JPH08115705A - Mercury lamp and substance treatment method using the mercury lamp - Google Patents

Abstract

PURPOSE: To provide an economical substance treatment method and a mercury lamp for using in the treatment. CONSTITUTION: In a mercury lamp prepared by sealing mercury and a noble gas in a luminescent tube made of quartz glass and having electrodes sealed at both ends, the amount of mercury sealed is specified to 1.0-5.0mg per cm<3> of the inner volume of the luminescent tube, and the inner diameter of the luminescent tube is specified to 3.0-20.0mm. A fluid to which a material forming an oxidizing active material by receiving light having a wave length of 200-280nm is added is irradiated with the mercury lamp to treat the fluid itself or an another material by the fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photochemical reaction using ultraviolet rays in the wavelength region of 200 nm to 280 nm, such as a water treatment method of oxidizing and removing organic substances by adding an oxidizing agent such as ozone and irradiating ultraviolet rays. And a fluid treatment method using the same.

[0002]

2. Description of the Related Art Conventionally, a water treatment method which combines irradiation of an ultraviolet lamp and addition of an oxidizing agent such as hydrogen peroxide or ozone has been used for the primary treatment of ultrapure water and industrial wastewater treatment. These oxidizers have absorption in the wavelength range of 200 nm to 280 nm, photolyze in water to generate hydroxy radicals, and oxidize organic substances to remove them as vaporizable substances. Also, irradiate ozone-containing air with ultraviolet rays,
A method of decomposing and activating ozone to obtain nascent oxygen and treating the substance with the oxygen is applied to, for example, precision cleaning or sterilization of the surface of an object. 200 nm wavelength for the above treatment
A UV lamp with good radiation efficiency in the wavelength range of 280 nm is required. Among them, the radiation efficiency of the low-pressure mercury lamp is 20 in the wavelength range of 200 nm to 280 nm.
% -30% is good, but the power per lamp is usually 1
Since it is less than kW, it is necessary to use a large number in order to process a large amount of fluid. On the other hand, a single high-pressure mercury lamp can be used with a power of several tens of kW and can process a large amount of fluid, but the radiation efficiency of the conventional one is about 10 in the wavelength range of 200 nm to 280 nm. %
Therefore, the radiation efficiency is inferior to that of the low-pressure mercury lamp.

[0003]

When the low pressure mercury lamp is used, since the number of lamps used is large, the device is obviously large. Moreover, the cost of maintenance such as lamp replacement and cleaning of the lamp jacket and space is higher than that of the high pressure mercury lamp. On the other hand, the conventional high-pressure mercury lamp has poor radiation efficiency, and therefore is twice to 3 times as high as the low-pressure mercury lamp.
Since it requires twice as much power, the electricity bill is higher than for low pressure mercury lamps. However, increasing the output of a low-pressure mercury lamp has an upper limit to the nature of the lamp. Therefore, it is necessary to provide a high-efficiency high-pressure mercury lamp to provide a fluid treatment method that uses fewer lamps. The present invention has been made in view of the above circumstances, and an object thereof is to provide a more economical method of treating a substance and a mercury lamp therefor.

[0004]

The object of the present invention can be achieved by designing a mercury lamp as follows. (1) In a mercury lamp in which mercury and a noble gas are enclosed in a quartz glass arc tube with electrodes sealed at both ends, the amount of enclosed mercury is 1.0 mg per 1 cm ^{3 of the} lamp arc tube inner volume.
To 5.0 mg, and the inner diameter of the arc tube is 3.
The length is 0 mm to 20.0 mm.

The fluid treatment method is as follows. (2) Is the fluid itself treated by irradiating with a mercury lamp as described in (1) above a fluid to which a substance that generates an oxidative active substance upon receiving light in the wavelength range of 200 nm to 280 nm is added? Alternatively, another substance is treated with the fluid.

[0006]

FIG. 1 shows the respective spectral distributions when the high pressure mercury lamp used conventionally and the mercury lamp of the present invention are lit with the same power. The solid line is the spectral distribution of the conventional lamp and the dotted line is the spectral distribution of the lamp of the present invention. The lamp of the present invention has a wavelength of 20.
In the wavelength range from 0 nm to 240 nm, a continuous spectrum is emitted by molecular emission that is stronger than that of conventional lamps, and a spectral band (S) that extends to the long wavelength side of the resonance line of 254 nm wavelength of mercury due to intermolecular force (S) Emit. For the above reason, the high pressure mercury lamp of the present invention has a wavelength of 200
The radiation efficiency in the range of nm to 280 nm is about 1.4 times that of the conventional lamp. We also found that the efficiency is further improved by using synthetic quartz glass for the arc tube.

The transmittance between synthetic quartz glass and ordinary quartz glass is usually different at room temperature at short wavelengths of 200 nm or less, and not at wavelengths of 200 nm or more. However, the arc tube temperature of the high-pressure mercury lamp is 700 ° C during lighting and use.
As described above, at that temperature, the absorption edges of both quartz glasses move to the long wavelength side, and the transmittance of ordinary quartz glass in the wavelength range of 200 nm or more is greatly reduced. On the other hand, in synthetic quartz glass, the absorption edge moves to the long wavelength side,
No significant change is observed in the range of 0 nm or more. For these reasons, it is presumed that the synthetic quartz glass becomes larger in the wavelength range of 200 nm or more, and the above-mentioned action occurs.

Therefore, in the fluid to be treated, a wavelength of 200n
When a substance that absorbs light in the wavelength range from m to 280 nm to generate an oxidatively active substance, such as ozone, hydrogen peroxide, hypochlorous acid or chlorine, is added and irradiated with the lamp of the invention, productivity is improved. High-performance fluid treatment is possible. The surface of plastics can be modified with this fluid.

[0009]

EXAMPLE An example of the present invention will be described with reference to FIG. FIG. 2 is an explanatory view of an embodiment of the mercury lamp of the present invention. In the figure, there are sealing parts 2 at both ends of an arc tube 1, and an electrode 4 and an external lead bar 5 are provided on both sides of a molybdenum foil 3 embedded in the sealing part 2.
Are welding. The arc tube 1 is filled with mercury 6 and argon as a starting gas. The distance between the electrodes was 100 mm, and the material of the electrodes was thoriated tungsten. 12mm arc tube inner diameter, 18 mm, and 24 mm, the mercury filling amount as ^{0.2mg / cm 3 ~6.0mg / cm 3} , was measured radiation efficiency manufactured various lamps. The electric input of the lamp was turned on at 80 W and 120 W per 1 cm of arc length, and the radiation efficiency of each was measured.

The above measurement results are shown in the table of FIG. The value is the value (%) obtained by dividing the radiant flux (W) in the wavelength range of 200 nm to 280 nm by the power consumption (W) and multiplying by 100.
Is. From this result, it can be seen that at 80 W / cm, the radiation efficiency is 10% or more when the inner diameter of the arc tube is 12 mm and the amount of enclosed mercury is in the range of 1.0 mg / cm ³ to 5.0 mg / cm ³ . Enclosed mercury amount is 5.0 mg / cm
^If it is more than ³ , the lamp voltage is high and the pressure in the lamp is high, so it was judged to be unsuitable for practical use. It was also confirmed that increasing the electrical input density improves the efficiency.

The following experiment was conducted to further investigate the conditions. The electrical input is 80 W / cm. With the amount of enclosed mercury kept constant at a value of 3.9 mg / cm ³ , various lamps were produced in which the inner diameter of the arc tube was changed in the range of 3.0 mm to 20.0 mm, and the radiation efficiency was measured in the same manner as above. . As a result, it was confirmed that an arc tube having an inner diameter of 3.0 to 20.0 mm had an efficiency of 10% or more. The results are shown in the table of FIG. The meaning of the numerical values of the data is the same as in the table of FIG. Here, the inner diameter of the arc tube is 12 mm and the amount of enclosed mercury is 3.
The arc tube of the 9 mg / cm ³ lamp was changed to synthetic quartz glass, and the electric input was 80 W / c for a distance between the electrodes of 100 mm.
When turned on at m and measured the radiation efficiency, the above value is 1
It was 5.8%. Further, when the electric input was 120 W / cm, the above value was 17.5%.

Next, an example of a liquid-phase photochemical reaction using the mercury lamp of the present invention will be described. The mercury lamp of the present invention and the conventional high-pressure mercury lamp were used to decompose organic substances by ultraviolet rays, and the treatment effects of both were compared. For the decomposition of organic substances by ultraviolet rays, an aqueous solution of hydrogen peroxide is added to the water to be treated, and by irradiation of ultraviolet rays, hydroxyl radicals are generated from the hydrogen peroxide and reacted with the organic compounds in the water to be treated, and then they are converted into carbon dioxide and water. It is decomposed and removed.

In the experiment, 1 m ^{3 of} simulated waste water containing methanol, 2-propanol and acetone was poured into a reaction tank, and then hydrogen peroxide was added in an amount of 70 g in terms of hydrogen peroxide. Then, a quartz glass lamp jacket incorporating the mercury lamp of the present invention was inserted into the reaction vessel, and the lamp was turned on. At this time, the reaction tank is kept in a stirring state so that the reaction is sufficiently carried out. In the above lamp, the inner diameter of the arc tube is 12 mm, the amount of mercury is 3.9 mg / cm ³ , and the distance between the electrodes is 100 mm. In contrast, conventional lamps
Inner diameter of arc tube is 24 mm, mercury content is 0.98 mg / cm
^A comparative experiment was carried out using a ^three- electrode distance of 100 mm. Each of the lamps was turned on at a power of 1 kW, and the total organic carbon (TOC) concentration was measured at regular intervals. As a result, it was confirmed that the amount of decrease in TOC concentration with the lamp of the present invention was about 1.3 times that with the conventional lamp for the same irradiation time.

FIG. 5 is an explanatory diagram of data obtained from the above experiment. The vertical axis represents the TOC concentration, and the horizontal axis represents the irradiation time of the lamp. The curve indicated by the solid line is for the conventional lamp, the curve indicated by the dotted line is for the lamp of the present invention, and it is understood that the reduction rate of TOC is higher in the present invention. Therefore, it helps improve water quality.

Next, an example of a chemical reaction in a gas phase using the mercury lamp of the present invention will be described. The surface of polyethylene terephthalate resin was modified using the mercury lamp of the present invention and the conventional high pressure mercury lamp, respectively. After the lamp has been lit and the discharge has become stable, the polyethylene terephthalate resin measuring 3 cm x 3 cm x 1 mm in thickness is placed in a position 100 mm away from the arc tube of the lamp and irradiated for 10 seconds in an atmosphere of oxygen. did. In the case of the conventional lamp, the contact angle of pure water changed from 90 ° to 60 °.
In the lamp of the present invention in which the synthetic quartz glass was used for the arc tube, the above value changed from 90 ° to 43 °. That is, it can be seen that the hydrophilicity is sufficiently increased as compared with the case where the conventional lamp is used, and the surface is modified.

Further, although the above is the one in which the surface treatment of the plastics is carried out by utilizing the gas phase reaction, it is obvious that it can also be used in the sterilization treatment method of the atmosphere itself.

[0017]

According to the present invention, the wavelength is from 200 nm to 2
The radiation efficiency of ultraviolet rays in the range of 80 nm is 1.4 to 1.7 times that of the conventional lamp. Then, the electric power for obtaining the same ultraviolet energy can be suppressed to 71 to 58%. Alternatively, if the same electric power as in the conventional case is used, the photoreaction processing time can be suppressed to 71 to 58%. The mercury lamp of the present invention is advantageous over the method of using the low-pressure mercury lamp because the cost is reduced by improving the radiation efficiency. Therefore, when using the mercury lamp of the present invention to treat a fluid or to treat a solid surface, it is possible to perform a faster treatment than to use conventional lamps or to perform a sufficient treatment at the same treatment time. It has the advantage that the cost can be achieved cheaply, and the economical treatment method can be planned as a whole.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a spectral distribution of a conventional high pressure mercury lamp and a mercury lamp of the present invention.

FIG. 2 is an explanatory diagram of a mercury lamp of the present invention.

FIG. 3 shows a wavelength of the mercury lamp of the present invention from 200 nm to 2
It is explanatory drawing of the measurement result of the radiation efficiency in the range of 80 nm.

FIG. 4 shows a wavelength of the mercury lamp of the present invention from 200 nm to 2
It is explanatory drawing which shows the result of having investigated the radiation efficiency in the range of 80 nm in detail about the inner diameter of an arc tube.

[Explanation of symbols]

 1 Arc Tube 2 Sealing Part 3 Molybdenum Foil 4 Electrode 5 External Lead Rod 6 Mercury

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[Procedure amendment]

[Submission date] February 1, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 5

[Correction method] Added

[Correction content]

FIG. 5 is an explanatory diagram showing the results of examining the treatment effect by decomposition of organic substances by ultraviolet rays using the mercury lamp of the present invention and a conventional high pressure mercury lamp.

Claims (4)

[Claims] 1. A mercury lamp in which mercury and a rare gas are enclosed in a quartz glass arc tube having electrodes sealed at both ends,
The amount of enclosed mercury is 1.0 per 1 cm ^{3 of the} internal volume of the lamp arc tube.
A mercury lamp characterized in that the inner diameter of the arc tube is in the range of 3.0 mm to 20.0 mm and is defined in the range of mg to 5.0 mg. 2. The mercury lamp according to claim 1, wherein the arc tube is a cylindrical long synthetic quartz glass. 3. The mercury-containing lamp according to claim 1 is irradiated with a fluid to which a substance that produces an oxidative active substance upon receiving light in the wavelength range of 200 nm to 280 nm is added to treat the fluid itself. Or a method of treating a substance, which comprises treating another substance with the fluid. 4. The method for treating fluid according to claim 3, wherein the substance is a substance selected from ozone, hydrogen peroxide, hypochlorous acid or chlorine, and the fluid is water or air. .