JPH07290071A - Method for removing organic matter and device therefor - Google Patents

Abstract

PURPOSE:To improve the efficiency in removing org. matter in the device to oxidize and decompose the org. matter in the water to be treated by irradiating the water with UV by heating the water to a specified temp. to oxidize and decompose the org. matter. CONSTITUTION:A mercury lamp 5 is set in the water tank 2 of a UV oxidation device, and an aerator 6 is provided at the lower part of the tank. The aerator 6 has a diffuser pipe 7 pierced with many holes, and air or nitrogen is introduced from a gas pipe 8 into the tank through the holes to agitate the water to be treated. UV rays mainly with 365nm wavelength are emitted when a high-pressure mercury-vapor lamp is used as the lamp 5, however the light is insufficient to dissociate the interatomic bond of the org. matter. Accordingly, an appropriate amt. of oxidizing agent is added to the water to be treated in the tank 2 from an oxidizing agent tank 12, the water is heated to 50-80 deg.C in the presence of the agent to oxidize and decompose the org. matter by irradiating the water with UV rays, and the decomposing rate is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing organic substances for producing ultrapure water and the like used in the production of semiconductors and liquid crystal displays, and an apparatus used therefor.

[0002]

2. Description of the Related Art The amount of ultrapure water used as semiconductor manufacturing water is increasing year by year, and further improvement in water quality is required as the degree of LSI integration increases. In the production of ultrapure water, the inorganic salts and organic substances contained in the water to be treated (raw water) are removed. Among them, the removal of organic substances is an extremely important process for improving the quality of ultrapure water.

The removal of organic substances contained in the water to be treated depends on the combination of various unit operations. For example, coagulation precipitation, adsorption by activated carbon, ion exchange, reverse osmosis membrane and UF
Treatments such as separation using a membrane are performed, and after most of the organic substances are removed by these treatments, the remaining organic substances are oxidatively decomposed by an ultraviolet oxidizer and removed.

[0004]

The ultraviolet oxidizer has a mechanism of irradiating ultraviolet rays of a specific wavelength from a mercury lamp to oxidize and decompose organic substances contained in the water to be treated. As a mercury lamp, a low-pressure mercury lamp is used. And there is a high pressure mercury lamp.

Generally, in treated water having a high concentration of organic substances, such as the above-mentioned cleaning waste water in a waste water recovery system for recovering a part of waste water after using ultrapure water as cleaning water during semiconductor manufacturing and recycling it. A high-pressure mercury lamp is used to perform the organic substance decomposition treatment, and the concentration of organic substances such as the treated water after the removal of inorganic salts and the removal of organic substances from the treated water or raw water after the removal of organic substances in the wastewater recovery system is performed. A low-pressure mercury lamp is used for the decomposition treatment of organic matter in the water to be treated having a very low water content. In either case, the organic substance decomposition treatment has conventionally been performed at room temperature.

In the organic substance decomposing process using the above-mentioned ultraviolet oxidizer, the organic substance removing efficiency has conventionally been a problem. For example, in a normal UV oxidizer, the concentration of methanol as an organic source is about 10 mg TOC /
When it is liter, the decomposition rate of organic matter is 1-2g TOC
/ KWH, which had a low organic matter removal efficiency (where TOC represents the total organic carbon used in the measurement of the organic matter concentration).

Therefore, if water containing the above concentration of methanol is treated at a flow rate of 10 m ³ / hr, 50 to 10
There is a problem in that a mercury lamp of 0 kW is required, which causes an increase in power cost.

Further, generally, when the organic substance concentration is high, it is necessary to increase the irradiation amount of ultraviolet rays, which leads to an increase in electric power cost. On the other hand, when the organic substance concentration is low, the reaction efficiency is lowered, so that it is important The decomposition rate of organic matter also becomes small, so in order to perform processing at a predetermined decomposition rate, the irradiation dose of ultraviolet rays must be increased,
Therefore, in this case as well, there is a problem in that the power cost also increases.

Since most of the cost required for the decomposition treatment of organic substances using the ultraviolet oxidation device is the electric power cost of the mercury lamp, it is necessary to reduce the electric power cost by the manufacturing cost in the ultrapure water production and the recovery in the waste water recovery system. It leads to cost reduction. Therefore, how to increase the decomposition rate of organic substances by ultraviolet irradiation and increase the removal efficiency thereof has been studied as an important technical problem.

The present inventor has conducted various studies on the above points. When the water to be treated is heated to 40 ° C. or higher and subjected to an ultraviolet oxidation treatment, the decomposition rate of organic substances remarkably increases,
It was found that the water temperature of 40 ° C. or higher is a very important temperature for improving the removal efficiency of organic substances.

The present invention has been completed based on such findings, and an object of the present invention is to provide a method for removing organic substances which can increase the decomposition rate of organic substances and improve their removal efficiency to contribute to the reduction of electric power cost.

Another object of the present invention is to provide an organic substance removing apparatus for carrying out the above method.

[0013]

Means for Solving the Problems In the present invention, (1) when irradiating ultraviolet rays to oxidatively decompose and remove organic matter in water to be treated, the water to be treated is heated to 40 ° C. or higher to oxidize and decompose. A method for removing organic substances, characterized by performing a treatment,
(2) The oxidative decomposition treated water in a heated state after the completion of the oxidative decomposition treatment is caused to flow into the heat exchanger, and heat is exchanged with the treated water in the heat exchanger to add the treated water. While warming, the water to be treated is further heated by using an auxiliary heating means to 40
The method for removing organic matter according to (1) above, wherein the water temperature is at least ℃, (3) the oxidative decomposition water in a heated state after completion of the oxidative decomposition treatment is caused to flow into a heat exchanger, and the heat The oxidative decomposition treated water is cooled by performing heat exchange with the water to be treated in the exchanger, and the cooled oxidatively decomposed treated water is passed through an ion exchange device using at least an anion exchange resin to oxidize. (4) A method for removing an organic substance according to the above (1) or (2), characterized in that a decomposition product is removed.
The method for removing organic substances according to (3) above, wherein the ion exchange resin used in the ion exchange apparatus is an externally regenerated ion exchange resin, and (5) the treated water is irradiated with ultraviolet rays to be treated. An ultraviolet oxidizer for oxidizing and decomposing organic matter in water, and a treated water heating device provided in the ultraviolet oxidizer or on the treated water inflow side of the ultraviolet oxidizer. The organic matter removing device, (6) the treated water heating device is composed of a combination of a heat exchanger into which oxidative decomposition treated water in a heated state after completion of oxidative decomposition treatment is introduced and an auxiliary heating means. The feature is the organic substance removing device described in (5) above.

The method and apparatus of the present invention are preferably used for ultrapure water production, but are not limited thereto and can be used, for example, for pharmaceutical water production. Examples of ultrapure water in the case of ultrapure water production include water for semiconductor production and water for liquid crystal display production. This ultrapure water production process is divided into several systems as described below, and the present invention can be applied to any system including oxidative decomposition treatment of organic substances in the process.

That is, in the ultrapure water production process, most of the impurities contained in the raw water are removed, and in particular, the organic matter concentration is reduced to the order of ppb, and a small amount of primary pure water contained in the primary pure water. After the ultrapure water is manufactured by completely removing the impurities in the product and improving the water quality to an impurity concentration close to that of theoretical pure water, and after using the manufactured ultrapure water as semiconductor manufacturing water (cleaning water), etc. It consists of a wastewater recovery system for recovering and reusing a part of the wastewater (washing wastewater).

In the primary pure water system, the raw water is passed through an aggregating / filtering device, a reverse osmosis membrane device, a degassing device, an ion exchange device equipped with a regenerator, and the like to remove inorganic salts and organic substances in the raw water, and further fine particles. Remove most. In the subsystem, the primary pure water obtained from the primary pure water system is passed through an ultraviolet oxidation device, a cartridge type ion exchange device without a regeneration facility, an ultrafiltration device, etc. , The concentration of fine particles is reduced to the utmost, and the desired pure water is obtained.

Further, in the waste water recovery system, the washing waste water is passed through an activated carbon filtration device, an ultraviolet oxidation device, an ion exchange device, etc. to remove acids, alkalis and organic substances in the waste water.

An ultraviolet oxidizer is used in the above-mentioned subsystem and waste water recovery system to oxidize and decompose organic substances, but a low pressure mercury lamp is usually used in the ultraviolet oxidizer in the subsystem.
A high pressure mercury lamp is usually used for the ultraviolet oxidation device in the waste water recovery system. INDUSTRIAL APPLICABILITY The present invention can be applied to the oxidative decomposition treatment of organic matter by ultraviolet irradiation carried out in such a subsystem and wastewater recovery system. That is, the present invention can be applied to any of the above-mentioned subsystems and waste water recovery systems. Therefore, the present invention can also be applied to any of an ultraviolet oxidation device using a low pressure mercury lamp or an ultraviolet oxidation device using a high pressure mercury lamp. Is possible.

In the present invention, the water to be treated is heated to 40 ° C. or higher, and known heating means is used for this heating. For example, as shown in FIG. 1, the water tank 2 of the ultraviolet oxidation apparatus 1 is used.
A method of installing an electric heating type heater 3 therein, a method of providing steam heating by providing a steam heating passage in the water tank 2, which is not particularly shown, and the like are adopted. Further, the heating device for heating is not limited to the mode provided in the ultraviolet oxidation device 1, and as shown in FIG. Alternatively, a heating device 4 adopting a known heating method may be installed, and the water to be treated heated to a predetermined temperature by the device 4 may be guided to the ultraviolet oxidation device 1.

Further, as will be described later, it is possible to employ a heating method in which heating by passing through a heat exchanger and heating by an auxiliary heating means are combined.

When the present invention is applied to the production of ultrapure water, the primary pure water treated by the primary pure water system or water obtained by mixing the primary pure water with the wastewater recovered treated water by the wastewater recovery system. Is usually used as the water to be treated in the present invention, but is not limited to these.

The ultraviolet oxidation device shown in FIG. 1 represents a basic configuration example of the device of the present invention. A mercury lamp 5 is installed in the water tank 2 and an aerator 6 is installed in the lower part of the tank. There is. The aeration device 6 is an air diffuser 7 having a large number of holes.
And introducing air or nitrogen gas into the tank from the gas pipe 8,
It has the effect of stirring the water to be treated. The number of mercury lamps 5 installed is appropriately determined according to the concentration of organic substances in the water to be treated.

Reference numeral 9 is a stabilizer electrically connected to the mercury lamp 5, 10 is an inflow pipe for the water to be treated, and 11 is an outflow pipe for the oxidative decomposition treated water.

Reference numeral 12 denotes an oxidizer tank, which is constructed so that the oxidizer can be supplied from the oxidizer tank 12 into the water tank 2 through a supply pipe 13 provided in communication with the inflow pipe 10. When a high-pressure mercury lamp is used as the mercury lamp 5, ultraviolet rays having a wavelength of 365 nm are mainly generated, but the energy of the light having this wavelength is insufficient to dissociate the interatomic bond of the organic substance, and therefore the oxidizer Combination is required. Therefore, in this case, an appropriate amount of the oxidizing agent is added to the water to be treated in the water tank 2 from the oxidizing agent tank 12, and the organic matter is oxidatively decomposed by the irradiation of ultraviolet rays in the combined use state of the oxidizing agent. Hydrogen peroxide, sodium hypochlorite, chlorine, ozone and the like are used as the oxidizing agent, and hydrogen peroxide is most preferable. The amount of the oxidizing agent added is determined by the concentration of organic substances in the water to be treated.

On the other hand, when a low-pressure mercury lamp is used as the mercury lamp 5, a wavelength of 1
It emits 85 nm UV light, and this 185 nm UV light has enough light energy to dissociate the interatomic bonds of organic substances. Therefore, when a low pressure mercury lamp is used, it is not necessary to use an oxidizing agent together. It is possible to oxidize and decompose organic substances.

As described above, according to the present invention, the water to be treated is 40
The organic substance is oxidatively decomposed by heating it to a temperature of not lower than 40 ° C. The water temperature of the water to be treated is set to 40 ° C. or higher because the decomposition rate of the organic substance cannot be increased so much at a temperature lower than 40 ° C. That is, when the water temperature is 40 ° C. or higher, the decomposition rate tends to rapidly increase. Therefore, in order to effectively improve the decomposition rate, the water temperature must be 40 ° C. or higher. The higher the water temperature, the greater the effect of increasing the decomposition rate, but when the water temperature reaches 100 ° C., boiling occurs and handling becomes troublesome, so the water temperature is preferably less than 100 ° C. In the present invention, the preferred water temperature is 50 ° C. or higher, 8
It is less than 0 ° C. By setting the temperature to 50 ° C. or higher, the decomposition rate of organic substances can be sufficiently increased, which is extremely effective in reducing the power cost. Further, if the temperature is higher than 80 ° C., the thermal cost becomes high, which is not economically advantageous.

As described above, the low-pressure mercury lamp or the high-pressure mercury lamp is used as the mercury lamp 5. Which mercury lamp is used is determined by the quality of the water to be treated. For example, in the case of water to be treated that has a low organic matter concentration and is reduced to the ppb order, such as primary pure water in the ultrapure water production process described above, a low-pressure mercury lamp is usually used. A high-pressure mercury lamp is usually used for water to be treated which has a relatively high concentration of organic substances and a concentration of the order of ppm, such as cleaning wastewater in a wastewater recovery system during the ultrapure water production process.

In the above structure, the water to be treated is caused to flow into the water tank 2 of the ultraviolet oxidation device 1 through the inflow pipe 10, and the oxidant is supplied from the oxidant tank 12 into the water tank 2 as necessary.

A gas such as air or nitrogen gas is sent into the water tank 2 from the aeration device 6 to stir the water to be treated, and at the same time, the water to be treated is heated by the heater 3 to bring the water temperature to 40 ° C. or higher. While maintaining the water temperature at 40 ° C. or higher, ultraviolet rays are radiated from the mercury lamp 5 to oxidize and decompose organic substances contained in the water to be treated. After the oxidative decomposition treatment is completed, treated water (oxidative decomposition treated water) is caused to flow out from the outflow pipe 11.

Taking methanol as an organic substance as an example, the oxidative decomposition by ultraviolet irradiation will be described. The ultraviolet oxidation reaction is carried out as follows. CH ₃ OH + 1 / 2O ₂ → HCHO + H ₂ O ··· (1) HCHO + 1 / 2O ₂ → HCOOH ··· (2) HCOOH + 1 / 2O ₂ → CO ₂ + H ₂ O ... ・ (3)

In the present invention, the water temperature of the water to be treated during the reaction is 40 ° C.
By the above, the reaction rate can be significantly increased in any of the reactions of the above formulas (1) to (3).

The above oxidation reaction may be stopped by the reaction of the formula (2) if necessary. In this case, the organic acid (HCOOH) generated as an oxidative decomposition product is usually removed by a deionization treatment as a post process. As the deionization treatment, an ion exchange treatment is generally performed with an ion exchange resin, and an organic substance which is an oxidative decomposition product is adsorbed by the anion exchange resin and removed. Even when the reaction proceeds to the formula (3), CO ₂ which is an oxidative decomposition product can be similarly removed by the anion exchange resin.

FIG. 2 shows a process diagram when the ion exchange process is performed as a post process. As shown in this process diagram, an ion exchange device 14 is installed at the subsequent stage of the ultraviolet oxidation device 1. In this case, the oxidative decomposition treated water flowing out from the ultraviolet oxidizer 1 has a water temperature of 40 ° C. or higher, and the oxidative decomposition treated water having such a high temperature is directly transferred to the ion exchange device 1.
If it is brought to 4, the ion exchange resin, particularly the anion exchange resin, may be thermally deteriorated. Therefore, as shown in FIG. 2, it is preferable to install a cooling device 15 in front of the ion exchange device 14, cool the treated water to a predetermined temperature or lower by the cooling device 15, and then guide the treated water to the ion exchange device 14. . In the figure, 35 indicates a treated water outflow pipe.

A heat exchanger 16 as shown in FIG. 3 may be used as a means for cooling the oxidative decomposition treated water. In the embodiment shown in the figure, the heat exchanger 16 is the ultraviolet oxidation device 1
The oxidative decomposition treatment water which is provided in the previous stage, that is, on the inflow side of the water to be treated and which has flowed out from the ultraviolet oxidation device 1 flows into the main casing 17 of the heat exchanger 16 through the outflow pipe 11. On the other hand, the water to be treated supplied from the first inflow pipe 18 flows into the flexible pipe 19 provided in the main body casing 17.

The oxidatively decomposed water is mixed in the heat exchanger 16 with the flexible pipe 1.
By contacting with the water to be treated via 9, heat exchange is carried out, whereby the oxidative decomposition treated water is cooled and, conversely, the water to be treated is heated. The oxidatively decomposed water thus cooled flows out from the outlet of the main body casing 17, and is guided to the ion exchange device 14 via the water supply pipe 20. In order to prevent thermal deterioration of the ion exchange resin, the oxidative decomposition treated water is 20 ° C ~
It is preferable to cool to 30 ° C.

The embodiment shown in FIG. 3 also shows a mode in which the water to be treated is heated through the heat exchanger 16 as described above. Although it is possible to heat the water to be treated to a certain temperature by such a method, it is difficult to heat the water to a target water temperature of 40 ° C. or higher only by the heat exchange. Therefore, as shown in the figure, it is necessary to install a heating device 21 such as a heater as an auxiliary heating means in the ultraviolet oxidation device 1 and combine the heating by the heat exchanger 16 and the heating by the auxiliary heating means. Is. According to the embodiment shown in FIG. 3, the water to be treated, which has been heated to a certain temperature by the heat exchanger 16, flows into the ultraviolet oxidation device 1 through the second inflow pipe 22, and is heated by the heating device 21 in the device. It is further heated and raised to a water temperature of a predetermined temperature (40 ° C. or higher).

The auxiliary heating means is not limited to the case where it is installed in the ultraviolet oxidation device 1, and as shown in FIG.
A heating device 23 as an auxiliary heating means may be provided between 6 and the ultraviolet oxidation device 1.

Further, the auxiliary heating means may be a heat exchanger as shown in FIG. That is, the figure shows the ultraviolet oxidation device 1
Two heat exchangers 24, 25 are installed on the inflow side of the untreated water, and the first heat exchanger 24 is used for heating the untreated water and for cooling the oxidative decomposition treated water, and also for the second heat exchange. A mode in which the vessel 25 is used for auxiliary heating of the water to be treated is shown. In the same figure, the water to be treated is fed from the first inflow pipe 26 to the first
It flows into the flexible pipe 27 of the heat exchanger 24. On the other hand, the oxidative decomposition treated water flowing out from the ultraviolet oxidizer 1 flows into the main body casing 28 of the first heat exchanger 24 via the outflow pipe 11, and heat exchange is performed with the water to be treated flowing in the flexible pipe 27. And
As a result, the water to be treated is heated to a certain temperature. The oxidatively decomposed water is cooled by heat exchange and is cooled by the body casing 28.
Out of the outlet of the ion exchange device 1 through the water pipe 20
Guided to 4.

The heated water to be treated flows into the flexible pipe 30 of the second heat exchanger 25 through the connecting pipe 29. Hot water is supplied from a hot water inflow pipe 32 into the main body casing 31 of the second heat exchanger 25, the hot water comes into contact with the water to be treated through the flexible pipe 30, and the main body passes through the hot water outflow pipe 33. It flows out of the casing 31. Due to the heat exchange at this time, the water to be treated is heated to a higher temperature and reaches the target water temperature of 40 ° C. or higher. In this way, the second heat exchanger 25 treats the water to be treated at 40 ° C.
It functions as an auxiliary heating means for raising the temperature to the above water temperature. The water to be treated which has been raised to a predetermined temperature by the second heat exchanger 25 flows into the ultraviolet oxidation device 1 through the second inflow pipe 34.

As described above, the oxidative decomposition treated water in a heated state after the completion of the oxidative decomposition treatment of the organic substance is supplied to the heat exchanger,
If the heat exchanger is configured to exchange heat with the water to be treated, the heat energy can be effectively recovered and the treatment cost can be reduced.

Thus, in the present invention, the ultraviolet oxidation device 1
When the ion exchange device 14 including at least an anion exchange resin is installed in the subsequent stage, the oxidative decomposition product can be removed from the treated water after the organic substance decomposition treatment (oxidative decomposition treated water), Treated water with excellent water quality can be obtained, and the obtained treated water can be used as, for example, ultrapure water. Here, it is also possible to use a regenerated ion exchange resin that is regenerated outside as the ion exchange resin. The regenerated ion exchange resin is a cartridge type in which the ion exchange resin regenerated in advance is packed in a tower, and the handling method thereof is roughly as follows. That is, a plurality of cartridge type ion exchange resins (regenerated ion exchange resins) are prepared, and when the ion exchange resin in use is in an ion saturated state, the regeneration process is not performed on the spot, and other prepared in advance. Replace with the regenerated ion exchange resin. Since it is a cartridge type, replacement work is easy. The reproduction process is carried back to another place. The cartridge type ion exchange device is preferably used in a subsystem having a small amount of impurity ions.

The regenerated ion exchange resin used in the ion exchange device 14 may be any one as long as it contains at least an anion exchange resin, for example, a mixture of a regenerated cation exchange resin and a regenerated anion exchange resin, Alternatively, the regenerated anion exchange resin may be a single product, or a combination of the mixed product and the single product.

[0043]

EXAMPLES Examples of the present invention will be described below. EXAMPLE 42 liters of water to be treated was placed in a water tank made of stainless steel, and a mercury lamp was installed so as to be located in the water. As the mercury lamp, a 400 W high-pressure mercury lamp capable of generating ultraviolet rays having a main wavelength of 365 to 366 nm (90%) was used. The water to be treated has a methanol concentration of approximately 100 mg TOC
/ Liter of water (prepared by diluting methanol with ultrapure water) was used. Methanol concentration of 1 mg
20 mg / l hydrogen peroxide per TOC / l was added.

The water to be treated was heated by a heater installed in the water tank, and an aerator was installed in the water tank to introduce air to stir the water to be treated. Ultraviolet rays were irradiated from a high pressure mercury lamp to oxidize and decompose methanol. At this time, the water temperature of the water to be treated was variously changed as shown in Table 1, and the time until the methanol concentration reached 5 mg · TOC / liter was measured under each water temperature. The results are shown in Table 1.

The organic substance decomposition rate at each water temperature was calculated from the measurement result of the above time, and the organic substance decomposition rate at other water temperatures was calculated as a relative value when the organic substance decomposition rate at the water temperature of 20 ° C. was set to 1. This is shown in Table 1 as a relative ratio of the organic substance decomposition rate. FIG. 6 is a graph showing the relationship between the numerical value of the relative rate of the decomposition rate of organic matter and the water temperature.

[0046]

[Table 1]

According to the above results, the organic substance decomposition rate at a water temperature of 40 ° C. is 1.6 times that at a water temperature of 20 ° C., and similarly, at a water temperature of 80 ° C., it is 11 times. From this, it is understood that the rate of decomposition of organic substances can be greatly increased by heating the water to be treated to 40 ° C. or higher. Moreover, according to the graph of FIG.
It was found that the decomposition rate of organic matter increased rapidly, and the water temperature was 40
This proves that the temperature range of ℃ or above has a critical significance.

[0048]

As described above, according to the method of the present invention, the treated water is
Since the organic substances are oxidatively decomposed by being heated to 0 ° C. or higher and irradiated with ultraviolet rays, the decomposition rate of the organic substances can be remarkably increased, and as a result, the removal efficiency of the organic substances can be dramatically improved.

Thus, according to the method of the present invention, the efficiency of removing organic substances can be improved, and as a result, it is possible to perform the treatment at a desired rate without increasing the wattage and the number of mercury lamps to be installed, thus reducing the power consumption. It is possible to contribute to the reduction of the processing cost.

Further, since the apparatus of the present invention is provided with the treated water heating apparatus, it is possible to easily control the temperature of the treated water and adjust the temperature, and change the set temperature during the oxidative decomposition treatment. Etc., there is an advantage that free temperature control can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration example of a device of the present invention.

FIG. 2 is a diagram showing a treatment process of the present invention including an ion exchange treatment process.

FIG. 3 is a diagram showing a treatment process of the present invention including a heat recovery process of oxidative decomposition treated water.

FIG. 4 is a diagram showing a processing step of the present invention in another aspect of the heat recovery step.

FIG. 5 is a diagram showing a processing step of the present invention in another aspect of the heat recovery step.

FIG. 6 is a graph showing the relationship between the relative ratio of the decomposition rate of organic matter and the water temperature.

[Explanation of symbols]

 1 UV oxidizer 2 Water tank 3 Heater 4 Heating device 5 Mercury lamp

Claims (6)

[Claims] 1. Removal of organic matter by irradiating ultraviolet rays to oxidatively decompose and remove organic matter in the water to be treated, wherein the water to be treated is heated to 40 ° C. or higher to perform the oxidative decomposition treatment. Method. 2. The oxidative decomposition treated water in a heated state after completion of the oxidative decomposition treatment is caused to flow into a heat exchanger, and heat is exchanged with the water to be treated in the heat exchanger to obtain the treated water. The method for removing organic substances according to claim 1, wherein the water to be treated is further heated by using an auxiliary heating means to bring the water temperature to 40 ° C. or higher. 3. Oxidative decomposition treatment by causing oxidative decomposition treatment water in a heated state after completion of oxidative decomposition treatment to flow into a heat exchanger, and causing heat exchange with water to be treated in the heat exchanger. 3. The organic substance according to claim 1 or 2, wherein water is cooled and the cooled oxidative decomposition treated water is passed through an ion exchange device using at least an anion exchange resin to remove oxidative decomposition products. Removal method. 4. The method for removing organic substances according to claim 3, wherein the ion exchange resin used in the ion exchange apparatus is a regenerated ion exchange resin regenerated outside. 5. An ultraviolet oxidizer for irradiating the water to be treated with ultraviolet rays to oxidize and decompose organic matter in the water to be treated, and an ultraviolet oxidizer provided inside the ultraviolet oxidizer or on the inflow side of the ultraviolet oxidizer to the water to be treated. An apparatus for removing organic matter, comprising: 6. The treated water heating apparatus is configured by a combination of a heat exchanger into which warmed oxidative decomposition treated water after completion of oxidative decomposition treatment is introduced and an auxiliary heating means. The organic matter removing device according to claim 5.