JPH1087701A - Porous cellulose support and selective separation of metal using the support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject polymer-modified porous cellulose consisting of a cellulose composed of a specific glucose unit, having high affinity to a metal, especially to a heavy metal and capable of selectively absorbing it. SOLUTION: This modified cellulose consists of a cellulose composed of a glucose unit having a side chain consisting of a recurrent unit of formula I [R<1> is H or a bond to a glucose unit; (n) >=1], preferably a recurring unit of formula II [R<2> is H or methyl; R<3> is CO, etc.; (n) and (p) are each one or more; A is a bond to a glucose unit], and the modified cellulose is made porous. Further, in order to introduce the side chain into a cellulose, e.g. a CH2 OH group of a glucose is activated, a functional group such as an epoxy group is introduced into it, and further the cellulose, to which the functional group has been introduced, is made to react with a polyethylene in an inert medium at a temperature of about 90-100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer-modified porous cellulose having a high affinity for metals, especially heavy metals such as mercury, copper and lead, and selectively adsorbing the same, and a method for using the same. And a method for selectively separating heavy metals.

[0002] Establishment of a method capable of selectively separating the background metal invention has a wide range of applications. For example, removing metals, especially heavy metals, from wastewater is very important from an environmental conservation point of view, since metals are often toxic. Furthermore, it would be more preferable if heavy metals from wastewater and the like could be collected and reused.

Conventionally, methods for isolating or separating metals include:
For example, a so-called precipitation method in which an anion that forms a salt having a large solubility constant is selected and added is known. further,
A method using an ion exchange resin, a method using a chelating agent, and the like are known.

[0004]

SUMMARY OF THE INVENTION The present inventors have now reported that polyethyleneimine-bound porous cellulose has a high affinity for metals, especially heavy metals such as mercury, copper and lead, and selectively adsorbs them. Then I found the finding. It has also been found that cellulose obtained by grafting polyethyleneimine with an appropriate polymer interposed between cellulose and cellulose can further improve the affinity for heavy metals. The present invention is based on this finding.

Accordingly, an object of the present invention is to provide a polymer-modified porous cellulose having a high affinity for metals, particularly heavy metals, and selectively adsorbing the same.

Another object of the present invention is to provide a method for selectively adsorbing metals, especially heavy metals, and removing or recovering them.

The porous cellulose according to the present invention comprises, as a first embodiment, the following repeating unit (I)
And a cellulose comprising a glucose unit having a side chain having the formula: wherein the cellulose is a porous cellulose.

-(NR ¹ -CH ₂ CH ₂ ) n- (I) wherein R ¹ represents a bond to a hydrogen atom or a glucose unit, and n represents an integer of 1 or more. As a second embodiment, the porous cellulose is a cellulose comprising a glucose unit having a side chain having the following repeating unit (II), and the cellulose is porous.

[0009]

Embedded image (Wherein, R ² represents a hydrogen atom or a methyl group, R ³
Is group -CO-, a group ^{_{-CO-O-CH 2 CHR 4}} CH 2-
(Where R ⁴ represents —OH or —SH), or a group — (p-phenylene) — (CH ₂ ) q —CHR ⁵ CH ₂
-(Where q represents an integer of 1 or 2, and R ⁵ represents -O
H or -SH), n and p each represent an integer of 1 or more, and A represents a bond to a glucose unit.) The porous cellulose according to the present invention has a third aspect in which A cellulose comprising a glucose unit having a side chain having a unit (III),
Further, the cellulose is a porous cellulose.

[0010]

Embedded image (Wherein, R ⁶ represents a group —COH or a group —CO-lower alkyl), X represents a halogen atom, n and p represent an integer of 1 or more, and A represents a bond to a glucose unit. In a fourth aspect, the porous cellulose according to the present invention is a cellulose comprising a glucose unit having a side chain having the following repeating unit (IV), and the cellulose is porous. .

[0011]

Embedded image (Wherein, R ⁷ represents a hydrogen atom, a methyl group, or a phenyl group, and R ⁸ represents a group —CO—O— (CH 2) r— (where r is 1 to 6, preferably 1 to 4 Represents an integer),
A group-(p-phenylene)-(CH2) r- (where r is as defined above), a group-(CH2) r- (where r is as defined above), or a group p-phenylene Represents X
Represents a halogen atom, n and p represent an integer of 1 or more, and A represents a bond to a glucose unit.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The repeating units (I), (II),
(III) and (IV) According to the first aspect of the present invention,
Cellulose comprises glucose having a side chain having the repeating unit (I). This repeating unit (I)
Is polyethyleneimine, in other words, the cellulose of the first embodiment according to the present invention can be said to be cellulose into which polyethyleneimine has been introduced.

According to a preferred embodiment of the present invention, the molecular weight of the side chain portion having the repeating unit (I) is 70,000 or less, more preferably 300 to 20,000. The terminal group of the repeating unit (I) and the terminal groups of the repeating units (II), (III), and (IV) described below have a slight molecular weight as compared with the molecular weight of these repeating units. Thus, the type does not significantly affect the properties of the molecule, but can be, for example, hydrogen or an amino group.

According to a second aspect of the present invention, the cellulose comprises glucose having a side chain having the repeating unit (II). N in the formula is-(N-CH _{2) in the} formula.
It is preferable that the CH ₂ ) n- moiety has a value such that the molecular weight is substantially the same as that of the side chain portion having the repeating unit (I).

According to a preferred embodiment of the present invention, in this second embodiment, R ² represents a hydrogen atom or a methyl group, and R ³ represents a group —CO—O—CH ₂ CHR ⁴ CH ₂ — (where R ⁴ represents —OH).

According to a third aspect of the present invention, the cellulose comprises glucose having a side chain having the repeating unit (III). In the formula, the alkyl group of the group —CO-lower alkyl represented by R ⁶ preferably represents C _1-6 alkyl, more preferably C _1-4 alkyl. Further, the halogen atom represented by X represents a fluorine, chlorine, bromine, or iodine atom. Further, n in the formula is-(N-CH ₂ C) in the formula.
It is preferable that the H ₂ ) n-part has a value such that it has a molecular weight similar to that of the side chain part having the repeating unit (I).

According to a fourth aspect of the present invention, the cellulose comprises glucose having a side chain having the repeating unit (IV). N in the formula is-(N-CH _{2) in the} formula.
It is preferable that the CH ₂ ) n- moiety has a value such that the molecular weight is substantially the same as that of the side chain portion having the repeating unit (I).

In the present invention, regardless of the side chain having the repeating unit (I) or the side chain having the repeating unit (II), this side chain is the H of the --CH ₂ OH group of glucose.
And is preferably introduced after substitution.

Cellulose Cellulose in the present invention is a porous material. According to a preferred embodiment of the present invention, the cellulose is preferably a foam having a porosity of 80% or more and an average pore diameter of 0.05 to 2.0 mm. More preferably, the particle size is 1.0 to 5.0 mm,
It is a cellulose having a porosity of 97% or more, an average pore diameter of 0.3 to 2.0 mm, and a specific gravity of 1.4 to 1.7 g / cm ³ .

Cellulose is natural cellulose (crystal type I).
Type) or regenerated cellulose (crystal type II).

The cellulose preferably used in the present invention is, for example, a high-purity pulp made of wood is chemically treated to form viscose, and then a third component is added to form pores, mixed, and injected into a mold. Thereafter, it can be obtained by heating and coagulating to remove the third component as appropriate. As the third component, a substance that can be easily removed after the foam is formed is used. For example, water-insoluble or hardly-soluble crystals, waxes, surfactants having a low HLB value, sublimable substances, and the like are used. The operation of removing the third component is performed according to the nature of the third component, for example, by extraction with an organic solvent, sublimation by heating, or the like. According to such a method, a substrate having desired physical properties (porosity, pore size, etc.) can be easily obtained by appropriately selecting the size, type, and amount of the third component.

In the present invention, commercially available cellulose can be used. Preferred examples of cellulose include those commercially available from Biomaterials Co., Ltd. as BM Aquacell (trade name).

To side-chain cellulose having a repeating unit
A repeating unit (I) to a glucose unit of the introduced cellulose,
The introduction of the side chain having (II), (III), or (IV) can be performed by synthesizing the side chain and then introducing it into glucose, or after introducing a functional group into glucose, The polymer may be introduced by polymerizing and growing a chain having these repeating units via the polymer. Chains having these repeating units can be produced by any convenient method.

More specifically, cellulose having a side chain having a repeating unit (I) can be produced as follows. First, after activation by such as sodium methylate -CH ₂ OH group of glucose, introducing a functional group such as epoxy by using, for example epichlorohydrin. Furthermore, it can be obtained by reacting cellulose having a functional group introduced therein and polyethyleneimine in a solvent (eg, DMF) not involved in the reaction at a temperature of about 90 to 100 ° C. Also,
Among celluloses having a side chain having a repeating unit (II), those in which R ³ is a group —CO— can be produced as follows. First, acrylic acid or methacrylic acid is polymerized in a suitable solvent (for example, water) at a temperature of 20 to 25 ° C. for 0.5 to 1 hour in the presence of cellulose. Next, the obtained polymer is converted into an acid chloride using, for example, thionyl chloride. This acid chloride is prepared by mixing polyethylene chloride with polyethyleneimine in a suitable solvent (eg, tetrahydrofuran) at a temperature of 20 to 25 ° C.
After reacting for a time, both are linked by an amide bond.

In the cellulose having a side chain having the repeating unit (II), R ³ is a group represented by —CO—O—CH ₂
CHR ⁴ CH _2-or a group - (p-phenylene) - (CH ₂₎
q-CHR ⁵ CH ₂ - in which one can be prepared as follows. First, in the presence of cellulose, glycidyl acrylate, glycidyl methacrylate, thioglycidyl acrylate, thioglycidyl methacrylate, vinyl benzyl glycidyl ester, vinyl phenyl glycidyl ester, vinyl benzyl thioglycidyl ester, or vinyl phenyl thioglycidyl ester in a suitable solvent (eg, , Water) at a temperature of 20-25
The polymerization is carried out by reacting at a temperature of 1 to 2 hours.
The obtained polymer is mixed with polyethyleneimine in a suitable solvent (eg, DMF) at a temperature of 90 to 100 ° C. for 3 to 3 minutes.
It can be obtained by reacting for 5 hours.

The cellulose having a side chain having a repeating unit (III) can be produced as follows. First, in the presence of cellulose, α-haloacrylic acid or lower alkyl α-haloacrylate is dissolved in a suitable solvent (for example, water) at a temperature of 20 to 25 ° C. for 0.1 hour.
The polymerization is carried out by reacting for 5 to 1 hour. Polyethyleneimine can be obtained by introducing a polyethyleneimine into the obtained polymer by a quaternization reaction (Menstockkin reaction) in a suitable solvent (eg, DMF) at a temperature of 80 to 100 ° C. for 1 to 2 hours. .

The cellulose having a side chain having a repeating unit (IV) can be produced according to the method for producing a cellulose having a side chain having a repeating unit (III). That is, in the presence of cellulose, haloalkyl acrylate, haloalkyl methacrylate, haloalkylstyrene, α- (haloalkyl)
Styrene or halostyrene is polymerized by reacting in a suitable solvent (eg, water) at a temperature of 20 to 25 ° C. for 3 to 5 hours. It can be obtained by introducing polyethyleneimine into the obtained polymer according to the quaternization reaction (Menstockkin reaction).

After the reaction, the obtained cellulose is preferably washed sufficiently to remove unreacted components. It will be apparent to those skilled in the art that cellulose having a molecular weight and other desired physical properties can be produced by appropriately selecting reaction conditions such as temperature, types of monomers, and reaction time.

Selective separation of heavy metals Cellulose according to the invention has a selective affinity for metals, especially heavy metals. Therefore, the cellulose according to the present invention can be preferably used for selectively separating metals from a certain system.

The metals having affinity for the cellulose according to the present invention include Hg, Cu, Cd, Pb, Zn, Cr,
Co, Ni, Mn, Al and the like can be mentioned. According to a preferred embodiment of the present invention, the cellulose of the present invention has a high affinity for heavy metals. Particularly preferred heavy metals include H
g, Cu, Cd, and Zn, and has a particularly high affinity for Hg.

The reason that the cellulose according to the present invention has an affinity for a metal is that a plurality of residues including a nitrogen atom present in the repeating unit are coordinated and bound to a metal ion to form a structure similar to a chelate. It is expected from.

According to a preferred embodiment of the present invention, cellulose having the above-mentioned repeating unit (II), (III) or (IV) is preferred from the viewpoint of its high adsorption capacity. In the case of cellulose having repeating units (II), (III), or (IV), the residue portion containing a nitrogen atom can be present more frequently than in the case of cellulose containing repeating unit (I). It is considered to be advantageous because the movement is relatively free and the metal ions are easily captured.

Further, in the cellulose according to the present invention, after the metal is once adsorbed, the metal can be eliminated by washing with an acid. Thus, the cellulose according to the invention can also be used for recovering metals.

Further, it is advantageous in that the affinity of the cellulose for the metal is maintained even after the acid washing, and the cellulose can be reused again for isolating the metal.

The selective separation of the metal by the cellulose according to the present invention can be carried out by bringing the solution containing the metal into contact with the cellulose.

In the cellulose according to the present invention, the metal is adsorbed not only by a batch treatment but also by a continuous treatment in which a solution flowing through the cellulose is brought into contact, because of the high adsorption speed.

According to a preferred embodiment of the present invention, the cellulose according to the present invention has an adsorption capacity of about 300 mg / g with respect to Hg. Further, Cu, Cd, and Zn have adsorption capacities of about 50 mg / g, about 40 mg / g, and about 15 mg / g, respectively.

The cellulose according to the present invention can be effectively used for separating or recovering metals from industrial wastewater.

[0039]

EXAMPLES The present invention will be described in detail with reference to the following Examples, but the present invention is not limited to these Examples.

The material cellulose used was commercially available from Biomaterial Co., Ltd. as BM Aquacell (trade name). This cellulose is highly porous (pore diameter: 20
0 μm) (approximately 1 mm ³ ).

As a control, a CS-03 adsorbent (pore diameter: 0.15 mm, manufactured by Fuji Boseki Co., Ltd.), which is a chitosan modified with a polyamine chelate group, was prepared.
Polyethyleneimine (PEI) was provided by Nippon Shokubai Co., Ltd. All other reagents were purchased from Wako Pure Chemical Industries, Ltd.

Example A1 : Porous cellulose Cell-PE
Preparation of I Cellulose (0.50 g) was immersed in dry dimethylsulfoxide (DMSO) (30.0 ml) at 60 ° C. and stirred for 2 hours. To this reaction solution was added sodium methylate (26.0 ml), and the mixture was further stirred at room temperature under a nitrogen stream for 1 hour. The obtained product was washed with dry DMSO.

5 g of sodium cellulose (1.0 g)
Immerse in dry DMSO containing 0.0 ml of epichlorohydrin (78.0 ml) at 50 ° C. under nitrogen flow
For 2 hours. After the reaction, the produced epoxypropylcellulose was separated, washed with distilled water and ethanol, and then dried under reduced pressure.

The obtained epoxypropylcellulose (1
g) and PEI (5-fold excess, molecular weight 300, 600, 1
200 and 20,000) in dimethylformamide (DMF) under nitrogen gas at 100 ° C. with constant stirring for 4 hours. The obtained porous cellulose (cell-PEI) was separated by filtration, sufficiently washed with hot water (50 ° C.) and ethanol, and then dried under vacuum.

The results of elemental analysis of the obtained epoxypropylcellulose and cell-PEI are as shown in the following table.

[0046]

[Table 1] As is clear from the table, an epoxypropylcellulose carrier having an epoxide substitution degree close to 100% was obtained. Further titration experiments confirmed 99.1% epoxide.

Cell-PEI was synthesized using PEI having different molecular weights according to the above method. Obtained Cell
Elemental analysis results of PEI were as shown in Table 2 below.

[Table 2] In the synthesis of Cell-PEI, a sample having an amine / epoxide ratio (i.e., amine / glucose ratio) in the range of 1.66 to 2.04 was obtained depending on the molecular weight of PEI used. These values indicate that one PEI molecule is bonded to a plurality of epoxy groups.

Further, a porous cellulose-ethylenediamine (Cell-ED) was synthesized by reacting epoxypropylcellulose with ethylenediamine in the same manner as described above.

Example A2 : Porous cellulose Cell-PE
Adsorption of Hg to I The adsorption of Hg to porous cellulose was evaluated as follows.
A predetermined amount of Cell-PEI obtained in Example A1 was
0 mg / l HgCl ₂ salt solution 20.00 ml,
Equilibrated. The pH of the solution was 0.1 mol / l bis-
Tris-adjusted with 0.1 mol / l HCl buffer. The mixture was mechanically and continuously mixed by a shaker. After the adsorption was completed, the adsorbent was separated by vacuum filtration, and the concentration of Hg in the filtrate was determined.

For comparison, the same operation as above was performed in cell
-ED was also performed. The above results were as shown in FIG. In the figure, Co indicates the initial concentration of Hg, and Ce indicates the Hg concentration in the filtrate.

Example A3 : Porous cellulose Cell-PE
Continuous adsorption of heavy metals on I The adsorption capacity of Hg on Cell-PEI was evaluated under the following conditions.

A height / diameter ratio of 5.5 (0.5 mm) was applied to a glass chromatography column (Amicon Co.) having an inner diameter of 1 cm.
(Corresponding to 2262 g of adsorbent).
-Filled with PEI adsorbent. About 10 mg / l mercury chloride solution was fed to the column at flow rates of 25, 60, and 120 ml / hour. The mercury ion concentration in the effluent was measured regularly. The result was as shown in FIG.

At flow rates of 120, 60 and 25 ml / h, 159, 239.0 and 26 respectively
An adsorption capacity of 0.0 mg / g was obtained. Using these values, the adsorption capacity at the minimum flow rate (0 ml / hr) was estimated to be 292.0 mg / g. This value almost coincides with the value obtained from the batch adsorption experiment (288.0 mg / g).

Example A4 : Porous cellulose Cell-PE
Adsorption of Various Metals on I The adsorption of various metals shown in FIG. 3 on porous cellulose was measured according to the method described in Example A2, except that the pH was adjusted to 7. The above results were as shown in FIG.

Example A5 : Adsorption and desorption of metal First, 0.001 of porous cellulose cell-PEI
Four groups of 5 g each were immersed in 20 ml of a mercury solution having a mercury concentration of 10 ppm, and mercury was adsorbed on the porous cellulose. The amount of mercury adsorbed at this time is as shown in Table 1 below.
0.1 as indicated in the batch as Cell-PEI
The range was 78-0.181 mg. These four groups of porous cellulose Cell-PEI were added to 0.5 M, 1.0
It was immersed in M, 2.0 M, and 4.0 M hydrochloric acid to desorb mercury. The amount of mercury desorbed was shown as the amount of the first batch desorbed in Table 3 below.

Porous cellulose Cel from which mercury has been eliminated
l-PEI was again used as a 20 m mercury solution having a mercury concentration of 10 ppm.
1 to allow mercury to be adsorbed. As a result, the four groups of porous celluloses respectively adsorbed mercury in amounts shown as adsorption amounts of the second batch in Table 3 below.

The four groups of porous cellulose Cell-
PEI was immersed in 4.0 M hydrochloric acid to remove mercury again. The amount of mercury desorbed was as shown in Table 3 below as the adsorption amount of the second batch.

The porous cellulose Cell-PEI from which mercury had been desorbed in this manner was immersed again in 20 ml of a mercury solution having a mercury concentration of 10 ppm to adsorb mercury. As a result, the four groups of porous cellulose Cell-PEI adsorbed mercury in amounts shown as the adsorption amounts of the third batch in Table 3 below.

As is clear from the above results, the metal adsorbed on the porous cellulose Cell-PEI can be eliminated by hydrochloric acid. In this experimental example,
By using 4.0 M hydrochloric acid, almost completely adsorbed mercury could be desorbed. In addition, despite repeating mercury desorption twice, the porous cellulose Cell
-No decrease in the mercury adsorption capacity of PEI was observed.

[0060]

[Table 3]

Example B1 : Porous cellulose poly (CG
Preparation of MAPEI) The reaction temperature was controlled at 20 ° C. using a water bath. A predetermined amount of a mixture of cellulose and water was first heated for 15 minutes to remove a trace amount of air trapped inside the porous cellulose, and then allowed to cool to a reaction temperature under a nitrogen gas atmosphere. For kraft polymerization, glycidyl methacrylate is added, vigorously stirred at 300 rpm, and cerium nitrate (I
V) The reaction was performed by adding a solution of ammonium (CAN) (0.1 M). After completion of the reaction, the resulting poly (cellulose-
Glycidyl methacrylate) product was isolated, washed with tetrahydrofurfuryl and dried in vacuo.

Subsequently, the Cell-PEI described in Example A1 was used.
According to the synthesis method, polyethyleneimine (molecular weight: 600) was introduced into the poly (cellulose-glycidyl methacrylate) obtained above (in DMF, at 100 ° C.) to obtain a porous cellulose poly (CGMAPEI).

Cel synthesized at various polymerization times
Elemental analysis and calculated composition of 1-PEI and poly (cell-GMA-PEI) were as shown in Table 4 below. Elemental analysis confirmed poly (CGMAPEI) with a higher degree of amine substitution than Cell-PEI. Graft polymerization has been shown to introduce epoxides at higher densities.

[Table 4]

Example B2 : Porous cellulose poly (CG
Preparation of MAPEI) In the method described in Example B1, the concentration of the initiator CAN is varied by the weight ratio of cellulose to obtain a porous cellulose poly.
(CGMAPEI) was synthesized. Elemental analysis of the synthesized porous cellulose was as shown in Table 5 below.

[0065]

[Table 5] Crosslinking of glycidyl methacrylate is carried out when the ratio CAN / Glu of CAN to glucose (constituent unit of cellulose) is 1.5.
It was especially high at the time.

Example B3 : Porous cellulose poly (CG
Adsorption of heavy metals on MAPEI) To 15.00 ml of various metal solutions with a concentration of 10 mg / l,
Poly produced by the method of Examples B1 and B2
(CGMAPEI) was brought into contact, and the metal was adsorbed by equilibration. The adsorption temperature and pH conditions were 25 ° C. and pH 7, respectively. After the adsorption, the porous cellulose was separated, and the equilibrium metal concentration in the filtrate was determined.

The results are as shown in FIG. 4 for the porous cellulose synthesized in Example B1, and as shown in FIG. 5 for the porous cellulose synthesized in Example B2. For comparison, cell-PEI and CS-03 were used.
Was also evaluated for its adsorption ability.

As is apparent from FIG. 4, Hg, Cu, C
For o and Zn, 350 mg / g, 4
5 mg / g, 8.5 mg / g, and 17.5 mg / g
Adsorption capacity was achieved. Even poly (CGMAPEI) with the lowest amine content for 30 min had higher metal affinity for Cell 3 than for Cell-PEI.

Example B4 : Porous cellulose poly (CG
Continuous adsorption of heavy metals on MAPEI) The adsorption capacity of metals on poly (CGMAPEI) was determined under the following conditions. With a flow rate of 60 ml / hour, C
u, Co, and Zn were measured according to Example A3. The result was as shown in FIG. The concentration of the effluent decreased to the level of the ppb level. For Co and Zn, the residual concentration was reduced to 0.5 ppm and 0.05 ppm, respectively.

Example B5 : An experiment was conducted assuming a wastewater treatment in which different metals were simultaneously adsorbed on a column. Specifically, first, a column having an inner diameter of 1 cm has a height / diameter of 5.5.
The porous cellulose poly (CGMAPE
I) 0.83 g was charged. Ni, P
b, Zn, Cd, Cr, Al, Co, Mn, Cu, Hg
Was flowed at a flow rate of 60 ml / hour. The ratio of each metal concentration in the effluent to the initial concentration at that time was plotted against the effluent. The result was as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the amount of Hg adsorbed on porous cellulose and pH according to the present invention.

FIG. 2 is a diagram showing continuous adsorption of heavy metals on porous cellulose according to the present invention.

FIG. 3 is a graph showing the amounts of various heavy metals adsorbed on porous cellulose according to the present invention.

FIG. 4 is a diagram showing the amounts of various heavy metals adsorbed on porous cellulose according to the present invention on which polyethyleneimine is grafted.

FIG. 5 is a graph showing the amounts of various heavy metals adsorbed on porous cellulose according to the present invention on which polyethyleneimine is grafted.

FIG. 6 is a graph showing the continuous adsorption amounts of various heavy metals to porous cellulose according to the present invention on which polyethyleneimine is grafted.

FIG. 7 is a diagram showing the amount of heavy metal adsorbed on porous cellulose according to the present invention when different metals are simultaneously adsorbed on a column assuming wastewater treatment.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Ronald, Navarro, Inventor 2-1 Tennodai, Tsukuba, Ibaraki Prefecture 37-105, No. 1 Dormitory, Tsukuba University Building 205 Room (72) Inventor Masatoshi Matsumura 1250-2, Takano, Tsukuba, Ibaraki (72) Inventor Naoyuki Fujii 3-3-10 Gakuen, Fukui City, Fukui Prefecture

Claims (13)

[Claims] 1. Cellulose comprising a cellulose comprising a glucose unit having a side chain having the following repeating unit (I), wherein the cellulose is porous. -(NR ¹ -CH ₂ CH ₂ ) n- (I) (wherein, R ¹ represents a bond to a hydrogen atom or a glucose unit, and n represents an integer of 1 or more.) 2. The cellulose according to claim 1, wherein the molecular weight of the side chain portion having the repeating unit (I) is 70,000 or less. 3. A cellulose comprising a cellulose comprising a glucose unit having a side chain having the following repeating unit (II), wherein the cellulose is porous. Embedded image (Wherein, R ² represents a hydrogen atom or a methyl group, and R ³ represents a group —CO—, a group —CO—O—CH ₂ CHR ⁴ C
H _2-(wherein, R ⁴ represents -OH or -SH), or a group - _{(p-phenylene) - (CH 2) q-} CHR 5 C
H ₂ — (where q represents an integer of 1 or 2; R ⁵ represents —OH or —SH); n and p represent an integer of 1 or more; and A represents a bond to a glucose unit. Represent) (4) R ² represents a hydrogen atom or a methyl group;
³ group ^{_{-CO-O-CH 2 CHR 4}} CH 2 - ( wherein,
R < ⁴ > represents -OH). 5. A cellulose comprising a cellulose comprising a glucose unit having a side chain having the following repeating unit (III), wherein the cellulose is porous. Embedded image (Wherein, R ⁶ represents a group —COH or a group —CO-lower alkyl), X represents a halogen atom, n and p represent an integer of 1 or more, and A represents a bond to a glucose unit. 6. A cellulose comprising a cellulose comprising a glucose unit having a side chain having the following repeating unit (IV), wherein the cellulose is porous. Embedded image (Wherein, R ⁷ represents a hydrogen atom, a methyl group, or a phenyl group; R ⁸ represents a group —CO—O— (CH 2) r— (where r represents an integer of 1 to 6); Group-(p-phenylene)-(CH
2) r- (where r is as defined above), a group-(CH
2) r- (where r is as defined above) or a group p
X represents a halogen atom, n and p each represent an integer of 1 or more, and A represents a bond to a glucose unit. 7. A repeating unit (I), (II), (III),
Or, the side chain represented by (IV) is -CH _{2 of} glucose.
The cellulose according to any one of claims 1 to 6, which is introduced by replacing OH with H. 8. The cellulose according to claim 1, wherein the cellulose is a foam having a porosity of 80% or more and an average pore diameter of 0.05 to 2.0 mm.
The cellulose according to any one of the above. 9. A cellulose having a particle size of 1.0 to 5.0 m.
m, porosity 97% or more, average pore diameter 0.3 to 2.0 mm,
A specific gravity of 1.4~1.7g / cm ^3, cellulose according to claim 8. 10. The cellulose according to claim 1, which is used for selective separation of a metal. 11. The cellulose according to claim 10, wherein the metal is a heavy metal. 12. A solution containing a metal, wherein the solution contains a metal.
A method for selectively separating metals, comprising the step of contacting with cellulose according to any one of claims 9 to 9. 13. The method according to claim 12, wherein the metal is a heavy metal.