JPH11104632A - Device and method for cleaning water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for cleaning water in which useless organic substances existing in water to be cleaned is efficiently decomposed and removed at large treatment capacity by using a low-voltage ultraviolet lamp of high output. SOLUTION: The device for cleaning water is equipped with a first reaction vessel 3 whose inside is a cylindrical shape, a UV-lamp 7 provided along the central vertical axis of the first reaction vessel 3, an injection nozzle 8 for injecting water to be cleaned in the circumferential direction in a belt-shape to the prescribed part of the outer periphery in the inside of the first reaction vessel and a dissolving circulation means 10 which draws out water to be cleaned from the lower part of the vicinity of the central vertical axis and dissolves ozone and circulates water to be cleaned to the injection nozzle 8. Furthermore, the device for cleaning water is equipped with a second reaction vessel 18 introducing intermediately cleaned water of the first reaction vessel 3, the UV-lamp 7 provided along the central vertical axis of the second reaction vessel 18, a circulation means 21 which diffuses gas in the lower part of the vicinity of the central vertical axis and circulates the introduced intermediately cleaned water and a pulling-out means 25 for flowing out cleaned water in which organic substances remaining in the intermediately cleaned water is decomposed and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purification apparatus and a water purification method for efficiently decomposing and removing useless organic substances present in water to be purified.

[0002]

2. Description of the Related Art Ozone is irradiated with ultraviolet rays in water to generate hydroxyl radicals (hereinafter also referred to as "OH.") Having extremely strong oxidizing power, thereby efficiently oxidizing and decomposing unnecessary organic substances present in water. As a water purification device or a water purification method for reducing the values of sterilization or decolorization of factory wastewater, particularly COD, BOD, TOC (total organic carbon content), and the like,
Various types have been proposed or put into practical use, all of which have a single vertically elongated reaction tube, in which a straight-tube ultraviolet lamp is arranged on or along the center axis thereof, and a fine ultraviolet lamp is arranged from the bottom of the reaction tube. The water to be purified is continuously introduced from the lower or upper part of the reaction tube while blowing a bubble-like ozone-containing gas or after dissolving ozone in advance, and is purified by irradiating ultraviolet rays.

[0003]

However, since all of the above-mentioned water purifying apparatuses or water purifying methods use low-output low-pressure ultraviolet lamps as light sources, when a large amount of water is to be treated, the ultraviolet lamps are not used. A complicated structure with a large number of UV lamps installed, and therefore an inconvenient and expensive one is used, or a large number of those with a small number of UV lamps are required. There was.

[0004] On the other hand, attempts have been made to use high-output low-pressure ultraviolet lamps in order to reduce the number of ultraviolet lamps used, but the efficiency is poor and the practicality is poor.

An object of the present invention is to provide a water purification apparatus or a water purification method for purifying water to be purified, in which unnecessary organic substances present in the water to be purified can be efficiently decomposed and removed, and the processing ability is large. It is.

[0006]

The present invention irradiates ozone with ultraviolet light in water to generate OH. Having an extremely strong oxidizing power, thereby efficiently oxidizing and decomposing unnecessary organic substances present in the water and disinfecting it. Or decolorization of industrial wastewater, especially CO
A water purifying apparatus or a water purifying method for reducing the values of D, BOD, TOC (total organic carbon content), etc. Provided is an efficient water purification device or a water purification method having more than ten times the processing capacity.

[0007] The inventors of the present invention have found that the change in the composition of the components in the reaction system with time is different between the case where the purified water containing ozone is irradiated with high illuminance using a high output lamp and the case where a low output ultraviolet lamp is used. Were compared in detail. As a result, even if an attempt is made to use a reaction tube having a size commensurate with the light reaching distance according to the intensity of the lamp output, the absorption rate of ultraviolet light by ozone is extremely high. Unless all the water is brought close to the lamp surface, only the ozone in the immediate vicinity of the UV lamp surface is used for water purification reaction by the generation of OH.Enhancing the UV lamp output does not directly contribute to the scale-up of the equipment. further, high ultraviolet intensity in order to produce a high concentration OH · from a high concentration of ozone, change in H ₂ O ₂ met with OH · between than its OH · to oxidize and decompose it met organics It has been found that the decomposition efficiency is reduced due to an increase in the rate of the decomposition.

[0008] Based on these findings, the decomposition reaction of organic matter after the decomposition of ozone passes through a slow reaction of changing H ₂ O ₂ to OH · by ultraviolet rays, so that it is suitable for the reaction, In consideration of the necessity of a purifying device or a purifying method for irradiation while stirring, the present inventors have made extensive studies and studies and as a result have arrived at the present invention. That is, in a water purification device that irradiates ultraviolet rays to ozone contained in the supplied purified water to decompose organic substances contained in the purified water and removes and removes the organic matter, a reaction vessel having a cylindrical inside, An ultraviolet lamp provided along the center vertical axis of the reaction vessel, blowing means for blowing the water to be purified in the circumferential direction of the inner periphery of the reaction vessel, and the water to be purified from below the vicinity of the center vertical axis. A first reaction tank provided with a dissolving and circulating means for extracting and dissolving ozone and circulating it to the blowing means, and intermediate purified water treated in the first reaction tank is introduced through an outlet near the central vertical axis. A second reaction tank, wherein the second reaction tank is provided with an ultraviolet lamp provided along a central vertical axis of the reaction tank, a circulating means for circulating the introduced intermediate purified water, and Break down the remaining organic matter, It is provided with a draw-out means for flowing out the removed purified water.

The first reaction tank is provided with a blowing means for blowing the water to be purified in the circumferential direction of the inner circumference of the reaction vessel.
The water to be purified is blown in the circumferential direction of the inner circumference of the reaction vessel having a cylindrical shape. Further, the water to be purified is drawn out from the vicinity of the center vertical axis, and the water to be purified initially moves along the inner periphery of the reaction vessel by the dissolving and circulating means for dissolving the ozone and then circulating the water to the blowing means, and gradually the central vertical axis. Gradually approaching the ultraviolet lamp while moving or turning in a spiral shape around the ultraviolet lamp. In the process, harmful organic matter in the water to be purified is decomposed.

[0010] The first reaction tank in which the above decomposition reaction is carried out comprises:
The structure is such that the whole of the water to be purified, including ozone, passes near the UV lamp. The water to be purified is introduced from the far side of the UV lamp on the vertical axis of the center of the reaction vessel, and circulates spirally around the UV lamp. As it gradually approaches the UV lamp. Therefore, the cleaning water containing a high concentration of ozone was only introduced into the reaction vessel, because generating a low concentration OH · of being irradiated to the far illuminance weak ultraviolet originally lamps, to H ₂ O ₂ The rate of change is small, and it efficiently encounters organic matter and decomposes it, and as a result, ozone water, which gradually becomes low in concentration, gradually absorbs ultraviolet light and transmits light far away. Even so, the volume of the reaction tank can be used effectively. In addition, even if the illuminance increases as the UV lamp is approached, the ozone concentration is low and only low-concentration OH is generated, so the generation of H ₂ O ₂ is slow and the organic matter decomposition reaction proceeds efficiently. Can be done.

Further, in the above-mentioned water purifying apparatus, the blowing means is a blowing nozzle provided at a predetermined position on the inner periphery of the reaction vessel for blowing the water to be purified in a belt shape in a circumferential direction. With this blowing nozzle, the water to be purified can be reliably blown in a laminar band along the inner periphery of the reaction vessel and moved or swirled in a spiral manner with a simple structure.

[0012] The intermediate purified water introduced into the second reaction tank is circulated by the circulating means while the H produced in the first reaction tank is circulated.
₂ O ₂ is irradiated by ultraviolet rays generated from an ultraviolet lamp provided in the second reaction tank, and is slowly decomposed into OH ·, thereby oxidizing and decomposing remaining organic substances in the intermediate purified water.

The circulating means is provided in the vicinity of the central vertical axis to diffuse gas and circulate the intermediate purified water by an air lift method, and the intermediate purified water is an ultraviolet lamp on the central vertical axis. Circulates in the form of a donut centered at the center, and receives uniform ultraviolet irradiation.

In short, the feature of the water purification method is that ozone is contained in the supplied water to be purified, and ultraviolet light is applied to the water to decompose, remove, and remove the organic substances contained in the water to be purified. In the purification method, a first water purification step of decomposing an organic substance by a hydroxyl radical (OH.) Directly generated from the ozone-containing water to be purified and ultraviolet light, and hydrogen peroxide and ultraviolet light mainly generated from the hydroxy radical, and A second water purification step of decomposing remaining organic substances in the intermediate purified water, which has purified the water to be purified in the first water purification step, with hydroxyl radicals generated from water containing ozone and ultraviolet rays.

Further, the feature of the water purification method is that the first
In the water purification step, the water to be purified containing the ozone is introduced into a location far from the ultraviolet lamp, and is gradually approached to the ultraviolet lamp while being circulated in a spiral around the ultraviolet lamp. Then, the intermediate purified water purified in the first water purification step is circulated as uniformly as possible so as to irradiate the ultraviolet rays emitted by the ultraviolet lamp.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a water purification apparatus and a water purification method of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a system diagram showing an embodiment of a water purification apparatus according to the present invention, and FIG. 2 is a sectional view taken along the line II of FIG. The water purification device 1 of the present embodiment decomposes and removes organic substances contained in the water 39 to be purified by irradiating the ozone contained in the water 39 to be purified supplied by the pump 6 or gravity with ultraviolet rays. The first reaction tank 2 and the second reaction tank 17 are used as main parts. That is, the first reaction vessel 2 includes a first reaction vessel 3 whose inside is a cylindrical reaction vessel, and a UV lamp (or an ultraviolet lamp) 7 provided along the center vertical axis 4 of the first reaction vessel. A blowing nozzle 8 as a blowing means for blowing the water to be purified 39 in the circumferential direction of the inner periphery 5 of the first reaction vessel; And a dissolution circulation means 10.

As shown in FIG. 2, the first reaction vessel 3 has at least a cylindrical inner shape, and is provided with a protective tube 30 for inserting the UV lamp 7 at the center thereof. Of course, the protection tube 30 is formed of a material that transmits ultraviolet rays. The blowing nozzle 8 is provided at a predetermined position on the inner periphery of the first reaction vessel 3 and blows the purified water 39 in a belt shape in the circumferential direction. Further, as shown in FIG.
An inlet 8a for introducing purified water 39 at an intermediate position or a lower end of the first reaction vessel 3 at a length as close as possible to the height dimension of the first reaction vessel 3 is provided. And a slit 8b which is opened so as to blow out at a uniform speed in a strip shape. In the present embodiment, the number of the blow nozzles 8 is one, but a plurality of blow nozzles 8 may be provided as appropriate in the circumferential direction.

The dissolving and circulating means 10 is provided with a discharge port 12 provided near the center of the first reaction vessel 3, and through this discharge port 12, water to be purified which is being purified is extracted, and ozone (O ₃ ) is discharged.
It has a pump 13 for forcibly dissolving 41 and circulating it to the blowing nozzle 8, and a circulating pipe connecting these.

Further, the water purification apparatus 1 of the present embodiment has a second reaction tank 17, which converts the intermediate purified water 40 reacted with the purified water 39 in the first reaction vessel 3 into a first reaction tank 17. A second reaction vessel 18 as another reaction vessel introduced through an opening 15 which is an outlet near the central vertical axis 4 common to the central vertical axis of the vessel 3 and a second reaction vessel 18 provided along the central vertical axis 4 1 UV lamp 7 provided in common with a UV lamp provided along the central vertical axis of reaction vessel 3, circulating means 21 for circulating introduced intermediate purified water 40, and decomposing the remaining organic matter in intermediate purified water 40 And an extraction means 25 for allowing the purified water 42 removed to flow out.

The second reaction vessel 18, like the first reaction vessel 3, has at least a cylindrical inner shape and is provided with a protection tube 30 for inserting the UV lamp 7 at the center thereof.
Of course, the protection tube 30 is formed of a material that transmits ultraviolet rays. An exhaust hole 31 is provided on the upper surface of the second reaction vessel 18.

The circulating means 21 is provided with an annular gas diffuser 22 in the vicinity of the central vertical axis 4 to diffuse gas (air) 43 to circulate the intermediate purified water 40 in a donut shape in the second reaction vessel 18. It is. The annular gas diffuser 22 is provided with a gas diffuser (not shown) through which gas 43 is appropriately diffused in the circumferential direction.

The withdrawing means 25 has a withdrawal outlet 26 for withdrawing from a substantially central portion of the donut-shaped circulating flow in the second reaction vessel 18,
There is an overflow tank 28 for storing the extracted purified water 42 by overflowing from the overflow port 27, and a pipe for connecting these. The outlet 26 is provided between the first reaction vessel 3 and the second reaction vessel 18.
Of the outer peripheral portion of the partition wall 35 with the first reaction tank, for example, the position 37
It may be attached around.

The water purifying apparatus 1 of the present embodiment having the above structure operates as follows. That is, the water 39 to be treated
Is supplied by a pump 6, and ozone is forcibly dissolved by a dissolving and circulating means 10 through an ozone dissolving and circulation pump 13 on the way. Further, the purified water 39 is blown in a band shape along the inner circumference of the first reaction vessel 3 by the blowing nozzle 8, initially moves along the inner circumference of the first reaction vessel 3, and gradually has a UV lamp having a central vertical axis. 7 gradually approaches the UV lamp 7 while moving or turning in a spiral around the periphery of the UV lamp 7. During that time, the dissolved ozone becomes OH. A part of the ozone is used for decomposing organic substances, and the rest is changed to H ₂ O ₂ .

At this time, most of the water to be purified is withdrawn from the outlet 12 near the UV lamp 7 at the bottom of the first reaction vessel 3, and the other part is a small amount of dissolved ozone and most of the oxygen. Then, the liquid flows through the opening 15 to the second reaction vessel 18 together with the foam. The purified water extracted from the outlet 12 is pump 1
The ozone is dissolved again by 3 and introduced into the first reaction vessel 3 through the inlet 8a and circulated.

The first reaction tank 2 is designed so that the whole of the water to be purified containing ozone is temporarily approached toward the surface of the UV lamp 7. The UV light is introduced from the axial UV lamp 7 in the tangential direction of the cylindrical reactor, and gradually approaches the UV lamp 7 while circulating in a spiral around the UV lamp 7. Therefore, since a high concentration of ozone contained in the purified water that has just been introduced into the first reaction vessel 3 produces a far illuminance is irradiated with weak ultraviolet lightly doped OH · from UV lamp 7, H ₂ The rate of change to O ₂ is small, and the ozone water that efficiently meets organic matter and decomposes it, thereby gradually reducing the concentration, gradually loses the absorption of ultraviolet rays, so that it transmits light far away, The used capacity of the reaction tank can be used effectively. Moreover, even if the illumination is higher as the distance from the UV lamp 7, the ozone concentration is lower because not low concentration OH · of only a generation, slower generation of H ₂ O _2,
The organic matter decomposition reaction can proceed efficiently.

Further, the intermediate purified water 40 introduced into the second reaction tank 17 is circulated by the circulating means 21 so that the UV lamp is illuminated by the area lift effect of the entrained air bubbles and the auxiliary air bubbles evacuated from the annular evacuation pipe 22. The H ₂ O ₂ generated in the first reaction tank rises at a high illuminance near 7 and O ₂
H. The OH. Reacts with the remaining organic matter remaining in the intermediate purified water 40 to be decomposed. The intermediate purified water 40 containing the residual H ₂ O ₂ is converted into a doughnut-shaped circulating flow by the circulating means 21 to circulate and stay from a place where the UV illuminance is strong to a place where the UV illuminance is weak, and H ₂ O ₂ is almost completely decomposed. And
The air is discharged as overflow from the overflow port 27 through the final outlet 26, and the air bubbles are discharged from the exhaust hole 31.

Further, in the water purification apparatus 1 of the present embodiment, the water to be purified is supplied to the first reaction tank 2 and the second reaction tank 2 at the respective optimum average residence times determined from the concentration of dissolved ozone and the illuminance of the UV lamp. It is designed so as to pass through the reaction tank 17 according to the amount of water to be purified. In the above example, the first reaction tank 2 and the second reaction tank 17 are arranged below and share the UV lamp protection tube, but the effect is the same even if they are separated into two tanks.

[0029]

Next, examples of the present invention will be described. 1 and 2, the first reaction tank 2 has a diameter of 100 cm and a depth of 25 cm, and the second reaction tank 17 has a diameter of 100 cm and a depth of 75 cm.
cm, the inflow rate of the water 39 to be treated 0.9 m ³ / hr, and its T
When the OC value is 2 ppm, the low-pressure UV lamp output is 1.5 KW, and the circulation speed by the pump 13 is 3.4 m ³ / hr, the TOC of the purified water 42 that has been processed and overflowed from the overflow port 27 is 5
00 ppb.

FIG. 3 shows a water purification apparatus 100 as a comparative example.
FIG. The water purification device 100 is a reaction tank without a partition 35 like the water purification device 1 of FIGS.
01 is supplied to the reaction tank 105 by the pump 102.
The water to be treated 101 supplied to the reaction tank 105 is
After circulating through the inside of the pump 05, it is withdrawn from the outlet 107 near the top by the pump 103 as intermediate purified water 108,
Ozone 104 is forcibly dissolved and supplied again to the reaction tank 105 from the inflow port 109, and is purified by the UV lamp 106 disposed at the center of the reaction tank 105. In the case of this water purification apparatus 100, as a result of the reaction performed at the same flow rate and circulation speed, the TOC of the purified water discharged is 1.8 ppm.
Then, the value of the water purification device 1 of the present embodiment is 500 ppb.
The water purification device 1 of the present embodiment is much larger than
It can be seen that the organic matter in the water to be purified is decomposed and removed more efficiently than the water purification apparatus 100.

[0031]

According to the water purification apparatus and the water purification method of the present invention, unnecessary organic substances present in the water to be purified can be efficiently decomposed and removed, and the processing capacity is large.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a water purification device according to the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a system diagram of a water purification device as a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water purification apparatus 2 First reaction tank 3 First reaction vessel (reaction vessel) 4 Center vertical axis 5 Inner circumference 7 UV lamp (ultraviolet lamp) 8 Blowing nozzle (blowing means) 10 Melting circulation means 15 Opening (outlet) 17 Second reaction tank 21 Circulation means 25 Extraction means 39 Purified water 40 Intermediate purified water 42 Purified water

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ikuei Origata 8-8-23 Kinuta, Setagaya-ku, Tokyo (72) Inventor Jun Tanaka 1-4-9 Kawagishi, Toda City, Saitama Prefecture Organo Corporation In-house (72) Inventor Makio Tamura 1-4-9 Kawagishi, Toda City, Saitama Prefecture Organo Research Institute

Claims (5)

[Claims] 1. A water purification apparatus for irradiating ozone contained in supplied water to be irradiated with ultraviolet rays to decompose, remove, and flow out organic substances contained in the water to be purified, and has a cylindrical reaction inside. A vessel, an ultraviolet lamp provided along the center vertical axis of the reaction vessel, blowing means for blowing the water to be purified in the circumferential direction of the inner circumference of the reaction vessel, and the vessel from below the vicinity of the center vertical axis. A first reaction tank provided with a dissolving and circulating means for extracting purified water to dissolve ozone and circulating the purified water to the blowing means, and passing the intermediate purified water passing through the first reaction tank through an outlet near the center vertical axis. A second reaction tank, which is provided along the central vertical axis of the reaction tank, and a circulating means for circulating the introduced intermediate purified water, Further, the ultraviolet rays in the second reaction tank A water purifying apparatus comprising: a discharge means for decomposing remaining organic matter in the intermediate purified water by the lamp and the circulation means, and for discharging the purified water removed. 2. The water purification apparatus according to claim 1, wherein the blowing means is a blowing nozzle provided at a predetermined location on the inner periphery of the reaction vessel and configured to blow the water to be purified in a belt shape in a circumferential direction. apparatus. 3. The water purifying apparatus according to claim 1, wherein the circulating means is provided below the vicinity of the center vertical axis and diffuses gas to circulate the intermediate purified water. . 4. A water purification method for irradiating ultraviolet light to ozone contained in supplied water to be purified to decompose, remove, and flow out organic substances contained in the water to be purified, wherein the ozone-containing water is purified. A first water purification step of decomposing organic substances by hydroxyl radicals (OH.) Directly generated from water and ultraviolet rays, and a hydrogen peroxide and ultraviolet rays mainly generated from the hydroxyl radicals, and a hydroxyl group generated from water and ultraviolet rays containing ozone. A second water purification step of decomposing remaining organic matter in the intermediate purified water obtained by treating the water to be purified in the first water purification step by radicals. 5. The method according to claim 4, wherein in the first water purification step, the water to be purified containing ozone is introduced into a location far from an ultraviolet lamp, and gradually circulated around the ultraviolet lamp in a spiral manner. Make it closer to the UV lamp,
In the second water purification step, the intermediate purified water purified in the first water purification step is circulated as uniformly as possible so as to irradiate the ultraviolet rays emitted by the ultraviolet lamp.