JPH06327970A - Adsorbing material - Google Patents

Abstract

PURPOSE:To obtain an adsorbent for selectively, simply and efficiently adsorbing and removing harmful material such as an organic halogen compound slightly contained in water by using a polymer composition having a specific component of hydrogen bonding strength of three dimensional solubility parameter. CONSTITUTION:The polymer composition such as polysulfone, polyacrylonitrile 1-5 (cal<1/2>cm<-3/2>), preferably 1.5-4.5, more preferably 2.0-4.5 in component deltah of hydrogen bonding strength of three dimensional solubility parameter is used. The polymer composition has fine porous form having many numbers of narrow pores from equal to below several mum which increase adsorbing quantity due to the increase of adsorption surface area. The adsorbing material obtained by this manner extremely easily adsorbs harmful materials such as trihalomethane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorbent for effectively removing organic halogen compounds such as trihalomethane which is a harmful substance contained in a trace amount in water.

[0002]

2. Description of the Related Art In recent years, trihalomethane (THM) such as chloroform and organic halogen compounds (especially chlorine-based organic solvent COS) have been widely used in mechanical metal manufacturing industry, IC manufacturing industry, and cleaning industry to clean rivers, soil, and groundwater. It is polluted. In addition, the generation of trihalomethanes has recently been recognized in the process of purification of river water.

Some of these substances have been found to be carcinogenic, and have become a major social problem. Therefore WH
O and THM, CO by US Environmental Protection Agency (EPA)
A provisional standard value for S has been set, and the control target value has been notified by the Ministry of Health and Welfare in Japan.

As measures for removing THM and COS in water, aeration method and activated carbon adsorption method {Shigekazu Nakano, surface, 31,
1, (1993)} is performed. On the other hand, as a new method to replace this, removal of THM in a water purification plant by reverse osmosis (RO) membrane has been reported {Shinji Kasai, Yoshihiro Taboku, Masao Nasu, Masaomi Kondo, Sanitary Chemistry, trihalomethane in water and chlorine system. Removal of organic solvent by film, 36, 3,
(1990)}.

[0005]

However, the aeration method may cause air pollution, and the activated carbon adsorption method cannot easily be in a form suitable for the purpose.
Each of them has a problem such as adsorbing chlorine added as a bactericide.

[0006] Further, the removal by the RO membrane has a large removal effect and can efficiently process a large amount of water, but it has a drawback that it cannot be completely removed even if the apparatus becomes large and the removal rate is large. have.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies in order to overcome the drawbacks of the prior art, and have arrived at the present invention. That is, the present invention provides an adsorbent which selectively and easily and efficiently adsorbs and removes harmful substances such as organic halogen compounds contained in a trace amount in water at low cost.

The present invention has the following constitution in order to solve the above problems.

Adsorption which is mainly composed of at least one polymer composition having a hydrogen bonding force component δ _{h of the} three-dimensional solubility parameter of 1 to 5 (cal ^1/2 cm ^-3/2 ). Material.

The present invention will be described in detail below.

The component δ _h of the hydrogen bonding force of the three-dimensional solubility parameter referred to in the present invention is determined in the literature {Take Matsuura, Basics of Synthetic Membranes, p26-33 (1985), Kitami Shobo} (hereinafter,
It is as described in the cited document 1) and the like, but its outline is as follows.

That is, Hildebr for estimating heat of mixing
and the _{formula: ΔH M = V M [(} ΔE 1 / V 1) 1/2 - (ΔE 2 / V 2) 1/2] 2 Φ 1 Φ 2 [ΔH M is the total heat of mixing (J / mol), V _M is the total molar volume of the mixture (m ³ / mol), ΔE is the evaporation energy (J
/ Mol), V is molar volume (m ³ / mol), Φ is volume fraction, and subscripts 1 and 2 are constituent components 1 and 2 in the mixture]
It is clear that the closer the ΔE / V of 1 and 2 are to each other, the less the heat of mixing, that is, the easier the mixing (dissolution) of the constituents 1 and 2 is. Therefore, Δ
E / V is called the solubility parameter.

Also, three interactions that act on the evaporation energy (ΔE) between molecules, the London dispersive force ΔE _d , the force acting on the permanent dipoles ΔE _p , and the hydrogen bonding force ΔE _h.
And δE / V = δE _d / V + δE _p / V + δE _h
/ V or δ _sp ² = δ _d ² + δ _p ² + δ _h ² .

Here, δ _d = (E _d / V) ^1/2 , δ _p =
(E _p / V) ^1/2 , δ _h = (E _h / V) ^1/2 , and
The components of the solubility parameter dispersive power, polarity, and hydrogen bonding are shown respectively.

In the present invention, among δ _d , δ _p and δ _h calculated based on such an idea, the value of δ _h (hydrogen bond component) is 1 to 5 (cal ^1/2 cm). ^-3/2 ), an adsorbent mainly composed of at least one polymer composition, which has been found to adsorb the non-adsorbate well, preferably 1.5 to 4.5, More preferably, it is a polymer composition in the range of 2.0 to 4.5.

The value of δ _h is known for various polymers (Cited document 1), but a known value corresponding to the constituent element of the organic compound recommended in the cited document 1 or the like is used. It is also possible to calculate from the molecular structure of the repeating unit of the polymer.

That is, it can be calculated by the following equation.

Δ _h = (ΣE _hi / ΣV _g ) ^1/2 For example, in the case of polyvinyl chloride, the constitutional unit of the repeating unit is However, these are referred to as constitutional units 1, 2 and 3, respectively, and E _hi and V _g of the constitutional unit i are respectively E _hi i
(J / mol) and V _g i (cm ³ / mol), from the reference document 1, E _hi 1 = 400, V _g 1 = 19.9 E _hi 2 = 0, V _g 2 = 15.85 E _{Since hi} 3 = 0 and V _g 3 = 9.45, ignoring the molecular ends, δ _h = {(E _hi 1 + E _hi 2 + E _hi 3) / (V _g 1 + V _g 2 + V _g 3)} ^1/2 = {(400 + 0 + 0) / (19.9 + 15.85 + 9.45)} ^1/2 = 2.97 (J ^1/2 cm ^-3/2 ) or 1.45 (cal ^1/2 cm ^-3/2 ) Calculated.

From the value of δ _h thus obtained, the polymer composition of the present invention is, for example, polyvinyl chloride, polymethyl methacrylate, diallyl polyphthalate, polyethylene glycol, polypropylene glycol, sulfonated polyphenylene oxide, polyacrylonitrile. , Polyvinyl butyral, polyvinyl acetal, polyvinyl formal, polysulfone, polyphenylene sulfone, cellulose phthalate ester, polypiperazine ester, polyether sulfone, polyphenylene sulfide and the like.

Of these, polysulfone and polyacrylonitrile are particularly preferable because of their adsorptivity and easy availability.

The adsorbent composed of the polymer composition of the present invention can be desorbed, of course, but it is difficult to desorb under normal use conditions, so there is no concern about secondary contamination.

After being used, the adsorbent of the present invention can be desorbed by heat treatment or solvent treatment and reused.
It is also possible to discard the adsorbent as it is.

In the present invention, the polymer composition is usually used alone, but it is preferably used when two or more kinds are mixed and expected to exhibit a synergistic effect.

The polymer composition of the present invention may be in the form of powder, granules, granules, pellets, fibers, felts, knits, woven fabrics, papers, membranes, non-woven fabrics, films, cords and the like. Further, these cut products and the like can be mentioned.

Among these forms, the granular, film-like, and film-like ones are preferable, and further, since the adsorption surface area is increased, the adsorption surface area is increased, and the adsorption rate and the adsorption amount are increased. Those having a large number of (microporous) are particularly preferable.

If the pore size is too large, the surface area of the adsorbent will be small and the effect will be reduced or the strength will be poor. Also, if it is too small, the speed of adsorbing non-adsorbed substances becomes slow. For this reason,
The pore size is particularly preferably 0.001 to 5 μm.

The production method can be carried out by any known method, and is not particularly limited. For example, in the case of a membrane, the pore size can be determined arbitrarily depending on the casting solution such as solvent, concentration and temperature. Select.

Further, in the present invention, in view of the strength and ease of use of the adsorbent, other materials may be combined with one side or both sides as a reinforcing material in a sheet form. In this case, the reinforcing material and form are not particularly limited as long as they do not interfere with the effect of the adsorbent. For example, polypropylene, polyethylene, polyester, polyamide-based non-woven fabrics and fabrics are suitable.

If the proportion of the reinforcing material is too large, the adsorption effect is lost, and if it is too small, the reinforcing effect is lost and it is difficult to form a composite. Therefore, 10 to 90% is preferable, and 30 to 90 is preferable.
%.

As an embodiment of the present invention, it is of course possible to use the adsorbent as it is by immersing it in a liquid containing the substance to be adsorbed, but in addition to that, for example, granules or cut products are packed in a column or a membrane is used. Water can be used by passing the material through a method such as mounting the material in a filter cartridge or processing it into a spiral shape, or filling the hollow fiber membrane in the same manner as in a known water purifier. Alternatively, it can be used by any known method suitable for each form and is not particularly limited.

When used in combination with a reverse osmosis membrane, an ultrafiltration membrane, etc., it is preferable from the viewpoint of safety and life, especially when producing drinking water.

Examples will be shown below, but the present invention is not limited thereto.

[0033]

[Examples] In the tests of each example, the dipping method in which the adsorption property of the adsorbent is most easily determined was used. That is, the following method was used.

50 ppm chloroform, 500 ppm
Each of the bromoform aqueous solution of 1 is placed in a 50 ml container to prepare an immersion liquid. 1 g of the test adsorbent was weighed and put in each dipping solution and sealed (22 ° C.).

The residual concentration in the aqueous solution was measured over time with a gas chromatograph (Shimadzu Gas Chromatograph GC-7A hydrogen flame ionization type detector), and the equilibrium adsorption amount per unit weight was calculated from a calibration curve prepared in advance.

The results obtained by making various adsorbents are shown below.

Example 1 Polysulfone (Udel-produced by Union Carbite Co.)
P3500) 15% dimethylformamide (DMF)
The solution was cast (20 ° C.) on a glass plate, immediately immersed in pure water and left for 5 minutes. It was taken out and peeled off from the glass plate to obtain a sponge-like polysulfone film. 90 this
The solvent was removed with hot water at 2 ° C for 2 minutes. The sponge-like polysulfone membrane has a pore diameter of 0.005 to 0.05 μm on the side exposed to air when cast and 1 on the opposite side.
Was ~ 5 μm.

The test results of the obtained adsorbent are shown in Table 1.

Example 2 Polysulfone (Udel-produced by Union Carbite Co.)
P3500) 18% dimethylformamide (DMF)
The solution (60 ° C.) was discharged into water from a nozzle having a hole diameter of 1 mm to remove the solvent and obtain a monofilament. This is 9
The solvent was removed by hot water at 0 ° C. for 2 minutes, and then cut into about 5 mm. The diameter of the pores on the obtained monofilament surface is
It was 0.003 to 0.07 μm.

Table 1 shows the test results of the obtained adsorbent.

Example 3 A 14% dimethylsulfoxide solution of polyacrylonitrile (manufactured by Toray Industries, Inc.) (relative viscosity 1200 poise at 45 ° C., intrinsic viscosity 3.15) was prepared at 60 ° C., and pore diameter was 1 m.
The monofilament was obtained by discharging from a nozzle of m into water and removing the solvent. This was cut into about 5 mm. The diameter of the surface pores of the obtained monofilament was 0.005.
Was about 0.02 μm.

Table 1 shows the test results of the obtained adsorbents.

Comparative Example 1 2 A 18% dioxane solution of cellulose acetate (manufactured by Eastman Kodak Co., acetylation degree 55.9%, intrinsic viscosity 0.95 measured with 25 ° C. dioxane solution, molecular weight 29000) was cast on a glass plate. (20 ° C.), immediately soak in pure water, and leave for 5 minutes. It was taken out and peeled off from the glass plate, and the solvent was removed to obtain a cellulose acetate film. Got,
The diameter of the pores was 0.0005 to 0.003 μm.

The test results of the obtained adsorbent are shown in Table 1.

Comparative Example 2 Polyethylene (HiZex 1300 manufactured by Mitsui Petrochemical Co., Ltd.
J) was made into a fibrous form (single yarn fineness 7 denier, total fineness 300,000 denier) by melt spinning, and then crimped with a crimper. Then, it was cut into 51 mm, opened with an opener and passed through a roller card to form a web. This web was needle punched to produce a felt of 50 g / m ² . The diameter of the pores on the surface of the fiber is 0.001
It was less than μm.

The test results of the obtained adsorbent are shown in Table 1.

Comparative Example 3 Polyethylene was poly-ε-capramide (6 nylon manufactured by Toray Industries, Inc., 1 g of polymer was dissolved in 100 ml of 98% sulfuric acid, and 98% measured by an Oswald viscometer at 25 ° C.).
Comparative Example 2 was repeated except that the relative viscosity to sulfuric acid was changed to 2.65).

The test results of the obtained adsorbent are shown in Table 1.

[0049]

[Table 1] As can be seen from Table 1, the adsorbent of the present invention was found to have extremely excellent trihalomethane adsorption performance as compared with the comparative example.

[0050]

The adsorbent of the present invention can very easily and efficiently adsorb harmful substances such as trihalomethane. In addition, since chlorine added is not adsorbed when the harmful substances in drinking water are removed, the sterilizing effect is not reduced and the product can be safely used for a long time.

Further, it is possible to produce a form suitable for the purpose, and since the adsorption amount is large and the adsorption speed is fast, it is possible to make the adsorption device lightweight and compact.

Claims (2)

[Claims] 1. It is mainly composed of at least one polymer composition having a hydrogen bonding force component δ _{h of the} three-dimensional solubility parameter of 1 to 5 (cal ^1/2 cm ^−3/2 ). Adsorbent to do. 2. The adsorbent according to claim 1, wherein the polymer composition is microporous.