JP2647776B2 - How to separate antibiotics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for adsorbing and removing dissolved antibiotics in water using a synthetic adsorbent having a halogen atom as a substituent. More specifically, using a synthetic adsorbent having a halogen atom content of 3 to 50% by weight in the synthetic adsorbent,
The present invention relates to a method for adsorbing an antibiotic having a hydrophobic group and a hydrophilic group in water. Among non-polar or micro-polar cross-linked copolymers, those with developed specific surface area and pore volume are called synthetic adsorbents, which are used for adsorption and purification of various substances because they can be regenerated with chemicals. I have. Among them, a styrene-divinylbenzene-based crosslinked copolymer has a large specific surface area and is widely used. Techniques for producing these synthetic adsorbents are known,
It is already manufactured and marketed under trademarks such as DIAION HP10, 20, 30, 40, 50 and Amberlite XAD2, 4.

[0002] The adsorption of a substance to these synthetic adsorbents is considered to be physical adsorption based on van der Waals force on the pore surface inside the adsorbent. Therefore, unlike activated carbon, it has a polarity such as methanol, ethanol and acetone. By washing the adsorbent with a high organic solvent, elution of the adsorbed substance from the adsorbent is possible. Utilizing such characteristics, it is widely used for the adsorption and purification of pharmaceuticals, the adsorption and purification of fragrances and natural pigments, and the decolorization of pulp wastewater and the adsorption and removal of COD components in general wastewater.

[0003] However, most of the known synthetic adsorbents are styrene-divinylbenzene (ethylvinylbenzene as an impurity is about 40 to 60%).
(Including) a crosslinked copolymer as a base material, and its adsorbing power and the like were not always satisfactory.
In view of such circumstances, the present inventors have conducted intensive studies and found that the content of halogen atoms (elemental analysis method: the same applies hereinafter) is 3 to 5
It has been found that synthetic adsorbents halogenated to 0% by weight have very good adsorptive power. Of course, the adsorption amount of the synthetic adsorbent depends on its specific surface area (BET method: hereinafter the same).
And the pore volume (mercury intrusion method: the same applies hereinafter) . The synthetic adsorbent used in the present invention is 2
00m ² / g or more preferably should have a specific surface area of more than 300m ² / g, 0.1ml / g or more, preferably should have the following pore volume 0.5 ml / g or more 2.0 ml / g is there.

That is, the gist of the present invention is that a hydrophobic group is contained in a molecule.
And a hydrophilic group, the hydrophobic part of which is
A method of contacting an aqueous solution containing an antibiotic which can be adsorbed by a Ruwars force with an adsorbent to adsorb and separate the antibiotic, wherein the following copolymer (A) is used as the adsorbent. It consists in a method of separating substances. Copolymer (A) (a) A halogenated crosslinked copolymer comprising an aromatic monovinyl monomer and an aromatic polyvinyl monomer, and (b) a specific surface area of the copolymer is 200 m ² g / As described above, the pore volume is 0.1 ml / g or more, and the content of halogen atoms is in the range of 3 to 50% by weight.

In order to explain the present invention in detail, a crosslinked copolymer of an aromatic monovinyl monomer and an aromatic polyvinyl monomer used as a substrate of an adsorbent used in the method of the present invention is styrene-divinylbenzene. Copolymers, trivinylbenzene-styrene copolymers, vinyltoluene-divinylbenzene copolymers and the like can be mentioned. However, industrially available divinylbenzene contains ethylvinylbenzene as an impurity, and as a result, each of the above copolymers can also contain ethylvinylbenzene as a constituent unit.

The crosslinked copolymer used as the adsorbent in the method of the present invention is obtained by halogenating the above-mentioned crosslinked substrate, and the amount of halogenation is determined by the halogen atom in the halogenated crosslinked copolymer. Content is 3% by weight or more 5
The range is set to 0% by weight or less. When the halogen atom content is less than 3% by weight, the adsorptivity becomes small, which is not preferable. The halogen is introduced into the main chain or the aromatic ring, but usually is introduced into the aromatic ring.

Examples of the halogen include fluorine, chlorine, bromine and iodine, and chlorine and bromine are particularly advantageous from the viewpoint of stability and ease of production. Specifically, for example, the halogenation is performed by using an elemental halogen in the presence or absence of a swelling agent such as dichloroethane, nitrobenzene, or the like to form a crosslinked base copolymer, and using ferric chloride, iodine, iron, pyridine, mercuric acetate, The reaction is performed in the presence or absence of a catalyst such as thallium acetate, thallium chloride, and boron fluoride.

As the halogenating agent, in addition to the above elemental halogens, other suitable halogenating agents such as sulfuryl chloride,
Sulfuryl bromide can also be used. The amount of the halogenating agent to be used is 0.03 mol or more based on 1 mol of the crosslinked substrate, and the halogen introduction rate can be arbitrarily changed depending on the amount of the halogenating agent used within the range described above.

The reaction conditions vary depending on the reaction to be performed.
Generally, it is carried out at a temperature of 0 ° C. to 80 ° C. for 1 to 10 hours.
The crosslinked copolymer obtained as described above is filtered off after the reaction,
After being sufficiently washed with an organic solvent such as an alcohol, it is used after being washed with water. The crosslinked copolymer thus obtained has a specific surface area of 200 m ² / g or more, preferably 300 m ² / g.
² / g or more, and the pore volume is 0.1 ml / g or more, preferably 0.5 ml / g or more. When the specific surface area and the pore volume are less than these values, the ability as a synthetic adsorbent is inferior, which is not preferable.

[0010] Such a cross-linked copolymer is used as a synthetic adsorbent.
As a method for removing antibiotics in water, any of a column method and a batch method can be used. In the column method, a resin tower is packed with a sufficient amount of an adsorbent to sufficiently adsorb and remove antibiotics in a liquid to be treated, and a liquid passing speed (superficial tower speed) of 0.1 hr ^-1 to
Treat at 0 ° C. to 60 ° C. at 20 hr ⁻¹ .

On the other hand, in the batch method, an adsorbent in an amount sufficient to sufficiently adsorb the antibiotics present in water is added to an aqueous solution containing the antibiotics, and the mixture is stirred under stirring or without stirring.
The contact is performed for about 40 hours. In the method of the present invention, examples of the antibiotic to be adsorbed include those having a hydrophobic group and a hydrophilic group in the molecule, the hydrophobic portion of which can be adsorbed to the adsorbent by van der Waals force . For example, antibiotics such as cephalosporin, streptomycin, kanamycin and the like can be mentioned.

In the present invention, these antibiotics contained in water can be selectively adsorbed and useful as a method for easily separating them.

[0013]

EXAMPLES The present invention will be described in detail with reference to the following Examples, but the present invention is not limited to the following Examples. Production Example-1 Commercially available styrene-divinylbenzene synthetic adsorbent DIAION HP20 (registered trademark of Mitsubishi Kasei Co., Ltd.) Dried product 1
00 g in a four-necked flask, and dichloroethane 500
g, and allowed to stand at room temperature for 1 hour.
And 123 g of molecular bromine were added and reacted at 0 ° C. for 8 hours. After completion of the reaction, 3 liters of water was added, and ethane dichloride was azeotropically distilled by heating to 90 ° C. Then, the brominated synthetic adsorbent was filtered and washed with water, and further 2 liters of methanol and 3 liters of 1N -Washed with hydrochloric acid, 3 l of demineralized water. Table 1 shows the bromine content, specific surface area, and pore volume of the obtained crosslinked copolymer.

Production Example-2 A procedure was performed except that 48 g of molecular bromine was used in Production Example-1 .
It was performed brominated in the same manner as forming Example -1. The results are shown in Table 1.

[0015] using an autoclave reaction vessel in Production Example -3 Preparation -1, except for using molecular chlorine 98g it is treated exactly the same manner as Example 1 was carried out chlorination. The results are shown in Table 1.

[0016]

[Table 1]

Example 1 Comparison of Adsorption Performance Commercially available synthetic adsorbent Diaion HP20 (registered trademark of Mitsubishi Kasei Co., Ltd. , abbreviated as “HP20” in the table ) and manufactured
Take 5.0ml of resin concrete examples 1, 2 and 3, respectively, cephalosporin C (chemical name: 7- [5-Amino-5 -carboxyvalera
mido] -cephalosporanic acid MW415) 2000
100m ppm solution (pH adjusted to pH 2.5 with hydrochloric acid)
After stirring at 25 ° C. for 5 hours, the supernatant was collected, and
The absorbance at 60 mμ was measured. Separate cephalosporin C
The concentration of cephalosporin C in the supernatant from the calibration curve prepared by measuring the absorbance by changing the concentration of cephalosporin (A)
I asked. Similarly, the cephalosporin C concentration (A ₀ ) of the cephalosporin C solution of 2000 ppm was accurately determined.

From these values, the adsorption amount (g) of cephalosporin C per liter of resin was determined by the following equation. Cephalosporin C adsorption amount (g / liter) = (A ₀ −
A) × 0.1 / 5.0 Since this value differs in each case in the equilibrium concentration, an isothermal adsorption line was separately added to cephalosporin C
Created by changing the concentration of cephalosporin C2000p
The equilibrium adsorption at pm was determined from the figure. Table 2 shows the results.
Summarized in In addition, a 1 cm quartz cell was used for the absorbance measurement, and a double beam spectrophotometer Model 200-20 was used.
(Hitachi, Ltd.) was used.

[0019]

[Table 2]

According to the method of the present invention, by using a synthetic polymer having a specific performance as an adsorbent , a molecule having a hydrophobic group and a hydrophilic group in a molecule existing in water and having a hydrophobic group is used.
The water is adsorbed to the adsorbent by van der Waals force.
The resulting antibiotic can be easily and selectively adsorbed and separated, which is useful.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiromi Teshima 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside the Mitsubishi Chemical Research Institute (72) Inventor Shigenori Wada 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical (56) References JP 54-163993 (JP, A)

Claims (1)

(57) [Claims] 1. A compound having a hydrophobic group and a hydrophilic group in a molecule,
Part can be adsorbed to the adsorbent by van der Waals force
That in the method the aqueous solution containing the antibiotic into contact with the adsorbent to adsorb the antibiotic separating method of separating antibiotic, characterized by using a copolymer of the following as an adsorbent (A). Copolymer (A) (a) A crosslinked copolymer of an aromatic monovinyl monomer and an aromatic polyvinyl monomer is halogenated, and (b) the copolymer has a specific surface area of 200 m ² / g or more. The pore volume is 0.1 ml / g or more, and the content of halogen atoms is in the range of 3 to 50% by weight.