KR102307823B1 - Benzalkonium chloride adsorbent using bernessite nanoparticles, and water treatment apparatus using the same - Google Patents

Abstract

The present invention relates to a benzalkonium chloride adsorbent containing birnesite nanoparticles, which has high adsorption efficiency of benzalkonium chloride and does not express secondary toxicity due to decomposition products. It can be useful.

Description

Benzalkonium chloride adsorbent using bernesite nanoparticles, and water treatment device using the same

The present invention relates to a benzalkonium chloride adsorbent using birnesite nanoparticles, a preparation method thereof, and a water treatment method using the same.

Benzalkonium chloride (BKC) is a mixture of quaternary ammonium substances with various carbon numbers, and is used for various purposes such as humidifier disinfectants, quasi-drugs, and detergents.

Benzalkonium chloride collects in the sewage and wastewater treatment plants of its production and use facilities and is discharged into the surrounding water system. Even a trace amount can cause aquatic toxicity. For example, benzyldodecyldimethylammonium chloride (BKC C12), a kind of benzalkonium chloride mixture, has been detected up to 35.78 μg/L in the river around the pharmaceutical complex, and this concentration is a hemi-lethal concentration of BKC C12 against daphnia. It was a value more than double the phosphorus 16 μg/L. Therefore, there is a need for a technology to reduce the concentration of benzalkonium chloride to less than the toxicity-inducing concentration before it is discharged from the sewage and wastewater treatment plant.

Chemical oxidation and biological decomposition methods have been commonly used for organic material treatment. However, there has been a problem in that when an organic material is treated by such an existing method, a decomposition product is formed and secondary toxicity is concerned.

Recently, metal oxide nanoparticles have been attracting attention for the removal of water contaminants. Metal oxide nanoparticles are nano-scale particles, and in general, iron oxide, iron oxide and iron hydroxide, titanium oxide, manganese oxide, and the like are mainly studied. Metal oxide nanoparticles have been attempted to be applied in various ways, such as catalysts, adsorbents, and ion exchange materials, in removing water contaminants.

The advantages of metal oxide nanoparticles are as follows. First, the specific surface area is large and the surface is rich in reactive sites and adsorption sites, so the organic matter oxidation and removal performance and heavy metal absorption and removal performance are very high. For example, iron oxide nanoparticles have a phenol removal rate of about 35 times and an ethylene glycol removal rate of 2 compared to the Fenton oxidation process, which has been used to remove difficult-to-decompose organic matter. to 4 times higher (Zelmanov and Semiat, 2008). In addition, it has been reported that micro-sized zinc oxide cannot adsorb or remove arsenic (As), but nano-sized zinc oxide has excellent arsenic adsorption and removal ability (Tiwari et al., 2008). Second, since the specific surface area is large and the contaminant removal efficiency per unit weight is high, when the same amount of contaminants are removed, the injection amount is reduced compared to the large-sized particles, so that it can be applied economically.

Accordingly, the present inventor confirmed that the birnesite nanoparticles adsorbed benzalkonium chloride through an ion exchange reaction, and completed the present invention in which secondary toxicity caused by decomposition products and the like are not expressed.

Republic of Korea Patent Publication No. 10-1473924 B1

One object of the present invention is to provide a benzalkonium chloride adsorbent comprising birnesite nanoparticles.

Another object of the present invention is to provide a method for producing a benzalkonium chloride adsorbent.

Another object of the present invention is to provide a benzalkonium chloride adsorbent according to the manufacturing method.

Another object of the present invention is to provide a water treatment method for adsorbing and removing benzalkonium chloride by adding a benzalkonium chloride adsorbent to wastewater.

One aspect of the present invention for achieving the above object provides a benzalkonium chloride adsorbent comprising birnesite nanoparticles.

The benzalkonium chloride adsorbent comprising the birnesite nanoparticles according to the present invention does not generate a separate decomposition product through an adsorption reaction with benzalkonium chloride, an organic cationic material, so that secondary toxicity is not expressed and easily benzalkonium chloride It has an excellent advantage in that it can be removed.

In the present invention, “bernesite” is a type of manganese oxide and has a layered structure and can be expressed by the _{chemical formula (Na 0.3} Ca _0.1 K _0.1 )(Mn ⁴⁺ ,Mn ³⁺ ) ₂ O ₄ ·1.5H _{2 O.} Vernesite has a very high cation exchange capability (CEC, cation exchange capability) of 200-350 cmol _c / kg, and is known to have a point of zero charge of pH 2. At pH 2 or higher, the birnesite surface has a negative charge and has a very high ability to adsorb benzalkonium chloride due to its high cation exchange capacity.

In the present invention, the benzalkonium chloride adsorbent containing the birnesite nanoparticles is for adsorbing benzalkonium chloride, an organic cationic contaminant.

In one embodiment of the present invention, the size of the birnesite nanoparticles may be 100 nm to 600 nm, for example, 400 nm to 600 nm for black birnesite and 100 nm to 200 nm for brown birnesite. can

In one embodiment of the present invention, the birnesite nanoparticles may have a distance between each layer of about 7 Å.

In one embodiment of the present invention, the birnesite nanoparticles may be black birnesite or brown birnesite. The black birnesite is in the form of a nanoflower, and preferably has a particle size of 400 nm to 600 nm. The brown birnesite is in the form of a nanosheet, and preferably has a particle size of 100 nm to 200 nm. According to the present invention, the birnesite nanoparticles are preferably brown birnesite, and have high benzalkonium chloride treatment efficiency.

In the present invention, the benzalkonium chloride adsorbent containing the birnesite nanoparticles can adsorb benzalkonium chloride at a low concentration in an environment causing aquatic toxicity, such as sewage and wastewater treatment plants, with very high efficiency.

In one embodiment of the present invention, the birnesite nanoparticles may be K-bernesite or Na-bernesite, preferably K-bernesite.

In one embodiment of the present invention, the benzalkonium chloride adsorbent may be one that adsorbs benzalkonium chloride having a cationic charge on the surface through an ion exchange reaction in which birnesite having a negative charge on the surface thereof.

In the present invention, the benzalkonium chloride adsorbent containing the birnesite nanoparticles adsorbs benzalkonium chloride through an ion exchange reaction, so no decomposition products are generated, so there is no risk of toxicity compared to treatment with other compounds, and the adsorbed chloride It is very easy to use because it can be disposed of together with benzalkonium.

One aspect of the present invention is

a) heating the permanganate;

b) adding an acidic solution to the heated permanganate of step a) and stirring; and

c) after cooling the permanganate stirred in step b) to obtain birnesite nanoparticles; provides a method for producing a benzalkonium chloride adsorbent, including.

The method for producing a benzalkonium chloride adsorbent according to the present invention may be a method for producing a benzalkonium chloride adsorbent containing black birnesite nanoparticles. Specifically, the method for preparing the benzalkonium chloride adsorbent containing the black birnesite nanoparticles includes a) heating the permanganate.

In the step a) of heating the permanganate, heating may be performed after adding the permanganate to about 5 to 10 times the weight of distilled water. Preferably, permanganate is added to distilled water of about 8 times the weight and then heated. Here, the heating may be to a temperature of about 80 to 100 ℃, preferably about 90 ℃. The permanganate may be _{preferably KMnO 4 .}

In one embodiment of the present invention, the method for producing a benzalkonium chloride adsorbent containing black birnesite nanoparticles comprises: a) heating the permanganate, and then adding distilled water in which polyvinylpyrrolidone (PVP) is dissolved. may additionally include. Preferably, the permanganate and polyvinylpyrrolidone may be added in a weight ratio of 5 to 7, preferably 6 in a weight ratio. After addition of polyvinylpyrrolidone, it may be heated and stirred at a temperature of 80 to 100°C, preferably about 90°C.

In one embodiment of the present invention, the method for producing a benzalkonium chloride adsorbent containing black birnesite nanoparticles includes b) adding and stirring an acidic solution to the heated permanganate.

In one embodiment of the present invention, b) adding an acidic solution to the heated permanganate and stirring may be adding a diluted hydrochloric acid solution in a molar ratio of 1 to 3 of the permanganate. Preferably, about 2 molar ratio of diluted hydrochloric acid solution may be added.

In one embodiment of the present invention, the method for producing a benzalkonium chloride adsorbent containing black birnesite nanoparticles includes c) obtaining the birnesite nanoparticles after cooling the stirred permanganate.

In one embodiment of the present invention, c) obtaining the birnesite nanoparticles after cooling the stirred permanganate may be cooling to about 20 °C to 30 °C. It may be cooled to room temperature, preferably about 25°C.

In one embodiment of the present invention, c) obtaining the birnesite nanoparticles after cooling the stirred permanganate may be to collect the precipitate by centrifugation.

The method for producing a benzalkonium chloride adsorbent according to the present invention may be a method for producing a benzalkonium chloride adsorbent containing Brown birnesite nanoparticles.

Specifically, the method for preparing the benzalkonium chloride adsorbent containing the above Brown birnesite nanoparticles may include a) heating the permanganate. The step of heating the permanganate may be heating by putting the permanganate in distilled water. Specifically, it may be heating after adding permanganate to 10 to 20 times the weight of distilled water. Preferably, it may be heated after adding permanganate to 16 times the weight of distilled water. Here, the heating may be to a temperature of about 80 to 110 ℃, preferably about 100 ℃.

In an embodiment of the present invention, the permanganate may be _{preferably KMnO 4 .}

The method for producing a benzalkonium chloride adsorbent containing brown birnesite nanoparticles according to the present invention includes b) adding an acidic solution to the heated permanganate and stirring.

In one embodiment of the present invention, b) adding and stirring an acidic solution to the heated permanganate may include adding a concentrated hydrochloric acid solution in a molar ratio of 1 to 3 of the permanganate. Preferably, a concentrated hydrochloric acid solution of about 2 molar ratio may be added. The hydrochloric acid may be added dropwise under stirring conditions.

In one embodiment of the present invention, the method for producing a benzalkonium chloride adsorbent containing brown birnesite nanoparticles includes the step of obtaining birnesite nanoparticles after cooling the permanganate stirred in step c) b). c) After cooling the stirred permanganate, the step of obtaining birnesite nanoparticles may be cooling at about 20°C to 30°C. It may be cooled to room temperature, preferably about 25°C.

In one embodiment of the present invention, c) obtaining the birnesite nanoparticles after cooling the stirred permanganate may be to filter the solids using a vacuum filtration method.

The present invention provides a benzalkonium chloride adsorbent prepared by the above method. The adsorbent according to the present invention has an excellent advantage in that it can easily remove benzalkonium chloride without exhibiting secondary toxicity due to decomposition products by absorbing benzalkonium chloride, which is an organic cationic material, with high efficiency.

The present invention provides a water treatment method for adsorbing and removing benzalkonium chloride by adding a benzalkonium chloride adsorbent to wastewater.

In one embodiment of the present invention, in the water treatment method for adsorbing and removing benzalkonium chloride by adding a benzalkonium chloride adsorbent to wastewater, an adsorbent containing birnesite nanoparticles is sprayed into sewage or wastewater treatment plants and benzalkonium chloride for a certain period of time. It may be to reduce the concentration of benzalkonium chloride in sewage or wastewater treatment plant effluent by precipitating it after reacting with it. The water treatment method according to the present invention may further include the step of adding a benzalkonium chloride adsorbent to wastewater to adsorb benzalkonium chloride, and then removing the adsorbent containing bernsite nanoparticles together with the adsorbed benzalkonium chloride.

The benzalkonium chloride adsorbent containing the bernesite nanoparticles according to the present invention has a high adsorption efficiency of benzalkonium chloride and does not generate a separate decomposition product, thereby not expressing secondary toxicity. It can be usefully used as a water treatment method, etc.

1 is a view showing SEM images of black birnesite and brown birnesite.
FIG. 2 is a diagram showing the time to reach the adsorption equilibrium of benzalkonium chloride in the birnesite nanoparticles prepared in Example 1. FIG.
3 is a diagram showing the Langmuir isothermal adsorption model of BKC 12 to the birnesite nanoparticles prepared in Example 1. FIG.
FIG. 4 is a diagram showing the processing efficiency of BKC 12 of black birnesite and brown birnesite prepared in Example 1. FIG.
FIG. 5 is a diagram showing the toxicity reduction effect of BKC C12 by black birnesite and brown birnesite prepared in Example 1. FIG.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Example One. vernesite Preparation of nanoparticles

Example 1-1. black vernesite Preparation of nanoparticles

Black birnesite nanoparticles were prepared according to the method proposed by Hao. 100 mL distilled water and 12.45 g of KMnO ₄ were placed in a 250 mL round-bottom flask. 10 mL distilled water in which 0.2 g of polyvinyl pyrrolidone (PVP) was dissolved was added thereto. The flask was placed in a heating mantle and the temperature was raised to 90°C with stirring. After adding 100 mL of 1.5 M hydrochloric acid solution, the mixture was stirred at 90° C. for 1 hour. After stirring, the mixture was cooled to room temperature and centrifuged at 4°C for 10 minutes at a speed of 10000 g to collect black-birnessite as a precipitate. The collected precipitate was washed 5 times with distilled water.

Example 1-2. Brown vernesite Preparation of nanoparticles

Brown birnesite nanoparticles were prepared according to the method proposed by McKenzie. 1.5 L distilled water and _{0.6 mol of KMnO 4} were placed in a 2 L beaker and heated with a heating stirrer. After the water started to boil, 1.2 mol of concentrated hydrochloric acid was added dropwise using a burette. After the hydrochloric acid injection was completed, it was further heated for about 20 minutes. After stirring and cooling to room temperature, the solid brown-birnessite was filtered out using vacuum filtration and washed sufficiently with distilled water.

Example 2. vernesite Confirmation of the structure of nanoparticles

The structure of the birnesite nanoparticles prepared in Example 1 was examined with a scanning electron microscope (JEOL (JSM-7610F)) at a voltage of 20 kV at a magnification of 20000, and is shown in FIG. 1 .

As can be seen in FIG. 1 , it was confirmed that the black birnesite prepared in Example 1-1 had a nanoflower shape. It was confirmed that the brown birnesite prepared in Example 1-2 had a nanosheet shape.

Example 3. vernesite of nanoparticles benzalkonium chloride Measurement of the time to reach the adsorption equilibrium

After reacting by administering benzyldodecyldimethylammonium chloride (BKC C12) to contaminated water at a concentration of 2.5 g/L, the time to reach the adsorption equilibrium was measured.

This is shown in FIG. 2 .

As can be seen in FIG. 2 , the adsorption equilibrium was reached 60 minutes after the reaction, which means that the dissolved phase concentration of BKC C12 was maintained at a constant level after 1 hour of the reaction.

Example 4. vernesite of nanoparticles benzalkonium chloride processing power Confirm

In a 50 mL Teflon tube, 75 mg of birnesite and 30 mL of benzyldodecyldimethylammonium chloride (BKC C12) solution were added to 10, 2, and 0.4 mM, respectively, and stirred on a horizontal stirrer for 24 hours. After completion of stirring, the supernatant was collected by centrifugation at a speed of 10000 g at 4° C. for 10 minutes. The concentration of benzalkonium chloride in the supernatant was analyzed using high performance liquid chromatography (HPLC). After the reaction, the Langmuir isothermal adsorption model was derived in FIG. 3 using the concentration of benzalkonium chloride in the supernatant and the concentration adsorbed to the birnesite. At this time, the concentration adsorbed to the birnesite was calculated as the value obtained by subtracting the concentration in the supernatant after the completion of the reaction from the initial concentration as shown in the following equation. Here, q denotes the amount of adsorption to birnesite in the equilibrium state of adsorption, and C _w denotes the amount of dissolved matter in the equilibrium state of adsorption.

When the low concentration benzalkonium chloride (1, 0.1 μM) was treated using the Langmuir model equation in FIG. 3, the concentration of benzalkonium chloride in the supernatant and the treatment efficiency thereof were predicted after the completion of the reaction, and the results are shown in FIG. The toxicity reduction effect was predicted based on FIG. 4 and shown in FIG. 5 .

The treatment efficiency was calculated by the following formula.

The toxicity index (toxicity unit, TU) of benzalkonium chloride was calculated by the following formula. Here, the toxicity index (toxicity unit) means the ratio of the BKC C12 concentration in the dissolved phase to the half-lethal concentration of BKC C12 (0.047 μM) after the reaction.

As can be seen in FIG. 4 , the lower the concentration, the higher the treatment efficiency. In particular, considering the concentration at which BKC C12 is detected in the environment (0.1 μM), the treatment efficiencies of black and brown birnesite were 83.3%, respectively. and 89.3%.

As can be seen in FIG. 5 , assuming that the initial concentration of BKC C12 is 0.1 μM, which is the maximum detection level in the environment, and that the concentration of BKC C12 decreases according to the BKC C12 treatment efficiency of FIG. Both techniques were predicted to reduce the toxicity of BKC C12 to within acceptable levels (TU = 1).

From the above description, those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. In this regard, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention should be construed as being included in the scope of the present invention, rather than the above detailed description, all changes or modifications derived from the meaning and scope of the claims described below and their equivalents.

Claims (8)

A benzalkonium chloride adsorbent comprising K-bernesite, black or brown birnesite nanoparticles. The adsorbent according to claim 1, wherein the size of the birnesite nanoparticles is 100 nm to 600 nm, and the distance between each layer is 7 Å. delete delete The adsorbent according to claim 1, wherein the adsorbent adsorbs benzalkonium chloride through an ion exchange reaction. a) heating the permanganate;
b) adding an acidic solution to the heated permanganate of step a) and stirring; and
c) after cooling the permanganate stirred in step b), obtaining black birnesite or brown birnesite nanoparticles, which are K-bernesite; The benzalkonium chloride adsorbent according to claim 6 . A water treatment method in which the benzalkonium chloride adsorbent according to any one of claims 1 to 2 and 7 is added to wastewater to adsorb and remove benzalkonium chloride.

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