JPS603083B2 - Manufacturing method of heavy metal adsorbent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a heavy metal adsorbent having a selective adsorption chamber for heavy metal ions dissolved in water as intestinal ions and lead ions.

Conventionally, cation or anion exchange resins, polyamine-based, iminoacetic acid-based chelate resins, and the like are known as metal ion adsorbents.

These resins adsorb many types of metals indiscriminately and have poor selective adsorption ability for specific useful metals. For example, when collecting uranium dissolved in seawater by adsorption, they have no adsorption ability at all.

Recently, titanic acid, resorcinol arsenic acid resin, triaminophenol/-ruglyoxal resin, etc. have been proposed as materials with adsorption chambers for uranium, but the adsorption chambers are unstable in maintaining their shape in water. It has not been put into practical use for several reasons.

In order to solve the above-mentioned problems, the present inventor conducted extensive and systematic research and completed the present invention. The object of the present invention is to provide a method for producing a heavy metal adsorbent having excellent selectivity and adsorption ability, especially for uranium. That is, the present invention uses polystyrene copolymers.

After chloromethylation or chlorosulfonation, the general formula '11 (
4-hydride represented by the formula (in which R is H or OH and X represents S, 0, or NH).

This is a method for producing a heavy metal adsorbent, which comprises reacting oxybenzimidazole, 4-hydroxybenzoxazole, 4-hydroxybenzothiazole, or a derivative thereof in the presence of an acid catalyst. The polystyrene copolymers used in the present invention include, for example, styrene-dipinylbenzene copolymers, styrene-vinylpyridine copolymers, styrene-chloromethylstyrene copolymers Z-bridged with amines, etc. It is.

Since the polystyrene copolymer has a crosslinked structure, it is possible to proceed with the reaction without melting during chloromethylation or chlorosulfonation, but if the degree of crosslinking is too high, conversely, chloromethylation or chlorZ sulfonation may occur. There is a mirror direction in which the reaction rate decreases, which increases the amount of 4 introduced into the copolymer.
- Appropriately check the degree of crosslinking in order to influence the reaction with hydroxybenzimidazole, 4-hydroxybenzoxazole, 4-hydroxybenzothiazole or its derivatives2
It is desirable to have a section. For example, when styrene and divinylbenzene are polymerized by emulsion polymerization or suspension polymerization, the molar ratio of divinylbenzene to styrene is 0.
It is preferably 5 to 30 mol%, particularly 0.5 to 5 mol%.

When styrene and chloromethylstyrene are copolymerized, the ratio of chloromethylstyrene to styrene is preferably 5 to 100% by mole, and the resulting copolymer is made into a powder or fiber and is used as an amine, e.g. At least difunctional amines such as ethylenediamine, jethylenetriamine, triethylenetetramine, piperazine, and xylylenediamine, and water or alcohols such as methanol, ethanol, propanol, butanol, or acetone, methyl ethyl ketone. Ketones such as, and furthermore, acetonitrile, nitromethane, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and other solvents by gradually raising the temperature from room temperature to 50 to 90°C over 1 to 1q hours to cause crosslinking. . In this case, if the overflow rate is higher than the above conditions, the surface of the copolymer melts and adheres to each other, forming a gum-like state.

When chloromethylating or chlorosulfonating the polystyrene copolymer, the reaction can be carried out by a conventional method.

In the case of chloromethylation, a polystyrene copolymer in the form of fibers, net granules, or powder is immersed in a formalin solution and hydrogen chloride gas is passed through it, or it is immersed in a dialkyl formal such as methylal and hydrochloric acid. The reaction is carried out by a method using hydrogen chloride, a method by reacting chloromethyl ethers without a solvent or in a solvent such as carbon disulfide or ether, or the like.

The nuclear reaction temperature is preferably in the range of 0°C to 8°C. Although the reaction will occur even if shark soot is not used, when chloromethyl ether is used, anhydrous salts such as aluminum chloride, zinc chloride, and tin chloride, or samba salts are used. Further, when formalin or dialkyl formal is used, sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, etc. are used as a catalyst. It was confirmed from the quantification of chlorine that 0.6 to 1 chloromethyl group was introduced per benzene nucleus by these methods. The approximate reaction rate of chlorsulfonation is to react the polystyrene copolymer with chlorosulfonic acid in the absence of a solvent or in an aliphatic halogenated hydrocarbon solvent at 12pi0 to 5bi○. Determined by quantification of sulfur, 0.5 to 0.0% per benzene nucleus. The chlorsulfone group of the needle box is introduced. The adsorbent according to the method of the present invention is a compound of the chloromethylated or chlorosulfonated polystyrene copolymer obtained as described above in the form of fibers, pongee grains, or powder. It is obtained by reacting with in the presence of an acid.

That is, 4-hydroxybenzimidazole, 4-hydroxybenzoxazole, 4-hydroxybenzothiazole, or a discussion conductor represented by the general formula [1} is dissolved in a solvent, and aluminum chloride, lead chloride, stannic chloride, and trichloride are dissolved in a solvent. The above chloromethylated or chlorosulfonated polystyrene copolymer is immersed in a system catalyzed by a Lewis acid such as boron fluoride, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, etc., and heated to 0.5°C at 0 to 130°C.
The reaction is completed by heating for ~lq hours.

1 The compound represented by the above general formula [11] is added in an amount of 1 to 2 q sonic molar equivalent of the chloromethyl group or chlorosulfone group of the chloromethylated or chlorosulfonated polystyrene copolymer, and the catalyst is also added in an amount of 0.1 to 5 molar equivalent. It is preferable to add

In addition, as a derivative of the compound represented by the above-mentioned formula '1', 4.
Examples include 6-hydroxybenzimidazole, 4,6-dihydroxybenzoxazole, and 4,6-dihydroxybenzothiazole.

The method for analyzing the reaction products in the process of manufacturing the adsorbent according to the method of the present invention is to quantify chlorine using the oxygen flask combustion method for chlormethyl-based materials, and to quantify sulfur using the gravimetric method as barium sulfate after combustion in an oxygen cylinder to determine the amount of chlorsulfone groups. Determined from quantitative measurements. The above-mentioned general compounds introduced by reaction with chloromethylated or chlorosulfonated polystyrene copolymers {
The reaction rate of the group of the compound represented by 1' can be determined by nitrogen analysis using the Kjeldahl method.

The adsorbent prepared by the method of the present invention was analyzed by the above method, and it was found that 0.25 to 0.49 cycles of the compound represented by the above-mentioned -Koshi formula '1' were introduced per benzene nucleus of the primary mirror of the polystyrene copolymer. There is.

When heavy metals are adsorbed using the adsorbent according to the method of the present invention, the nuclear adsorbent is packed in a column, and water containing heavy metal ions is passed through the column and brought into contact with the nuclear adsorbent, or the adsorbent is immersed in water containing heavy metal ions. Light up the light.

The multiplication value of heavy metal ion-containing water is between 4 and 95 for good adsorption properties, and is particularly preferably between 5.5 and 9.

When the multiplication value is 4 or less or 9.5 or more, the amount of heavy metal adsorption decreases. The heavy metal adsorbent according to the method of the present invention can particularly efficiently adsorb uranium even from water such as seawater in which many types of heavy metals are dissolved, and its selectivity is excellent.

Adsorbents placed alongside heavy metal ion-containing water can be easily desorbed and recovered using acids such as sulfuric acid, hydrochloric acid, nitric acid, and aqueous solutions containing alkalis such as soda carbonate, ammonium carbonate, caustic soda, and ammonia hydrogen depending on the metal. can.

The adsorbent obtained by the method of the present invention has extremely high industrial utility value, such as wastewater treatment or recovery of useful metals, especially uranium, from seawater. Examples will be described below.

Example 1 Styrene 10 surfactant containing 1 mol% divinylbenzene (1 mol % of Kao Atlas Co., Ltd. Emal 10)
In the evening, add Niolite PN-12 (manufactured by Kyoeisha Yushi Co., Ltd. for 1 night) to emulsify it in 250 cc of water, add 0.1 ml of potassium persulfate in a nitrogen stream, and stir vigorously at 8 pm.

After 30 minutes, 70 minutes of styrene containing 1 mol% divinylbenzene was filtered for 1 hour, and this system was further heated for 5 hours.
Rope worship at 8bi0.

The resulting latex is destroyed by adding concentrated hydrochloric acid, and the polystyrene copolymer is washed in a separate furnace.

This polystyrene copolymer powder is dried, and the mixture is gradually added to a 20% trichlene solution of chlorosulfonic acid while cooling with ice, and then stirred at room temperature for 30 minutes.

The obtained chlorosulfonated polystyrene copolymer was thoroughly washed with trichlene, dried, and the sulfur in the resin was burned in an oxygen cylinder and measured gravimetrically as barium sulfate. As a result, the sulfur content per night was 4.4mM. This means that 0.82 chlorosulfone groups were introduced per benzene nucleus. 4-Hydroxybenzimidazole 5
1.5 mL of the above chlorosulfonated polystyrene copolymer was added to a system in which 1.5 mL of the above chlorosulfonated polystyrene copolymer was dissolved in 50 mL of acetic acid, and the mixture was heated and mixed at 80° C. for 3 hours.

After washing the resin obtained by the reaction with water and drying it, nitrogen was added using the Kjeldahl method. As a result, the proportion of chlorosulfone groups that had reacted with 4-hydroxybenzimidazole was 42%.

A uranium adsorption test was conducted using the adsorbent thus obtained.

100 pieces of Fuji resin was placed in natural seawater to which 500 pieces of uranium had been added as uranyl nitrate. Uranium was quantified using X-ray analysis. As a result, 410 r2 of uranium was adsorbed per 100 copies of the resin. This is converted to 41 liters per night of adsorbent.
This means that 82% of the dissolved uranium was recovered. As a comparative example, titanic acid, which is a known adsorbent,
Table 1 shows the results of an adsorption test conducted in the same manner as above using 10 times each of resorcinol-arsenic acid resin and 2,4,6-triaminophenol-glyoxal resin as adsorbents. However, titanic acid is obtained by neutralizing titanium tetrachloride hydrochloric acid solution with caustic soda. Further, resorcinol-arsenic acid resin is obtained by formalin polymerization of resorcinol-arsenic acid in a conventional manner. Also, 2, 4, 6
-Triaminophenol-glyoxal resin is 2.4
・It is obtained by condensation polymerization of 6-triaminophenol and glyoxal using an acid catalyst. Table 1 Next, take out the resin that was subjected to optical X-ray measurement, and add 10 cc of IN hydrochloric acid.
The uranium was immersed at 70°C, and the same treatment was carried out again to elute the uranium. The ultraviolet halo of the uranium in the solution was measured using the sodium fluoride sphere method. As a result, the amount of uranium in the eluate was 405 Muta. .

Therefore, the uranium adsorbed on the 4-hydroxybenzimidazole-sulfony-styrene copolymer resin is easily and almost completely desorbed. As described above, it can be seen that the resin of the present invention has an excellent uranium adsorption capacity and is also very good in terms of adsorption rate and selectivity.

Example 2 A styrene-divinylbenzene copolymer resin was polymerized by emulsion polymerization while varying the charging ratio of divinylbenzene to styrene from 0** to 40 mol%.

Emulsion polymerization and chlorosulfonation of the resulting resin were carried out in the same manner as in Example 1 to obtain an adsorbent. One night of chlorosulfonated polystyrene was placed in 75 cc of a 10% acetic acid solution of 4,6-dihydroxybenzoxazole, and heated for 805 hours. The content of the 4,6-dihydroxybenzoxazole structure in the obtained adsorbent was determined from nitrogen analysis using the Kjeldahl method. 100 pieces of these resins were placed in an aqueous solution containing lead nitrate so that the lead concentration was 1 foot, and the mixture was exposed to light at room temperature for 24 hours. Analyzed by method.

The results are shown in Table 2.

Table 2 As can be seen from the results in Table 2, when the copolymerization ratio of divinylbenzene increases, the chlorosulfone group content and uranium adsorption capacity suddenly decrease, and when it exceeds 30 mol%, the amount of lead adsorption decreases synergistically. Therefore, it is not suitable for practical use.

In addition, polystyrene powder that does not contain divinylbenzene fuses with each other during chlorosulfonation, so the reaction rate does not increase. That is, the copolymerization ratio of dipinylbenzene is 0.
．． The range is preferably from 5 to 30 mol%, particularly preferably 0.5
It is in the range of ~5 mol%. Example 3 85 parts of styrene was mixed with 25 parts of chloromethylstyrene, and in a sealed tube purged with nitrogen, bulk polymerization was carried out at 8 pm using penzoyl peroxide as an initiator, and the resulting polymer was polymerized at 180°C. The fibers are melted and made into fibers with a diameter of 10 mm.

This was immersed in a 20% diethylene triamine solvent, heated for 3 hours at 3 pi○, and then heated for 3 hours to 7 ml.
The temperature was gradually raised to 0°C, and then the mixture was further treated at 7°C and 0°C for 2 hours. Two pieces of the fibers thus obtained were soaked in a mixed solution of 25 cc of chloromethyl ether and 50 cc of trichlene, added with lcc of stannic chloride, and stirred at 60° for 3 hours.

The fibers chloromethylated in this way were thoroughly washed with trichlene, washed with methanol, dried, and the amount of chlorine was determined using the oxygen flask combustion method.
It was found that 0.8 solid chloromethyl groups were introduced per unit. Etal 50c is prepared by dissolving one portion of this chloromethylated fiber and five portions of 4-hydroxybenzothiazole.
After adding 3 cc of concentrated hydrochloric acid, the mixture was heated under reflux for 5 hours.

The organic content of 4-hydroxybesozothiazole in this fiber adsorbent was determined by measuring the sulfur in the resin in the same manner as in Example 1.

As a result, the amount of skin equivalent per fiber was 1.1.

300 pieces of this fibrous adsorbent were packed into a column with a diameter of 1 inch in a length of 5 arcs. Ferric nitrate, ferric chloride, cadmium nitrate, uranyl nitrate, zinc chloride, lead nitrate, nickel acetate,
An aqueous solution containing 0.1 traces of each heavy metal was prepared using dichromic acetate and manganese (0) nitrate, and this 5Z was passed through the column for 2 feeding hours to remove the heavy metals adsorbed onto the fibers. was quantified by crab light X-ray analysis.

The results are shown in Table 3.

As is clear from Table 3, the heavy metal adsorption ability of the fiber was excellent, and it is thought that almost all of the uranylion was adsorbed.

In addition, when desorbing heavy metals from fibers on which heavy metals have been adsorbed, hydrochloric acid, sulfuric acid, and nitric acid were used to examine the desorption ability of each.

As for the attachment/detachment method, each 0. Soak 100 o of fiber adsorbent in 25 cc of Norisato solution for 5 and 30 minutes, and repeat this operation for 20 minutes.
The test was repeated several times, and the amount of heavy metals in the fibers was then measured by honeycomb X-ray analysis. As a result, when hydrochloric acid, sulfuric acid, and nitric acid were used, the desorption rate was between 96 and 100% for each metal, but
When hydrochloric acid was used, the lead desorption rate was 60%. Example 4 Using the same polystyrene copolymer resin powder as in Example 1, chloromethylation was performed by the method used in Example 3, followed by 4-hydroxybenzimidazole, leg 4-hydroxybenzoxazole, 'C}4 -Hydroxybenzothiazole were reacted to produce adsorbents (A, B, C).

The heavy metal salt used in Example 3 was used, and each metal concentration was 0.
10 c of the adsorbent was added to an aqueous solution of 5 AM solution.
was added, and the amount of adsorbed metal was determined by afterlight X-ray measurement.

The results are shown in Table 4. As is clear from the results shown in Table 4, these adsorbents also adsorb metal ions at low concentrations well, but have particularly high selectivity for uranyl ion and then copper ion.

Example 5 Using the same chlorosulfonated polystyrene copolymer resin as in Example 1, 4,6-dihydroxybenzoxazole ■ and 8-hydroxyquinoline legs were reacted to each other to bind adsorbents A and B. I put 10 false o's in natural seawater and 50 o'clock and worshiped with 3 pi○ for 2 hours.

The adsorbed metals were measured by crab light X-ray analysis.

The results are shown in Table 5. Similar adsorption tests were conducted on other uranium adsorbents used in Example 1, such as titanic acid and resorcinol-arsenate resin. , 20 mountains and evenings.

Claims (1)

[Claims] 1 After chloromethylating or chlorosulfonating a polystyrene copolymer, the general formula (1) ▲ includes numerical formulas, chemical formulas, tables, etc. ▼ (In the formula, R is H or OH, and X is S , O, or NH) and 4-hydroxybenzimidazole, 4-hydroxybenzoxazole, 4-hydroxybenzothiazole, or a derivative thereof, in the presence of an acid catalyst. Method. 2. The method for producing a heavy metal adsorbent according to claim 1, wherein the polystyrene copolymer is a styrene-divinylbenzene copolymer. 3. The method for producing a heavy metal adsorbent according to claim 1, wherein the polystyrene copolymer is a styrene-chloromethylstyrene copolymer crosslinked with an amine.