JP2019098324A - Polar substance adsorption active carbon - Google Patents

Abstract

To provide a polar substance adsorption active carbon capable of chemically adsorbing a polar substance and scattering the same through a pore, and having adsorption performance derived from the pore of active carbon.SOLUTION: There is provided adsorption active carbon for adsorbing a polar substance, having surface oxide amount on a surface of the adsorption active carbon of 0.35 meq/g or more, BET specific surface area of 900 to 2020 m/g, all pore volume of 0.4 to 1.2 cm/g, average pore diameter of 1.8 to 2.6 nm, and further methylene blue adsorption performance of the adsorption active carbon in a measurement according to JIS K 1474-1 (2014) of 120 mL/g or more and packing density of 0.56 g/mL or less.SELECTED DRAWING: None

Description

  The present invention relates to, for example, activated carbon having an adsorption ability of polar substances.

  A water purifier used to remove residual components and foreign substances from drinking water such as tap water has a structure provided with an adsorbing member of an inorganic material such as activated carbon or ceramic and, if necessary, an organic polymer membrane for filtration, etc. .

  Polar substances are generally soluble, and in particular compounds such as ammonia and chloramine exhibit a distinctive odor. Tap water is required to be disinfected with chlorine from the viewpoint of hygiene. However, a chlorine compound such as chloramine is produced from the reaction of ammonia, which is added for the purpose of sterilization, hypochlorous acid, etc. with ammonia. Also, in recent years, chloramine itself is used for the purpose of disinfecting clean water. Therefore, depending on the condition of the raw water withdrawn, the amount of chlorine compounds to be added, and the amount of chloramine added, the odor often becomes a problem. This chloramine is less volatile than chlorine. For this reason, when drinking tap water, in particular the demand for removal has increased in recent years.

  In recent years, with the demand for higher performance of water purifiers and air purifiers, activated carbon is frequently used for these filters and the like. For example, since chloramine and ammonia are basic, it is considered that activated carbon having an acidic functional group on the activated carbon surface is effective (see, for example, Patent Document 1). That is, the adsorption efficiency is enhanced by the chemical bonding using the acid-base reaction.

  Then, it came to develop an activated carbon effective in the adsorption capacity of other low molecular components with chloramine and ammonia by controlling the suitable development of the amount of acidic functional groups in activated carbon, and the physical property of activated carbon itself.

JP 2002-338222 A

  The present invention has been made in view of the above-mentioned point, and is capable of chemically adsorbing a polar substance and being capable of trapping through a pore, and further having an adsorption ability derived from the pore of activated carbon. An adsorption activated carbon is provided.

That is, the first invention is an adsorption activated carbon for adsorbing a polar substance, wherein the surface oxide amount on the surface of the adsorption activated carbon is 0.35 meq / g or more, and the BET specific surface area is 900 to 2020 m ² / g The present invention relates to a polar substance-adsorbed activated carbon characterized in that

A second invention is the polar substance according to the first invention, wherein the adsorption activated carbon has a total pore volume of 0.4 to 1.2 cm ³ / g and an average pore diameter of 1.8 to 2.6 nm. It relates to adsorption activated carbon.

  3rd invention is the methylene blue adsorption performance of the said adsorption activated carbon in the measurement based on JISK1474-1 (2014) is 120 mL / g or more, The said adsorption activated carbon in the measurement based on JISK1474-1 (2014) The polar substance-adsorbed activated carbon according to the first or the second aspect of the present invention, wherein the packing density of

  A fourth invention relates to the polar substance-adsorbed activated carbon according to any one of the first to third inventions, wherein the polar substance is either or both of chloramine and ammonia.

According to the polar substance-adsorbed activated carbon of the first invention, it is an adsorptive activated carbon for adsorbing a polar substance, wherein the surface oxide amount on the surface of the adsorptive activated carbon is 0.35 meq / g or more, and the BET specific surface area is 900 Since it is -20 ²⁰ m ² / g, it is possible to adsorb polar substances chemically and capture through pores, and further, it has an adsorption capacity derived from the pores of activated carbon.

According to the polar substance-adsorbed activated carbon of the second invention, in the first invention, the pore volume is 0.4 to 1.2 cm ³ / g and the average pore diameter is 1.8 to 2.6 nm. The adsorption efficiency of polar substances can be further enhanced through pore control of activated carbon.

  According to the polar substance-adsorbed activated carbon of the third invention, in the first or second invention, the methylene blue adsorption performance of the adsorptive activated carbon in measurement according to JIS K 1474-1 (2014) is 120 mL / g or more, JIS Since the packing density of the adsorptive activated carbon in the measurement according to K1474-1 (2014) is 0.56 g / mL or less, the adsorption performance required for the activated carbon can also be provided.

  According to the polar substance-adsorbed activated carbon of the fourth aspect of the invention, in any of the first to third aspects of the invention, the polar substance is either one or both of chloramine and ammonia, so that chloramine and ammonia are effectively adsorbed. can do.

  Activated carbon is usually used as a filter material in household and industrial water purifiers that purify tap water that is raw water. Activated carbon is inexpensive, excellent in filtration capacity, and stable in quality. According to JIS S 3201 (2010), the filtration performance of the target substance of such a water purifier is “free residual chlorine, turbidity, 2-chloro-4,6-bisethylamino-1,3,5-triazine ( CAT (abbreviated as CAT), 2-methylisoborneol (abbreviated as 2-MIB), soluble lead, chloroform, bromodichloromethane, dibromochloromethane, bromoform, tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane, and total trihalomethane The evaluation is based on a total of 13 items.

In addition to this, the adsorptive demand for chloramine (monochloramine: NH ₂ Cl, dichloramine: NHCl ₂ , trichloramine: NCl ₃ etc.) is increasing in recent years because of increasing use for tap water sterilization. Therefore, the activated carbon of the present invention is suitable for water purification applications such as tap water utilizing the adsorption performance of pores developed in activated carbon while placing emphasis on adsorption of chloramine while utilizing acid-base reaction. It is. In addition, in hemodialysis, the high removal of chloramine is desired, so use in the device for hemodialysis is also envisaged.

  The raw materials of activated carbon include wood (waste wood, thinning wood, sawfish), coffee grounds, coconut shell, bark, fruits and the like. The raw materials derived from these natural products tend to develop pores by carbonization and activation. Moreover, since it is secondary use of waste etc., it can be procured inexpensively. In addition, tires, petroleum pitches, baked products derived from synthetic resins such as urethane resins and phenol resins, and also coal and the like can be used as raw materials. In each trial production example described later, coconut shell and coal are used as raw materials in consideration of stable procurement.

  Activated carbon materials such as coconut husks are heated and carbonized in a temperature range of 200 ° C. to 600 ° C. to form micropores. Subsequently, the activated carbon raw material is exposed to water vapor and carbon dioxide in a temperature range of 600 ° C. to 1200 ° C. to be activated. As a result, activated carbon having various pores developed is completed. In addition, there is also zinc chloride activation and the like at the time of activation. In addition, sequential cleaning is also performed.

  Also in the activated carbon thus produced, an acidic functional group is formed on the surface of the activated carbon to form a predetermined acidic state. However, in order to further increase the efficiency of small molecule and basic molecule adsorption as in the above-mentioned chloramine, there is a limit to simply relying on the pore. Therefore, we succeeded in increasing the number of acidic functional groups on the surface of activated carbon in order to improve the adsorption capacity.

  In the activated carbon obtained by firing and activating the raw carbon source, various functional groups exist on the surface of the activated carbon. The acidic functional groups, which are increased by the surface oxidation of activated carbon, are mainly hydrophilic groups such as carboxyl groups and phenolic hydroxyl groups, which affect the adsorption capacity. The amount of these acidic functional groups can be grasped as the amount of surface oxide. When the surface oxide amount of the activated carbon is increased, the hydrophilicity of the activated carbon surface is increased, and the adsorption of the hydrophobic substance tends to be reduced.

  Specifically, activated carbon is carried into a rotary kiln or the like and heated again, and oxidation of surface residues proceeds to develop an acidic functional group. That is, oxidation in an air or oxygen atmosphere. Alternatively, at the same time, air having a temperature of 25 to 40 ° C. and a humidity of 60 to 90% is also introduced under an air atmosphere. Then, it heats at 150-900 degreeC over 1 to 10 hours, and the adsorption activated carbon of this invention is completed. It is believed that heating with wet air causes oxidation of hydrocarbon groups such as alkyl groups present on the surface of activated carbon, and introduction of hydroxyl groups of water to the surface to increase the acid functional groups.

  The amount of the acidic functional group on the surface of the adsorption activated carbon can be measured as the amount of surface oxide as in each of the following trial production examples. Specifically, the surface oxide amount is in the range of 0.2 meq / g or more, more preferably 0.35 meq / g or more. If it is less than 0.2 meq / g, the hydrophobicity of the activated carbon becomes too high, which deteriorates the contact efficiency with the water to be filtered. As a result, the pores of the activated carbon are not activated and the filtration performance of the target substance of adsorption decreases, and the adsorption performance of the desired polar substance chloramine and ammonia decreases.

Next, an index that defines the physical properties of the activated carbon itself is also added. This definition is controlled by the above-mentioned conditions of activation. First, the specific surface area of the activated carbon is in the range of 900 to 2020 m ² / g. In the present specification, the specific surface area of each trial example is a measurement by the BET method (Brunauer, Emmett and Teller method). If the specific surface area is less than 900 m ² / g, the pore volume will be small, and the species that can be adsorbed by a single activated carbon will be limited. When the specific surface area exceeds 2020 m ² / g, the pore diameter is greatly expanded, and the removal performance of low molecular weight molecules is lowered. From this, in the polar substance-adsorbed activated carbon according to the present invention, the range value of the specific surface area is derived as appropriate.

Second, the total pore volume is in the range of 0.4 to 1.2 cm ³ / g. By increasing the total pore volume, it exerts an effect on the adsorption of other compounds in addition to the desired chloramine and ammonia, and as a whole, the capacity as an activated carbon adsorbent is improved. If the total pore volume is less than 0.4 cm ³ / g, the pores themselves are too small to obtain sufficient adsorption capacity of activated carbon. Also, the upper limit of 1.2 cm ³ / g is a value considered from the limit in producing the activated carbon of the object of the present invention.

  Third, the average pore diameter is in the range of 1.8 to 2.6 nm. The average pore diameter in this range mainly corresponds to the micropore range. Since chloramine as described above is a low molecular weight compound, the pores developed in the activated carbon have micropores developed corresponding to the low molecular weight compounds. If the average pore diameter is in the above range, micropores, mesopores, and macropores are developed, and it is possible to adsorb low molecular weight compounds such as chloramine while improving the molecular adsorption capacity of activated carbon itself. Be

  In addition to the physical properties of the activated carbon itself, it is possible to define the physical properties of the adsorptive activated carbon by adding an indicator of the adsorption capacity of the activated carbon. Concretely, the methylene blue adsorption performance of the said adsorption activated carbon in the measurement based on JISK1474-1 (2014) is 120 mL / g or more. Methylene blue is a polar molecule and is convenient as an indicator of the adsorption capacity of the polar molecule to be provided by chloramine-adsorbed activated carbon. Therefore, the lower limit is 120 mL / g or more, more preferably 160 mL / g or more. The upper limit is considered to be 250 mL / g in terms of the performance of activated carbon.

  Moreover, the packing density of the said adsorption activated carbon in the measurement based on the same specification is 0.56 g / mL or less. Generally, the higher the packing density, the better. However, if it becomes high, there is a concern that the water density at the time of filtration may decrease due to densification. As a result, the pressure loss is excessive and the filtration efficiency is reduced. Therefore, the efficiency of filtration is taken into consideration and the aforementioned packing density is defined while maintaining the efficiency of packing. The lower limit of the packing density is considered to be around 0.35 g / mL.

  Furthermore, the mercury pore volume is 0.2 g / mL or more. If the mercury pore volume is less than 0.2 g / mL, it is considered that the macropores are underdeveloped and the uptake of the substance to be adsorbed into the activated carbon adsorbent is delayed.

  The chloramine-adsorbed activated carbon of the present invention defined by the requirements based on various physical properties is, for example, directly packed in a filtration column such as a water purifier, or processed into a cylindrical body in which activated carbon and a binder etc. are aggregated and loaded in the apparatus. Be done. It also applies to sites where chloramine removal is required, such as water filtration sites for artificial dialyzers.

[Used activated carbon]
The inventors used the following raw materials to make a polar substance-adsorbed activated carbon.
Activated carbon: Futamura Chemical Co., Ltd .: coconut shell activated carbon "Taiwa CW 360 BL" (average particle size: 0.34 mm)
{Hereafter, it is written as C1. }
Futamura Chemical Co., Ltd .: coconut shell activated carbon "Taiwa CW 360 B" (average particle size: 0.34 mm)
{Hereafter, it is written as C2. }
Futamura Chemical Co., Ltd .: coconut shell activated carbon "Taiba CW 360 SZ" (average particle size: 0.40 mm)
{Hereafter, it is written as C3. }
Futamura Chemical Co., Ltd .: Coal activated carbon "Taiba GM 360 B" (average particle size: 0.34 mm)
{Hereafter, it is written as C4. }

[Treatment of Adsorbed Activated Carbon]
Prototype 1
Charcoal obtained by steaming the coconut shell for one day was crushed and sieved with a 30 to 60 mesh sieve to prepare the adsorption activated carbon of Prototype Example 1.

Prototype 2
Futamura Chemical Co., Ltd. “Taiwa CW 360 BL” (C1) was used as the adsorption activated carbon of Trial Example 2.

Prototype 3
Futamura Chemical Co., Ltd. “Taiwa CW 360 B” (C 2) was used as the adsorption activated carbon of Trial Example 3.

  The inventors used activated carbon (C1, 2) made of coconut husk as a raw material and performed heat treatment on these activated carbons to produce the adsorption activated carbons of Prototype Examples 4-9.

Prototype 4
In a rotary kiln, 200 g of activated carbon (C2) was charged and the temperature was raised to 900 ° C., and the temperature was maintained. Water was introduced into the rotary kiln at a flow rate of 0.3 mL / min and further heated for 20 hours while maintaining 900 ° C. After that, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 4.

Prototype 5
The rotary kiln was charged with 200 g of activated carbon (C1), and the temperature was raised to 300 ° C., and the temperature was maintained. Pressurized air was introduced into the rotary kiln at a flow rate of 24 L / min and heated for 1 hour while maintaining 300 ° C. After that, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 5.

Prototype 6
In a rotary kiln, 200 g of activated carbon (C1) was charged and the temperature was raised to 500 ° C., and the temperature was maintained. Air (5-35 ° C., relative humidity 45-85%) was introduced under pressure into a rotary kiln at a flow rate of 1 L / min and heated for 2 hours. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 6.

Prototype Example 7
The rotary kiln was charged with 200 g of activated carbon (C1), and the temperature was raised to 300 ° C., and the temperature was maintained. Air at 30 ° C. humidified to a relative humidity of approximately 90% was introduced into the rotary kiln at a flow rate of 24 L / min under pressure and heated for 1 hour while maintaining 300 ° C. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 7.

Prototype 8
In a rotary kiln, 200 g of activated carbon (C1) was charged and the temperature was raised to 500 ° C., and the temperature was maintained. Air at 30 ° C. humidified to a relative humidity of about 90% was introduced into the rotary kiln at a flow rate of 24 L / min under pressure and heated for 1 hour while maintaining 500 ° C. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 8.

Prototype Example 9
In a rotary kiln, 200 g of activated carbon (C1) was charged and the temperature was raised to 500 ° C., and the temperature was maintained. Air at 30 ° C. humidified to a relative humidity of about 90% was introduced into the rotary kiln at a flow rate of 24 L / min under pressure and heated for 2 hours while maintaining 500 ° C. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 9.

Prototype 10
In a rotary kiln, 200 g of activated carbon (C1) was charged and the temperature was raised to 500 ° C., and the temperature was maintained. Air at 30 ° C. humidified to a relative humidity of about 90% was introduced into the rotary kiln at a flow rate of 24 L / min under pressure and heated for 3 hours while maintaining 500 ° C. After that, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 10.

Prototype 11
Futamura Chemical Co., Ltd. “Taiwa CW 360 SZ” (C3) was used as the adsorption activated carbon of Trial Example 11.

Prototype 12
In a rotary kiln, 200 g of activated carbon (C3) was charged, and the temperature was raised to 500 ° C., and the temperature was maintained. Air at 30 ° C. humidified to a relative humidity of about 90% was introduced into the rotary kiln at a flow rate of 24 L / min under pressure and heated for 2 hours while maintaining 500 ° C. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 12.

Prototype 13
Futamura Chemical "Taiba GM 360 B" (C4) was used as the adsorption activated carbon of Trial Example 11.

Prototype 14
In a rotary kiln, 200 g of activated carbon (C4) was charged and the temperature was raised to 500 ° C., and the temperature was maintained. Air at 30 ° C. humidified to a relative humidity of about 90% was introduced into the rotary kiln at a flow rate of 24 L / min under pressure and heated for 2 hours while maintaining 500 ° C. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 12.

[Measurement of Adsorbed Activated Carbon]
The amount of surface oxides (meq / g) is determined by applying Boehm's method, shaking the adsorbed activated carbon of each example in 0.05 N aqueous solution of sodium hydroxide and filtering it, and the filtrate is neutralized and titrated with 0.05 N hydrochloric acid. The amount of sodium hydroxide at the time of

The specific surface area (m ² / g) is determined by the BET method by measuring the nitrogen adsorption isotherm at 77 K using an automatic specific surface area / pore distribution measuring apparatus “BELSORP-mini II” manufactured by Microtrac Bell Inc. (BET specific surface area).

For the total pore volume (mL / g), the nitrogen adsorption amount (V) at a relative pressure of 0.990 is calculated according to the following formula (i) using the apparatus used to measure the specific surface area described above and applying Gurvitsch's law. And the volume of the liquid nitrogen (V _p ). In Formula (i), M _g is the molecular weight of the adsorbate (nitrogen: 28.020), and _{g g} (g / cm ³ ) is the density of the adsorbate (nitrogen: 0.808).

The average pore diameter (nm) is calculated using the values of pore volume (mL / g) and specific surface area (m ² / g), assuming that the shape of the pore is cylindrical, and using the values of pore volume (mL / g) and specific surface area (m ² / g) Obtained from ii).

  The mercury pore volume (g / mL) is set at a contact angle of 130 °, a surface tension of 484 dynes / cm (4.84 mN / m) using an autopore 9500 manufactured by Shimadzu Corporation, and a pore diameter of 7. The pore volume value (g / mL) was determined by mercury porosimetry at 5 to 15000 nm.

  The measurement of methylene blue adsorption performance (mL / g) and packing density (g / mL) was measured according to JIS K 1474 (2014).

The processing conditions and physical properties of the adsorptive activated carbon of each of the prototype examples are as shown in Tables 1 to 3. From the top of Table 1, heating temperature (° C.), heating time (h), presence or absence of humidification, surface oxide amount (meq / g), BET specific surface area (m ² / g), total pore volume (cm ³ / g) Average pore diameter (nm), mercury pore volume (g / mL), methylene blue adsorption performance (mL / g), and packing density (g / mL).

[Measurement of chloramine adsorption amount]
Ammonia water and sodium hypochlorite solution were mixed to prepare monochloramine from mutual reaction. Water was added here to dilute the combined chlorine concentration to about 100 μg / L. Then, the chloramine solution was adjusted so that pH may be converged in the range of 8.8-9.2 by adding an appropriate amount of hydrochloric acid.

  In the measurement of the chloramine adsorption amount, the adsorption activated carbon of the prototype example was crushed and completely dried. A predetermined amount of adsorption activated carbon was charged into a 200 mL flask, into which 100 mL of the chloramine solution prepared above was injected. Shake for 60 minutes in a 25 ° C. thermostat. The solution was filtered using filter paper to make each solution for test. The amount of residual chloramine was calculated indirectly by measuring the amount of chlorine in the solution by DPD (diethyl-p-phenyldiamine) spectrophotometry (553 nm).

  The concentration of chlorine and the concentration of free chlorine in the test solution of each example were determined, and the concentration of combined chlorine was calculated from the difference. The combined chlorine concentration corresponds to the concentration of chloramine. That is, the adsorption of chloramine is equivalent to the combined chlorine concentration (equivalent number of moles). Therefore, the combined chlorine adsorption rate (%) before and after charging the adsorption activated carbon was taken as the chloramine adsorption rate. The test was performed at 25 ° C.

  In Tables 4 to 6, the activated carbon addition concentration (g / L), the combined chlorine concentration (mg / L), and the adsorption amount per unit mass of activated carbon (mg / L) when the amount of the adsorption activated carbon of each prototype example is changed and added g) and combined chlorine adsorption rate (chloramine adsorption rate) (%).

[Ammonia ventilation test]
10 ml of activated carbon of each example was packed in a 25 mm diameter column, and ammonia gas was prepared so that the concentration was in the range of 16 to 24 ppm and the humidity was in the range of 45 to 55%. The gas was blown into each column at a flow rate of 2.9 L / min. Thereafter, the concentration of ammonia gas at the inlet and outlet of each column was measured to calculate the breakthrough rate, and the processing time until the breakthrough rate exceeded 20% was determined.

  In Tables 7 to 9, the concentration (ppm) of the ammonia gas at the column inlet and the concentration (ppm) at the column outlet in the time course (min) when the aeration test of ammonia was conducted for the adsorption activated carbon of each trial example The excess rate (%) was shown.

  In addition, Table 10 shows the time when the breakthrough rate is 20% for each of the prototype examples.

[Results and discussion]
From the tendency of all examples, the bound chlorine adsorption rate (chloramine adsorption rate) is proportional to the amount of the activated carbon added. From the comparison of trial production examples 1 to 3 without any treatment, trial production example 4 without air introduction, and trial production examples 5 and 6 by a combination of air introduction and heat treatment, the combined chlorine adsorption rate of trial examples 5 and 6 is It rose in the same addition amount. Also, from the results of the aeration test, the adsorption performance of ammonia is higher than those of prototype examples 1 to 3 without any treatment, prototype example 4 without air introduction, and prototype examples 5 and 6 by a combination of air introduction and heat treatment. It showed that it improved. From this, it was possible to confirm the superiority of the combination of air introduction and heating in the fifth and sixth prototype examples.

  The main difference between Prototype 5 and Prototype 7 is the humidity of the introduced air. From this, the humidity of the air is more effective. Prototypes 8 and 9 are examples in which the heating temperature is raised. As a result, even with air of the same humidity, the performance is further improved. In addition, prototype examples 8 to 10 are examples in which the heating time is changed. As a tendency in this case, it was also confirmed that the longer the heating time, the more effective.

  The physical properties of Tables 1 to 3 were overlapped with the results of bonded chlorine adsorption rates of Tables 4 to 6 and the results of gas passing tests of Tables 7 to 9, respectively. From the difference between the prototype examples 1 to 6, 11 and 13 and the prototype examples 7 to 10, 12 and 14, it was found that the adsorption performance of the polar substance is further improved when the surface oxide content is 0.35 meq / g or more.

The BET specific surface area, to the 930 not because good results greater than 930 m ² / g of Prototype Example 5 and 6 is in the range of 2020m ² / g. From the same tendency, the total pore volume is in the range of 0.4 to 1.2 cm ³ / g, and the average pore diameter is in the range of 1.8 to 2.6 nm.

  Furthermore, focusing on methylene blue adsorption performance, the lower limit is 120 mL / g or more from the difference between each of the prototype examples, and more preferably 160 mL / g or more from the difference between the prototype examples 5 and 6. The upper limit is considered to be 350 mL / g in terms of the performance of activated carbon. In addition, the packing density is 0.56 g / mL or less, preferably 0.54 g / mL or less.

  By overlapping the physical properties of activated carbon, it was possible to obtain an activated carbon that is effective for adsorbing polar substances such as chloramine and ammonia. Therefore, in addition to the active carbon that is effective for the adsorption of polar substances, it is also possible to combine with other active carbons to broaden the adsorption target.

  Since the polar substance-adsorbed activated carbon of the present invention is effective for adsorbing polar substances such as chloramine and ammonia, it is used as a filter material for removing polar substances from tap water, and further, filtration of purified water for artificial dialysis , Suitable for use in preparation.

In addition to the physical properties of the activated carbon itself, it is possible to define the physical properties of the adsorptive activated carbon by adding an indicator of the adsorption capacity of the activated carbon. Concretely, the methylene blue adsorption performance of the said adsorption activated carbon in the measurement based on JISK1474-1 (2014) is 120 mL / g or more. Methylene blue is a polar molecule and is convenient as an indicator of the adsorption capacity of the polar molecule to be provided by chloramine-adsorbed activated carbon. Therefore, the lower limit is 120 mL / g or more, more preferably 160 mL / g or more. The upper limit is considered to be 350 mL / g in terms of the performance of activated carbon.

Prototype 6
In a rotary kiln, 200 g of activated carbon (C1) was charged and the temperature was raised to 500 ° C., and the temperature was maintained. Air (5-35 ° C., relative humidity 45-85%) was introduced under pressure into a rotary kiln at a flow rate of 24 L / min and heated for 2 hours. Thereafter, it was taken out and cooled to prepare an adsorption activated carbon of Prototype Example 6.

Claims (4)

Adsorbed activated carbon for adsorbing polar substances,
The amount of surface oxides on the surface of the adsorption activated carbon is 0.35 meq / g or more,
A polar substance-adsorbed activated carbon characterized by having a BET specific surface area of 900 to 2020 m ² / g. The polar substance-adsorbed activated carbon according to claim 1, wherein the adsorption activated carbon has a total pore volume of 0.4 to 1.2 cm ³ / g and an average pore diameter of 1.8 to 2.6 nm.   The methylene blue adsorption performance of the adsorptive activated carbon in the measurement according to JIS K 1474-1 (2014) is 120 mL / g or more, and the packing density of the adsorptive activated carbon in the measurement according to JIS K 1474-1 (2014) is 0. The polar substance-adsorbed activated carbon according to claim 1 or 2, which is 56 g / mL or less.   The activated carbon for polar substance adsorption according to any one of claims 1 to 3, wherein the polar substance is one or both of chloramine and ammonia.