KR20100012697A - A regenerant for ion exchange resin of water softner in substitution for sodium cloride - Google Patents

Abstract

PURPOSE: A regenerant for ion-exchange resin for a water softener is provided to replace salt when the ion-exchange resin is regenerated by functionalizing the surface of a silica nano-particle to a cation functional group, and to improve economical efficiency of the regenerant. CONSTITUTION: A regenerant for ion-exchange resin for a water softener is manufactured by attaching a cation functional group on the surface of a silica nano-particle. The size of the silica nano-particle is 50-500nm. The cation functional group is one or more component selected from a group consisting of a Tributyl ammonium group, a Tetradecyl dimethyl ammonium group, a diedecyl methyl ammonium group and aminoethylaminopropylpropyl.

Description

A regenerant for ion exchange resin of water softner in substitution for sodium cloride}

The present invention relates to a salt substitute regeneration agent of the ion exchange resin for water softeners, and more particularly for water softeners that can replace the salt that can be prepared by functionalizing the surface with a cationic functional group after the production of nano-sized silica particles. The present invention relates to a regenerant of an ion exchange resin.

The manufacture of water softener using ion exchange resin is the most generalized system and is commercialized as the best system in terms of economy and efficiency. However, when the salt used in the regeneration of the ion exchange resin is discharged into the sewage, sodium ions reduce the water penetration of the ground and chlorine has the disadvantage of toxic to plants. In addition, salts promote corrosion in pipes and, in some cases, toxic chlorine compounds. Because of these problems, the recent movement in California has banned the use of water softeners using salt regeneration.

However, considering the excellent hardness removal effect and economical efficiency of the ion exchange resin, it seems that there is no replacement technology yet.

Therefore, the present inventors are considering the above point, while researching to replace the recyclable material with another material instead of salt while using an ion exchange resin, it can behave like ions and has a positive charge on the surface, as well as hardness materials and ions. It is expected that a material that can be exchanged can replace sodium ions, and after preparing nanoparticles having a cationic functional group, the surface is cationic functional group trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group The present invention was completed by confirming that functionalization with aminoethylaminopropylpropyl group can be used as a regenerant of an ion exchange resin in place of salt.

Accordingly, an object of the present invention is to provide a regenerant of the soft water ion exchange resin that can replace salt by functionalizing the surface with a cationic functional group after preparing the nano-sized silica particles.

In one aspect, the present invention provides a regeneration agent of an ion exchange resin for a softener that can replace salt, in which a cationic functional group is functionalized and attached to the surface of nano-sized silica particles.

The present invention provides a regenerating agent for an ionizing resin for a softener having a cationic functional group attached to a surface of silica nanoparticles.

In the present invention, the nanoparticles may have a size of 50 nm to 500 nm.

In the present invention, the silica nanoparticles may be redispersed in ethanol through ultrasonication.

In the present invention, the cationic functional group is at least one selected from the group consisting of an ammonium group, trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group and aminoethylaminopropylpropyl group.

As another aspect, the present invention provides a method for preparing silica nanoparticles having a cationic functional group for use as a regeneration agent of an ionizing resin for a softener by reacting the silica nanoparticles with a silane compound having a cationic functional group.

As an embodiment of the present invention, the method for preparing the silica nanoparticles with the cationic functional group may be performed by mixing the ethanol dispersion solution of the silica nanoparticles and the silane compound having the cationic functional group by a vortex mixer.

As another embodiment of the present invention, the method for preparing the silica nanoparticles to which the cationic functional group is attached may include the following steps:

Dispersing the silica nanoparticles in ethanol through sonication;

Removing the precipitate from the dispersion and diluting with ethanol;

Adding and stirring the silane compound having a cationic functional group to the diluent; And

Removing the solvent when the reaction is complete.

In the present invention, the silane compound having a cationic functional group is N-triethoxysilyl-N, N, N-trimethylammonium chloride (N-triethoxysilyl-N, N, N-trimethylammonium chloride), N-trimethoxysilylpropyl -N, N, N-trimethylammonium chloride (N-trimethoxysilylpropyl-N, N, N-trimethylammonium chloride), tetradecyldimethyl (3-trimethoxysilylpropyl) ammonium chloride, N-trimethoxysilylpropyl-N, N, N-tri-n-butylammonium chloride, N, N, -didecyl-N- M-N- (3-trimethoxysilylpropyl) ammonium chloride (N, N-didecyl-N-methyl-N- (3-trimethoxysilylpropyl) ammonium chloride), N- (trimethoxysilylpropyl) isothiouronium N-trimethoxysilylpropyl) isothiouronium chloride) 3- (N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane hydrochloric acid (3- (N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane hydrochloride) and N- (trimethoxysilylethyl) benzyl-N, N, N-trimethylammonium chloride (N- (trimethoxysilylethyl) benzyl-N, N, N- trimethylammonium chloride) at least one member selected from the group consisting of:

In another aspect, the present invention also provides a method for regenerating a softener ionizer by immersing the softener ionizer in a regenerant of the softener ionizer resin having a cationic functional group attached to the surface of the silica nanoparticles.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated in detail.

Ion exchange resins are generally of surface functional groups sulfonic acid groups, which is applied to the current water softener _{(sulfonic acid) (- SO 3} -) , and take the form which is in sodium ion bonded to it. Let it passes through the raw water (hard water) to the cation exchange resin in Na-form as described above to the reaction scheme 1 Ca ^{2 +,} in the raw water, such as Mg ^{2 +} is Na ⁺ ion-exchange (adsorption) in the resin is so soft water is produced. The regeneration of the ion exchange resin for the softener is the reverse reaction of the reaction.

Ca ^{2 +} + 2R-2Na ↔ 2R-Ca + 2Na ⁺

In the softening reaction, if a particle type regenerant substituted with a cationic functional group is used instead of sodium ions, the use of sodium ions may be sufficiently substituted. In addition, the regenerant in the particulate state can be recovered, so if used, it is possible to provide an automatic regeneration and recirculation type softening system.

That is, it can replace the cation performance of sodium ions Function  If you use a particle-type regenerator that has been created so as not to be discharged to the outside during water passage, Breakthrough Can be reduced.

Figure 1a is a schematic of the water softener system currently in use, Figure 1b shows a system that eliminates the use of salt during regeneration using silica beads (50 ~ 500 nm) attached to the cationic functional group instead of Na ⁺ . Here, the role of silica beads is to prevent the cationic functional groups from being discharged to the outside from the softener, and when the UF filter or the like is installed at the bottom of the softening system, the external discharge can be effectively prevented.

It is important to consider the selectivity of the functional groups to be attached to the silica beads.

The selectivity for the cation of SO ₃ ⁻ , a cation exchanger, is in the following order.

Ba ^{2 +} > Pb ^{2 +} > Sr ^{2 +} > Ca ^{2 +} > Ni ^{2 +} > Cd ^{2 +} > Cu ^{2 +} > Co ^{2 +} > Zn ^{2 +} > Mg ^{2 +} > Ag ⁺ > Cs ⁺ > K ⁺ > NH ₄ ⁺ > Na ⁺ > H ⁺

In addition, the order of selectivity of the most common anions with respect to the anion exchange resin is as follows.

_{^{SO 4 2 -> I ->}} NO 3 -> CrO 4 2 -> Br -> Cl -> OH -

In view of the above selectivity, the functional group to be attached to the silica nanoparticles may be selected to have an ionic strength similar to that of Na ⁺ ions.

Specific examples of the ionic strength similar to Na ⁺ ions in the present invention include ammonium group, trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group, amino among functional groups used in general purpose anion exchange resin. Ethyl amino propyl propyl group is mentioned.

Considering the selectivity for the cation first, it can be predicted that the ammonium group, trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group, aminoethylaminopropylpropyl group, and the like have similar characteristics. The order is Ca ^{2 +} > Mg ^{2 +} > cation functional group> Na ⁺ . Therefore, cationic functional groups such as trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group, aminoethylaminopropylpropyl group, etc. It can be easily exchanged with the hardness material.

Further, tributyl ammonium, tetradecyl dimethyl ammonium, di-decyl methyl ammonium group, aminoethyl selectivity to the anion having groups cationic functionality, such as aminopropyl-propyl group is _{^{SO 4 2 -> Cl ->}} OH - Since, any anion other the Even if present, it binds strongly with SO ₄ ^{2 -} to replace the role of Na ⁺ ions.

Silica (SiO ₂ ) production of nanoparticles in the present invention can be prepared using the stober method of Scheme 2, but is not limited thereto.

In the present invention, attaching the cationic functional group for removing the hardness material on the surface of the silica nanoparticles may be performed by reacting the silica nanoparticles with the silane compound having the cationic functional group.

As a specific embodiment, in the present invention, attaching the cationic functional group for removing the hardness material on the surface of the silica nanoparticles may be performed by reacting the silica nanoparticles with trimethylammonium triethoxysilane as in Scheme 3 below.

The present invention is prepared by preparing nano-sized silica particles and functionalizing the surface with cationic functional groups such as trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group, aminoethylaminopropylpropyl group and the like. It has a very good effect of providing a regenerant of the water exchanger ion exchange resin that can replace the salt.

Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to examples, but these examples are merely illustrative of the present invention, and the scope of the present invention is not limited only to these examples.

Example  1: 400 nm  Silica nanoparticles manufacturing

Silica nanoparticles of uniform size were prepared by Stober method. This method was prepared by hydrolysis reaction of silicon alkoxide.

First, 168 mL of ethanol, 51.2 mL of ammonium hydroxide and 100 mL of deionized water were vigorously stirred to prepare a mixed solution. 20 mL of TEOS (Tetraethoxysilane) was slowly added to the mixed solution for 1 minute and then stirred for 48 hours.

When the reaction was completed, washing was performed by centrifugation three times to prepare 400 nm silica nanoparticles. The prepared silica nanoparticles were re-dispersed in ethanol through sonication and stored.

Example  2: 60 nm  Silica nanoparticles manufacturing

First, 25 mL of TEOS (Tetraethoxysilane) was added to 450 mL of ethanol and stirred for 20 minutes.

20 mL of ammonium hydroxide (NH ₄ OH) was slowly added to the stirred solution for 1 minute, followed by stirring for 24 hours.

After the reaction was completed, the solvent was removed by a rotary evaporator. The result was a slightly bluish white solid product.

Silica nanoparticles were prepared by pulverizing the product produced as described above with a grinder. The prepared silica nanoparticles were stored in conical tubes.

Example  3: 400 nm  Cation on Silica Nanoparticles Function  Attach

To the ethanol dispersion solution of silica nanoparticles prepared in Example 1, N-triethoxysilyl-N, N, N-trimethylammonium chloride having the structure of Formula 1 was added at a concentration of 0.05 M and a vortex mixer By mixing with), a trimethylammonium functional group was self-attached to the surface of the silica nanoparticles as a single layer to prepare a silica nanoparticle solution to which a cationic functional group was attached.

Example  4-7: 60 nm  Cation on Silica Nanoparticles Function  Attach

200 mL of ethanol was added to 10 g of the silica nanoparticles prepared in Example 2, and the silica nanoparticles were dispersed in ethanol through sonication for 3 hours.

The precipitate was removed from the dispersion and diluted with ethanol such that the total volume of silica nanoparticle colloidal solution was 300 mL.

15 mL of the silane compound having a cationic functional group shown in Table 1 was added to the dilution solution, followed by stirring for 24 hours.

After the reaction was completed, the solvent was removed by a rotary evaporator. As a result, a slightly yellow and opaque residue remained. It was redispersed by sonication for 3 hours in 300 mL of deionized water.

division Silane compound with cationic functional group Compound name Compound structural formula Example 4 N-trimethoxysilylpropyl-N, N, N-trimethylammonium chloride

Example 5 Tetradecyldimethyl (3-trimethoxysilylpropyl) ammonium chloride

Example 6 N, N, -didecyl-N-methyl-N- (3-trimethoxysilylpropyl) ammonium chloride

Example 7 N- (trimethoxysilylpropyl) isothiouronium chloride

Experimental Example  1: Evaluation of ion exchange resin regeneration capacity of salt substitute regenerator of the present invention

An ion exchange resin (IER) was saturated and adsorbed with a hardness material.

First, the reproducibility of the silica nanoparticle solution with a cationic functional group prepared in Example 3 was evaluated.

To this end, 20 g of the ion exchange resin saturated with the hardness material was added to 200 mL of the silica nanoparticle solution with the cationic functional group prepared in Example 3 to immerse for 5 minutes to regenerate the ion exchange resin.

The silica nanoparticles activated with ammonium attached on the regenerated ion exchange resin using the silica nanoparticle solution of Example 3 are shown in FIG. 2.

The hardness removal performance of the regenerated ion exchange resin was tested using the silica nanoparticle solution of Example 3. At this time, the flow rate was 534 mL / min (line speed: 60 m / hr), the cross-sectional area is 5.1 cm 2, the weight of the ion exchange resin used was 130 g (Figure 3). As a result, as shown in FIG. 4, the hardness removal rate after 19 minutes was 19%, and the hardness removal rate after 13 minutes was 13%.

In addition, the reproducibility of the silica nanoparticle solution prepared in Examples 4 to 7 was evaluated.

To this end, 20 g of the ion exchange resin saturated with the hardness material is added to 200 mL of the silica nanoparticle solution with the cationic functional group prepared in Examples 4-7, and stirred for 1 hour to regenerate the ion exchange resin. I was.

The ion exchange resin regenerated as described above was washed with deionized water, dried in an oven, and tested for a hardness removal rate.

In order to measure the hardness removal rate, 3 g of the dried ion exchange resin, which was regenerated and washed as described above, was added to tap water having a hardness of 100 ppm, mixed for 5 minutes, and then subjected to hardness titration for 100 mL of the mixed solution. titration).

The hardness removal rate was also measured using a cation exchange resin to compare the hardness removal rate of each regenerant, and the hardness removal rate was also measured using an ion exchange resin regenerated using a saturated aqueous NaCl solution for comparison with Na ⁺ . .

The results are shown graphically as shown in FIG.

As can be seen from Figure 5, the present invention was found to be a bit less than the salt, but showed a significant level of hardness removal rate.

As a result of the experiment, the hardness removal rate did not meet the expectations because the ionic bonding force between the functional surface of the silica and the sulfone group of the cation exchange resin was large. It was judged that the hardness removal rate would be good.

As described above through the above examples and experimental examples, the present invention regenerates the ion exchange resin for water softener which can replace the salt which can be prepared by preparing nano-sized silica particles and functionalizing the surface with a cationic functional group. It is a very useful invention in the water softener industry because it has a very good effect to provide the agent.

FIG. 1A is a schematic diagram of a softening system using ionizer resin for softener using Na ⁺ .

Figure 1b is a schematic diagram of a soft water system that eliminates salt use by using silica beads with a cationic functional group of the present invention instead of Na ⁺ .

2 is an ion exchange regenerated using silica nanoparticles to which a cationic functional group is attached using N-triethoxysilyl-N, N, N-trimethylammonium chloride, which is one of the salt substitutes provided in the present invention. It is a photograph showing the appearance of activated silica nanoparticles with ammonium attached on the regenerated ion exchange resin by measuring the resin by SEM.

Figure 3 is to perform the hardness removal performance test of the ion exchange resin regenerated by silica nanoparticles with a cationic functional group using N-triethoxysilyl-N, N, N-trimethylammonium chloride as a salt substitute regeneration of the present invention A photograph showing the device for

Figure 4 shows the hardness removal performance test results of the ion exchange resin regenerated with silica nanoparticles with a cationic functional group using N-triethoxysilyl-N, N, N-trimethylammonium chloride as a salt substitute regeneration of the present invention It is a graph.

5 is a graph comparing the hardness removal rate of each regeneration agent according to the type of cationic functional group. In this case, the hardness removal rate of the regenerated ion exchange resin using the ion exchange resin and saturated aqueous NaCl solution was also shown as a control.

Claims (8)

A regenerant for water softener ionizers, wherein a cationic functional group is attached to the surface of silica nanoparticles. The regenerant of claim 1, wherein the silica nanoparticles are 50 to 500 nm in size. The water softener according to claim 1, wherein the cationic functional group is at least one member selected from the group consisting of an ammonium group, trimethylammonium group, tributylammonium group, tetradecyldimethylammonium group, didecylmethylammonium group and aminoethylaminopropylpropyl group. Regenerant of ionized resin. A method for preparing silica nanoparticles having a cationic functional group for use as a regenerant of a water ionizer resin by reacting the silica nanoparticles with a silane compound having a cationic functional group. The method of claim 4, wherein the method for preparing silica nanoparticles having a cationic functional group is performed by mixing an ethanol dispersion solution of the silica nanoparticles and a silane compound having a cationic functional group with a vortex mixer. A method for producing silica nanoparticles to which a cationic functional group is attached for use as a regenerant for paper. 5. The method of claim 4, wherein the method for preparing silica nanoparticles to which the cationic functional group is attached comprises preparing the silica nanoparticles to which the cationic functional group is attached for use as a regenerant of the ionizer resin for the softener. How to: Dispersing the silica nanoparticles in ethanol through sonication; Removing the precipitate from the dispersion and diluting with ethanol; Adding and stirring the silane compound having a cationic functional group to the diluent; And Removing the solvent when the reaction is complete. The method of claim 4, wherein the silane compound having a cationic functional group is N-triethoxysilyl-N, N-N, trimethylammonium chloride, N-trimethoxy N-trimethoxysilylpropyl-N, N, N-trimethylammonium chloride, tetracyldimethyl (3-trimethoxysilylpropyl) ammonium chloride ), N-trimethoxysilylpropyl-N, N, N-tri- n-butylammonium chloride (N-trimethoxysilylpropyl-N, N, N-tri-n-butylammonium chloride), N, N, -didecyl- N-methyl-N- (3-trimethoxysilylpropyl) ammonium chloride (N, N-didecyl-N-methyl-N- (3-trimethoxysilylpropyl) ammonium chloride), N- (trimethoxysilylpropyl) isothio N-trimethoxysilylpropyl isothiouronium chloride, 3- (N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane hydrochlora 3- (N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane hydrochloride) and N- (trimethoxysilylethyl) benzyl-N, N, N-trimethylammonium chloride (N- (trimethoxysilylethyl) benzyl-N, N, N -trimethylammonium chloride) method for producing silica nanoparticles with a cationic functional group for use as a regenerant for the ionizer resin for water softener, characterized in that at least one member selected from the group consisting of. A method of regenerating a softener ionizer resin by immersing the softener ionizer resin in the regenerant of any one of claims 1 to 3.

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