JP3693544B2 - Activated carbon and water purifier provided with the same - Google Patents

Description

【００３１】
（実施例１）
市販のヤシガラ粒状活性炭（クラレケミカル＝クラレコールＧＷ）の２種類の粒度分布である１００−２７５（μｍ）と７５−１５０（μｍ）を３：２の割合で混合したものでＢＥＴ法により求めた比表面積は１０２０ｍ²／ｇである。
【００３２】
（実施例２）
市販のヤシガラ粒状活性炭（クラレケミカル＝クラレコールＧＷ）の２種類の粒度分布である１００−２７５（μｍ）と７５−１５０（μｍ）を２：１の割合で混合したものでＢＥＴ法により求めた比表面積は１０２０ｍ²／ｇである。
【００３３】
（実施例３）
市販のヤシガラ粒状活性炭（クラレケミカル＝クラレコールＧＷ）の２種類の粒度分布である１００−２７５（μｍ）と７５−１５０（μｍ）を１：１の割合で混合したものでＢＥＴ法により求めた比表面積は１０２０ｍ²／ｇである。
【００３４】
（比較例１）
市販のヤシガラ粒状活性炭（クラレケミカル＝クラレコールＧＷ）の１種類の粒度分布である１００−２７５（μｍ）でＢＥＴ法により求めた比表面積は１０２０ｍ²／ｇである。
【００３５】
（比較例２）
市販のヤシガラ粒状活性炭（クラレケミカル＝クラレコールＧＷ）の１種類の粒度分布である７５−２７５（μｍ）でＢＥＴ法により求めた比表面積は１０２０ｍ²／ｇである。
【００３６】
（比較例３）
市販のヤシガラ粒状活性炭（クラレケミカル＝クラレコールＧＷ）の１種類の粒度分布である７５−１５０（μｍ）でＢＥＴ法により求めた比表面積は１０２０ｍ²／ｇである。
【００３７】
上述の特性を有する活性炭のトリハロメタンの吸着特性を以下の方法で測定した。ＪＩＳ Ｓ３２０１（１９９９）６．２．３揮発性有機化合物除去性能試験に準拠した。まず、予め活性炭と０．２μｍフィルターにより浄化処理した水道浄化水に、トリハロメタン類を１００ｐｐｂ添加したものを調整原水とした。ついで、体積容量５０ｍｌ、厚さ２０ｍｍの円筒形カラムに上述の特性を有する活性炭を充填し、前述の調整原水をＳＶ値９００で活性炭層に通過させた。活性炭層を通過した流出水中のトリハロメタン類の濃度を、パージ・アンド・トラップ法で濃縮前処理し、ガスクロマトグラフ−質量分析装置で定量測定した。この時、活性炭層通過前後で、流入水に対する流出水のトリハロメタン類の水中濃度が、２０％以上になる点を破過点とし、活性炭の吸着材としての寿命とした。また、上述の特性を有する活性炭の濁度性能は、ＪＩＳ Ｓ３２０１（１９９９）６．２．２濁り除去性能試験に準拠した。まず、予め活性炭と０．２μｍフィルターにより浄化処理した水道浄化水に、試験用カオリン添加し、濁度２±０．２度を保持したものを調整原水とした。圧力一定の条件下で流量（Ｌ／分）が初期の５０％となるところを寿命とした。
【００３８】
得られた実施例１から３と比較例１から３の粒状活性炭の濁度除去寿命と総トリハロメタン類除去寿命を（表１）に示す。いずれの実施例も比較例１に比べると総トリハロメタン類の除去性能は上回っており、その中でも特に実施例１は比較例１と比較して総トリハロメタン類は１．１倍となっており、濁度除去性能は比較例３に比べると１．６倍となっており、やはり比較例２の単独で作られた活性炭と比較すると濁度除去寿命と総トリハロメタン類除去寿命がバランスのとれた活性炭となっている。
【００３９】
【発明の効果】
本発明の請求項１に記載の発明によれば、同じ材質の粒状活性炭で、濁度除去性能と総トリハロメタン類除去性能を高めることができる。動的吸着特性が優れた活性炭とすることができる。
【００４１】
本発明の請求項２に記載された発明によれば、濾過性の優れた浄水器を得ることができる。
【図面の簡単な説明】
【図１】本発明の実施の形態１における活性炭の粒度分布を示す図
【図２】本発明の実施の形態１における活性炭の混合比率を変えた場合の粒度分布を示す図
【図３】本発明の実施の形態における浄水器の構造図
【符号の説明】
１ 浄水器本体
２ 活性炭
３ 流入口
４ 流出口
５ 中空糸膜
６ 蛇口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to activated carbon excellent in adsorption characteristics of organochlorine compounds that are harmful components in water, particularly trihalomethanes, and also excellent in turbidity removal performance, and a water purifier equipped with the same in water purification treatment. .
[0002]
[Prior art]
Tap water provided for drinking needs to contain a certain concentration or more of residual chlorine added for the purpose of sterilization, and the operation method and the like are regulated by the Water Supply Law from the viewpoint of health and public health. However, chlorine added for the purpose of sterilization has an oxidizing action of inorganic substances and an oxidative decomposition action of organic substances in addition to the sterilizing action, and humic substances, which are a kind of natural organic substances contained in raw tap water, etc. It is oxidatively decomposed to produce trihalomethanes that are carcinogenic substances. On the other hand, the quality of raw water used for tap water, etc. has been on the decline in recent years due to the expansion of pollution, and as a result, the amount of humic substances contained in the raw water has also increased. The concentration of trihalomethanes is also increasing.
[0003]
For this reason, various purification treatments using activated carbon having an adsorption action have been studied as means for removing trihalomethanes. In general, activated carbon for water treatment has been used to increase the adsorption capacity per unit volume of the object to be removed, and activated carbon having a large surface area with good characteristics such as iodine adsorption performance and methylene blue adsorption performance. In addition to the surface area, activated carbon having many pores having a pore diameter of 10 mm or less has been studied for the removal of adsorbed particles.
[0004]
Furthermore, by reducing the particle size of the activated carbon, the bulk specific gravity is increased, the efficiency of filling the water purification cartridge or the like is increased, and activated carbon with good contact efficiency has been studied. For example, Japanese Patent Laid-Open No. 9-110409 uses activated carbon based on phenolic resin to remove organochlorine compounds, and in particular, the pore diameter occupying a pore volume with a pore diameter of 100 mm or less. Activated carbon in which the proportion of 6-8% is 65 vol% or more is disclosed.
[0005]
These had a large equilibrium adsorption amount, which is a static adsorption force of trihalomethanes, and the adsorption capacity was 3 mg or more per 1 g of activated carbon. Moreover, it is desirable that the activated carbon for water treatment has high hydrophilicity, and most of the activated carbon is steam activated as a gas activation. In addition, chemical activated carbon obtained by activation treatment with alkali hydroxide is also used. It is done. The activated carbon has various shapes, and in addition to powder, crushed, spherical, granular, and fibrous, molded cylindrical, disc, granular, spherical, and the like are manufactured and used.
[0006]
[Problems to be solved by the invention]
However, the above-mentioned conventional activated carbon forms an adsorption zone where trihalomethane is adsorbed when raw water is passed through, but there are few pores with a diameter of 10 mm or less, and there is a problem that adsorption performance is not sufficient for removing trihalomethane. .
[0007]
Therefore, reducing the particle size of the activated carbon should increase the packing efficiency, increase the contact efficiency between water and activated carbon, and increase the water adsorption performance of trihalomethane. There was a problem that clogging occurred and the turbidity life was shortened.
[0008]
In addition, in order to improve the above problem, it is conceivable to keep the turbidity life almost the same as before by increasing the particle size distribution only in a direction smaller than the conventional range, and to improve the trihalomethane removal performance, When activated carbon is granulated, there is a tendency that a peak is formed in the larger particle size distribution, so it is difficult to create an ideal particle size distribution with excellent trihalomethane removal performance from one type of activated carbon. There was a problem.
[0009]
The present invention solves the above-mentioned conventional problems, and provides an activated carbon having a large adsorption capacity for trihalomethanes from raw water, excellent dynamic adsorption characteristics and excellent turbidity removal life, and a water purifier equipped with the activated carbon. The purpose is to do.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the activated carbon of the present invention has a particle size distribution of 75 to 275 (μm) and a particle size distribution of 75 to 165 (μm) in the particle size distribution expressed by the content rate (%). To 275 (μm), each content rate (%) has at least one peak value of 15% or more (excluding those each having a single distribution) .
[0011]
As a result, it is possible to obtain activated carbon having a large adsorption capacity for trihalomethanes from raw water and having excellent adsorption characteristics such as malodorous components and colored components.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, in the particle size distribution expressed by the content (%), the particle size distribution is 75 to 275 (μm), the particle size distribution is in the range of 75 to 165 (μm), and 165 to 275. In the range of (μm), at least one peak value with a content (%) of 15% or more (excluding those each having a single distribution) is activated carbon, so dynamic adsorption Since the characteristics are improved and the adsorption capacity is further increased, other adsorption characteristics such as turbidity components, residual chlorine, chromaticity components, odor components and the like are also excellent.
[0013]
Here, the content rate (%) is a ratio of the activated carbon having a predetermined particle size in the total amount of various particle sizes of the activated carbon.
[0014]
When there is only one peak in the particle size distribution range of 75 to 275 (μm), the distribution tends to be larger toward the larger particle size in terms of grain formation, so the turbidity removal life tends to be high but the trihalomethane removal life tends to be low This is not preferable.
[0015]
However , the particle size distribution is 75 to 275 (μm), and the particle size distribution is 75 to 165 (μm) and 165 to 275 (μm), each having at least one peak value (each Excluding those with a single distribution.) Since it is activated carbon, the adsorptive power becomes high, and the adsorption removal ability can be enhanced for various components other than trihalomethane.
[0016]
Here, the raw material of the activated carbon is a coconut shell which is a coconut shell as a main material. In addition to wheat, straw, straw, corn, and rice), a mixture of organic or inorganic binders may be used.
[0017]
Further, it may be a synthetic resin such as a phenol resin. In addition, a synthetic resin (acrylonitrile resin, melanin resin, polyvinyl alcohol resin) that can be a carbon source, cellulosic material (for example, wood waste or rice husk), or starch (for example, rice, wheat, A mixture of organic or inorganic binder can also be used. As a result, the adsorption rate of activated carbon can be increased in the purification method for trihalomethanes in water, where an adsorption zone is formed and the treated water passes through the adsorption zone, thereby improving the adsorption capacity of trihalomethanes. Can do.
[0018]
Since invention of Claim 2 of this invention is a water purifier which fills the activated carbon of Claim 1 and filters raw | natural water, the water purifier excellent in filtration performance can be obtained.
[0019]
(Embodiment 1)
FIG. 1 is a diagram showing the particle size distribution of activated carbon according to Embodiment 1 of the present invention, and FIG. 2 is a diagram showing the particle size distribution when the mixing ratio of activated carbon is changed according to Embodiment 1 of the present invention.
[0020]
As shown in FIG. 1, the activated carbon of the present invention has a content rate (%) in the range of 75 to 275 (μm) in the particle size distribution in the particle size distribution expressed by the content rate (%). It has at least two peak values of 15% or more, and has at least one peak value in the particle size distribution range of 75 to 165 (μm) and 165 to 275 (μm), respectively . This particle size distribution will be described below.
[0021]
Among the removal performances of activated carbon, the trihalomethane removal life and the turbidity removal life are contradictory performances. If the particle diameter of the activated carbon is larger than 275 (μm), the outer surface area of the activated carbon particles becomes small and the gap between the activated carbon particles becomes too large. The removal life of trihalomethanes is shortened. On the other hand, when the particle diameter of the activated carbon is smaller than 75 (μm), the activated carbon is fine, so the density is increased and the pressure loss is increased, and the turbidity life is shortened. Thus, in order to remove turbidity, the particle diameter had to be larger than 75 (μm), and in order to remove trihalomethane, it had to be 275 (μm) or less. Conventionally, the turbidity removal life should be mainly considered when trihalomethane is not closed up, and the particle size distribution is 100 to 275 (μm) shown in Comparative Example 1 in FIG. In contrast, 75 to 150 (μm) shown in Comparative Example 3 are excellent in the total trihalomethane removal lifetime. From these two circumstances, if the particle size distribution 75 to 275 (μm) is configured with the maximum width of both, activated carbon capable of simultaneously removing trihalomethane and removing turbidity should be obtained. The peak of is formed near 275 μm and is not formed near 160 (μm) which is the center of the whole. When activated carbon is granulated, it tends to form a peak with a larger particle size distribution, making it difficult to create an ideal particle size distribution with excellent trihalomethane removal performance from one type of activated carbon. It is. That is, even if activated carbon having a particle size distribution of 75 to 275 (μm) is formed by one type of activated carbon, the content (%) does not have a peak value at a particle size of 75 to 150 (μm). Although turbidity removal can Toriharometa emissions removal performance is made lower.
[0022]
Therefore, as shown in FIGS. 1 and 2, the present invention mixes two types of activated carbon within a range of 75 to 275 (μm) in order to obtain a particle size distribution of the activated carbon represented by examples described later. Is the ideal particle size distribution of activated carbon. These two types of activated carbon are those having a particle size distribution in the range of 100 to 275 (μm) and those in the range of 75 to 150 (μm). Thus, by mixing two types of activated carbon at a predetermined ratio, at least two peaks can be formed at a content rate of 15 (%) or more.
[0023]
Next, why these two types of activated carbon do not form two or more peaks unless the content rate is 15% or more, and how the particle size distribution changes when the mixing ratio is changed. The point will be described.
[0024]
The particle size distribution of the activated carbon produced by mixing in FIG. 2 is such that the ratio of 100 to 275 (μm) and 75 to 150 (μm) of 75 to 275 (μm) is 1: 1. (Example 3) Those of 3: 2 (Example 1) and 2: 1 (Example 2). As can be seen from FIG. 2, when the ratio of the particle size of 100 to 275 (μm) and the particle size of 75 to 150 (μm) is larger than 2: 1, the particle size formed in the range of 75 to 150 (μm). The distribution peak becomes lower than the threshold value of 15%, and the distribution and characteristics in the range of 60 to 275 (μm) of the activated carbon (Comparative Example 2) made of a single type are almost close, and the total trihalomethanes removal performance is It will be lower. That is, the trihalomethane removal performance does not show performance exceeding that of Comparative Example 2 configured with one kind of activated carbon. Moreover, the peak value from 100 to 275 (μm) at this time does not become high as in Comparative Example 2 around 230 (μm), and at least the turbidity removal performance is inferior to that of Comparative Example 2. For the reasons described above, in order to improve the trihalomethane removal performance over the conventional activated carbon (Comparative Example 2) configured with a single particle size distribution, a peak value in the range of at least 75 to 150 (μm) is set to the threshold value 15 (% ) More than that. As can be seen from FIG. 2, if the mixing ratio of the above two types of activated carbon is set to a ratio exceeding 3.5: 1, it will be 15% or less. In order to make the value appear, it is appropriate to select a ratio of 2: 1 (Example 2) or less.
[0025]
As described above, the particle size distribution is 75 to 275 (μm), and the particle size distribution is 75 to 165 (μm) and 165 to 275 (μm), each having one or more peak values. (Excluding those each having a single distribution.) Since activated carbon is used, activated carbon having high total trihalomethane removal performance and high turbidity removal performance can be realized. Furthermore, the adsorptive power is increased, the dynamic adsorption characteristics are particularly excellent, and the adsorption / removal ability for various components other than trihalomethane can be enhanced.
[0026]
(Embodiment 2)
FIG. 3 is a structural diagram of the water purifier in the embodiment of the present invention.
[0027]
In FIG. 3, 1 is a water purifier main body, 2 is activated carbon described in Embodiment 1, 3 is an inlet of raw water provided in the water purifier main body 1, 4 is an outlet of treated water treated with activated carbon 2, 5 is a hollow fiber membrane, and 6 is a faucet for supplying tap water as raw water. The raw water discharged from the tap water tap 6 flows into the water purifier from the inlet 3 provided in the water purifier main body 1. The water purifier is filled with activated carbon 2, turbidity removal and trihalomethane removal are performed, general bacteria are removed by the hollow fiber membrane 5, and discharged from the outlet 4.
[0028]
Since the water purifier of the second embodiment is thus filled with the activated carbon 2 described in the first embodiment, the raw water that has flowed from the inlet 3 has both turbidity and total trihalomethanes by the activated carbon 2. It can be removed with high efficiency.
[0029]
【Example】
Examples of the present invention will be described below with reference to (Table 1).
[0030]
[Table 1]

[0031]
(Example 1)
Two types of particle size distributions of commercially available coconut shell granular activated carbon (Kuraray Chemical = Kuraray Coal GW) 100-275 (μm) and 75-150 (μm) were mixed at a ratio of 3: 2 and determined by the BET method. The specific surface area is 1020 m ² / g.
[0032]
(Example 2)
Two types of particle size distributions of commercially available coconut shell granular activated carbon (Kuraray Chemical = Kuraray Coal GW) 100-275 (μm) and 75-150 (μm) were mixed at a ratio of 2: 1 and determined by the BET method. The specific surface area is 1020 m ² / g.
[0033]
(Example 3)
Two kinds of particle size distributions of commercially available coconut shell granular activated carbon (Kuraray Chemical = Kuraray Coal GW) 100-275 (μm) and 75-150 (μm) were mixed at a ratio of 1: 1, and determined by the BET method. The specific surface area is 1020 m ² / g.
[0034]
(Comparative Example 1)
The specific surface area determined by the BET method with 100-275 (μm), which is one kind of particle size distribution of commercially available coconut palm granular activated carbon (Kuraray Chemical = Kuraray Coal GW), is 1020 m ² / g.
[0035]
(Comparative Example 2)
The specific surface area determined by the BET method using 75-275 (μm), which is one kind of particle size distribution of commercially available coconut shell granular activated carbon (Kuraray Chemical = Kuraray Coal GW), is 1020 m ² / g.
[0036]
(Comparative Example 3)
The specific surface area determined by the BET method with 75-150 (μm), which is one kind of particle size distribution of commercially available coconut shell granular activated carbon (Kuraray Chemical = Kuraray Coal GW), is 1020 m ² / g.
[0037]
The adsorption characteristic of trihalomethane on activated carbon having the above characteristics was measured by the following method. It conformed to JIS S3201 (1999) 6.2.3 volatile organic compound removal performance test. First, adjusted raw water was prepared by adding 100 ppb of trihalomethanes to tap water purified in advance using activated carbon and a 0.2 μm filter. Next, activated carbon having the above-described characteristics was packed into a cylindrical column having a volume capacity of 50 ml and a thickness of 20 mm, and the above-mentioned adjusted raw water was passed through the activated carbon layer with an SV value of 900. The concentration of trihalomethanes in the effluent water that passed through the activated carbon layer was subjected to concentration pretreatment by the purge and trap method, and quantitatively measured with a gas chromatograph-mass spectrometer. At this time, before and after passing through the activated carbon layer, the point where the concentration of the trihalomethanes in the effluent with respect to the influent was 20% or more was defined as the breakthrough point, and the lifetime of the activated carbon as an adsorbent was defined. Moreover, the turbidity performance of the activated carbon having the above-described characteristics conformed to the turbidity removal performance test of JIS S3201 (1999) 6.2.2. First, test kaolin was added to purified tap water previously purified with activated carbon and a 0.2 μm filter, and a turbidity of 2 ± 0.2 degrees was maintained as adjusted raw water. The lifetime was defined as the point where the flow rate (L / min) reached 50% of the initial value under a constant pressure condition.
[0038]
The turbidity removal life and total trihalomethane removal life of the granular activated carbons of Examples 1 to 3 and Comparative Examples 1 to 3 obtained are shown in (Table 1). In any of the examples, the removal performance of the total trihalomethanes exceeded that of Comparative Example 1, and in particular, in Example 1, the total trihalomethanes was 1.1 times that of Comparative Example 1, and the turbidity The degree of removal performance is 1.6 times that of Comparative Example 3, and the activated carbon with a balanced turbidity removal life and total trihalomethane removal life as compared with the activated carbon of Comparative Example 2 alone. It has become.
[0039]
【The invention's effect】
According to the first aspect of the present invention, it is possible to improve the turbidity removal performance and the total trihalomethane removal performance with the granular activated carbon made of the same material. Activated carbon with excellent dynamic adsorption characteristics can be obtained.
[0041]
According to the invention described in claim 2 of the present invention, a water purifier having excellent filterability can be obtained.
[Brief description of the drawings]
FIG. 1 is a graph showing the particle size distribution of activated carbon in Embodiment 1 of the present invention. FIG. 2 is a graph showing particle size distribution when the mixing ratio of activated carbon is changed in Embodiment 1 of the present invention. Structure diagram of water purifier in an embodiment of the invention [Explanation of symbols]
1 Water Purifier Body 2 Activated Carbon 3 Inlet 4 Outlet 5 Hollow Fiber Membrane 6 Faucet

Claims (2)

In the particle size distribution expressed by the content rate (%), the particle size distribution is 75 to 275 (μm), and the particle size distribution ranges from 75 to 165 (μm) and 165 to 275 (μm). ) Has at least one peak value of 15% or more (excluding those each having a single distribution) . A water purifier for filling the activated carbon according to claim 1 and filtering raw water.

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