JPS6393327A - Treatment of waste ozon - Google Patents

Abstract

PURPOSE:To maintain or recover ozon collecting capability of an ozon collecting agent, by using ion exchange fiber or active carbon as ozon collecting agent, irradiating said collecting agent with ultraviolet rays and decomposing collected ozon. CONSTITUTION:An ion exchange filter 3 is prepared by filling with ion exchange fiber constituted with natural fiber or artificial fiber and a substrate of ion exchange material, Waste O3l discharged out of an O3 reactor and the like for sewage treatment is decomposed down to a comparatively low concentration in a catalyst filling section 2 filled with an ozon decomposing catalyst, and then treated with an ion exchange filter 3 to be discharged as treated gas 4 of extremely low concentration. The filter 3 is irradiated with ultraviolet rays continuously or intermittently, and O3 collected by the filter 3 is decomposed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for treating waste ozone.

[Prior Art] and [Problems to be Solved by the Invention] Ozone (Ol) is used in a wide range of fields because of its strong bactericidal and oxidizing power.

For example, it is used for water treatment such as high-level treatment of wastewater, for deodorization in residential areas and production processes, and for food storage and medical fields. Table 1 shows the uses of O3 However, on the other hand, there is a problem with the release of unreacted O3 after using O3 (O2 flowing out without reacting. Waste Oz) O03 is highly toxic even at low concentrations and poses a pollution problem. Please do not waste 0.0. Complete and highly efficient processing is desired.

The concentration of waste 03 is generally from several ppm to several hundred ppm (depending on the field and application), but it is necessary to treat it so that the concentration is 0.1 pp- or less when discharged into the atmosphere. Therefore, for example, 100100pp is 0.1
To reduce the amount to ppm+ or less, a processing efficiency of 99.9% or more (highly efficient processing) is required.

Moreover, the waste O1 is 0. In addition to the release of unreacted O3 when using O, for example, O generated from copying machines,
,? i! There is Ol generated during the use of particle beam accelerators, etc., and waste 0. There is a problem due to

By the way, the activated carbon method is a conventional O1 treatment method.

Catalytic methods, chemical cleaning methods, thermal decomposition methods, etc. are known.
Each has the following drawbacks.

■ Activated carbon method i0s and activated carbon react to produce CO and CO.

Since the 0 reaction that generates and consumes activated carbon is an exothermic reaction, there is a risk of fire or explosion if used incorrectly. For this reason, it is necessary to adequately manage driving operations. Additionally, pressure loss is high and running costs are relatively high.

■Catalytic method: The effect may be low if used intermittently.

■ Chemical cleaning method; pharmaceutical costs are high. Since it is a wet method, a scrubber is required, the equipment is relatively large, and waste liquid treatment is required.

(2) Thermal decomposition method; requires a temperature of 350°C or higher, which is unfavorable in terms of economy and compactness.

Also, it is not suitable for intermittent use.

Furthermore, in these methods Φ~■, relatively high concentration of Ol
Although the treatment can be carried out with relatively high efficiency, there is a problem that the treatment efficiency is low at a low temperature of 24 degrees (eg, several ppm or less).

In view of the above-mentioned conventional demands and drawbacks of the conventional method, the present inventors have proposed that by using ion exchange fibers, waste Os, especially low concentration waste O1, can be reduced.
A method for treating waste O3 from a wide variety of sources with high efficiency, and if necessary (using one type of waste O3 emission source, etc.) in combination with the above conventional O3 treatment method. Patent application 1986-192 for the effective method
This was proposed in the specification of No. 134.

However, in the method proposed above, the ion exchange fiber
Since the ion exchange fiber mainly utilizes adsorption, the ion exchange fiber becomes saturated with ozone during use and loses its ozone removal ability, so there is a problem that it must be replaced with a new one as needed.

[Means for solving problems]

In order to solve the above problems, the present invention collects and removes ozone using a scavenger such as the ion exchange fiber, and irradiates the scavenger with ultraviolet rays to decompose the captured ozone and remove it. This is designed to maintain or restore the ozone capturing ability of the scavenger.

That is, the present invention brings an ozone-containing gas into contact with an ozone-containing gas and an ozone-containing gas made of at least one of ion-exchange fibers and activated carbon in which an ion-exchanger is supported on natural fibers or artificial fibers, and also exposes the ozone-containing agent to ultraviolet rays. This is a waste ozone treatment method characterized by performing irradiation and decomposing the collected ozone.

In addition, the present invention applies ozone-containing gas to at least one of catalytic decomposition treatment using an ozone decomposition catalyst, adsorption decomposition treatment using activated carbon, thermal decomposition treatment by heating, and absorption treatment using a chemical solution. An ozone-containing gas is brought into contact with an ozone-containing gas that is made of at least one of ion-exchange fibers and activated carbon that support an ion exchanger, and the ozone-containing agent is irradiated with ultraviolet rays to remove the collected ozone. This is a waste ozone treatment method characterized by decomposition treatment.

The present invention will be explained in detail below.

First, to explain ion exchange fibers, they are natural fibers, man-made fibers (chemical fibers or synthetic fibers), or blended yarns or mixed yarns of these fibers that support cation exchangers and/or anion exchangers. The material may be directly supported on a fibrous support, or it may be formed into a woven, knitted or flocked form and then supported thereon. In any case, it is sufficient that the fiber ultimately supports the ion exchanger.

The natural fibers include wool, silk, etc., the chemical fibers include rayon and acetate, and the synthetic fibers include those made from hydrocarbon polymers and fluorine-containing polymers. Alternatively, polyvinyl alcohol, polyamide, polyester, polyacrylonitrile, cellulose, cellulose acetate, etc. can be used.

Examples of the hydrocarbon polymer include polyethylene, polypropylene, polybutylene, polybutene, polystyrene,
polyα-methylstyrene, polyvinylcyclohexane,
Aliphatic, aromatic or alicyclic polymers such as polyvinyl alcohol, polyamide, cellulose, cellulose acetate, polyester, acrylic, polyurethane, or copolymers thereof are used.

In addition, examples of the fluorine-containing polymer include polytetrafluoroethylene, polyvinylidene fluoride, ethylene 7-B fluorinated ethylene copolymer, tetrafluoroethylene-hexafluorinated propylene copolymer, vinylidene fluoride-6 A fluorinated propylene copolymer or the like is used.

Furthermore, fibers made from natural materials such as wool, silk, cotton, and linen can also be used.

A mixture of the above raw materials may also be used.

These materials, that is, the supports are used as porous materials, and can be easily grafted and have a resistance to 0. A material with good properties, high mechanical strength, and low cost is preferable, and can be appropriately selected in consideration of the shape, economy, effectiveness, etc. of the device.

When incorporating the ion exchange fiber into the 01 removal device, for example, a non-woven fabric, a woven fabric, a knitted fabric, or a fibrous form can be used as appropriate, and the shape can be determined as appropriate in consideration of the O1 removal effect, economy, etc. .

The above-mentioned "fibrous form" refers to the state of ion-exchange fibers as they are, and can be applied in the form of filaments (long fibers) or fabrics. In addition, in the case of textiles, it can be constructed from multiple types of ion-exchanged fibers with different supports; for example, it can be constructed by using a blended yarn of multiple types of ion-exchanged fibers or by interweaving them. It is possible.

Regarding ion-exchange fibers, anion-exchange fibers are more effective in O2 treatment than cation-exchange fibers;
Both anion-exchange fibers and cation-exchange fibers can be used for deodorizing as they are often accompanied by other odorous components and other pollutants.

S(h), the latter being an alkaline gas (e.g. N)1.
) are each effective in removing 1iIi collections.

Next, as the ion exchanger, various cation exchangers or anion exchangers can be used without particular limitation.

For example, carboxyl group, sulfonic acid group, phosphorus i! 12
groups, cation exchange group-containing bodies such as phenolic hydroxyl groups,
Anion exchange group-containing bodies such as primary to tertiary amino groups, quaternary ammonium groups, sulfonium groups, phosphonium groups, or polymerized or condensed types containing the above positive and negative ion exchange groups, Examples include homogeneous or heterogeneous ion exchangers.

Representative examples of these include condensation polymers of sodium phenolsulfonate and aldehydes or ketones; condensation polymers of aromatic amines and aldehydes or ketones; acrylic acid, methacrylic acid, vinylbenzenesulfonic acid, styrene, ar-halomethyl Styrene, acyloxystyrene, hydroxystyrene, aminostyrene, vinylpyridine, 2-methyl-5-vinylpyridine, 2-methyl-
There are polymers of monomers having cationic or anionic exchange groups or groups convertible thereto, such as 5-vinylimidazole, acrylonitrile, sulfuric acid, chlorosulfonic acid, and sulfonic acid. Also, a copolymer of the above monomer and a monomer having two or more double bonds such as divinylbenzene, trivinylbenzene, butadiene, ethylene glycol, divinyl ether, ethylene glycol dimethacrylate,
Alternatively, polyethylene, polyvinyl fluorocarbon ether, polytetrafluoroethylene grafted with styrene, etc. may be positively and/or
Alternatively, there are ion exchangers in which an anion ion exchange group is introduced or converted into an ion exchange group.

Next, as a method for supporting the ion exchanger on the support, for example, the support may be exposed to ultraviolet rays, α rays, β rays, electron beams, γ rays, etc.
irradiate with ionizing radiation such as radiation, or use oxygen, ozone,
Chlorsulfonic acid, hydrogen peroxide, penzoyl peroxide,
There is a method in which a monomer that forms an ion exchanger is grafted and supported by treatment with an oxidizing agent such as peracetic acid.

Specifically, for example, ion exchange fibers can be obtained by irradiating polyethylene with radiation, immersing it in a solution containing hydroxystyrene monomer and isoprene, performing graft polymerization, and after the reaction, performing quaternary amination.

〔Example〕

The embodiments of the present invention will be described based on the drawings.
This is a flow sheet when a primary treatment using a conventional ozone decomposition catalyst and a secondary treatment using a packing body filled with ion exchange fibers according to the present invention (hereinafter referred to as an ion exchange filter) are used in combination.

That is, 1 is waste O1 discharged from the 03 reactor (not shown) in sewage treatment, and is a relatively high concentration waste O1.
s 1 is decomposed to a relatively low concentration in the catalyst filling section 2, which is a reactor filled with an ozone decomposition catalyst, and then treated with an ion exchange filter 3 to reach an extremely low concentration (0,1
ppm or less) and is discharged as a processing gas 4.

The decomposition catalyst is usually a metal oxide catalyst such as MnOz, Co oxide-added MnOz, Fed, or NiO, Ag, or PL.

A catalyst in which a noble metal such as Pd is supported on SiO□ or γ-alumina, or a photocatalyst in which a noble metal such as Ag, Pt, or Pd is added to a semiconductor material and the like is irradiated with light is used. The catalyst in this example is HnOt with Go oxide added. The O5 decomposition rate of the catalyst filling section 2 is usually 9.
It is used so that it is about 0 to 99%. That is, in the catalyst filling section 2, 0. The concentration of waste O1 is several ppm to several thousand ppm, usually several tens of ppm to several hundred ppm, but the concentration of waste O1 is 1 to several tens of ppm.
It is processed until it becomes about pm.

Then waste 0. The ion exchange filter 3 changes the concentration from about 1 to several tens of paw to 0.1 ppm or less, usually 0.
．． Processed to O5ppm or less.

The ion exchange filter 3 is filled with waste at appropriate times. During the process, the filter is continuously or approximately 0. UV rays are intermittently irradiated from an ultraviolet source such as an ultraviolet lamp (not shown) at a time when the ion exchange filter 3 is saturated, and the Ol collected in the ion exchange filter 3 is decomposed.

Any source of ultraviolet light may be used as long as it emits ultraviolet light that can decompose the 0 collected on the ion exchange filter 3. In addition, the wavelength of normal ultraviolet rays is 150 rv to 30 rv.
0n+i, for example, ultraviolet rays around 254n1m are preferable, and among wavelengths shorter than 300nm, 0. It is preferable not to use ultraviolet rays with wavelengths that generate 03, for example around 185 nm. If the ultraviolet rays include wavelengths that generate 03, unnecessary wavelengths can be removed using a well-known method. 6. For example, the ultraviolet rays may be removed by passing them through a filter for removing ultraviolet rays. Also, as the ultraviolet lamp, a low pressure mercury lamp, a medium to high pressure mercury lamp, or a deuterium lamp can be used.

The filling amount and filling ratio of the ion exchange fibers in the ion exchange filter 3, the form of the ion exchange fibers, etc. are determined by the concentration and concentration ratio of the substance to be removed (0 alone or Ol and odorous components), and the shape of the filling container. .

The law may be determined as appropriate, taking into account the structure, purpose, effect, etc.

In this embodiment, the ion exchange filter 3 is filled with anion exchange fibers and cation exchange fibers at a volume ratio of 4:1, since the filter also serves to remove malodorous substances at a sewage treatment plant.

This example is a case where a catalyst method is used as the above-mentioned secondary treatment method for waste O1, and this secondary treatment method uses a relatively high concentration of O. A method that can process to a relatively low concentration is fine, but treatment efficiency and cost operability are important.

A catalyst method or an activated carbon method is preferable from the viewpoint of equipment scale and the like.

Preferable 0. If the waste O7 has a relatively high to medium concentration, the treatment method includes primary treatment using a conventional method, and waste O7 treatment using ion exchange fibers and/or activated carbon. In addition to removing this 0.
It is reasonable to use a secondary treatment method in which O1 is decomposed by ultraviolet irradiation, and if the concentration is relatively low, to perform the secondary treatment method alone.

Laws can be established as appropriate, taking into account the scale, economics of two coexisting components, effects, etc.

In addition, 0. Activated carbon for collection may be any type as long as it can collect Ol, and in addition to normal shapes such as granules, fibrous or band-like activated carbon, and even those manufactured and processed by well-known methods can be used.

(Experimental Example 1) fl+ Experimental Conditions Ozone-containing gas (0, concentration 10 ppm) from an ozone generator was added to an ion exchange filter using ion exchange fibers manufactured by the method described below, or to commercially available activated carbon.
The ozone concentration at the outlet was measured by running for a long time with and without irradiation of ultraviolet light to the ion exchange filter or activated carbon.

Ultraviolet source: Low pressure mercury lamp, IOW Ozone generator: Discharge method Type of ion exchange filter: Anion exchange filter Size of ion exchange filter: 100 + uX100 Dragon x 30 m1 Activated carbon: City version activated carbon for reagents, 100 am x 10
0 + n × 301) (2) Space below the experimental results (Experimental Example 2) fi+ Experimental conditions Same as Experimental Example 1, ozone-containing gas (o
:+? The ozone was passed through the waste ozone treatment equipment shown in the drawing at a rate of 21/min. Ozone concentration was measured.

Ultraviolet source: Low pressure mercury lamp, IOW Ozone generator: Type of discharge type ion exchange filter: Anion exchange filter catalyst: Co oxide addition Mn0z (150℃) Equipment size tm): 200 length x 200 width x 250 height (2) Experimental results The following is a description of the method for producing the ion exchange fiber. Semi-Anion exchange fiber: Fibrous polypropylene (diameter 30μ
m) is irradiated with an electron beam of 20 Mrad in nitrogen,
Next, it was immersed in a solution containing hydroxystyrene monomer and insoprene to complete graft polymerization. After the reaction, quaternary amination was performed to obtain anion-exchanged fiber.

■ Cation exchange fiber: fibrous polypropylene 2
An electron beam of 20 Mrad was applied to the tube (30 μm in diameter) in nitrogen.
After 2 irradiation, followed by immersion in an acrylic acid aqueous solution to carry out graphite polymerization, a cation exchange fiber was obtained by treatment with ?8fj of sodium hydroxide.
When processing waste 1 and waste 03, the specified 0
．． By using the scavenger Sl and irradiating it with ultraviolet rays, waste 03 can be treated with high efficiency and stably for a long time.
j ■ Emission 0. The concentration can be reduced to a virtually negligible concentration,
i ■ There is an intermediary effect in both continuous use and intermittent use. ■ 0. Other pollutants (odorous components, e.g. 0□,
His, NOx, HCI, NHO31NH3, various solvents.

D agent neck, malodorous substances (mercaptans, sulfide pages, thiophenes), tar-like substances or fine particles (F-) can be collected and removed at the same time;

: By manually applying a method of irradiating a predetermined O3 scavenger with ultraviolet rays and a conventional O1 treatment method using an ozone decomposition catalyst, etc., it is possible to: ■ remove waste O1 from a wide variety of sources; The processing is spectacular. In other words, this is an extremely effective processing method that takes advantage of the strengths of each. Specifically, the conventional 03 treatment method is based on a decomposition reaction, and the higher the concentration of O1, the more effective it is. -y, since the method using the 03 scavenger is thought to be mainly due to adsorption, the lower the concentration, the more effective it is.

■ Continuous operation 2 Intermittent operation as well as 0 waste. Even if the concentration varies by 1), highly practical processing can be performed.

[Brief explanation of the drawing]

The drawing is a flow sheet illustrating an embodiment of the invention. 1... Waste O3, 2... Catalyst filling section, 3... Ion exchange filter, 4... Processing gas. Patent applicant: Ebara Research Institute, Inc. Agent: Patent attorney: Pharmacist: Takatsugu Yoda

Claims (7)

[Claims] (1) An ozone-containing gas is brought into contact with an ozone-containing gas and an ozone-containing gas is brought into contact with an ozone-containing agent made of at least one of ion-exchange fibers and activated carbon in which an ion-exchanger is supported by natural fibers or man-made fibers, and the ozone-containing agent is irradiated with ultraviolet rays. A method for treating waste ozone, which comprises decomposing the collected ozone. (2) The ultraviolet irradiation has a wavelength of 150 nm to 300 nm.
The treatment method according to claim 1, which is carried out using ultraviolet rays of m. (3) The treatment method according to claim 1 or 2, wherein ozone-containing gas is brought into contact with a fabric, knitted fabric, or nonwoven fabric made of the ion exchange fiber. (4) The treatment method according to claim 1 or 2, wherein an ozone-containing gas is brought into contact with a filling body formed by filling filaments or cloth of the ion exchange fibers. (5) The treatment method according to any one of claims 1 to 4, wherein the ion exchange fiber is one that supports an anion exchanger. (6) The treatment method according to claim 5, wherein the ion exchange fiber is a natural fiber or an artificial fiber graft-polymerized with an ion exchanger. (7) After the ozone-containing gas is subjected to at least one of the following treatments: catalytic decomposition treatment using an ozone decomposition catalyst, adsorption decomposition treatment using activated carbon, thermal decomposition treatment by heating, or absorption treatment using a chemical solution, the ozone-containing gas is processed into natural fibers or artificial fibers. Ozone-containing gas is brought into contact with an ozone scavenger made of at least one of ion exchange fibers and activated carbon supporting an ion exchanger, and the ozone scavenger is irradiated with ultraviolet rays to decompose the captured ozone. A method for treating waste ozone, the method comprising: