JP2007069097A - Wastewater treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase an area where water to be treated is irradiated with ultraviolet light by an optical fiber 1. <P>SOLUTION: The ultraviolet light irradiates the water to be treated of a river, a lake, a wastewater treatment tank, a drainage canal or the like from outside through the optical fiber 1, and air is diffused from the bottom. The ultraviolet light 12 conflicts air bubbles 4 generated by air diffusion to cause irregular reflection 12', and at the same time the air bubbles are retained on the water surface, and the generated air bubble layer prevents radiation of the ultraviolet light from the water surface, which increases irradiation efficiency of the ultraviolet light in a tank S, and performs smooth disinfection/sterilization of the water to be treated, with the ultraviolet light. It is desirable in terms of long retention of air bubbles 4 to perform the air diffusion intermittently. The intermittent air diffusion is performed by selectively opening and closing a valve 7. The optical fibers 1 are separated from each other by partition walls 6, which facilitates understanding of condition of disinfection/sterilization action in each separated zone, and prevents occurrence of turbulence by making flow of the air bubbles generated by the air diffusion have a constant rising speed to perform more smooth disinfection/sterilization action. A leak can be formed by bending the optical fiber in the middle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wastewater treatment apparatus for disinfecting and sterilizing water to be treated in wastewater treatment plants such as rivers, lakes, sewage treatment plants and factories and drainage channels (wastewater channels) such as inflow or outflow channels to them. Is.

  Conventionally, disinfection and sterilization of this type of water was mainly done with chlorine, but toxicity to aquatic organisms due to the release of chlorine and the toxicity of trihalomethane produced by chlorine to humans are regarded as problems, and it replaces chlorine. As a disinfection and sterilization method, a method using ultraviolet rays or ozone has been put into practical use.

As a wastewater treatment apparatus using a disinfection and sterilization method using ultraviolet rays, there is an apparatus in which an optical fiber is inserted into water to be treated, and ultraviolet rays are irradiated from the outside of the water to be treated to the inside through the optical fiber (Patent Document 1). 1-4).
JP-A-8-238476

In addition, as a water treatment device using ozone, an ultraviolet lamp is disposed in the water to be treated (liquid), and an air diffuser tube is provided below the lamp. , Which generates nascent oxygen and active oxygen from ozone contained in the group of fine bubbles, and removes impurities in the water by oxidation, reduction, sterilization, or combination with both oxygens. (Refer to patent document 2 abstract).
JP 2004-329988 A

Since the conventional disinfection sterilization apparatus (wastewater treatment apparatus) by ultraviolet irradiation through an optical fiber has an ultraviolet generator such as an ultraviolet lamp installed outside the water, the generator may be made inexpensive. In addition, it has the advantage of being easy to maintain.
However, since many optical fibers are irradiated with light only from the tip, there is a problem that the irradiation area is narrow. Widening the irradiation area requires an increase in the number of optical fibers, which makes the installation mode complicated and increases the cost.

  This invention makes it a subject to expand the ultraviolet irradiation area by an optical fiber.

  In order to achieve the above object, the present invention provides a water treatment device using an air diffuser described in Patent Document 2 described above, wherein ultraviolet rays are irradiated onto a group of fine bubbles and reflected on the surface of the bubbles. In other words, it was found that ultraviolet rays were irregularly reflected, and the ultraviolet rays were diffusely reflected by the diffused bubbles even in the ultraviolet irradiation by the optical fiber.

If the ultraviolet rays irradiated from the optical fiber are diffusely reflected by the diffused bubbles, the irradiation area of the ultraviolet rays is remarkably widened, the disinfection and sterilization area by the ultraviolet rays is widened, and the disinfection and sterilization action is smoothly performed. Aeration also performs a considerable cleaning action on the optical fiber.
In addition, the diffused bubbles diffusely reflect ultraviolet rays, and various impurities adhere while rising in the water, so that they stay on the water surface. Since the accumulated bubbles cover the water surface, ultraviolet rays are prevented from being emitted from the water surface by reflecting the ultraviolet rays on the bubble layer. For this reason, ultraviolet rays are sterilized and sterilized by repeating irregular reflection in the water to be treated until the energy disappears.

  In the present invention, the ultraviolet rays irradiated from the optical fiber are diffusely reflected by the diffused bubbles and the radiation of the ultraviolet rays from the water surface is prevented, so that the irradiation area is greatly increased compared to the ultraviolet irradiation of the optical fiber alone. In addition, the processing efficiency is improved because effective use of ultraviolet rays is achieved.

  As an embodiment of the present invention, an optical fiber is inserted into the water to be treated, an air diffuser is provided at the bottom of the water to be treated, and ultraviolet rays are passed from the outside of the water to be treated to the inside through the optical fiber. In addition, the air diffused from the air diffuser and diffused by applying the ultraviolet rays to the bubbles caused by the diffused air, and the bubbles are retained on the water surface, and the bubble layer prevents radiation of the ultraviolet rays from the water surface. The configuration can be adopted.

The water to be treated includes all water that needs to be sterilized and sterilized by ultraviolet rays, such as rivers, lakes, wastewater treatment tanks, and drainage channels. In particular, water to be treated such as a sewage treatment plant, a factory wastewater treatment plant, and an inflow channel and an outflow channel thereof are preferable.
The longer a bubble stays in water, the more it performs a diffused reflection of ultraviolet rays. For this reason, it is preferable to use fine bubbles as much as possible. This is because as the bubbles become finer, the rising speed becomes slower.

In the treatment apparatus having this configuration, impurities in the water to be treated adhere to the irradiating part of the optical fiber and the diffusing part of the air diffusing apparatus, and the action is likely to deteriorate. If a cleaning brush is provided between them, and the cleaning brush cleans the irradiating portion of the optical fiber and the diffusing portion of the diffuser, the irradiation and the diffusing action can be prevented.
At this time, if the irradiation part of the optical fiber and the diffuser part of the diffuser are arranged linearly in the same direction, and the cleaning brush can be moved in the linear form, the cleaning brush becomes linear, etc. They can be cleaned and moved by simply moving them.

  As the optical fiber, a general optical fiber in which a cladding is provided on the outer surface of the core may be adopted, but only the core can be used. This is because the water to be treated, which is the object of disinfection / sterilization, usually has a refractive index lower than that of the core, so that the water to be treated serves as a cladding. In the case of only the core, whether or not the water to be treated serves as a clad is confirmed by adopting its properties and adopted.

Further, in the case of the core, when it is bent in water, ultraviolet rays leak from the bent portion, so that the leaked portion also becomes an irradiation portion. The number and position of the leakage portions are appropriately selected in consideration of irradiation efficiency. Even in an optical fiber having a clad, if this leakage action is obtained by bending, it can be bent. The leakage portion may be formed by lacking the clad of the bent portion.
As described above, the fact that the irradiation portion can be formed in the middle of the optical fiber means that the ultraviolet light can be irradiated in the middle of the optical fiber even when the optical fiber is lengthened and guided to a deep water depth. For this reason, it is not necessary to use long and short optical fibers that are irradiated only from the tip.

The installation direction (length direction) of the optical fiber may be set as appropriate in consideration of irradiation efficiency such as horizontal, vertical, and tilted. For example, when multiple optical fibers are provided in the vertical direction The bubble partition plate may be provided between the optical fibers.
Thus, if each optical fiber and air diffuser are partitioned by the partition plate, it is easy to grasp the state of disinfection and sterilization action in each partition, and the flow rate of bubbles due to the air diffuse becomes constant. Therefore, smooth disinfection and sterilization are performed by performing smooth UV irregular reflection.

Aeration may be performed constantly, but intermittent is preferable. When the air is constantly diffused, convection occurs in the water to be treated, the bubble rising path is fixed, the ultraviolet ray irregular reflection effect becomes partial, the bubble rising speed increases, and the efficiency of diffuse reflection decreases. Because it does. More preferably, the air is instantaneously diffused for about one second at intervals of several seconds.
Further, if the air diffused is individually provided between the partition plates, the air can be diffused according to the properties of the water to be treated between the partition plates, so that disinfection / sterilization can be performed efficiently. .
Furthermore, if ultraviolet rays hit the bubbles, as described in Patent Document 2, ozone is generated, and the disinfection and sterilization action by the ozone is also performed. However, if ozone is actively mixed in the air diffuser, The disinfection and sterilization action by ozone is further improved.

  An embodiment is shown in FIG. 1, and this embodiment is an embodiment in which the present invention is applied to a treatment tank S of a sewage treatment plant, and a plurality of optical fibers 1 are vertically arranged in the treatment tank S in the vertical direction. In addition to being inserted in parallel, the diffuser 2 is provided at the bottom of the processing tank S.

  Each optical fiber 1 is led to an ultraviolet ray generator 10 provided outside the treatment tank S, and the ultraviolet ray 12 from the ultraviolet lamp 11 is led into the treatment tank S and from its tip (irradiation unit 13). Irradiate.

  The air diffuser 2 is supplied with air from an air supply device 3 such as a compressor or a blower outside the processing tank S and diffuses. The diffused air rises as bubbles 4 in the treatment tank S. The air can contain ozone. As the air diffuser, a well-known tube such as a tube closed at one end and holes formed at regular intervals in the circumferential wall length direction is adopted.

The bubbles 4 diffused from the diffuser tube are irradiated with the ultraviolet rays 12 irradiated from the optical fiber 1 and diffusely reflected 12 ′ as shown by the arrows in the figure, and are uniformly irradiated over the entire area of the processing tank S. For this reason, the inside of the processing tank S is sterilized and sterilized by the irradiation of the ultraviolet rays 12 over the entire area. At this time, the aeration (bubble 4) performs a considerable cleaning action on the optical fiber 1.
In addition, the bubbles 4 diffusely reflect the ultraviolet rays 12 and various impurities adhere to the bubbles 4 while rising in the treatment tank S, so that the bubbles 4 stay on the water surface. Since the accumulated bubbles 4 cover the water surface, the ultraviolet rays 12 are reflected from the bubble layer, and the radiation of the ultraviolet rays 12 from the water surface is prevented. For this reason, the ultraviolet rays 12 are sterilized and sterilized by repeating irregular reflection in the treatment tank S until the energy disappears.

In the embodiment shown in FIG. 2, a diffuser tube of the diffuser 2 is provided in the parallel direction of the optical fiber 1, and the cleaning brush rotates between the tip (irradiation unit 13) of the optical fiber 1 and the diffuser tube. 5 is provided.
By moving the cleaning brush 5 in the above-mentioned parallel direction while rotating, the tip of each optical fiber 1 and the air diffuser (hole) of the air diffuser tube are cleaned, and deterioration of their operation is prevented (returning the operation). )
The movement of the cleaning brush 5 employs means such as moving the support portion of the cleaning brush 5 on the rail and rotating it by the movement. The movement is considered to be a traveling wire, and the rotation is considered to be the engagement of a rack and a pinion.

In the embodiment shown in FIG. 3, the optical fiber 1 is bent halfway, and the bent portion serves as a leakage portion (irradiation portion) 13 of the ultraviolet rays 12. The position and number of the bent portions (irradiation portions) 13 may be appropriately selected by experimentation / actual operation in consideration of irradiation efficiency and the like.
Thus, forming the irradiation unit 13 in the middle of the optical fiber 1 makes it possible to irradiate ultraviolet rays in the middle of the optical fiber 1 even if the optical fiber 1 is lengthened and guided to a deep water depth. For this reason, it is not necessary to use the long and short optical fiber 1 only for tip irradiation.

  In the embodiment shown in FIG. 4, each optical fiber 1 is partitioned by a partition plate 6. The partition plate 6 is preferably provided with a function of reflecting 12 'the ultraviolet rays 12 as indicated by the arrows in the figure. This is because the ultraviolet rays 12 are evenly distributed throughout the entire processing tank S due to the reflection 12 ′ on the surface of the partition plate 6 and perform disinfection and sterilization.

  Thus, if each optical fiber 1 is partitioned by the partition plate 6, it is easy to grasp the state of the disinfection / sterilization action in each partition, and the rising speed of the flow of the bubbles 4 due to aeration is constant. Therefore, smooth disinfection and sterilization are performed by performing smooth UV irregular reflection.

In the embodiment shown in FIG. 5, in the embodiment of FIG. 4, a diffuser pipe is individually provided in combination with a partition by each partition plate 6, and an electromagnetic on-off valve 7 is provided in each air pipe to the diffuser pipe. Is.
Each electromagnetic on-off valve 7 is appropriately opened and closed to diffuse air intermittently. The intermittent degree of the aeration is appropriately set by experiments and actual operations in consideration of “effective disinfection and sterilization with ultraviolet rays” and “cleaning of the optical fiber 1 by aeration”.
This partial diffusion can also be employed in the embodiment of FIGS.

  In these embodiments, when ultraviolet rays 12 hit the bubbles 4, ozone is generated and disinfection and sterilization by the ozone is performed as described in Patent Document 2. At that time, if ozone is actively mixed in the air diffuser, the disinfection / sterilization action by the ozone is further improved.

  Although the said Example was the case of the processing tank S of a sewage treatment plant, this invention is the wastewater treatment plants, such as the above-mentioned rivers, lakes, sewage treatment plants, factories, and inflow or outflow channels to them. Of course, any apparatus can be employed as long as it is an apparatus for disinfecting and sterilizing treated water in a drainage channel (wastewater channel) with ultraviolet rays.

Schematic diagram of one embodiment Schematic diagram of another embodiment Schematic diagram of another embodiment Schematic diagram of another embodiment Schematic diagram of another embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Air diffuser 3 Air supply apparatus 4 Bubble 5 Washing brush 6 Partition plate 7 Electromagnetic on-off valve 10 Ultraviolet generator 11 Ultraviolet lamp 12 Ultraviolet lamp 12 'Diffuse reflected light 13 Ultraviolet irradiation part S Treatment tank in a sewage treatment plant

Claims (7)

  The optical fiber 1 is inserted into the water to be treated, such as a river, a lake, a wastewater treatment tank, a drainage channel, and the aeration device 2 is provided at the bottom of the water to be treated. While irradiating the ultraviolet rays 12 through the optical fiber 1 and diffusing from the air diffuser 2, the ultraviolet rays 12 are applied to the bubbles 4 due to the diffusing and diffused, and the bubbles 4 are retained on the water surface. A wastewater treatment apparatus characterized in that radiation of ultraviolet rays 12 from the water surface is prevented by a bubble layer.   A cleaning brush 5 is provided between the irradiation unit 13 of the optical fiber 1 and the diffusion unit of the diffuser 2, and the cleaning brush 5 diffuses the irradiation unit 13 of the optical fiber 1 and the diffuser 2. The waste water treatment apparatus according to claim 1, wherein the air part is washed.   The irradiation unit 13 of the optical fiber 1 and the diffuser unit of the diffuser 2 are arranged in a line in the same direction, and the cleaning brush 5 can be moved in the line. The waste water treatment apparatus as described.   The wastewater treatment apparatus according to any one of claims 1 to 3, wherein the optical fiber (1) is bent in water and ultraviolet rays (12) are leaked from the bent portion (13).   The optical fiber (1) is provided in a vertical direction and a plurality of optical fibers (1) are provided in a horizontal direction, and a partition plate (6) for the bubbles (4) is provided between the optical fibers (1). The waste water treatment device according to crab.   6. The waste water treatment apparatus according to claim 1, wherein the air diffuser is intermittently diffused.   The wastewater treatment apparatus according to any one of claims 1 to 6, wherein the wastewater treatment apparatus according to claim 5 can be individually diffused between the partition plates (6). apparatus.

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