JP2001029443A - Deodorizing filter and method for removing lower aliphatic aldehyde in atmosphere - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorizing filter having a high efficiency for removing acetaldehydes and a method for removing acetaldehydes in an atmosphere. SOLUTION: This deodorizing filter for removing aldehydes comprises activated charcoal to which an aromatic compound having both an amino group and a sulfonic group is added. The filter further contains a moisture absorbent and the moisture absorption coefficient characteristic of the filter is in the range of 15 to 40% in terms of the coefficient of moisture absorption measured at a relative humidity of 50% as specified by JIS Z 0701. When aldehydes in an atmosphere are removed by reacting with the aromatic compound having both an amino group and a sulfonic group and added to the activated charcoal, the reaction between the aromatic compound and aldehydes is effected in the presence of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing filter excellent in removing lower aliphatic aldehydes, especially acetaldehyde, and a method for removing acetaldehyde in an atmosphere.

[0002]

2. Description of the Related Art In an atmosphere such as a living space or a working space such as a room or a car, various types of odors are generated.
Above all, due to the problem of smoke pollution which has recently become a focus, there is an increasing demand for the removal of tobacco odor in the atmosphere. The main components of the tobacco odor are acetaldehyde, ammonia, acetic acid, etc. Among them, acetaldehyde has the strongest odor, and acetaldehyde is a substance which is more difficult to remove than other odor components. The reason for this is that lower aliphatic aldehydes such as acetaldehyde have a unique property that they have low adsorptivity to activated carbon and zeolite, which are typical deodorants. Further, the lower aliphatic aldehyde has a problem that reactivity with an acid or a basic substance attached to the surface is low in order to improve the adsorptivity of the activated carbon and the zeolite.

[0003] In order to solve this problem, a deodorant filter in which a chemical substance is impregnated on activated carbon, particularly emphasizing the removal performance of lower aliphatic aldehydes (hereinafter, simply referred to as aldehydes),
Conventionally, various proposals have been made. For example, Japanese Patent Publication No. 60-5409
No. 5 and JP-A-3-98642 propose an activated carbon in which aniline or aniline phosphate is impregnated. Further, Japanese Patent Application Laid-Open Nos. 4-2350 and 5-23588 propose an activated carbon in which an amino acid or aminobenzoic acid is impregnated. Further, in Japanese Patent Application Laid-Open No. Hei 7-136502, aminobenzene sulfonic acid (sulfanilic acid) is added to activated carbon fibers.
In Japanese Unexamined Patent Publication No. 9-239213, those in which an activated carbon is impregnated with an aromatic amine are described in JP-A-10-711.
No. 93 proposes activated carbon in which aminobenzenesulfonic acid and a zinc compound are impregnated.

[0004]

However, these conventional deodorizing filters have a problem that they are not practical for removing aldehydes. For example, Japanese Patent Publication No. 60-54
Although aniline and aniline phosphate disclosed in JP-A No. 095 and JP-A-3-98642 have excellent aldehyde removal performance, they have a problem that they have a strong odor and are difficult to use as general-purpose deodorants or air purifiers. The same applies to the aromatic amine disclosed in JP-A-9-239213.

[0005] Both the aminobenzenesulfonic acid disclosed in JP-A-7-136502 and the aminobenzenesulfonic acid and the zinc compound disclosed in JP-A-10-71193 remove aldehydes from the metal oxides and amino acids. Although it has excellent performance, there is a problem that the reaction rate is still low and the removal efficiency is not improved.

The basic mechanism of removing aldehydes in these conventional deodorizing filters is mainly that an adsorbent such as activated carbon is impregnated with a drug such as aniline or an amine, and the amino group of the drug and the adsorbent are removed. The chemical reaction of the aldehyde with the aldehyde physically adsorbed on the aldehyde is intended to improve the removal performance by immobilizing the aldehyde on the drug. Therefore, in this removal method, an important precondition is that the agent impregnated in the adsorbent has excellent reactivity with the aldehyde.

However, it has excellent reactivity with aldehydes.
At the same time, (active) drugs also have the property of easily generating heat due to chemical reactions. For example, among the above-mentioned prior arts, chemicals such as aniline and amine having excellent reactivity with aldehydes are particularly remarkable in this exothermic property. As a result, a phenomenon occurs in which the aldehyde having a low boiling point once physically adsorbed to the adsorbent is desorbed from the adsorbent due to heat generated by the reaction, and the aldehyde removal rate as a deodorizing filter is rather lowered. On the other hand, in order to suppress this heat generation, the activity and reactivity of the drug itself or the amount of the drug must be suppressed, the reactivity of the drug with the aldehyde is reduced, and the aldehyde is removed as a deodorizing filter. Leads to lower rates.

That is, the inconsistency between the reactivity of these agents with aldehydes and the exothermicity during the reaction is caused by the chemical reaction with the agents impregnated in the adsorbent. This was a major factor in the low removal rate. And there is no deodorizing filter that has solved this contradiction.

The present invention has been made in view of the above circumstances and aims to solve the above contradiction and to provide a deodorizing filter having excellent aldehyde removal performance.

[0010]

[MEANS FOR SOLVING THE PROBLEMS]
The gist of the deodorizing filter of the present invention is a deodorizing filter for removing aldehyde obtained by impregnating activated carbon with an aromatic compound having both an amino group and a sulfone group.The filter further contains a moisture absorbent and has a moisture absorption characteristic of JIS. Z 07
15 at a relative humidity of 50% measured according to the provisions of 01
To be in the range of ~ 40%.

The gist of the method for removing aldehydes of the present invention is to remove aldehydes in the atmosphere by reacting the aldehydes in the atmosphere with an aromatic compound having both an amino group and a sulfone group attached to activated carbon. The reaction with the aldehyde is performed in the presence of moisture.

The present inventors have studied a deodorizing filter of the type that removes aldehydes by a chemical reaction with a drug impregnated in an adsorbent. In particular, the present inventors have studied the reactivity of aminobenzenesulfonic acid as a drug with acetaldehyde. investigated. As a result, it was found that the presence of an appropriate amount of water in the vicinity of the reaction field significantly increased the reaction between the two, and suppressed the heat generated by the reaction. As a result, they found that the efficiency of removing acetaldehyde was remarkably improved when viewed as a deodorizing filter. That is, the present inventor has found that the presence of moisture makes it possible to significantly improve the acetaldehyde removal capability of a deodorizing filter from the two aspects of promoting the reaction and suppressing the heat generated by the reaction.

In order to further accelerate the reaction, it is preferable that the deodorizing filter further contains an acidic or basic substance. Acidic substances themselves also emit protons, further accelerating the reaction. Basic substances also increase the nucleus attack on acetaldehyde, which is possessed by the lone pair of electrons in the aminobenzenesulfonic acid molecule.
(Corresponding to claim 7).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each requirement of the present invention will be described in detail including its critical significance. (Activated Carbon) First, the present invention is a deodorizing filter basically made of activated carbon. Activated carbon as a basic component is
As is well known, it is a porous body (porous body) having many fine pores (micropores) on its surface, and has a function of adsorbing a large amount of odor components such as acetaldehyde.

As the porous body having the adsorption performance,
In addition to activated carbon, zeolite, activated alumina, silica, silica gel, diatomaceous earth and the like are present. However, according to the findings of the present inventors, the effect of removing acetaldehyde when using activated carbon was most excellent. Although the reason for this is not clear, it is considered that activated carbon promotes the reaction between an acetaldehyde and an aromatic compound having both an amino group and a sulfone group, which will be described later. Further, in consideration of practical utility as a deodorizing filter, it is necessary to remove odor components other than acetaldehyde, and a porous body itself having a deodorizing performance is preferable. In this regard, activated carbon has the ability to remove many odor components other than acetaldehyde. Therefore, for these reasons, in the present invention, the porous body of the deodorizing filter is limited to activated carbon.

On the other hand, as the activated carbon having these deodorizing performances, known activated carbon can be used, such as wood, sawdust, coconut shell, pulp waste liquor, coal, heavy petroleum oil, pitch, rigid polymer compounds and the like. Activated carbon can be used as a starting material.

The shape of the activated carbon is not particularly limited either, and may be various, such as granular, spherical, pellet, powder, or bulk (plate, linear, etc.), depending on the use environment and conditions. Is selected.

For example, when powdered activated carbon is used,
By adding an organic or inorganic binder, a monolith-like deodorizing filter of a honeycomb or a sheet can be obtained. This deodorizing filter can be conveniently and conveniently arranged in an air purifier in a room or in a vehicle, or in a vent, and has many advantages in use such as easy replacement and maintenance. Further, the present air purifying agent can be impregnated on a porous substrate molded into an arbitrary shape according to the purpose. As the porous substrate, a porous synthetic resin, a polyurethane foam, a nonwoven fabric, a honeycomb structure (ceramics, metal, paper, resin, or the like), a loop-shaped laminate, or the like is used.

(Aromatic Compound Having Both Amino Group and Sulfone Group) In the present invention, an aromatic compound having both an amino group and a sulfone group was selected as a chemical to be reacted with an aldehyde because these aromatic compounds are activated carbon. The aldehyde physically adsorbed on the filter exhibits an important function of chemically fixing it on the filter by the above-mentioned reaction, and as a preferable condition, from the practicality of a deodorizing filter, these aromatic compounds have a strong odor. Because it has no properties.

The aromatic compounds satisfying these functions and properties include sulfanilic acid, 2-naphthylamine-6-sulfonic acid, 4-amino-2methylbenzene-1-sulfonic acid,
Amino-5-methylbenzene-1-sulfonic acid and the like are exemplified. Of these, sulfanilic acid and 4-amino-2-methylbenzene-1-sulfonic acid are particularly excellent in reactivity with acetaldehyde (corresponding to claims 3 and 4).

On the other hand, there are aniline and aminobenzoic acid as other chemicals for removing aromatic compounds or acetaldehyde, which do not have a sulfonic acid group and are more aldehyde than the aromatic compounds of the present invention. Is not suitable as a deodorizing filter because of its poor reactivity with odor and relatively strong odor.

In order for the aromatic compound to exhibit acetaldehyde removal performance, one standard is to add 3 parts of the aromatic compound to 100 parts by weight of activated carbon.
It is desirable that the content be not less than parts by weight. The aromatic compound is
If the amount is less than 3 parts by weight, the removal efficiency of acetaldehyde is reduced as a deodorizing filter, and the duration of the removal effect is shortened, which is not practical. Conversely, if the amount of the aromatic compound exceeds 50 parts by weight, the amount of activated carbon decreases, and the effect of adsorbing acetaldehyde decreases. Therefore, the amount of the aromatic compound impregnated with respect to 100 parts by weight of the activated carbon is
Preferably, the amount is 3 to 50 parts by weight (corresponding to claim 2).

(Moisture Absorption Characteristics of Filter) Next, the moisture absorption (water content) of the filter of the present invention will be described. As described above, the water contained in the filter promotes the release of protons from the aminobenzenesulfonic acid molecule, and accelerates the attack of acetaldehyde physically adsorbed on the activated carbon by the protons on the carbonyl carbon, thereby reducing the carbonyl carbon. Facilitates the reaction with the amino group of aminobenzenesulfonic acid, and significantly improves the efficiency of removing acetaldehyde.

The effect of water is more effective when a specific amount of water is present in a deodorizing filter (activated carbon filter) which is a reaction system between aminobenzenesulfonic acid (the aromatic compound of the present invention) and acetaldehyde. Be demonstrated.

However, it is difficult to measure the amount of water in the actual reaction system. Therefore, in the present invention, it has been found that this moisture content correlates well with the moisture absorption characteristics of the filter, and that the moisture content can be quantified as the moisture absorption characteristics of the filter.

More specifically, in the present invention, the amount of water in the reaction system was measured according to JIS Z 0701.
The moisture absorption (moisture content) characteristics of the filter when the relative humidity is 50%, and the moisture absorption is specified in the range of 15 to 40%. If the moisture absorption characteristic of the filter does not exist within this range, the effect of removing acetaldehyde by the aromatic compound of the present invention cannot be efficiently achieved.

If the moisture absorption characteristic of the filter is less than 15%,
The effect of promoting acetaldehyde removal of the aromatic compound by the water is not exhibited. On the other hand, if the moisture absorption characteristic of the filter exceeds 40%, moisture is adsorbed on the activated carbon, and the effect of activated carbon on adsorbing acetaldehyde becomes extremely low. As a result, the effect of the filter for removing acetaldehyde decreases. Therefore, the moisture absorption characteristic of the filter is set in the range of 15 to 40%.

Although there are various methods for measuring the moisture absorption of the filter, the measurement of the moisture absorption of the filter of the present invention is performed in order to prevent variation in the results due to the difference in the measurement method and to provide reproducibility. The method shall be a measured value at a relative humidity of 50% in accordance with JIS Z 0701 (silica gel desiccant for packaging).

A specific method for measuring the moisture absorption of a filter based on the JIS Z 0701 method will be described below. First, the sample collected from the filter is pulverized in advance, sieved using a size of 840 or less according to JIS Z 8801 (standard sieve), mixed well, and heated (dried) at 170 to 190 ° C for 2 hours. Weigh 0.2-0.4 g (W ₀ ), sulfuric acid solution (43.4
(% By mass) in a glass container maintained at a relative humidity of 50%, and kept at a temperature of 25 ± 2.5 ° C. for 48 hours to absorb moisture. Immediately after completion of the retention, the mass (W ₁ ) of the moisture-absorbed sample is weighed. In addition,
These operations are performed by placing the sample in a flat weighing bottle.
Weighing is performed with a chemical balance. Then, the moisture absorption of the filter is calculated by (W ₁ −W ₀ ) / W ₀ × 100% excluding the mass of the flat weighing bottle.

(Hygroscopic Agent) When an atmosphere such as indoor air is used as a deodorizing filter, the indoor air naturally has humidity and can naturally serve as a supply source of water into the deodorizing filter. However, as is well known, the humidity in this atmosphere
(Moisture) varies greatly depending on the environment. For this reason,
In a filter containing no hygroscopic agent, the above-mentioned moisture absorption rate of 15 to
It is difficult to control within the range of 40% (within the range of optimal water content).

On the other hand, when the humidity of the atmosphere is high, the supply amount of water into the deodorizing filter becomes large, and in the filter containing no hygroscopic agent, there is no substance capable of absorbing moisture. In addition, the effect of activated carbon for adsorbing acetaldehyde becomes extremely low. As a result, the effect of the filter for removing acetaldehyde decreases.
Therefore, in the present invention, the deodorizing filter (inner) positively contains a moisture absorbent.

The term "hygroscopic agent" as used in the present invention means that the moisture content of the deodorizing filter can be in the above-mentioned range of 15 to 40%, and that it contains only the amount that is possible. Can be used. For example, polyhydric alcohols such as ethylene glycol and glycerin, salts having water of crystallization such as calcium chloride, diphosphorus pentoxide, magnesium perchlorate, magnesium chloride, lithium chloride,
Deliquescent substances such as zinc chloride, CaO and BaO, porous substances such as activated alumina, molecular sieves and silica gel, water-absorbent resins such as polyacrylates, polyvinyl alcohol, polyacrylamide, polyoxyethylene, starch, and cellulose Is exemplified. Among these, diphosphorus pentoxide and a water-absorbing resin are preferable because they have a relatively high moisture absorbing effect and are stable (corresponding to claims 5 and 6).

If these moisture absorbents are used in the form of powder and mixed with activated carbon or an aromatic compound having both an amino group and a sulfone group (for example, powder), it is most easily and uniformly contained in the deodorizing filter as a moisture absorbent. And the moisture content of the deodorizing filter can be adjusted. For example, it is possible to dispose it in a certain place in the deodorizing filter as a bulk, but it is difficult to make the water content in the deodorizing filter uniform, and the acetaldehyde removal performance of the aromatic compound is uniformly exhibited. Removal may be difficult, and the removal efficiency may be reduced.

It should be noted that the amount of the hygroscopic agent for exhibiting the function of adjusting the moisture content of the deodorizing filter is different depending on the type (performance) of the hygroscopic agent, but it is difficult to say unconditionally. 100 parts by weight of compound
It is preferably at least 1 part by weight. If the amount of the hygroscopic agent is less than 1 part by weight, the efficiency of removing acetaldehyde as a deodorizing filter decreases, and the duration of the removing effect is short, which is not practical. Conversely, when the amount of the moisture absorbent is 5
If the amount exceeds 0 parts by weight, the content of the activated carbon and the aromatic compound in the filter is reduced, and the deodorizing effect is not sufficiently exerted. Therefore, the preferred amount of the hygroscopic agent is in the range of 1 to 50 parts by weight based on 100 parts by weight of the aromatic compound.

(Acid or Basic Substance) In order to further promote the reaction between acetaldehyde and an aromatic compound having both an amino group and a sulfone group attached to activated carbon, an acidic or basic substance is further added to the deodorizing filter. Preferably, it is included (corresponding to claim 7). As described above, the acidic substance itself emits a proton, which further accelerates the reaction. In addition, the basic substance enhances the sphere nucleus attack on acetaldehyde, which is possessed by the shared electron pair in the molecule of aminobenzenesulfonic acid.

Examples of the acidic substance having this effect include boron fluoride, aluminum chloride, magnesium chloride, zinc chloride, and potassium hydroxide. On the other hand, examples of the basic substance include calcium hydroxide, sodium hydrogen carbonate, ammonium carbonate, and ammonium hydrogen carbonate. Some of these acidic or basic substances have a function as the moisture absorbent. Of these, aluminum chloride is used as the acidic substance, and as the basic substance,
The effect of calcium hydroxide and the like is relatively high, and it is preferable in that it itself is odorless and easy to handle (corresponding to claims 8 and 9).

[0037]

EXAMPLES The results of the actual removal of acetaldehyde using a deodorizing filter in which an aromatic compound having both an amino group and a sulfone group is attached to the activated carbon of the present invention will be described below.

Tables 1 to 3 show the mixing ratio and the moisture absorption (based on the JIS method) of the deodorizing filter. The filter was manufactured by mixing powdered activated carbon, an aromatic compound, a hygroscopic agent, and an acidic or basic substance shown in Tables 1 to 3 at a predetermined ratio, further adding an organic binder, and diluting with water. Thereafter, granules were formed by extrusion molding, dried and cut to obtain a deodorizing filter having a particle size of 2 mm.

In the flow test for measuring the acetaldehyde removal rate, air mixed with acetaldehyde having a concentration of 20 ppm was flowed at a flow rate of 0.2 m / s into a sample folder in which 0.5 g of each deodorizing filter was charged, and the inlet and the The acetaldehyde concentration at the outlet is measured and measured at regular intervals,
The acetaldehyde removal rate (deodorization rate) was calculated using the following equation. Deodorization rate (%) = [(Ci─Co) / Ci]
× 100 [However, Ci: acetaldehyde (odorous component gas)
Inlet concentration, Co: acetaldehyde (odorous component gas) outlet concentration]. With respect to the measurement results, the change over time of the acetaldehyde removal rate of each air purifying agent is shown in FIGS. Tables 1 to 3 correspond to Figs.
The numbers of the examples described in 1 to 3 respectively correspond to the numbers of the examples in FIGS.

First, as is clear from Table 1 and FIG.
Inventive Examples Nos. 1 and 2, which are within the range of the composition and moisture absorption of the filter of the present invention, are comparative examples in which the composition of the filter is out of the range although the moisture absorption of the filter of the invention is within the range.
No. 3 to 8 (Comparative Example No. 3 contained no hygroscopic agent and desorbed moisture,
(Comparative Examples Nos. 4 to 6 have an activated carbon impregnated with an aromatic compound other than the present invention, and Comparative Examples Nos. 7 and 8 have no activated carbon.) The rate of decrease in the rate over time is small, and the utility as a deodorizing filter is remarkably excellent.

Next, as is clear from Table 2 and FIG.
Inventive Examples Nos. 9, 10 and 11, which are within the range of the composition and the moisture absorption of the filter of the present invention, are compared with Comparative Examples Nos. 12 and 13 in which the composition of the filter of the present invention is satisfied but the moisture absorption is out of the range. As a result, the removal rate of acetaldehyde itself is high, and the reduction rate of the removal rate is small over time, which makes the filter practically excellent as a deodorizing filter.

Further, as is clear from Table 3 and FIG.
Invention Examples Nos. 14 to 17 of the present invention further containing an acidic or basic substance and having a filter composition and moisture absorption within the range.
Compared with Comparative Examples Nos. 18 and 19, in which the aromatic compound to be blended in the filter is out of the range (aniline), the removal rate of acetaldehyde itself is high, the reduction rate of the removal rate is small over time, and the deodorizing filter It is remarkably excellent in practicality.

The high acetaldehyde removal rate itself of these invention examples is due to the presence of an appropriate amount of water in a reaction field (filter) between an aromatic compound (drug) having both an amino group and a sulfone group and acetaldehyde. This shows that the reaction between (drug) and acetaldehyde increased dramatically, and the heat generated during the reaction was suppressed. And actually, no heat generation of the deodorizing filter in these invention examples was observed.

On the other hand, even when the chemical used is within the range of the present invention, the acetaldehyde removal rate is low in Comparative Examples in which the moisture absorption characteristics of the deodorizing filter are out of the range of the present invention.
In particular, in Comparative Examples Nos. 3, 12, and 13, in spite of using sulfanilic acid as a drug, because the moisture absorption of the deodorizing filter was lower than the range of the present invention, an exothermic reaction was observed,
Once the low boiling aldehyde physically adsorbed to the adsorbent,
This proves that the heat generated causes desorption from the adsorbent, which in turn lowers the aldehyde removal rate as a deodorizing filter.

Further, these examples proved that the deodorizing filter of the present invention and the method for removing acetaldehyde in the atmosphere proved to have an effect of removing acetaldehyde having a low removal rate with activated carbon or the like. Other tobacco odor components, such as ammonia and acetic acid, which have relatively high rates, are also shown to be practically removable.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

[0049]

As described above, the deodorizing filter and the method for removing acetaldehyde in the atmosphere of the present invention have excellent aldehyde removing performance. Therefore, the use of the activated carbon filter can be expanded, and its industrial value is great.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a change with time of the acetaldehyde removal rate of a deodorizing filter of the present invention according to an example.

FIG. 2 is an explanatory diagram showing the change over time of the acetaldehyde removal rate of the deodorizing filter of the present invention according to an example.

FIG. 3 is an explanatory diagram showing a change over time in the acetaldehyde removal rate of the deodorizing filter of the present invention according to an example.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 20/26 B01J 20/26 DF Term (Reference) 4C080 AA05 BB02 CC02 HH05 JJ09 KK08 LL03 LL08 LL10 MM05 MM18 NN01 QQ03 4G066 AA05B AA13B AA32B AA50B AB13B AB15B AE06C BA36 BA38 CA02 CA29 CA43 CA52 CA56 DA03 FA37

Claims (12)

[Claims] 1. A deodorizing filter in which an activated carbon is impregnated with an aromatic compound having both an amino group and a sulfone group,
In addition to containing a moisture absorbent, the moisture absorption characteristics of the filter, relative humidity 50% measured according to the provisions of JIS Z 0701
A deodorizing filter having a moisture absorption in the range of 15 to 40%. 2. The amount of the aromatic compound impregnated on activated carbon 10
The deodorizing filter according to claim 1, wherein the amount is in the range of 3 to 50 parts by weight based on 0 parts by weight. 3. The deodorizing filter according to claim 1, wherein the aromatic compound is sulfanilic acid. 4. The deodorizing filter according to claim 1, wherein the aromatic compound is 4-amino-2methylbenzene-1-sulfonic acid. 5. The method according to claim 1, wherein the hygroscopic agent is a hygroscopic resin.
5. The deodorizing filter according to any one of items 4 to 4. 6. The deodorizing filter according to claim 1, wherein the hygroscopic agent is phosphorus pentoxide. 7. The deodorizing filter according to claim 1, wherein the deodorizing filter further contains an acidic or basic substance. 8. The deodorizing filter according to claim 7, wherein the acidic substance is aluminum chloride. 9. The deodorizing filter according to claim 7, wherein the basic substance is sodium hydroxide. 10. The deodorizing filter according to claim 1, wherein the deodorizing substance is acetaldehyde in the atmosphere. 11. A lower aliphatic aldehyde in an atmosphere,
A method for removing by an aromatic compound having both an amino group and a sulfone group attached to activated carbon, wherein the reaction between the aromatic compound and acetaldehyde is performed in the presence of moisture. A method for removing aliphatic aldehydes. 12. The activated carbon filter according to claim 11, wherein said reaction is carried out by an activated carbon filter having a characteristic of a moisture absorption in a range of 15 to 40% at a relative humidity of 50% as measured according to JIS Z 0701. 3. The method for removing a lower aliphatic aldehyde in the atmosphere described in 1. above.