JP2001286860A - Water treating device and water treating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the service life of activated carbon and to lower a TOC concentration of water to be treated. SOLUTION: An oxidizing agent is added to the water to be treated containing organic compounds, and the water to be treated to which the oxidizing agent is added is passed through the activated carbon 2, thus the organic compounds contained in the water to be treated are adsorbed on the activated carbon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment apparatus and a water treatment method, and more particularly, to a water treatment apparatus and a water treatment method which are suitably applied to a case where treated water containing organic compounds is treated with activated carbon.

[0002]

2. Description of the Related Art Conventionally, there has been a method of removing an organic compound from treated water containing an organic compound by passing the treated water containing the organic compound through activated carbon.

[0003]

However, in the method of passing treated water containing an organic compound through activated carbon, the organic compound is adsorbed on the activated carbon when the treated water is passed through the activated carbon, and the activated carbon is saturated. , Organic compounds cannot be removed. For this reason, this method has a problem that the activated carbon must be frequently replaced when the amount of water passing through the activated carbon increases.

[0004] Therefore, an object of the present invention is to provide a water treatment apparatus and a water treatment method capable of extending the life of activated carbon and reducing the TOC concentration of the water to be treated.

[0005]

According to the present invention, there is provided, in accordance with the present invention, a step of adding an oxidizing agent to water to be treated containing an organic compound; And passing water through activated carbon.

[0006] This makes it possible to suppress the saturated adsorption of activated carbon when the water to be treated containing the organic compound is passed through the activated carbon, to prolong the life of the activated carbon, and to increase the life of the activated carbon. It becomes possible to reduce the TOC concentration of the water to be treated.

Here, it is preferable that the oxidizing agent is hydrogen peroxide.

Thus, the cost of the oxidizing agent can be reduced, and the oxidizing agent can be easily handled.

Further, the TOC concentration of the organic compound is 0.1.
5 to 50 ppm, the flow rate LV of the water to be treated is 5 to 1
0 m / h, and the concentration of the oxidizing agent is preferably 10 to 100 ppm. When the oxidizing agent concentration is low, the effect of the present invention cannot be expected much.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a water treatment apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example of a water treatment apparatus according to one embodiment of the present invention. In FIG. 1, an oxidizing agent adding device 1 adds an oxidizing agent to water to be treated containing an organic compound. The water to be treated to which the oxidizing agent has been added is passed through the activated carbon 2, and the organic compounds contained in the water to be treated are adsorbed by the activated carbon 2, whereby the organic compounds are removed from the water to be treated containing the organic compounds.

Here, an oxidizing agent is added to the treated water containing the organic compound before the treated water containing the organic compound is passed through the activated carbon 2 so that the organic compound adsorbed on the activated carbon 2 can be oxidized. As a result, it becomes possible to suppress the saturated adsorption of activated carbon by oxidative decomposition. As a result, the life of the activated carbon can be extended, and the TOC concentration of the water to be treated treated with the activated carbon can be reduced.

Also, the oxidizing agent is decomposed by the activated carbon,
Since oxygen is generated, it is possible to activate the aerobic microorganisms present in the activated carbon, and it is possible to further decompose the oxidatively decomposed organic compound.

Here, examples of the organic compounds contained in the water to be treated include surfactants and alcohols. Also,
The TOC concentration of the organic compound contained in the water to be treated is 0.5
It is preferably about 50 ppm.

As the oxidizing agent to be added to the water to be treated, hydrogen peroxide, ozone, sodium persulfate, ammonium persulfate, chlorine and the like can be used, but from the viewpoint of cost and ease of handling, hydrogen peroxide is used. Preferably, there is. The concentration of the oxidizing agent added to the water to be treated is 10%.
Preferably it is １００100 ppm.

As the activated carbon, coal-based or coconut shell-based can be used, but coal-based is preferred from the viewpoint of the adsorption power of organic compounds and the life.

The temperature at which the water to be treated to which the oxidizing agent has been added is passed through the activated carbon 2 may be room temperature, and the velocity LV of the water to be treated is preferably 5 to 10 m / h.

Although the pH of the water to be treated does not need to be particularly adjusted, it is preferably pH 3 to 6.

FIG. 2 is a block diagram showing a configuration example in which the water treatment apparatus according to one embodiment of the present invention is applied to an ultrapure water production apparatus. In FIG. 2, in the primary pure water apparatus 11, raw water is introduced into a pretreatment apparatus 12, and suspended substances and the like in the raw water are separated and removed. Next, the water to be treated, which has been treated by the pretreatment device 12, is sent to the activated carbon filtration tower 13, where the organic compounds contained in the water to be treated are removed. Here, the activated carbon filtration tower 13 is provided with an oxidizing agent addition device 1 for adding an oxidizing agent to the water to be treated sent to the activated carbon filtration tower 13. , The life of the activated carbon 2 can be improved.

Next, the water to be treated from which the organic compounds have been removed is sent to a two-bed, three-column tower 14. The two-bed three tower 14 is provided with a cation exchange resin tower, a vacuum degassing tower and an anion exchange resin tower, and the two-bed three tower 14 removes ionic components from the water to be treated. Next, the water to be treated from which the ionic components have been removed is introduced into the reverse osmosis device 15 to remove fine particles, colloidal substances and the like.

Next, the water to be treated, from which fine particles and colloidal substances have been removed, is supplied to a low-pressure ultraviolet lamp oxidation apparatus 1.
The dissolved organic matter remaining in the water to be treated is decomposed. Next, the water to be treated, in which the dissolved organic matter has been decomposed, is sent to the mixed-bed ion exchange device 17, where the ionic components in the water to be treated are removed.

The primary purified water obtained from the primary purified water apparatus 11 is further subjected to an ultraviolet oxidation apparatus 19 and a polisher 20.
By passing through a secondary pure water device 18 composed of an ultrafiltration membrane 21 and the like, a trace amount of impurities slightly remaining in the primary pure water is removed.

The ultrapure water thus produced is supplied to a use point (water sampling point) 22 in a semiconductor manufacturing plant, an LCD manufacturing plant, etc., and the wastewater discharged from the use point 22 passes through an activated carbon filtration tower 23. BOD in drainage
The COD can be reused by reducing the COD and discharging it, or by refluxing it before the activated carbon filtration tower 13. Here, the activated carbon filtration tower 23 includes:
An oxidizing agent adding device 1 for adding an oxidizing agent to the water to be treated sent to the water is provided, and after adding the oxidizing agent to the water to be treated,
The treatment in the activated carbon filtration tower 23 can improve the life of the activated carbon.

Next, an experimental example of the water treatment apparatus according to one embodiment of the present invention will be described.

FIG. 3 is a diagram showing an example of the configuration of an experimental apparatus for a water treatment apparatus according to one embodiment of the present invention. In FIG. 3, an acrylic column 31 of 25 mmφ × 1300 mm is shown.
Activated carbons 32a and 32b were respectively filled into 300a and 31b. Here, F300 (coal-based activated carbon) manufactured by Toyo Calgon Co., Ltd. was used as the activated carbons 32a and 32b.

Also, a water 30a containing a surfactant and a water 30b containing only a surfactant are prepared, and a water 30b containing only a surfactant is prepared. To columns 31a and 3a, respectively.
Water was passed through 1b. And these to-be-treated waters 30a, 3
The TOC concentration at the outlets of the columns 31a and 31b of Ob was measured. Here, the pH of the water to be treated 30a, 30b is 10
Was adjusted to As the surfactant, NCW601A manufactured by Wako Pure Chemical Industries, Ltd. was used. In addition, Shimadzu TOC5000 was used for the measurement of the TOC concentration.

Further, as a first embodiment, the water to be treated 30a
The TOC concentration at the inlet of the column 31a of the surfactant in Example 1 was 50 ppm, the hydrogen peroxide concentration was 50 ppm, the water flow rate LV was 5 m / h, and as Comparative Example 1, the inlet of the surfactant column 31b in the water 30b to be treated. The conditions were set such that the TOC concentration was 50 ppm and the water flow rate LV was 5 m / h.

In Example 2, the concentration of TOC at the inlet of the column 31a of the surfactant in the water to be treated 30a was 10 ppm, the concentration of hydrogen peroxide was 10 ppm, and the water flow rate LV was 10 m / h. The TOC concentration at the inlet of the column 31b of the surfactant in the water to be treated 30b was set to 10 ppm, and the flow rate LV was set to 10 m / h.

FIG. 4 is a diagram showing experimental results of Example 1 of the present invention in comparison with Comparative Example 1. 4, in Comparative Example 1, the water flow rate was 2000B. V. (Bed Volu
(me: unit indicating how many times the amount of the activated carbon charged water was passed)), the TOC concentration at the outlet of the column 31b reached the TOC concentration at the inlet of the column 31b.

On the other hand, in Experimental Example 1, the water flow was 80
0B. V. In the vicinity, the TOC concentration at the outlet of the column 31a starts to increase, and the flow rate becomes 1200 B. V. In the vicinity, the TOC concentration at the outlet of the column 31a is about 38 ppm, but even if the water flow rate is further increased, the TOC concentration at the outlet of the column 31a is maintained at about 38 ppm, and the water flow rate is 2,000 B.P. V. , The TOC concentration at the outlet of the column 31b did not reach the TOC concentration at the inlet of the column 31b. As a result, it has become possible to extend the life of activated carbon by adding hydrogen peroxide to an aqueous solution to which a surfactant has been added.

FIG. 5 is a diagram showing experimental results of Example 2 of the present invention in comparison with Comparative Example 2. In FIG. 5, in Comparative Example 2, the flow rate is 1000 B. V. In the vicinity, column 31
b. The TOC concentration at the outlet of b starts to increase, and
00B. V. , Column 31b began to show a tendency to saturate.

On the other hand, in Experimental Example 2, the water flow rate was 20
00B. V. In the vicinity, the TOC concentration at the outlet of the column 31a starts to increase, and the water flow rate becomes 10000B. V. In the vicinity,
The TOC concentration at the outlet of the column 31a is about 6.6 ppm.
The TOC concentration at the outlet of a is maintained at about 6.6 ppm,
The TOC concentration at the outlet of the column 31b did not reach the TOC concentration at the inlet of the column 31b.

Next, when the water flow rate is 12000B. V. , The addition of hydrogen peroxide to the water to be treated 30a of Example 2 was stopped, and the water to be treated 30b of Comparative Example 2 was stopped.
, The addition of hydrogen peroxide was started.

FIG. 6 is a diagram showing the experimental results of Example 2 when the addition of hydrogen peroxide was stopped halfway, in comparison with Comparative Example 2. In FIG. 6, when the addition of hydrogen peroxide in the water to be treated 30a is stopped halfway, the column 31b
The TOC concentration at the outlet of the plant started to rise, and
0B. V. In the vicinity, the TOC concentration at the outlet of the column 31b reached the TOC concentration at the inlet of the column 31b.

On the other hand, even if the addition of hydrogen peroxide to the water to be treated 30b is started after the activated carbon is saturated with the surfactant, the TOC concentration at the outlet of the column 31b does not decrease, and The TOC concentration at the outlet of the column 31b after the start of the addition is the same as that of the column 3 before the start of the hydrogen peroxide addition.
It was found that the value was about the same as the TOC concentration at the outlet of 1b.

[0036]

As described above, according to the present invention,
When passing treated water containing organic compounds through activated carbon,
By continuously adding the oxidizing agent to the water to be treated, the life of the activated carbon can be extended, and the TOC concentration of the water to be treated treated with the activated carbon can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a water treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example in which a water treatment apparatus according to an embodiment of the present invention is applied to an ultrapure water production apparatus.

FIG. 3 is a diagram showing a configuration example of an experimental device of a water treatment device according to one embodiment of the present invention.

FIG. 4 is a diagram showing experimental results of the water treatment device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an experimental result of the water treatment apparatus according to the second embodiment of the present invention.

FIG. 6 is a diagram showing experimental results of a water treatment apparatus according to Embodiment 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oxidizer addition apparatus 2 Activated carbon 11 Primary pure water apparatus 12 Pretreatment apparatus 13, 23 Activated carbon filtration tower 14 2 Beds 3 towers 15 Reverse osmosis apparatus 16, 19 Ultraviolet oxidizing apparatus 17 Mixed bed tower 18 Secondary pure water apparatus 20 Polisher 21 Ultrafiltration membrane 22 Use points

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Junichi Ouchida 2-9-8 Okada, Atsugi-shi, Kanagawa F-term in Nomura Micro Science Co., Ltd. 4D024 AA03 AB04 BA02 BB01 BC01 CA01 DA05 DA07 DB05 DB10 DB19 DB23 4D050 AA05 AB02 AB07 AB14 BB09 BC05 BC10 BD06 BD08 CA03 CA07 CA08 CA09 CA15

Claims (4)

[Claims] 1. A water treatment method comprising: a step of adding an oxidizing agent to water to be treated containing an organic compound; and a step of passing the water to be treated to which the oxidizing agent has been added to activated carbon. 2. The water treatment method according to claim 1, wherein the oxidizing agent is hydrogen peroxide. 3. The organic compound having a TOC concentration of 0.5 to 0.5.
50 ppm, the flow rate LV of the water to be treated is 5 to 10 m.
The water treatment method according to claim 1 or 2, wherein the concentration of the oxidizing agent is 10 to 100 ppm. 4. An activated carbon, an oxidizing agent adding means for adding an oxidizing agent to water to be treated containing an organic compound, and an activated carbon water flowing means for flowing the treated water to which the oxidizing agent is added through the activated carbon. A water treatment apparatus comprising: