JPH11179154A - Method and apparatus for cleaning of air pollution hazardous substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decompose and remove even air pollution hazardous substances such as chloroform in a paper pulp manufacturing process, etc., by utilizing photocatalytic reaction and to continuously use a photocatalyst body without decreasing function of the photocatalyst body, under a stable condition and for a long time. SOLUTION: Air pollution hazardous substances in a gas poured into a photocatalytic reactor B in which a photoreactive semiconductor carrying substance A is stored are irradiated with a UV rays-contg. light from a light source C for irradiating the UV rays-contg. light. Acidic gases generated in a decomposed gas decomposed by photocatalytic reaction are reacted with water or a basic substance in a gas collector D to perform cleaning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for purifying air pollutants, and more particularly, to a method for purifying air pollutants such as chloroform generated in a paper pulp manufacturing process using a photocatalytic reaction. The present invention relates to a purification method and apparatus for decomposing and removing.

[0002]

2. Description of the Related Art With increasing interest in the living environment, there has been an increasing demand for the removal of harmful substances in daily life such as odors, and the development of air purifiers incorporating odor removal devices and the like has been actively carried out. I have. In these apparatuses, a filter mainly containing activated carbon is used, and a method of adsorbing malodorous substances on activated carbon has been adopted. However,
Activated carbon has an adsorption effect but has no decomposition ability, so it will be saturated when it absorbs a certain amount of harmful substances such as malodorous substances.
The filters had to be replaced periodically.

In recent years, as a solution to such a problem, a composite material in which activated carbon and a catalyst for decomposing harmful substances are combined has been developed. For example, Japanese Patent Application Laid-Open No. 1-2347
No. 29 discloses an air conditioner incorporating a photoreactive semiconductor composite in which titanium oxide as a photocatalytic layer for decomposing odor components is supported on activated carbon having a honeycomb shape or the like that adsorbs odor components. In this case, a part of the adsorbed malodorous component is decomposed by OH radicals generated from the surface of the photoreactive semiconductor, so that the adsorbing ability of activated carbon can be maintained for a relatively long time. However, in this method, activated carbon having a special structure such as a honeycomb shape is required to support the photoreactive semiconductor and increase the photoreaction efficiency, and titanium oxide is retained on the surface of the activated carbon and the inside of the honeycomb. A special process was required. Further, as a method of removing harmful substances in the gas phase using titanium oxide as a catalyst for photodecomposing harmful substances, for example, Japanese Patent Application Laid-Open No. 2-253848 discloses a method in which an anatase type titanium oxide is supported on an inorganic fibrous carrier. Ozonolysis catalysts are disclosed.

In addition, Japanese Patent Application Laid-Open No. 3-233100 discloses a ventilating facility comprising a mixture of titanium dioxide and activated carbon and a light source for irradiating the mixture with light having a wavelength of 300 nm or more. -256755,
It is disclosed that by supporting titanium dioxide or the like on granular pulp, it can be used as a household deodorant and deodorant. Further, Kusunaga et al. Performed photodecomposition of organic halogen compounds by holding titanium dioxide on ceramic paper (Journal of the Electrochemical Society, vol. 60, pp. 107,
1992). On the other hand, from the viewpoint of global environmental protection, reduction of air pollution harmful substances emitted from various chemical factories is being implemented. In the paper industry, chemicals such as chloroform, benzene and formaldehyde emitted from factories are being reduced. Substances are subject to reduction.

[0005] However, in the above-mentioned prior art, no consideration was given to various acids which are secondary products generated by photolysis of harmful substances in the gas phase. For example, aldehydes such as formalin, which is one of the air pollutants due to photocatalytic decomposition of titanium oxide, are carboxylic acids as decomposition intermediates, and hydrogen chloride as a final product from chlorine-containing compounds such as chloroform, N
Various acids such as nitric acid are generated as final products from nitrogen-containing compounds such as Ox, and sulfuric acid is generated as final products from sulfur-containing compounds such as SOx. Since these strong acids are adsorbed on the solid surface of a photocatalyst such as titanium oxide, the decomposition efficiency of harmful substances on the photocatalyst carrier is significantly reduced, and secondary air pollution such as the release of the generated strong acids into the atmosphere is also observed. Cause problems. In particular, it efficiently decomposes chloroform, one of the air pollutants generated in the pulp bleaching process by chlorine-based chemicals during the pulp manufacturing process, and hydrogen chloride that is secondarily generated from the titanium oxide photocatalyst solid surface in the process There has been no purification method or apparatus capable of efficiently removing methane.

[0006]

DISCLOSURE OF THE INVENTION The present invention efficiently decomposes air pollution harmful substances such as chloroform generated in a chlorine-based pulp bleaching step in a pulp manufacturing step, and generates an acid such as hydrogen chloride generated in the process. It is an object of the present invention to provide a purification method and a device for efficiently removing methane.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, decomposed air pollutant harmful substances in gas containing air pollutant harmful substances by photocatalytic reaction into decomposed gas. The generated acidic gas may be purified by reacting it with water or a basic substance. In order to carry out this method of purifying air pollutant harmful substances, a gas containing air pollutant harmful substance is injected from a gas inlet. A photocatalytic reactor containing a reactive semiconductor carrier, a light source for irradiating light containing ultraviolet light into the photocatalytic reactor, and an acid gas decomposed by a photocatalytic reaction in a gas passing through the photocatalytic reactor with water or The present inventors have determined that an air pollution harmful substance purifying apparatus provided with a gas collector for reacting with a basic substance is suitable, and completed the present invention.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for purifying air pollutants according to the present invention will be described in detail with reference to the drawings. FIGS. 1 to 3 are conceptual views showing one embodiment of an air pollution harmful substance purifying apparatus according to the present invention. FIG. 4 is a conceptual diagram showing the air pollution harmful substance purifying apparatus according to the present invention shown in FIG. It is a key map showing one example which installed an example in tandem. In the drawings, A is a photoreactive semiconductor carrier, B is a photocatalytic reactor, C is a light source for irradiating light containing ultraviolet light, D is a gas collector, and E is a gas circulation device with a flow control function. , F indicates an inlet, G indicates an outlet with an on-off valve, and the arrow in the drawing indicates the direction of gas flow in the apparatus for purifying air pollutants.

The photoreactive semiconductor used in the present invention is a semiconductor having a bandgap of 0.5 to 5 eV, preferably 1 to 3 eV, which causes a photocatalytic reaction. As such a photoreactive semiconductor, metal oxide particles such as zinc oxide, tungsten trioxide, titanium dioxide, and cerium oxide are preferable, and titanium dioxide is particularly preferable.

These metal oxide particles usually have a specific surface area of 10 to 500 m ² / g, and titanium dioxide preferably has a specific surface area of 50 to 400 m ² / g. Further, by supporting a noble metal such as platinum and palladium on the surface of the photoreactive semiconductor, the catalytic effect can be improved.

In the present invention, a photoreactive semiconductor is supported on various substrates and incorporated in a photocatalytic reactor B as a photoreactive semiconductor carrier A. Known photoreactive semiconductor carriers A can be widely used. For example, as shown in FIG. 1, ultrafine particles of the photoreactive semiconductor, such as titanium oxide, are added to a pellet-shaped inorganic porous material such as ceramic, glass, quartz glass, activated carbon, activated clay, zeolite, synthetic zeolite, sepiolite, and bentonite. Mixing, kneading,
As shown in FIG. 3, ceramic, glass, quartz glass, activated carbon,
Ultra-fine particles of the photoreactive semiconductor such as titanium oxide are mixed, kneaded, and fired to a particulate or flake-like inorganic porous material such as activated clay, zeolite, synthetic zeolite, sepiolite, bentonite, and the like. As shown in FIG. 2, ultra-fine particles of a photoreactive semiconductor are supported by mixing, kneading, and firing on a fibrous material composed of organic or inorganic synthetic polymer fibers. Ultra-fine particles of a photoreactive semiconductor are carried in or on a gas-permeable sheet such as a nonwoven fabric, a woven fabric, a paper or a woven fabric made of an inorganic synthetic polymer fiber. Alternatively, an inorganic porous material having a honeycomb shape or a three-dimensional network structure formed by foaming or molding may support ultrafine particles of a photoreactive semiconductor. Among these, ceramic, glass, quartz glass,
Ultrafine titanium dioxide having an X-ray particle size of 5 to 30 nm mixed, kneaded, calcined or granulated with an inorganic porous substance in the form of pellets such as bentonite, or a nonwoven fabric, woven fabric, Paper made of natural fibers,
The photoreactive semiconductor carrier A is preferably processed into a honeycomb shape by carrying ultrafine titanium dioxide having an X-ray particle size of 5 to 30 nm in or on a permeable sheet such as a woven cloth.

The photoreactive semiconductor carrier A thus manufactured is incorporated in a photocatalytic reactor B, and is irradiated with light containing ultraviolet rays from a light source C for irradiating light containing ultraviolet rays. The light source C for irradiating the light containing this ultraviolet light has a wavelength of 200 to 400 nm and an ultraviolet intensity of 1 to 100 m.
Sunlight, fluorescent light, black light, germicidal lamp, mercury lamp, halogen lamp, incandescent lamp that generates W / cm ² ultraviolet light can be used alone or in combination. Furthermore,
By heating the photocatalyst reactor B from outside to 100 to 300 ° C., the acidic gas in the decomposition gas generated in the photoreactive semiconductor carrier A in the photocatalyst reactor B is efficiently guided to the gas collector D. You can also.

A gas collector D is connected to the photocatalytic reactor B, and strong acids such as hydrogen chloride, sulfuric acid and nitric acid, which are secondary products generated by the photocatalytic reaction in the photocatalytic reactor B, are gaseous. It is collected in the collector D. This gas collector D can be treated by neutralizing it with a basic aqueous solution after taking out as acidic water by injecting water. By injecting, the collection process and the neutralization process can be performed simultaneously. Further, by filling the gas collector D with a basic solid, the neutralization treatment can be performed in a solid state. In this case, the size of the basic solid is 0.
1 to 10 mm is desirable.

As a gas collecting method, it is conceivable to spray water or a basic aqueous solution in a mist on a gaseous strong acid substance such as hydrogen chloride, sulfuric acid or nitric acid which is a secondary product generated. In consideration of the removal efficiency, neutralization treatment is performed in a solid state by using a gas collector D containing water or a basic aqueous solution, or by installing a gas collector D filled with a basic solid. The method is excellent.

As the basic aqueous solution or basic solid substance to be injected or filled into the gas collector D, conventionally known basic substances can be used. Specific examples include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium hydrogen carbonate, calcium carbonate, aluminum hydroxide, aqueous ammonia, and the like.

In this way, a gas containing harmful air pollutants such as chloroform generated in the paper pulp manufacturing process is taken into the apparatus, and the photoreactive semiconductor carrier A in the photocatalyst reactor B undergoes photocatalytic decomposition. Then, the strong acid components such as hydrogen chloride, sulfuric acid and nitric acid which are generated secondarily are collected by the gas collector D.
Capture with water, basic aqueous solution or basic solid. Further, it is preferable to forcibly flow the gas in the apparatus by using a gas circulating apparatus E having a flow rate adjusting function such as a fan and a blower installed in the apparatus. As shown in FIGS. When B and the gas collector D are installed one by one, the gas in the apparatus is continuously circulated to decompose the air polluting harmful gas substances to a certain level, and then purified from the outlet G with the on-off valve. Although it is preferable to discharge the gas into the atmosphere as air, when the photocatalyst reactor B and the gas collector D are installed in a plurality of tandems as shown in FIG. Then, the air polluting harmful gas substances may be decomposed to a certain level and then discharged to the atmosphere.

According to the method and apparatus for purifying air pollutants according to the present invention, the photoreactive semiconductor carrier A
By irradiating light containing ultraviolet light from a light source C to a photocatalyst reactor B containing a chlorinated pulp, air pollution harmful substances such as chloroform generated in a chlorine-based pulp bleaching process are photo-decomposed. By collecting acidic substances such as hydrogen with the gas collector D connected to the photocatalytic reactor B, photocatalytic decomposition of air pollutants and removal of secondary air pollutants can be performed simultaneously. .

[0018]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. (Example 1) was diluted with water to 40 g / L of acidic titania sol obtained by thermal hydrolysis of titanyl sulfate in TiO ₂ basis, porous spherical ceramic bi this dilution - filling's (diameter 2 mm) The material was impregnated for 1 hour, neutralized to pH 7 by adding aqueous ammonia, and titanium oxide was attached to the surface of the filler. Further, the titanium oxide-attached filler was separated by filtration, dried, and then fired at a temperature of 600 ° C. for 1 hour. The fired filler was washed with water and dried to obtain a photoreactive semiconductor carrier A. 50 g of this carrier A was filled in a glass tube (inner diameter 20 mm × length 300 mm × thickness 1 mm) to obtain a photocatalytic reactor B. A black light (absorption peak at 352 nm), which is a light source C for irradiating light containing 20 W of ultraviolet light to a distance of 5 cm on both sides of the photocatalytic reactor B, is applied.
H), two gas collectors D into which water has been injected are connected to the photocatalytic reactor B, and an air pump is connected to the gas collector D as a gas circulation device E having a flow rate adjusting function. When the gas sent from the air pump E is supplied to an outlet G with an on-off valve and an inlet F for injecting a gas containing air pollutants, and the outlet G with an on-off valve is closed It is connected to the photocatalyst reactor B again to constitute the circulation system.
The air pollutant purification device set in was set up.

Using the purifying apparatus shown in FIG. 1, 3 ml of air containing gaseous chloroform having a concentration of 250,000 ppm was injected into the system from the inlet F using a syringe. At this time, the initial concentration of chloroform in the system measured from the inlet F was 150 ppm. The gas in the system was circulated at a flow rate of 10 liter / min by the air pump E while irradiating light from the black light C at an ultraviolet intensity of 4 mW / cm ² , and a continuous operation was performed for 10 hours.
After 10 hours, the outlet G with the on-off valve was opened, and the exhaust gas was collected from the outlet G, and the concentrations of chloroform and hydrogen chloride were measured. As a result, all the hydrogen chloride generated by the photocatalytic decomposition reaction of chloroform was dissolved in water in the gas collector D and changed into hydrochloric acid, and the concentration of hydrogen chloride was 0 ppm. The final concentration of chloroform was 5 ppm. Thus, the initial concentration of chloroform was 150 pp.
m and a final concentration of 5 ppm, the photocatalytic decomposition efficiency was 96.
It was 7%, and no reduction in the decomposition efficiency of the photoreactive semiconductor carrier A was observed even after continuous operation for 10 hours.

(Comparative Example 1) An experiment was carried out in the same manner as in Example 1, except that the gas collector D was not installed. As a result, the concentration of hydrogen chloride generated by the photocatalytic decomposition reaction of chloroform was 100 ppm, and the final concentration of chloroform was 50 ppm. Thus, from the initial concentration of chloroform of 150 ppm and the final concentration of 50 ppm, the photocatalytic decomposition efficiency was 66.7%, and a decrease in the decomposition efficiency of the photoreactive semiconductor carrier A was observed after continuous operation for 10 hours.

Example 2 The hydrous titanium oxide obtained during the production process of the sulfuric acid-processed titanium oxide was neutralized and washed with an aqueous sodium hydroxide solution, peptized with hydrochloric acid, and converted to titanium oxide by 4%.
A titania sol stock solution of 0% by weight and a pH of 1 was obtained. After diluting this titania sol stock solution 10 times, a methanol solution of a butynediol-based nonionic surfactant was added at 1000 ppm.
This was added to obtain a titania impregnating liquid. A nonwoven fabric (weight per unit area: 40 g / m ² ) made of polypropylene fiber whose strength was enhanced by the hydroentanglement method was subjected to corona treatment, and then immersed in the above titania sol impregnating solution and squeezed lightly. On the other hand, sodium bicarbonate is dissolved in water to prepare an aqueous solution for alkaline treatment of pH 8, a nonwoven fabric impregnated with titania sol is immersed in the aqueous solution for alkaline treatment, titanium oxide is supported on the nonwoven fabric, and the solution is treated at 80 ° C. for 3 minutes. The resultant was air-dried and further molded to obtain a photoreactive semiconductor carrier A having a honeycomb structure. This carrier A
(300mm length x 300mm width x 10mm thickness) into a glass tube (300mm inner diameter x 300mm length x 5mm thickness)
It was set as a photocatalyst reactor B inside. This photocatalytic reactor B
20 W germicidal lamp (absorption peak at 254 nm) which is a light source C for irradiating light containing ultraviolet rays to a distance of 5 cm on both sides of the
H) were installed. A gas collector D into which an aqueous solution of sodium hydroxide was injected was connected to the photocatalyst reactor B, and an air pump was connected to the gas collector D as a gas circulation device E having a flow rate adjusting function. The discharged gas is supplied to an outlet G with an on-off valve and an inlet F for injecting a gas containing air pollutants, and when the outlet G with an on-off valve is closed, the photocatalytic reactor B is again turned on. 2 and a circulation system was constructed, and a purification device for air pollutants having a total volume set to 5000 ml as shown in FIG. 2 was formed.

Using the purifying apparatus shown in FIG. 2, 3 ml of air containing gaseous chloroform having a concentration of 250,000 ppm was injected into the system from the inlet F using a syringe. At this time, the initial concentration of chloroform in the system measured from the inlet F was 150 ppm. Then, while irradiating light from the germicidal lamp C with an ultraviolet intensity of 4 mW / cm ² , the gas in the system was circulated at a flow rate of 10 liter / min by the air pump E, and the continuous operation was performed for 10 hours. After 10 hours, the outlet G with the on-off valve was opened, and the exhaust gas was collected from the outlet G, and the concentrations of chloroform and hydrogen chloride were measured. As a result, all the hydrogen chloride generated by the photocatalytic decomposition reaction of chloroform has been converted to sodium chloride by reacting with the aqueous sodium hydroxide solution in the gas collector D.
The concentration of hydrogen chloride was 0 ppm. The final concentration of chloroform was 4 ppm. Thus, from the initial concentration of chloroform of 150 ppm and the final concentration of 4 ppm, the photocatalytic decomposition efficiency was 97.3%, and no reduction in the decomposition efficiency of the photoreactive semiconductor carrier A was observed even after continuous operation for 10 hours. Was.

(Comparative Example 2) An experiment was carried out in the same manner as in Example 2, except that the gas collector D was not provided. As a result, the concentration of hydrogen chloride generated by the photocatalytic decomposition reaction of chloroform was 90 ppm. Also,
The final concentration of chloroform was 55 ppm. From the initial concentration of chloroform of 150 ppm and the final concentration of 55 ppm, the photocatalytic decomposition efficiency was 63.3%, and a decrease in the decomposition efficiency of the photoreactive semiconductor carrier A was observed after continuous operation for 10 hours.

(Example 3) LBKP fine pulp fiber 10
0 g is dispersed in 2000 ml of water with stirring for 1 hour,
To this pulp fiber dispersion was added 50 g of a 20% dispersion of ultrafine titanium oxide, and the mixture was stirred for 1 hour. Further, 50 g of a 10% aqueous polyvinyl alcohol solution was added and stirred for 1 hour. Next, the fine pulp fiber to which the ultrafine titanium oxide particles are adhered is filtered by a screen, and the filtrate is dried at 100 ° C. for 1 hour.
This was crushed to obtain a photoreactive semiconductor carrier A. This carrier A
50 g into a glass tube (inner diameter 20 mm x length 300 mm x
(1 mm thick) to form a photocatalytic reactor B. Two mercury lamps, which are light sources C for irradiating light containing 100 W of ultraviolet light, are installed at a distance of 5 cm on both sides of the photocatalytic reactor B, and a gas collector in which the photocatalytic reactor B is filled with solid sodium hydroxide. D, and an air pump is connected to the gas collector D as a gas circulating device E with a flow rate adjusting function. The gas sent from the air pump E contains an exhaust port G with an on-off valve and an air pollutant. 3 is connected to the photocatalyst reactor B to form a circulation system when the discharge port G with an on-off valve is closed. Is 50
An air pollutant purification device set to 00 ml was formed.

Using the purifying apparatus shown in FIG. 3, 3 ml of air containing gaseous chloroform having a concentration of 250,000 ppm was injected into the system from the inlet F using a syringe. At this time, the initial concentration of chloroform in the system measured from the inlet F was 150 ppm. The gas in the system was circulated at a flow rate of 10 liters / minute by the air pump E while irradiating light with a UV intensity of 20 mW / cm ² from the mercury lamp C, and a continuous operation was performed for 10 hours. After 10 hours, the outlet G with the on-off valve was opened, and the exhaust gas was collected from the outlet G, and the concentrations of chloroform and hydrogen chloride were measured. As a result, all of the hydrogen chloride generated by the photocatalytic decomposition reaction of chloroform reacted with the solid sodium hydroxide in the gas collector D and changed to sodium chloride, and the concentration of hydrogen chloride was 0 ppm. The final concentration of chloroform was 3 ppm. Thus, from an initial concentration of chloroform of 150 ppm and a final concentration of 3 ppm,
The photocatalytic decomposition efficiency was 98%, and no reduction in the decomposition efficiency of the photoreactive semiconductor carrier A was observed even after continuous operation for 10 hours.

(Comparative Example 3) An experiment was carried out in the same manner as in Example 3, except that the gas collector D was not installed. As a result, the concentration of hydrogen chloride generated by the photocatalytic decomposition reaction of chloroform was 125 ppm, and the final concentration of chloroform was 60 ppm. As described above, the photocatalytic decomposition efficiency was 60% from the initial concentration of chloroform of 150 ppm and the final concentration of 60 ppm, and a decrease in the decomposition efficiency of the photoreactive semiconductor carrier A was observed after continuous operation for 10 hours.

[0027]

As described above in detail, the method and apparatus for purifying air pollutants according to the present invention efficiently decompose air pollutants such as chloroform discharged from a chemical factory, and perform secondary decomposition. Air pollution harmful substances generated in
Because it can be removed, it is possible to purify air pollutants very efficiently and at the same time, it can be used continuously for a long time in a stable state without deteriorating the function of the photocatalyst. In particular, it is possible to efficiently decompose chloroform, one of the air pollutant harmful substances generated in the pulp bleaching process by chlorine-based chemicals in the pulp manufacturing process, and efficiently remove the hydrogen chloride secondary generated in the process. It is possible and its industrial value is very large.

[Brief description of the drawings]

FIG. 1 shows an apparatus for purifying harmful substances of air pollution according to the present invention.
It is a key map showing an example.

FIG. 2 is a conceptual diagram showing another embodiment of the air pollution harmful substance purifying apparatus according to the present invention.

FIG. 3 is a conceptual diagram showing another embodiment of the air pollution harmful substance purifying apparatus according to the present invention.

FIG. 4 is a conceptual diagram showing one embodiment in which the air pollution harmful substance purifying apparatus according to the present invention shown in FIG. 1 is installed in tandem.

[Explanation of symbols]

 Reference Signs List A photoreactive semiconductor carrier B photocatalytic reactor C light source that emits light containing ultraviolet light D gas collector E gas circulation device with flow rate adjustment function F inlet G outlet with on-off valve

Claims (5)

[Claims] An air pollution harmful substance in a gas containing an air pollution harmful substance is decomposed by a photocatalytic reaction, and an acid gas generated in the decomposition gas is reacted with water or a basic substance to purify the gas. To clean up air polluting harmful substances. 2. The method for purifying air pollutants according to claim 1, wherein the air pollutants are chloroform generated in a paper pulp manufacturing process or the like. 3. A photoreactive semiconductor carrier (A) into which a gas containing air pollutants is injected from a gas inlet (F).
, A light source (C) for irradiating light containing ultraviolet light into the photocatalyst reactor (B), and a photocatalytic reaction in gas passing through the photocatalyst reactor (B). Gas collector for reacting decomposed acidic gas with water or basic substance
(D), a purification device for air pollutant harmful substances. 4. The apparatus according to claim 3, wherein the basic substance in the gas collector (D) is a basic aqueous solution or a basic solid. 5. A light source (C) for irradiating light containing ultraviolet rays.
The air pollution harmful substance purifying apparatus according to claim 3 or 4, wherein the device is at least one light source selected from the group consisting of sunlight, a fluorescent lamp, a black light, a germicidal lamp, a mercury lamp, a halogen lamp, and an incandescent lamp.