases significantly, and the ability to decompose harmful substances in water increases.

As described above, the embodiments of the present invention include those having the following configurations, functions and functions.

The water to be treated is pumped up by a circulating pump and put into a feed tank, where air bubbles or the like are blown (aeration), and the water to be treated in the tank is agitated to achieve a uniform concentration of the contents. , The gas content is increased, and the nuclei of cavitation are sufficiently supplied. The water to be treated in the feed tank is supplied to the plunger pump, and the water is supplied to the plunger pump at 400 to 800 kgf / cm ² (4
The pressure is increased to 0 to 80 MPa), and a jet is blown into the reaction tube or directly into the water to be treated from a nozzle provided at the end of the straight and long reaction tube.

Since the inside of the reaction tube is filled with the treated water blown out as a jet, the high-speed jet blown from the nozzle becomes an underwater water jet accompanied by vigorous cavitation.
By the action of this severe cavitation, harmful organic chlorine compounds and the like contained in the water are decomposed into harmless substances. For example, dioxins decompose. In addition, plankton such as blue-green algae (green algae) will be destroyed and die if it is a measure to over-enrich lake ponds. At the outlet of the reaction tube, the treated water is returned to the original treated water area through an overflow pipe provided on the side opposite to the nozzle. At this time, the return position should be shifted from the pumped position even in the same water area.

Such a method is known as once-through.
h (once through) method, but in the case of hardly decomposable substances, it is also possible to make a circuit of circulation type. Increase the time required for disassembly.

Raw water containing contaminants (water to be treated) is once stored in a water storage tank. Here, air bubbles are blown in by aeration, and this contaminated water sufficiently contains cavitation bubble nuclei. This water is pressurized to a predetermined pressure by a plunger pump and fed through a high-pressure hose to a nozzle attached to a tubular reactor, and is directly blown into raw water, or a high-speed submerged water jet in a tubular reactor Blown as

Since the inside of the tubular reactor is filled with water that has been decomposed or is being decomposed, the jet blown into the tubular reactor is an underwater high-speed water jet. Intense cavitation is generated in this high-speed water jet, and the cavitation bubbles are collapsed.
The harmful substances are decomposed or broken by (2) thermal decomposition and (3) oxidation. Dioxins are mainly decomposed by the actions of (2) and (3) among the above three actions. On the other hand, pathogenic fungi in water die mainly by the action of (1) and (2).

[0039]

The effects obtained by embodying the present invention can be summarized as follows.

(1) Power consumption (energy) can be reduced as compared with other conventional methods. As a whole, processing costs can be reduced and processing efficiency can be increased.

(2) Ozone, hydrogen peroxide, coagulant, PH
Do not use any agents such as conditioning agents or additives.
Therefore, not only the cost is low but also there is no possibility of causing secondary pollution of the water area.

(3) Only the plunger pump is relatively heavy, and if it is equipped as a compact "kit" as a whole, it can be made portable so that there is a pollution problem in the water area. It can be taken out to the field for processing.

(4) Even a hardly decomposable chemical substance can be repeatedly circulated in the reaction tube, and the harmful substances in the pumped water can be reliably decomposed in the water in the contaminated water area. It is.

[Brief description of the drawings]

FIG. 1 is an apparatus for decomposing trace amounts of harmful organic compounds in water according to another embodiment of the present invention, showing an entire system using a tubular reactor.

FIG. 2 is still another embodiment of the present invention, which is an apparatus for decomposing a trace amount of harmful organic compounds in water, and is a view showing an entire system using a tubular reactor.

FIG. 3 shows details of the decomposition treatment method of the present invention;
It is a figure showing an example of a method of making a submerged water jet collide with a target.

FIG. 4 shows details of the decomposition treatment method of the present invention;
It is a figure which shows the other example of the method of making an underwater water jet collide with a target.

FIG. 5 is a diagram showing a configuration example of a water jet nozzle used in the present invention.

FIG. 6 is a view showing another configuration example of a water jet nozzle used in the present invention.

FIG. 7 is a diagram showing still another embodiment of the present invention.

FIG. 8 is a diagram showing injection conditions of a water jet according to the present embodiment.

FIG. 9 is a graph showing actual results when the present invention is applied, and specifically illustrating the effects of the present invention.

FIG. 10 is a graph showing results when the embodiment of FIGS. 1 and 13 is applied to the present invention and showing the concentration of harmful organic substances.

FIG. 11 is a diagram showing an entire system of a decomposition processing apparatus according to a conventional technique.

FIG. 12 is a diagram showing an entire system of a decomposition processing apparatus according to another conventional technique.

FIG. 13 is a diagram showing an entire system using a device for decomposing trace amounts of harmful organic compounds in water according to an embodiment of the present invention.

[Explanation of symbols]

 8 Purification target area 9 Nozzle 10 Underwater water jet with cavitation 11 Plunger pump 12 High pressure hose 13 Pumping line 14 Circulation pump 15 Water tank 16 High pressure water 20 Three-way switching valve 21 Return line 22 Tube reactor 23 Return line 24 Valve 25 Foreign matter Removal filter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazunori Fujita 3-36 Takara-cho, Kure-shi, Hiroshima F-term in Babcock Hitachi, Ltd. Kure Research Laboratory F-term (reference) 4D037 AA13 AB03 AB14 BA26 BB04 BB07 4D038 AA08 AB14 BA02 4D050 AA13 AA20 AB06 AB19 BB01 BC02

Claims (11)

[Claims] 1. Raw water containing harmful organic compounds is collected, the collected raw water is fed to a high-pressure pump and pressurized, the pressurized raw water is fed to a nozzle, and injected from the nozzle into the raw water at high pressure. An apparatus for decomposing trace amounts of harmful organic compounds in water, wherein the harmful organic compounds are decomposed and made harmless by the action of cavitation of the submerged water jet. 2. A raw water containing a harmful organic compound is collected, the collected raw water is fed to a high-pressure pump to be pressurized, and the pressurized raw water is fed to a nozzle provided at an inlet of a reactor. , An apparatus for decomposing trace amounts of harmful organic compounds in water, characterized in that harmful organic compounds are decomposed and made harmless by the action of cavitation of a submerged water jet in the reactor. . 3. The apparatus for decomposing trace amounts of harmful organic compounds in water according to claim 1 or 2, wherein the treated water discharged from the reactor is returned to a location different from the sampling point. Decomposition equipment for trace harmful organic compounds. 4. The apparatus for decomposing trace amounts of harmful organic compounds in water according to claim 2, wherein the water to be treated discharged from the reactor is circulated to the collected raw water, and a water jet is formed in the reactor. An apparatus for decomposing trace amounts of harmful organic compounds in water, characterized by being repeatedly sprayed. 5. The apparatus for decomposing a trace amount of harmful organic compounds in water according to claim 2, wherein gas is blown into the collected raw water in the form of fine bubbles by aeration, thereby forcing cavitation bubble nuclei into the raw water. An apparatus for decomposing trace amounts of harmful organic compounds in water, characterized in that they are supplied. 6. The apparatus for decomposing trace amounts of harmful organic compounds in water according to claim 1 or 2, further comprising an enlarged cavity extending toward the downstream at an outlet of the ejection hole of the nozzle. Decomposition equipment for harmful organic compounds. 7. The apparatus for decomposing trace amounts of harmful organic compounds in water according to claim 1 or 2, wherein an inlet of the nozzle is projected in a tubular shape toward a supply flow path of the pressurized raw water. Characteristic decomposition equipment for trace harmful organic compounds in water. 8. The apparatus for decomposing a trace amount of harmful organic compounds in water according to claim 1 or 2, wherein a target plate (collision plate) is provided in the raw water or in the reactor so as to collide with a water jet. Characteristic decomposition equipment for trace harmful organic compounds in water. 9. The apparatus for decomposing trace amounts of harmful organic compounds in water according to claim 8, wherein the position of the target plate is set at a first peak (first peak) of an impact distribution generated in the axial direction of the submerged water jet. A device for decomposing trace amounts of harmful organic compounds in water, characterized in that it is selected within the region corresponding to peaks). 10. The apparatus for decomposing a trace amount of harmful organic compounds in water according to claim 8, wherein the position of the target plate is determined by setting a second peak (second position) of an impact distribution generated in the axial direction of the submerged water jet. A device for decomposing trace amounts of harmful organic compounds in water, characterized in that it is selected within the region corresponding to peaks). 11. Raw water containing harmful organic compounds is collected,
The collected raw water is fed to a high-pressure pump to be pressurized, the pressurized raw water is fed to a nozzle, and injected from the nozzle into the raw water at a high pressure, and harmful organic compounds are decomposed by the action of cavitation of a submerged water jet. A method for decomposing trace amounts of harmful organic compounds in water, characterized by detoxification.