JP2019063771A - Metal absorption fiber, production method thereof and metal absorption method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal adsorption fiber which efficiently adsorbs a heavy metal contained in a liquid to be treated and does not adsorb an alkali metal and an alkaline earth metal component, and a method for producing the same. SOLUTION: The metal adsorbing polymer (20) for adsorbing a heavy metal and the cellulose (5) forming a fiber are provided, and the metal adsorbing polymer (20) has a carboxymethyl group (11') and is a heavy metal. The side chain is provided with a metal trapping portion (11) that coordinates with (M) and a repulsing portion (12) that has an amine and prevents the adsorption of alkali metal and alkaline earth metal in the liquid to be treated. The metal adsorption polymer (20) and cellulose (5) are bonded by hydrogen bonds between the nitrogen atom (12a) of the amine of the repulsion portion (12) and the hydrogen atom (5a) of the cellulose (5). Therefore, the heavy metal is efficiently adsorbed, and the metal adsorbing polymer firmly fixed to the metal adsorbing fiber is prevented from coming off. [Selection diagram] Fig. 3

Description

  The present invention relates to a metal-adsorbed fiber that adsorbs heavy metals contained in a liquid to be treated, a method for producing the metal-adsorbed fiber, and a metal adsorption method.

  Heavy metals such as arsenic (As), cadmium (Cd), lead (Pb), zinc (Zn), etc. are highly harmful to the environment and the human body, and are persistent in the earth and bioconcentrated, so they are discharged into the environment Must be completely removed from industrial wastewater, drinking water sources, etc. These harmful heavy metals have effluent standard values defined by the Water Pollution Control Law, and wastewater containing heavy metals can not be discharged to rivers without proper treatment. Heavy metals can be released into the rivers of drinking water sources and people ingesting their drinking water can cause poisoning. In addition, in old water pipes, in addition to iron (Fe) of red rust, heavy metals such as lead and zinc dissolve in the upper water of the pipe. If a small amount of drinking water containing a trace amount of heavy metals is ingested for a long time, heavy metals may be accumulated in the body to cause dysfunction. Therefore, metal adsorption technology is desired which can efficiently remove specific heavy metals dissolved in waste water, drinking water sources and drinking water, and the life of the removal action can be sustained.

  Heretofore, heavy metal removal by flocculating and settling using a flocculant is known. In addition, ion exchange resins and chelate resins are used as high-speed and high-speed removal methods. However, waste water often contains high concentrations of salts such as sodium (Na) and chloride, and organic matter, and ion exchange resin saturates ion exchange capacity (adsorption capacity) in a short time, and removes heavy metals It is difficult to maintain the

  Patent Document 1 shows a chelate resin which is carboxymethylated using 1.0 to 3.0 moles of a halogenated acetic acid which is 1.0 to 3.0 times the nitrogen amount of a compound having a polyethyleneimine skeleton, and is less susceptible to interference by alkaline earth metals. And a chelate resin excellent in element selectivity. The particulate or powdery chelate resin can be used by being transformed into any shape by container filling, depending on the processing amount of the liquid to be treated, the application and the installation environment of the treatment apparatus. In addition, the particle size and the loading amount can be selected, and the removal rate of the substance to be treated and the processing speed can be easily adjusted.

  However, the fine particles or powder of the chelate resin of Patent Document 1 are violently shattered and scattered at the time of filling the container, and the worker may suck the particles or powder or put them in the eyes. In addition, after filling the container, voids of the filled granular or powdery chelate resin are clogged due to self-load, vibration during conveyance, fluid flow or pressure during use, and the entire filling gradually compresses. Compression results in a significant reduction in liquid throughput and throughput, and prolonged use leads to premature clogging and blockage. It is not possible to laminate-fill the container with relatively large voids in the interstices of a large amount of particles or powder to prevent processing speed reduction and clogging.

  On the other hand, in the case of providing a plurality of voids in the laminate of the metal adsorbent, a fibrous metal adsorbent is preferable. The flexible fibrous metal adsorbent does not have the possibility of scattering during filling, and can be intertwined between multiple fibers in a complicated manner, maintain a desired void, and recover to its original shape by elasticity even when compressed by self load or vibration. . Further, the fibrous metal adsorbing material can increase the contact area with the metal contained in the liquid to be treated, and can be easily processed and formed due to the flexibility of the fiber. Furthermore, since the fibers are slightly shaken by the flow of the liquid, it is easy to desorb the metal from the fibers when flowing the liquid in the reverse direction to remove the adsorbed metal.

  However, fibers suitable for metal adsorbents can not be produced from the raw material and chelate resin of Patent Document 1. The raw material of the chelate resin of Patent Document 1: The structural formula of polyethylenimine is shown in Formula (1).

  In Patent Document 1, the polyethyleneimine of the above formula (1) is immobilized on a base resin (polymer carrier) by covalent bond with an epoxy group, carboxymethylated with a halogenated acetic acid in an alkaline solution, and a metal capturing portion Form a chelate resin. The chemical reaction formula is shown in FIG. The primary amine (30) in the side chain of polyethylenimine is highly reactive and is carboxymethylated to form a carboxymethyl group (amino carboxylic acid group) (31 ') as a metal capture portion (31). On the other hand, linear secondary amines (34) and tertiary amines (35) of polyethylenimine have lower reactivity than primary amines (30) and can be carboxymethylated even if halogenated acetic acid is added. Remain without. The secondary and tertiary amines (36, 37) in the remaining straight chain exert an effect (elimination effect) that is less likely to be disturbed by alkaline earth metals. The side chain does not exert the effect of eliminating alkaline earth metals.

  When a metal-adsorbed polymer (40) constituting a chelate resin obtained by carboxymethylation is spun by, for example, a known viscose rayon method, a carboxymethyl group (31 ') and cellulose are hydrogen-bonded to form a metal The adsorbed polymer (40) is bound to cellulose. At the same time, the linear secondary amine (36) of the metal-adsorbed polymer (40) and the nitrogen atoms (36a, 37a) of the tertiary amine (37) also hydrogen bond with the hydrogen atoms of cellulose. However, nitrogen atoms (36a, 37a) of linear secondary and tertiary amines (36, 37) have weak hydrogen bonding with cellulose. For this reason, in the cellulose fiber formed of the metal adsorbing polymer (40) of polyethyleneimine, the metal adsorbing polymer (40) is easily detached and dissolved in water. In addition, the hydrogen bond may be broken by heating, and the metal adsorbing polymer (40) may be separated from the cellulose fiber. Furthermore, yarn breakage is likely to occur during drawing in the spinning process. That is, in the metal-adsorbing polymer (40) in which the secondary and tertiary amines (36, 37) having weak hydrogen bonding power account for the majority of the amines, there is a defect in the bonding property with cellulose The metal-adsorbed polymer (40) constituting the chelate resin of Patent Document 1 is not suitable for fiberization. On the other hand, although it is possible to grind the chelate resin (solid particles) of Patent Document 1 and mix it into the fiber, it is impossible to mix the appropriate amount of chelate resin uniformly into the fiber, and the chelate resin is buried inside the fiber. Metal adsorption amount can not be obtained. Furthermore, chelate resin particles having a specific gravity larger than that of fibers are easily detached from the fibers. As mentioned above, in patent document 1, there is no idea and description of fiberization.

  In addition, since the reaction shown in FIG. 19 causes solid-liquid reaction of a solid polymer carrier on which polyethylenimine is immobilized (introduced) and halogenated acetic acid, the reaction efficiency is extremely low due to heterogeneous reaction. For this reason, in practice, sufficient carboxymethylation can not be achieved without about 3 moles of the halogenated acetic acid of the nitrogen amount of the compound having a polyethyleneimine skeleton.

  Further, tetraethylenepentamine represented by the formula (2) can be carboxymethylated to form a metal-adsorbable polymer containing an amine in a straight line, like the polyethyleneimine of Patent Document 1. However, as in the case of polyethyleneimine of Patent Document 1, since tetraethylenepentamine contains nitrogen atoms of secondary amine in a straight chain, hydrogen bondability with cellulose is weak, and metal-adsorbed polymer is enough for fibers. It is not fixed. Therefore, in the case of a cellulose fiber containing a metal-adsorbed polymer of tetraethylenepentamine, the metal-adsorbed polymer may be separated from the fiber and dissolved in water as in Patent Document 1.

Patent Document 2 discloses a fibrous metal adsorbent containing an N-carboxymethylated polyamine-based polymer. The flexible fibrous metal adsorbent can be easily processed and compressed without the possibility of scattering at the time of filling, and therefore can form an adsorbent having various shapes and freely adjusting the size of the voids. However, in the fibrous metal adsorbent of Patent Document 2, an excess amount (4 times mole) of sodium chloroacetate is added to the amine of the raw material polyamine polymer. For this reason, the side chain amine is completely carboxymethylated to form an N-carboxymethylated polyamine-based polymer. This polymer forms a tertiary amine (-NR ₂ ) in the side chain, but forms an aminocarboxylic acid group in which two carboxymethyl groups are bonded to a nitrogen atom. The amino carboxylic acid group does not exhibit the effect of eliminating hardness components such as calcium and magnesium. In addition, since the linear metal chain does not contain any amine, the fibrous metal adsorbent of Patent Document 2 can not exclude hardness components such as calcium and magnesium contained in the liquid to be treated, and the hardness component is a carboxymethyl group. Adsorb. As a result, adsorption saturation may occur prior to removal of the target heavy metal. In industrial waste water, harmful heavy metals must be completely removed, but it is not necessary to remove hardness components. Therefore, development of a metal adsorbent having selective adsorption characteristics that adsorbs heavy metals reliably but does not adsorb hardness components is desired.

  Further, in Patent Document 2, when forming an N-carboxymethylated polyamine-based polymer, an excess amount of sodium chloroacetate is added to completely carboxymethylate the amine in the raw material without leaving a primary amine. Do. Therefore, multiple steps are required to completely remove reaction by-products (salts). That is, in Patent Document 2, an aqueous solution of a polyamine-based polymer is added to an aqueous solution of sodium hydroxide in which sodium chloroacetate is dissolved, and reacted with stirring at 50 ° C. for 6 hours to perform carboxymethylation. Hydrochloric acid is added to the obtained solution of N-carboxymethylated polyamine-based polymer to precipitate a reaction product, and the supernatant is removed. An aqueous solution of sodium hydroxide is added to the obtained precipitate to dissolve it, and then hydrochloric acid is added again to precipitate a reaction product, and the supernatant is removed. The above precipitation dissolution and supernatant removal operations are further repeated twice (four times in total), and the resulting precipitate is washed with methanol and then vacuum dried, and then sodium hydroxide solution is added to dissolve, N-carboxymethyl The resulting polyamine-based polymer is obtained. Thereafter, the obtained N-carboxymethylated polyamine-based polymer is fiberized by the viscose method. Thus, in the step of forming a completely carboxymethylated N-carboxymethylated polyamine-based polymer, a multistep process is required, and therefore, a step of controlling pH and temperature together with a large amount of pH adjuster, and It requires a control device, and the reaction and drying steps take a long time. Therefore, development of a metal adsorbent that can be manufactured easily and in a short time is desired.

  BACKGROUND ART In recent years, biodiesel fuel derived from fats and oils such as vegetable oil, tallow and waste edible oil has attracted attention as an alternative energy to petroleum fuels. Obtained by reacting with raw materials fats and oils such as rapeseed oil, palm oil, olive oil, sunflower oil, soybean oil, rice oil, hemp oil, fish oil, fish oil, pork fat, beef fat, tempura oil and methanol in the catalyst and separating and removing glycerin. The used fatty acid methyl ester is used as biodiesel fuel. However, biodiesel fuel is easily hydrated, and trace amounts of heavy metals such as iron, zinc and copper elute from the fuel tank and piping into water. Current fuel filters using cellulose fiber material etc. remove foreign substances and moisture in the fuel but do not remove heavy metals. When heavy metals are contained in the fuel, the energy efficiency due to combustion is significantly reduced, and the heavy metals may be diffused into the environment. Not only biodiesel fuels, but also petroleum-based fuels have the same problems as described above due to heavy metal content. Therefore, development of a metal adsorbent capable of easily and efficiently removing heavy metals in biodiesel fuel and light oil is desired.

JP, 2010-194509, A JP, 2011-92864, A

  Therefore, an object of the present invention is to provide a metal-adsorbed fiber which adsorbs heavy metals contained in a liquid to be treated efficiently and does not adsorb alkali metals and alkaline earth metals, and a process for producing the same and a metal adsorption method. The present invention also provides a metal-adsorbed fiber capable of selectively adsorbing heavy metals without adsorbing alkali metals and alkaline earth metals by a structure including a primary amine in a side chain which has not been conceived before, a process for producing the same and a metal adsorption method The purpose is to Another object of the present invention is to provide a metal-adsorbing fiber in which the metal-adsorbing component does not separate from the fiber, a process for producing the same and a metal-adsorbing method. Another object of the present invention is to provide a metal-adsorbed fiber which can be manufactured easily and in a short time, a process for producing the same and a metal adsorption method. Another object of the present invention is to provide a metal-adsorbed fiber for removing heavy metals contained in fuel, a process for producing the same and a metal adsorption method.

The metal-adsorbed fiber of the present invention comprises a metal-adsorbed polymer (20) that adsorbs heavy metals, and a cellulose (5) that forms fibers. The side chain of the metal-adsorbed polymer (20) has a carboxyl group (-CH ₂ COOH) (11 ') and has a metal trapping portion (11) coordinated to a heavy metal (M) and an amine And a repulsive portion (12) for preventing adsorption of alkali metal and alkaline earth metal in the liquid to be treated. The metal-adsorbable polymer (20) and the cellulose (5) are bonded by the hydrogen bond between the nitrogen atom (12a) of the amine of the repelling part (12) and the hydrogen atom (5a) of the cellulose (5).

  The present invention includes a metal-adsorbed polymer (20) having a repelling portion (12) for blocking adsorption of alkali metal and alkaline earth metal components and a metal capturing portion (11) for selectively adsorbing heavy metal (M) In the metal-adsorbed fiber of the present invention, for example, when ions of calcium (Ca), magnesium (Mg), strontium (Sr) and barium (Ba) in the liquid to be treated approach the amine on the side chain of the metal-adsorbed polymer (20) The positively charged amine nitrogen atom (12a) repels ions of alkali metals and alkaline earth metals without repulsion, and strongly blocks access and adsorption to metal adsorbing polymers. In addition, since the amine has high reactivity as well as the repulsion, the nitrogen atom (12a) of the amine and the hydrogen atom (5a) of the cellulose (5) are hydrogen bonded to each other, whereby the metal-adsorbed polymer (20) And form a strong chemical bond between cellulose and cellulose (5). For this reason, the metal adsorbing polymer (20) is firmly fixed to the cellulose (5), and the detachment of the metal adsorbing polymer (20) from the metal adsorbing fiber is reliably prevented.

  The carboxymethyl group (11 ') of the metal capture portion (11) is a heavy metal (M) in liquid, such as iron (Fe), lead (Pb), copper (Cu), chromium (Cr), cadmium (Cd), Along with mercury (Hg), zinc (Zn), arsenic (As), manganese (Mn), cobalt (Co), nickel (Ni), molybdenum (Mo), tungsten (W), tin (Sn) and bismuth (Bi) It forms a complex by coordination bond and adsorbs heavy metal components reliably and selectively. A metal such that the oxygen atom and hydrogen atom of the carboxymethyl group (11 ′) of the metal capture portion (11) form a hydrogen bond with the hydrogen atom and the oxygen atom of cellulose (5) and the metal adsorbing polymer (20) is firmly bonded Form adsorption fibers. The metal-adsorbed fiber of the present invention having a highly hydrophilic cellulose fiber as a base material is easily compatible with the liquid to be treated without water repellency, and reliably incorporates and adsorbs the heavy metal (M) dissolved in the liquid to be treated.

  The process for producing a metal-adsorbed fiber according to the present invention forms a metal-adsorbed polymer (20) which adsorbs a heavy metal (M) by carboxymethylating a polyamine-based polymer which contains a nitrogen atom in a side chain and does not contain a linear chain. And a step of mixing viscose with the metal adsorbing polymer (20) to form a metal adsorbing fiber in which the metal adsorbing polymer (20) and the cellulose (5) are combined. The step of forming the metal-adsorbed polymer (20) comprises a metal capturing portion (11) having a carboxymethyl group (11 ') and coordinating to a heavy metal (M), a primary amine and And a step of forming a repulsive portion (12) which inhibits the adsorption of the alkali metal and the alkaline earth metal in the treatment liquid in the side chain of the metal adsorbing polymer (20). In the step of forming the metal-adsorbed fiber, the nitrogen atom (12a) of the primary amine in the repelling part (12) and the hydrogen atom (5a) of the cellulose (5) are hydrogen-bonded to form a metal-adsorbed polymer (20) And cellulose (5) are combined. In the present invention, a metal-adsorbed fiber that adsorbs heavy metals (M) and inhibits adsorption of alkali metals and alkaline earth metals can be formed simply and in a short time. In addition, since the polyamine-based polymer can be carboxymethylated in a liquid without immobilizing the raw material polyamine-based polymer on the base resin (polymer carrier), the reaction efficiency is high, and the metal-adsorbed polymer can be produced in a short time. (20) can be formed.

  In the metal adsorption method according to the present invention, a liquid to be treated having a pH of 4 to 7 is passed through a metal adsorption fiber produced by the method for producing a metal adsorption fiber according to the present invention to obtain a metal trapping portion (11 of metal adsorption polymer (20) And the repelling part (12) by contacting the liquid to be treated with the metal trapping part (11) of the metal adsorbing polymer (20), from arsenic, cadmium, copper, iron, lead and zinc in the liquid to be treated The process of adsorbing the selected one or more heavy metals and the process of blocking the adsorption of the alkaline earth metal in the liquid to be treated by the repulsive portion (12) of the metal adsorbing polymer (20) are included. In another metal adsorption method according to the present invention, a liquid to be treated having a pH of 6 to 7 is passed through a metal adsorption fiber produced by the method for producing a metal adsorption fiber according to the present invention to obtain a metal of metal adsorption polymer (20) Arsenic, cadmium, copper, iron, etc. in the liquid to be treated by the step of bringing the liquid to be treated into contact with the trapping portion (11) and the repelling portion (12), and the metal trapping portion (11) of the metal adsorbing polymer (20) A process of adsorbing one or more heavy metals selected from nickel, lead and zinc and a repulsive portion (12) of the metal adsorbing polymer (20) prevent the adsorption of alkaline earth metals in the liquid to be treated And process. In the present invention, specific heavy metals can be adsorbed with high efficiency while maintaining the effect of removing alkaline earth metals in the liquid to be treated.

  In the present invention, since adsorption of alkali metals and alkaline earth metals can be prevented, only heavy metals can be adsorbed efficiently. In addition, the metal-adsorbed polymer does not separate because it is strongly bonded to the fiber. Therefore, the heavy metal adsorption capacity can be maintained for a long time, and a long-life metal adsorption fiber can be provided. In addition, the present invention can prevent harmful heavy metals from being emitted and dispersed into the environment, and can prevent the retention and accumulation of heavy metals in soil, crops and organisms. It removes heavy metals in biodiesel fuel and light oil, improves fuel efficiency and prevents heavy metal diffusion into the environment. Furthermore, since the metal-adsorbed fiber of the present invention can be manufactured simply and in a short time, the manufacturing cost can be reduced and an inexpensive metal-adsorbed fiber can be provided.

A conceptual diagram showing a state in which the metal-adsorbed polymer of the metal-adsorbed fiber according to the present invention adsorbs heavy metals A conceptual diagram showing a metal-adsorbed polymer of metal-adsorbed fiber according to the present invention The metal adsorbing polymer of the metal adsorbing fiber according to the present invention is a conceptual diagram showing a mechanism for excluding alkali metals and alkaline earth metals Conceptual diagram showing the bonding between metal-adsorbed polymer and cellulose Conceptual diagram showing the bonding state of primary, secondary and tertiary amines with cellulose The figure which shows the chemical reaction formula which manufactures the metal adsorption polymer of the metal adsorption fiber by this invention Schematic diagram of the liquid flow test device Graph showing the result of metal (calcium) recovery rate by liquid flow test Graph showing the result of metal (magnesium) recovery rate by liquid flow test Graph showing the result of metal (strontium) recovery rate by liquid flow test Graph showing the result of metal (arsenic) recovery rate by liquid flow test Graph showing the result of metal (cadmium) recovery rate by liquid flow test Graph showing the result of metal (copper) recovery rate by liquid flow test Graph showing the result of metal (iron) recovery rate by liquid flow test Graph showing the result of metal (manganese) recovery rate by liquid flow test Graph showing the result of metal (nickel) recovery rate by liquid flow test Graph showing the result of metal (lead) recovery rate by liquid flow test Graph showing the result of metal (zinc) recovery rate by liquid flow test Diagram showing the chemical reaction formula for producing a conventional metal-adsorbed polymer (chelating polymer)

  Embodiments of a metal-adsorbed fiber according to the present invention, a method of manufacturing the metal-adsorbed fiber, and a metal adsorption method will be described with reference to FIGS.

The metal-adsorbed fiber according to the present invention comprises a metal-adsorbed polymer (20) that adsorbs heavy metals, and a cellulose (5) that forms fibers. FIG. 1 shows a part of a metal-adsorbed polymer (20) having a carboxymethyl group (—CH ₂ COOH) (11 ′) and a metal capture portion (11) in a side chain which coordinates to a heavy metal (M) Indicates The carboxymethyl group (amino carboxylic acid group) (11 ′) of the metal capture portion (11) is a heavy metal (M) in liquid, such as iron, lead, copper, chromium, cadmium, mercury, zinc, arsenic, manganese, It forms a coordination complex with cobalt, nickel, molybdenum, tungsten, tin and bismuth and reliably and selectively adsorbs heavy metal components.

  The metal trapping portion (11) of the metal adsorbing polymer (20) contains a tertiary amine, and two carboxymethyl groups (11 ') are bonded to the nitrogen atom (11a) of the tertiary amine. At this time, as shown in FIG. 1, the heavy metal (M) contained in the liquid to be treated is surrounded by a cage structure of two carboxymethyl groups (11 ') to form a complex by coordination bond. As a result, the heavy metal (M) and the metal trapping portion (11) of the metal adsorbing polymer (20) are firmly bonded, and the metal adsorbing fiber can reliably capture and adsorb the heavy metal component. Although the bonding state is not illustrated, the oxygen atom and hydrogen atom of the carboxymethyl group (11 ') of the metal trapping portion (11) form a hydrogen bond with the hydrogen atom and oxygen atom of cellulose (5), and metal adsorbing polymer (20) form a metal-adsorbed fiber (cellulose fiber) to be firmly bonded.

  FIG. 2 shows a portion of a metal adsorbing polymer (20) provided with a repelling moiety (12) having an amine in its side chain. The metal-adsorbed fiber according to the present invention prevents adsorption of alkali metals and alkaline earth metals in the liquid to be treated when the pH is 8 or less, preferably 7 or less, due to the positive charge of the amine. As shown in FIG. 3, when the alkali metal or alkaline earth metal ion in the liquid to be treated approaches the amine on the side chain of the metal adsorbing polymer (20), the nitrogen atom (12a) of the amine is positively charged. The nitrogen atom (12a) repels ions of alkali metal and alkaline earth metal without repelling, and strongly prevents access and adsorption to the metal adsorbing polymer (20). Alkali metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs). The alkaline earth metals include calcium (Ca), strontium (Sr) and barium (Ba), and further, in the present specification, beryllium (Be) and magnesium (Mg) are also included in the alkaline earth metals.

The amine in the repulsive portion (12) of the metal-adsorbed polymer (20) used in the present invention is a side chain primary amine. The primary amine in the side chain is positively charged and has a strong action to repel and push back the alkali metal and alkaline earth metal components. In particular, in the case of an acidic liquid to be treated, the repulsive effect is remarkable. For example, under acidity, proton (H ⁺ ) is added to the nitrogen atom (12a) of the primary amine (FIG. 3), and the primary amine bears a positive charge. In the liquid to be treated, calcium ions (Ca ²⁺ ) and sodium ions (Na ⁺ ) which are strongly positively charged can be electrically repelled to prevent approach and adsorption. On the other hand, in the Patent Document 1, since the alkaline earth metal is excluded by the linear (main chain) secondary and tertiary amines, the exclusion mechanism and the repelling site are clearly understood in the present invention. It is different.

  Secondary and tertiary amines are also positively charged, eliminating the access of alkali metals and alkaline earth metals. On the other hand, the fibrous metal adsorbent of Patent Document 2 of the prior art has a tertiary amine in the side chain, but forms an aminocarboxylic acid group which does not have the function of pushing back the alkali metal and the alkaline earth metal. It can not prevent access and adsorption. On the contrary, in the present invention, the repulsive force is provided by the presence of the primary amine in the side chain. Therefore, the metal-adsorbed fiber of the present invention containing a primary amine in the side chain of the metal-adsorbed polymer (20) has, for example, residual hardness components (calcium, magnesium) which need not be removed in treated liquids for use in beverages. Make sure to first adsorb heavy metals (M) that need to be removed. In addition, since the primary amine in the side chain is stronger than the secondary and tertiary amines in bonding with cellulose (5) by hydrogen bonding, the metal adsorbing polymer (20) does not separate from the fiber In addition, elimination of alkali metal and alkaline earth metal components can be sustained for a long time. In the metal-adsorbed polymer (40) of Patent Document 1 of the prior art, as shown in FIG. 19, the bond between the secondary and tertiary amines contained in the straight chain and the cellulose (5) is weak and can not be formed? Alternatively, even if fibers are formed, the metal adsorbing polymer (20) and the cellulose (5) are easily separated.

  The metal-adsorbed polymer (20) is different in chemical composition from the first structural unit (A) (FIG. 1) having a metal capture portion (11) in the side chain and in the first structural unit (A), and is in the side chain And a second structural unit (B) (FIG. 2) having a repulsive portion (12). The metal adsorbing polymer (20) includes the first and second structural units (A, B), and a plurality of side chains of the metal adsorbing polymer (20), the metal capturing portion (11) and the repelling portion (12) Since the metal-adsorbed fiber of the present invention adsorbs the heavy metal (M) and has the function of preventing the adsorption of the hardness component, the metal-adsorbed fiber of the present invention has two functions to prevent the adsorption of the hardness component.

  The plurality of side chains of the metal adsorbing polymer (20) include not only the first and second structural units (A, B) but also the third structural unit (C). The third structural unit (C) contains a secondary amine (13 in FIG. 6) in which one carboxymethyl group is bonded to the nitrogen atom of the side chain, and the second structural unit together with the oxygen atom and hydrogen atom of the carboxymethyl group. The nitrogen atom and hydrogen atom of the secondary amine form a hydrogen bond with cellulose to strengthen the bond between the metal-adsorbed polymer (20) and the cellulose (5).

  FIG. 4 shows the present invention in which the metal-adsorbed polymer (20) and the cellulose (5) are bound by the hydrogen bond (6) of the amine (primary amine) of the repelling part (12) and the cellulose (5). Shows a metal-adsorbed fiber of The amine in the repelling part (12) not only functions to repel and push back the alkali metal and alkaline earth metal components but also has high reactivity, so the nitrogen atom (12a) of the amine and the hydrogen atom (5a of cellulose (5) And hydrogen bond of amine and hydrogen atom of cellulose (5) with hydrogen atom of amine to form a strong chemical bond between metal adsorbing polymer (20) and cellulose (5) .

  For this reason, the metal adsorbing polymer (20) is firmly fixed to the metal adsorbing fiber of the present invention, and the detachment of the metal adsorbing polymer (20) from the fiber is surely prevented. The metal-adsorbed fiber of the present invention having a highly hydrophilic cellulose fiber as a base material is easily compatible with the liquid to be treated without water repellency, and reliably incorporates and adsorbs the heavy metal (M) dissolved in the liquid to be treated. Moreover, it is biodegradable and environmentally preferable.

  The side chain primary amine has a higher hydrogen bonding strength with cellulose (5) than secondary and tertiary amines. FIG. 5 schematically shows the bonding state of the primary, secondary and tertiary amines of the side chain of the metal-adsorbing polymer (20) and the cellulose (5). FIG. 5 does not consider the effect of hydrogen bonding of carboxymethyl groups. The primary amine of FIG. 5 (a) forms a large number of hydrogen bonds (6) with cellulose (5), and the metal-adsorbed polymer (20) and cellulose (5) are strongly bonded. The secondary amine in FIG. 5 (b) has a moderate degree of hydrogen bonding (6) with cellulose (5), and the tertiary amine in FIG. 5 (c) has hydrogen bonding with cellulose (5) ( There are a few 6). From FIGS. 5 (a) to 5 (c), it can be seen from the chemical structure that the side chain primary amine (FIG. 5 (a)) forms high bondability with cellulose (5).

  The raw material resin for forming the metal-adsorbed polymer (20) of the present embodiment is a polyamine-based polymer having a carbon skeleton containing no nitrogen atom in a straight chain (main chain). Polyamine polymers having an average molecular weight of 2,000 to 100,000 can be used. Since the linear chain of the metal-adsorbing polymer (20) does not contain nitrogen and amine, the avidity of the metal-adsorbing polymer (20) is lowered by the presence of the low-reactive secondary or tertiary amine in the linear chain ((20) FIG. 19 can be prevented, and the conventional problem, that is, the detachment of the metal adsorbing polymer (20) from the cellulose fiber can be completely suppressed.

  The raw material resin for forming the metal adsorbing polymer (20) is one or more polyamines selected from polyvinylamine, polyallylamine and polydiallylamine shown in the formulas (3), (4) and (5) respectively. It is a polymer.

  The amine of the resin forming the metal adsorbing polymer (20) is charged to a positive charge in the liquid to be treated having a pH of 8 or less, preferably 7 or less, to inhibit the adsorption with the dissolved alkali metal and alkaline earth metal . As a result, a hardness component that does not need to be removed remains in the treated water for beverage use, and the heavy metal (M) that needs to be removed is surely adsorbed first.

  Next, an embodiment of a method for producing a metal-adsorbed fiber according to the present invention will be described.

  First, a polyamine-based polymer containing a nitrogen atom in a side chain and not in a linear chain (main chain) is carboxymethylated to form a metal-adsorbed polymer (20) that adsorbs a heavy metal (M). Carboxymethylation is reacted with a polyamine-based polymer such as polyallylamine and a halogenated acetic acid such as chloroacetic acid or bromoacetic acid in a 0.5 to 2 M alkaline solution of sodium hydroxide, potassium hydroxide or sodium carbonate . The step of forming the metal-adsorbed polymer (20) comprises a metal capturing portion (11) having a carboxymethyl group (11 ') and coordinating to a heavy metal (M), a primary amine and And a step of forming a repulsive portion (12) which inhibits the adsorption of the alkali metal and the alkaline earth metal in the treatment liquid in the side chain of the metal adsorbing polymer (20).

FIG. 6 shows a chemical reaction formula for carboxymethylating polyallylamine to form a metal adsorbing polymer (20). The metal-adsorbing polymer (20) is a first structural unit (A) having a metal capture portion (11) in which _two carboxymethyl groups (—CH ₂ COOH) (11 ′) are bonded to a nitrogen atom of a side chain And a second structural unit (B) having a repulsive portion (12) in which two hydrogen atoms are bonded to a nitrogen atom in the side chain, and a carboxymethyl group and a hydrogen atom are bonded to a nitrogen atom in the side chain And a third structural unit (C) having a secondary amine (13).

  In addition, in the step of forming the metal-adsorbed polymer (20), 1.0 to 2.5 moles of a halogenated acetic acid is added to the nitrogen atom in the polyamine-based polymer to be carboxymethylated, and the metal capturing portion is formed. (11) (First structural unit (A)) and repulsive portion (12) (second structural unit (B)) are mixedly formed. 1.0 to 2.5 moles of a halogenated acetic acid is added to the nitrogen atom in the raw material polyamine polymer to partially carboxymethylate the nitrogen atom of the side chain of the polyamine polymer Together with some of the amine. As a result, the metal capture portion (11) that adsorbs heavy metals and the repulsion portion (12) that does not move the alkali metal and the alkaline earth metal are formed in combination. Therefore, in the present invention, the dual function of adsorbing heavy metal (M) and preventing adsorption of alkali metal and alkaline earth metal is simultaneously achieved. When the amount of the halogenated acetic acid added is less than 1.0 times the molar amount, the bond between the metal-adsorbable polymer (20) and the cellulose (5) is weakened to make it difficult to form a fiber. When the amount of the halogenated acetic acid added exceeds 2.5 times the molar, the bond with the cellulose (5) is strong but the action of inhibiting the alkali metal and the alkaline earth metal is reduced. The addition ratio of the halogenated acetic acid is preferably 1.2 to 2.0 times the mole of the nitrogen atom in the polyamine polymer. The polyamine-based polymer and the halogenated acetic acid react efficiently without adding 2.0 times or more moles of the halogenated acetic acid. This is because, unlike Patent Document 1 of the prior art, there is no need to immobilize a polyamine-based polymer on a base resin (polymer carrier), and carboxymethylation can be performed by a reaction in a homogeneous system.

  Viscose is mixed with the metal-adsorbed polymer (20), and a metal-adsorbed fiber according to the present invention in which the metal-adsorbed polymer (20) and the cellulose (5) are combined is formed by a known viscose rayon method. Specifically, alkali cellulose obtained by treating cellulose with sodium hydroxide is mixed with carbon disulfide to form sodium cellulose xanthate (viscose). Next, the metal-adsorbed polymer (20) and viscose are mixed, the mixed solution is extruded from a spinning nozzle, and in the spinning step in a dilute sulfuric acid coagulating bath, the viscose returns to cellulose and becomes a fiber by hydrogen bonding between molecules Reproduce. The spun fibers are washed with water, desulfurized, bleached and dried to form the metal-adsorbed fibers of the present invention. As a result, the nitrogen atom (12a) of the primary amine in the repelling portion (12) and the hydrogen atom (5a) of the cellulose (5) are hydrogen-bonded, and the metal adsorbing polymer (20) is bonded to the cellulose (5). Join.

  In the present invention, the metal-adsorbed fiber of the present invention can be applied not only to adsorb heavy metals in water as the liquid to be treated but also to remove heavy metals in any liquid such as biodiesel fuel and light oil fuel. Conventionally, a cellulose fuel filter is used to remove foreign matter and moisture in the fuel, but if the metal-adsorbed fiber according to the present invention is used, the heavy metals contained in the fuel can be efficiently maintained while maintaining the conventional removal effect. It can be removed. Moreover, the filter containing the metal-adsorbed fiber (cellulose fiber) of the present invention can be applied as it is to the existing filter device without changing the existing device.

  Examples of fiber evaluation, liquid flow tests 1 and 2 and elemental analysis of the metal-adsorbed fiber of the present invention will be described below.

[Production of Metal-Adsorbed Fiber of the Present Invention (Example 1)]
100 g of an aqueous solution of polyallylamine having an average molecular weight of 8,000 (PAN-08 manufactured by Nittobo Medical, 15% concentration) and 30.7 g of sodium chloroacetate equimolar (1.0-fold molar) with respect to the amount of nitrogen of polyallylamine Were mixed with an aqueous solution of sodium hydroxide in which The mixture was stirred at 70 ° C. for 3 hours for carboxymethylation to form a metal adsorbing polymer (20) containing a primary amine and a carboxymethyl group in the side chain. Next, the metal-adsorbed polymer (20) and viscose are mixed so that the metal-adsorbed polymer (20) contains 2.5% by weight (predetermined mixing ratio) in the metal-adsorbed fiber, and known viscose rayon The resultant was spun by a method to produce a metal-adsorbed fiber (Example 1) having a fineness of 1.7 dtex and a fiber length of 51 mm.

[Production of metal-adsorbed fiber of the present invention (Examples 2 to 5)]
100 g of an aqueous solution of polyallylamine having an average molecular weight of 8,000 (PAN-08 manufactured by Nittobo Medical, 15% concentration) and 1.2 times the molar (36.1 g), 1.5 times the amount of nitrogen of the polyallylamine It mixed with the sodium hydroxide aqueous solution which each melt | dissolved (45.4g), 2.0 times mole (60.6g), and 3.0 times mole (90.9g) sodium chloroacetate. A metal adsorbing polymer (20) was formed in the same manner as in Example 1 except for the above, to produce metal adsorbing fibers (Examples 2 to 5).

[Production of Metal-Adsorbed Fiber of the Present Invention (Example 6)]
Water in which 100 g of polyallylamine aqueous solution with an average molecular weight of 8,000 (PAN-08 manufactured by Nittobo Medical, concentration 15%) and 60.6 g of sodium chloroacetate 2.0-fold molar to the nitrogen amount of polyallylamine The mixture was mixed with an aqueous solution of sodium oxide, and a metal-adsorbed polymer (20) was formed in the same manner as in Example 1 above. Next, the metal-adsorbed polymer (20) and viscose are mixed such that the metal-adsorbed polymer (20) contains 6.0% by weight (predetermined mixing ratio) in the metal-adsorbed fiber, and known viscose rayon The resultant was spun by a method to produce a metal-adsorbed fiber (example 6) having a fineness of 1.7 dtex and a fiber length of 51 mm.

[Production of Conventional Metal-Adsorbed Fiber (Comparative Example 1)]
250 ml of an aqueous solution of polyallylamine having an average molecular weight of 8,000 (PAN-08 manufactured by Nittobo Medical, 15% concentration) and an aqueous solution of sodium hydroxide in which 317 g of 4-fold molar sodium chloroacetate is dissolved with respect to the nitrogen amount of allylamine Mix and perform N-carboxymethylation at 50 ° C. for 6 hours with stirring. Hydrochloric acid was added to the obtained solution of N-carboxymethylated polyallylamine to adjust the pH to 2 to precipitate a reaction product, and the supernatant was removed. A 0.1 M aqueous solution of sodium hydroxide was added to the precipitate to dissolve it, and then hydrochloric acid was added again to adjust the pH to 2 to precipitate a reaction product, and the supernatant was removed. After repeating the same operation of dissolving the precipitate and removing the supernatant twice (four times in total), the obtained precipitate was washed with methanol and then vacuum dried to obtain a metal-adsorbed polymer.

  The metal-adsorbed polymer is poly (N, N-dicarboxymethyl) allylamine in which all amino groups are carboxymethylated, and does not contain a primary amine. Next, the metal-adsorbed polymer (20) and viscose are mixed so that poly (N, N-dicarboxymethyl) allylamine is contained in the metal-adsorbed fiber in an amount of 2.5% by weight (predetermined mixing ratio). The conventional metal-adsorbed fiber (Comparative Example 1) corresponding to Patent Document 2 was manufactured by spinning using the viscose rayon method of

[Production of Conventional Metal-Adsorbed Fiber (Comparative Example 2)]
100 g of tetraethylenepentamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 23.4 g of sodium chloroacetate 2.0-fold mol to the nitrogen amount of tetraethylenepentamine dissolved in pure water are mixed and stirred. While performing N-carboxymethylation at 70 ° C. for 3 hours, a metal-adsorbed polymer was obtained in the same manner as in Comparative Example 1 above. Next, the metal-adsorbed polymer and viscose are mixed so that the metal-adsorbed polymer contains 6.0% by weight (predetermined mixing ratio) of the metal-adsorbed polymer, and the mixture is spun by a known viscose rayon method, A conventional metal-adsorbed fiber (comparative example 2) using tetraethylenepentamine as a raw material was produced.

[Method of fiber evaluation]
The state of the obtained metal-adsorbed fibers (Examples 1 to 5 and Comparative Examples 1 and 2) was evaluated by the presence or absence of yarn breakage during spinning at a constant tensile strength.

[Method of liquid flow test 1]
The obtained metal-adsorbed fibers (25) (Examples 1 to 5 and Comparative Example 1) are filled in the cylindrical flow-through test device (7) shown in FIG. 7 respectively, and the space velocity is adjusted to about 100 h ^-1 . A passing test of 10 ml of treated liquid (8) of known calcium concentration [mg / l] was conducted. Passing tests were conducted with pH values of the liquid to be treated (8) as 2, 3, 4, 5, 6, 7, 8 and 9. From the metal adsorption fiber (25) after passing the water, calcium and 3 mol nitric acid were used. The amount of calcium was measured by desorption and separation. In a similar method, a liquid permeation test is carried out for each of magnesium, strontium, arsenic, cadmium, copper, iron, manganese, nickel, lead and zinc to measure the amount of metal component adsorbed on the metal adsorption fiber (25). did.

[Method of liquid flow test 2]
A light oil containing zinc at a known concentration [mg / l] was added by adding 1 ml of a solution prepared by dissolving 0.99 g of 98% zinc chloride in 2 ml of a water draining agent (Furukawa Pharmaceutical Co., Ltd., water cut D). A treatment liquid) (8) was produced. Next, 0.21 g of the metal adsorption fiber (25) (Example 6) is filled in the tubular flow-through test device (7) of FIG. 7, and 200 ml of light oil (8) of the liquid to be treated is flowed about 24 ml / min. The solution was circulated by circulation. The zinc concentration [mg / l] of the treated liquid (9) after 4 cycles and after 10 cycles was measured by ICP emission spectroscopy (JIS K 0102 53.3).

[Method of elemental analysis]
In Examples 1 to 5, the metal-adsorbed fiber was manufactured so that the metal-adsorbed polymer (20) contained 2.5% by weight (the set mixing ratio) with respect to the metal-adsorbed fiber. EL III CHNOS Elemantal Analyzer Measurement mode: The actual mixing ratio of the metal-adsorbed polymer (20) was determined from the measured value of nitrogen element by CHNS). A value obtained by multiplying the nitrogen abundance ratio (measured value) by the formula weight 57 of polyallylamine and dividing it by the nitrogen atomic weight 14 was taken as “the actual mixing ratio”. Similarly, with respect to the metal-adsorbed fiber of Comparative Example 2 in which the set mixing ratio was 6.0% by weight, the actual mixing ratio was determined from the nitrogen existing ratio using the formula weight 189.3 of tetraethylenepentamine.
[Result of fiber evaluation and consideration]

  The state of each metal-adsorbed fiber (25) (Examples 1 to 5 and Comparative Examples 1 and 2) is shown in Table 1. The “degree of carboxymethylation (CMization degree)” in Table 1 is a value obtained by dividing the number of moles of sodium chloroacetate added by the number of moles of allylamine. The “fiber state” in Table 1 indicates that when spinning, no fiber breakage occurs and fiberization is extremely good “o”, and fiber breakage twice or less fiber formation “o”, The state of poor fiber formation of three or more thread breakages is indicated by “Δ”. As shown in Table 1, the condition of the fibers is very good in Examples 2 to 5 and Comparative Example 1. Both originate in using as a raw material polyallylamine which contains a primary amine in the side chain. The condition of the fibers of Example 1 is good. Comparative Example 2 is defective. In Comparative Example 2, since tetraethylenepentamine containing a secondary amine in a straight chain is used as a raw material, the bond strength between cellulose and the metal adsorbing polymer is weak.

[Result and Consideration of Liquid Flow Test 1]
FIGS. 8-18 shows the metal adsorption characteristic by each metal adsorption fiber (25) (Examples 1-5 and Comparative Example 1), a horizontal axis shows pH value and a vertical axis | shaft represents recovery [%]. The percentage of the value obtained by dividing the mass of metal desorbed and separated from the metal-adsorbed fiber (25) by the known metal mass in the liquid to be treated (8) was defined as the recovery rate [%].

  FIG. 8 shows the recovery of calcium (alkaline earth metal). In the range of pH 2 to 7 of Example 1 (1.0-fold mol), Example 2 (1.2-fold mol), Example 3 (1.5-fold mol) and Example 4 (2.0-fold mol) , An extremely low calcium recovery rate of 10% or less. In particular, Examples 1 and 2 had a low calcium recovery of 50% or less even in the pH range of 2-8. On the other hand, at pH 6 or more of Example 5 (3.0 times mol) and pH 4 or more of Comparative Example 1 (4.0 times mol), a high calcium recovery rate of 50% or more was obtained.

  FIG. 9 shows the recovery of magnesium (alkaline earth metal). In the range of pH 2 to 7 of Examples 1 to 4, the magnesium recovery was extremely low at 10% or less. In particular, Examples 1 and 2 had a low magnesium recovery of 40% or less even in the pH range of 2-8. On the other hand, at pH 6 or higher in Example 5, a high magnesium recovery rate of 50% or higher was obtained, and at pH 5 or higher in Comparative Example 1, an extremely high magnesium recovery rate of almost 100% was obtained.

  FIG. 10 shows the recovery of strontium (alkaline earth metal). In the pH range of 2 to 7 in Examples 1 to 4, the strontium recovery rate was 40% or less. In particular, Examples 1 and 2 had a low strontium recovery of 50% or less even in the pH range of 2-9. On the other hand, at pH 6 or higher in Example 5, a high strontium recovery rate of 50% or higher was obtained, and at pH 5 or higher in Comparative Example 1, an extremely high strontium recovery rate of almost 100% was obtained.

  From the results of FIGS. 8 to 10, in any of the alkaline earth metals, in Examples 1 to 4 (CM conversion degree 1.0 to 2.0 times mol), strong acids having pH 2 to 7 in a wide range of neutral to 40 It showed a low recovery rate of less than%, confirming the remarkable elimination effect of alkaline earth metals. On the other hand, Example 5 (3.0 times mol) shows low recovery rate of 50% or less only at pH 5 or less, but shows high recovery rate at pH 6 to 9, so the elimination (non-adsorption) effect of alkaline earth metals Do not have In Comparative Example 1 (4.0-fold mole), since pH 5 to 9 shows a very high recovery rate, it does not have an alkaline earth metal elimination effect. In FIGS. 8-10, similar recoveries are expected for alkaline earth metals. From the above results, only the first to fourth embodiments having the alkaline earth metal exclusion effect will be considered below.

  FIG. 11 shows the recovery rate of arsenic (heavy metal). At pH 3 or higher in Examples 1 to 4, the high recovery rate was approximately 50% or higher. FIG. 12 shows the recovery of cadmium (heavy metal). A high recovery rate of 50% or more was obtained at pH 6 or higher in Example 1, and a high recovery rate of 50% or higher was obtained at pH 3 or higher in Examples 2 to 4. FIG. 13 shows the recovery rate of copper (heavy metal). A high recovery rate of 60% or more was obtained at pH 3 or more of Example 1, and a high recovery rate of 50% or more was obtained at pH 2 or more of Examples 2 to 4. FIG. 14 shows the recovery rate of iron (heavy metal). At pH 3 or more in Examples 1 and 2, the recovery was extremely high at 80% or more, and at pH 2 or more in Examples 3 and 4, the recovery was extremely high at 80% or more. FIG. 15 shows the recovery of manganese (heavy metal). A high recovery rate of 50% or more is obtained at pH 8 or higher in Example 1, an extremely high recovery rate of 80% or higher at pH 7 or higher in Example 2, and 50% or higher at pH 5 or higher in Examples 3 and 4. High recovery rate. FIG. 16 shows the recovery rate of nickel (heavy metal). A high recovery rate of 50% or higher is obtained at pH 6 or higher in Example 1, a high recovery rate of 50% or higher at pH 5 or higher in Example 2, and 80% or higher at pH 4 or higher in Examples 3 and 4. The recovery rate was extremely high. FIG. 17 shows the recovery rate of lead (heavy metal). A high recovery rate of 50% or higher is obtained at pH 6 or higher in Example 1, a high recovery rate of 50% or higher at pH 5 or higher in Example 2, and 80% or higher at pH 4 or higher in Examples 3 and 4. The recovery rate was extremely high. FIG. 18 shows the recovery of zinc (heavy metal). A high recovery rate of 50% or higher is obtained at pH 6 or higher in Example 1, a high recovery rate of 70% or higher at pH 4 or higher in Example 2, and 80% or higher at pH 4 or higher in Examples 3 and 4. The recovery rate was extremely high.

From the above, in the vicinity of neutrality (pH 7) of Examples 1 to 4 (CM degree of 1.0 to 2.0), high recovery rate (about 50% or more) of all heavy metals together with alkaline earth metal exclusion effect Was confirmed. Moreover, in the range of weakly acidic to neutral (pH 6 to 7) of Examples 1 to 4, arsenic (FIG. 11), cadmium (FIG. 12), copper (FIG. 13), iron (FIG. High recovery rates (50% or more) of FIG. 14), nickel (FIG. 16), lead (FIG. 17) and zinc (FIG. 18) were confirmed. In addition, in the range of weakly acidic to neutral (pH 6 to 7) of Examples 2 to 4 (CM degree of 1.2 to 2.0), arsenic, cadmium, copper, iron, along with the alkaline earth metal exclusion effect. High recovery rates (more than 60%) of nickel, lead and zinc were confirmed. In the range of acidity to neutrality (pH 4 to 7) of Examples 2 to 4 (CM degree of 1.2 to 2.0), arsenic, cadmium, copper, iron, lead and zinc together with alkaline earth metal exclusion effect High recovery rate (more than 50%) was confirmed. Furthermore, high recovery (about 50% or more) of arsenic, copper, iron and lead could be confirmed even in a wide range of strong acidity to alkalinity (pH 3 to 9) of Examples 1 to 4. From the results of FIGS. 8 to 18, the CM adsorption degree of 2.0 (Example 4) is not the upper limit of application, and the metal adsorption fiber of the present invention up to the CM conversion degree of about 2.5, its production method and metal adsorption method It is an applicable range.
In Examples 1 to 6 and Comparative Example 1, an aqueous solution of polyallylamine having an average molecular weight of 8,000 (PAN-08 manufactured by Nitto-Bo Medical) was used as a raw material, but an aqueous solution of polyallylamine having an average molecular weight of 15,000 (Nitto-Bo Medical) Since the same result was obtained even when using company make, PAA-15), the description is omitted.

[Result and Consideration of Liquid Flow Test 2]
Table 2 shows the results of flow-through test 2 in which light oil containing zinc was passed through and circulated through the metal-adsorbed fiber of the present invention (Example 6). The percentage [%] of the value obtained by subtracting the zinc concentration [mg / l] of the treated liquid (9) from the liquid to be treated (8) and dividing the zinc concentration [mg / l] of the liquid to be treated 8 . From this result, it was confirmed that zinc can be adsorbed and removed at a high removal rate of 90% in four or more cycles in the metal-adsorbed fiber of the present invention (Example 6).

[Results and Consideration of Elemental Analysis]
The results of elemental analysis are shown in Table 3. In Examples 1 to 5, the actual mixing rate is 2.2 to 2.5% by weight with respect to the setting mixing rate of 2.5% by weight, and the metal adsorbing polymer (20) is almost completely bonded to the fiber I was able to confirm that. This indicates that, in the metal-adsorbed fiber of the present invention, which uses as a raw material polyallylamine having a primary amine in a straight chain, the bonding between the metal-adsorbed polymer (20) and the cellulose (5) is high. On the other hand, in Comparative Example 2 in which the set mixing rate was 6.0% by weight, the actual mixing rate was 1.2% by weight. Not only the result of the state of the fiber in Table 1 but also Comparative Example 2 showed that the bondability between the metal adsorptive polymer made of tetraethylenepentamine as a raw material and the cellulose is weak from the elemental analysis.

  The metal-adsorbed fiber of the present invention, the process for producing the same and the metal-adsorption method are not only waste water treatment for heavy metal removal but also recycling of rare metals and valuable metals, drinking water production, pure water production, underground contaminated water purification and biofuel purification Is also applicable.

  5 · · Cellulose, 11 · · Metal capture portion, 12 · · Repellent portion, 20 · · Metal adsorption polymer,

Claims (10)

A metal-adsorbing polymer that adsorbs heavy metals, and cellulose that forms fibers;
The side chain of the metal-adsorbed polymer has a carboxymethyl group and has a metal capture portion coordinated to a heavy metal, an amine and a repulsion to prevent adsorption of alkali metal and alkaline earth metal in the liquid to be treated Equipped with
A metal-adsorbed fiber characterized in that a metal-adsorbed polymer and cellulose are bonded by a hydrogen bond between a nitrogen atom of an amine of a repelling portion and a hydrogen atom of cellulose.   The metal-adsorbed fiber according to claim 1, wherein the amine in the repelling part is a primary amine provided on the side chain of the metal-adsorbed polymer.   The metal adsorbing fiber according to claim 1, wherein the side chain of the metal adsorbing polymer comprises a first structural unit having a metal capture portion and a second structural unit having a repulsive portion unlike the first structural unit.   The metal adsorbing fiber according to claim 3, wherein the side chain of the metal adsorbing polymer comprises a third constitutional unit having a secondary amine in which a carboxymethyl group and a hydrogen atom are bonded to a nitrogen atom. The metal capture portion of the metal adsorbing polymer contains a tertiary amine,
2. The metal-adsorbed fiber according to claim 1, wherein the nitrogen atom of the tertiary amine of the metal capture portion bonds to two carboxymethyl groups. The raw material for forming the metal-adsorbed polymer is a polyamine-based polymer having a carbon skeleton containing no nitrogen atom in a straight chain,
The metal-adsorptive fiber according to claim 1, wherein the polyamine-based polymer is one or more selected from polyvinylamine, polyallylamine and polydiallylamine. Carboxymethylating a polyamine-based polymer containing a nitrogen atom in a side chain and not in a linear chain to form a metal-adsorbing polymer that adsorbs heavy metals;
Mixing the metal-adsorbed polymer with viscose to form a metal-adsorbed fiber in which the metal-adsorbed polymer and the cellulose are combined;
The step of forming the metal-adsorbed polymer comprises: a metal trapping portion having a carboxymethyl group and having a coordination bond with a heavy metal, and a primary amine, and an adsorption of an alkali metal and an alkaline earth metal in the liquid to be treated Forming a repulsive portion that inhibits the formation of a repellent portion on the side chain of the metal adsorbing polymer,
The step of forming the metal-adsorbed fiber includes the step of hydrogen bonding the nitrogen atom of the primary amine in the repelling part with the hydrogen atom of the cellulose to bond the metal-adsorbed polymer and the cellulose. Production method of adsorption fiber.   In the step of forming the metal-adsorbed polymer, 1 to 2.5 moles of a halogenated acetic acid is added to the nitrogen atom in the polyamine-based polymer to be carboxymethylated, and a metal capture portion and a repulsion portion are mixed. The method for producing a metal-adsorbed fiber according to claim 7, comprising the step of forming. A step of passing a liquid to be treated having a pH of 4 to 7 into the metal-adsorbed fiber produced by the method of claim 7, and bringing the metal-trapping portion and the repelling portion of the metal-adsorbing polymer into contact with the liquid to be treated;
A process of adsorbing one or more heavy metals selected from arsenic, cadmium, copper, iron, lead and zinc in the liquid to be treated by the metal trapping portion of the metal adsorbing polymer;
And D. a step of preventing adsorption of the alkaline earth metal in the liquid to be treated by the repelling portion of the metal adsorbing polymer. A step of passing a liquid to be treated having a pH of 6 to 7 into a metal-adsorbed fiber produced by the method according to claim 7 or 8, and bringing the liquid to be treated into contact with the metal capture portion and the repulsion portion of the metal-adsorbed polymer;
A process of adsorbing one or more heavy metals selected from arsenic, cadmium, copper, iron, nickel, lead and zinc in the liquid to be treated by the metal trapping portion of the metal adsorbing polymer;
And D. a step of preventing adsorption of the alkaline earth metal in the liquid to be treated by the repelling portion of the metal adsorbing polymer.

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