TW592779B - Composite of chitosan and silver-containing activated carbon for use as a water filtration material - Google Patents

Abstract

Composite of chitosan and silver-containing activated carbon for use as a water filtration material is disclosed, wherein the weight ratio of chitosan to silver-containing activated carbon ranges from 1:9 to 9:1. The silver-containing activated carbon is embedded in or bound by chitosan, when the composite is mainly composed of the chitosan. The chitosan is deposited on the silver-containing activated carbon, when the composite is mainly composed of the silver-containing activated carbon. The composite is able to be used as a filtration material for removal of heavy metals, chlorine residue, odor, color, trihalomethane, and agricultural chemicals from water without accumulation of bacteria therein, and thus is suitable for the purification of drinking water, packaged water and various water sources.

Description

592779 A7 ____B7_ V. Description of the invention (i) Field of the invention The present invention relates to a water filter material containing chitosan, and more particularly to a water filter material containing chitosan that does not collect bacteria. BACKGROUND OF THE INVENTION Currently, there are many types of water purification materials on the market, including non-woven fabrics, activated carbon, and ion exchange resins. These filters have different functions. Non-woven fabrics are used to remove impurities in water. Activated carbon can be used to remove heavy metals and odors Taste, color, chloroform, etc., ion exchange resin is used to remove hard water. The adsorption capacity of activated carbon for heavy metals is quite limited. After the water stays for a while, the chlorine in the water will be lost, and the bacteria in the water can adhere to the surface of the activated carbon particles and grow into a biofilm, which will increase the number of bacteria in the activated carbon filter. Situation. Adding a silver-containing substance to the activated carbon filter media can solve the problem of growing bacteria, because the free silver ions can hinder the transmission of electrons, damage the cell membrane, and achieve an antibacterial effect. For example, it is mentioned in patents DE3 90 5 1 64 and CN 1123768 that the silver ions can be released by plating silver on the screen to achieve the antibacterial effect. The same Moshe et al. (USP 607 1 4 1 5) immersed living carbon in a silver-containing solution to make 2% to 14% silver-containing activated carbon, which is used to adsorb bromine or iodine in water. The most common method for the production of silver-containing activated carbon is to place the activated carbon in a silver-containing solution, such as silver nitrate, rinse and dry it (patent RU2 1 4525 9, RU2 15302). Although there is no doubt about the bacteriostatic effect of silver-containing activated carbon, its shortcoming is that there will be doubts about excessive release of silver ions. Silver ion is not a necessary mineral for the human body. It is easy to accumulate in the human body when ingested in excess. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X 297 mm) (Please read the precautions on the back before filling this page)

Line 1T _ Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 592779 A7 __ B7 V. Description of the Invention (2) "Argyria" will occur during ingestion. Although its degree of harm is unknown, However, it is certain that it will cause discoloration of the skin and human tissues. According to the US Environmental Protection Agency's "Drinking Water Regulations", the silver content must not exceed 0.1 ppm, and in Taiwan ', it cannot exceed 0.0 5 p p m. Generally, most of the water containing silver from contaminated water comes from contaminated water sources, and the use of silver-containing activated carbon filter materials may become one of the sources of water containing silver from water. Chitin and chhosan are natural non-toxic polymers and have biodegradability. Its structure is similar to that of cellulose. It consists of 1,000-3000 N-acetylglucosamine (N- ACETYL-2 AMIN0-2 DEOXY-dD-GLUCOSE ^ n-ACETYL-d-GLUCOSAMINE) ¥ ft A linear polymer saccharide composed of / 3 · 1, 4 bonds (the structural formula is shown below). In nature, chitin is the most abundant glycosaminoglycan-type polysaccharide on earth, second only to cellulose. It is mainly found in the shells of invertebrates such as insects and aquatic crustaceans, and fungi. The cell wall, which plays a role in living organisms, is mainly used as a body skeleton and protection. Chitosan is a product of chitin deacetylation. Generally, the degree of chitin deacetylation is more than 70%, and it can be turned into a chitosan product which is soluble in acid. This paper size applies to China National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 592779 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the Invention (3) CH3

Chitosan Chitosan is insoluble in water and organic solvents, but is soluble in some organic acids. Because it has functional groups such as -OH, -NH2, -CONH, it has good hydrophilicity and lipophilicity. Coupled with the porosity of the E-body structure, it has an active site for chemical and physical adsorption and is an excellent natural adsorbent. Using functional groups, chitosan can be coordinated with heavy metals to chelate, so it can be used to adsorb heavy metals. At present, many studies have confirmed that it has a very good effect on heavy metals such as copper, mercury, cadmium, lead, chromium, nickel, etc. Good adsorption effect (Tony C Yang, Ind. Eng. C hem. Prod. Res. Dev. ^ 23, 168-172, 1984 ', Chihpin huang, J. Hazard. Mater, 45, 265-277; Marsi MS, J. Appl. Polymer Sci., 1 8, 675-68 1, 1 974; Srivastava SK, Environ. Technol. 15, 353-361, 1994). In addition to the adsorption of heavy metals by chitosan, plutonium can be used to adsorb odorous molecules such as: atmosphere (USP35151), hydrogen sulfide (USP35151), indole (USP5932495), and fecal odor. This paper applies Chinese national standards (CNS) A4 Specifications (210 X 297 mm) (Please read the notes on the back before filling this page)

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 592779 A7 B7 V. Description of the invention (USP5932495), isovaleric acid (USP 5932495), triethylamine (USP 5 93 2495), methyl mercaptan (USP45 12968) And pesticides (Ta CA,

Ckm. Rox / co /., 37, 1147-1151, 1 999). Liquid chitosan can be used as a bacteriostatic agent, because the amine group (-NH2) of chitosan will be positively charged (-nh3 +) in the acid solution, and the cell wall of the microorganism is negatively charged, so it can bind to the cell wall And destroy the cell production, to achieve antibacterial effect. However, the solid chitosan is not soluble in neutral water and is not charged in water. In addition, chitosan is a porous biological polymer, which is more likely to become a breeding ground for microorganisms. Products using chitosan and chitin as filter media have gradually become popular. Although chitosan can be used to remove heavy metals, odor molecules and residual chlorine in water, there is still a hidden concern in its use. . Because chitosan is a biological polymer, when it is immersed in water for a long time and there are too many microorganisms in the water, after the biological polymer is attached by the microorganisms, it will form a hotbed for microbial growth, which will make the chitosan filter material grow bacteria. Stink, which shortens the service life of the chitosan water filter. Failure to renew chitin polysaccharide water filter material in time may cause harm to the human body. A main object of the present invention is to provide a water filtering material which does not have the disadvantages of the foregoing prior art. Another object of the present invention is to provide a water filtering material which does not collect bacteria and simultaneously retains the advantages of active carbon and chitosan. Summary of the invention The present invention uses a composite material of chitosan and silver-containing activated carbon as a water filter material, and has the advantages of both chitosan and silver-containing activated carbon, and the paper size of each other is applicable to Chinese National Standard (CNS) A4 Specifications (21〇X 297 mm) --------------------- Order --------- line (Please read the precautions on the back before (Fill in this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 592779 A7 ______B7 V. Description of Invention (5) The shortcomings can be made up for each other. Because chitosan has the ability to adsorb heavy metals, and silver-containing activated carbon has an antibacterial function, preparing these two materials into a composite material can have complementary effects, and chitosan can enhance the adsorption of filter materials to heavy metals. Effect, while the silver-containing activated carbon prevents the sapwood from collecting bacteria, and a part of the silver ions released by the silver-containing activated carbon can be adsorbed by chitosan, reducing the amount of silver ion release and reducing the silver-containing activity Harm of carbon to human body. DETAILED DESCRIPTION OF THE INVENTION The present invention discloses a chitosan-silver-containing activated carbon composite material that can be used as a water filter material, comprising: silver-containing activated carbon; and chitosan, wherein The weight ratio is 1: 9 to 9: 1; when the chitosan is the main component of the composite material, the silver-containing activated carbon is substantially embedded in the chitosan or the chitosan is Sticking; when the silver-containing activated carbon is the main component of the composite material, the chitosan is attached to the surface of the silver-containing activated carbon. Preferably, the silver-containing activated carbon powder, granular or fibrous form used in the present invention is used. Preferably, the chitosan is a main component of the composite material of the present invention, and the chitosan is granular, and the powdery, granular or fibrous silver-containing activated carbon is embedded in the chitin. Glycan. Preferably, the composite material of the present invention is obtained by mixing the powdery, granular or fibrous silver-containing activated carbon with an acidic aqueous solution of chitosan; adding a base to the obtained mixture, so that Chitosan is transformed into insoluble particles; and the insoluble chitosan particles formed by separation and drying are used---8-This paper size applies to China National Standard (CNS) A4 (210X 297 mm) (Please read the notes on the back before filling this page)

Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 592779 A7 B7____ 5. Description of the invention () Preparation. Preferably, the chitosan used in the present invention has a deacetylation degree of 60% to 99%, and a molecular weight of 10,000 to 1,000,000. Preferably, the silver-containing activated carbon used in the present invention contains 0.01 to 15% by weight of silver. Preferably, the composite material of the present invention has a shape of particles, fibers, films, squares or irregular blocks. A method for preparing a water filter material according to a preferred embodiment of the present invention includes dissolving chitosan in an acetic acid aqueous solution, adding silver-containing activated carbon to prepare a mixture, and then using a phase inversion method to dissolve the chitosan. Butan is transformed into a solid state and made into granular, fibrous or other shapes, and silver-containing activated carbon can be coated in chitosan. After washing and drying the product, it becomes antibacterial chitosan. / Activated carbon composite. This composite material has the following functions: (1) It can remove heavy metals, odor, residual chlorine, trihalomethane, color, and agricultural chemicals in water. (2) The filter material will not collect bacteria. (3) Can significantly reduce the release of silver ions in silver-containing activated carbon. (4) The ability to adsorb heavy metals is higher than using silver-containing activated carbon alone. Example 1 In this example, chitosan / silver-containing activated carbon particles (hereinafter referred to as composite particles) were prepared as a water filter material, and the bacteria collection condition was tested. The source of silver-containing activated carbon used in this example is Sri Lanka's Prime Carbons Lanka Limited, with a silver content of 2%. The preparation steps of the water filtration material are as follows: 1. 4 g of chitosan with a molecular weight of about 350,000 and 100 Dissolve in 1 ml of 1% acetic acid with stirring. This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) -------------------- Order --------- line (Please read the precautions on the back before filling out this page) 592779 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (7) 2. Add 2g of silver containing activated carbon particles with 2% silver content Stir in the aqueous solution in step 1. 3. Drop the mixture from step 2 into an equal volume of 30 ° /. Chitosan is solidified into particles in sodium hydroxide. 4. Take out the granular product and rinse it with deionized water until the conductivity and pH are the same as those of pure water. 5_ The granulated products washed and dried at 4CTC are made into composite granules. The composite particles, silver-containing activated carbon, and chitosan were simultaneously tested for bacteria collection, and Pseudomonas aeruginosa was used as a test object. Cultivate the above filter, water material and bacteria liquid for 2 hours, then clean the water filter material and continue incubating for 24 hours, and measure the number of bacteria to determine whether the filter material will collect bacteria. This experimental method is a shake flask method, and the source of the bacteria is the Institute of Food Industry. The experimental methods are described as follows: 1. Culture medium preparation: 44.5 g of Cetrimide gum (Agar) / 10 ml of glycerol / 1 L of reverse osmosis water. 2. Autoclave 100 ml of PBS (Phosphate Buffered Saline), sterile water and laboratory equipment. 3. Sterilize the water filter with UV. 4. Take 0.5 g of filtered water in 100 ml of PBS. 5. Add 1 ml of bacterial solution (1 xlO6 CFU / ml) to 100 ml of the sample solution. 6. Take 0.1 ml of the bacterial solution from the blank control group and apply it on the solid nutrient medium, and then take 1 ml of serial dilution to lx 102 CFU / tube. Take 0.1 ml of the plate from the tube and make it blank for 0 hours. number. 7. Shake flask for 2 hours. -10-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) I--I-- · I ----- Order ---- I ---- Line (Please read first Note on the back then fill out this page) 592779 A7 B7 Invention description (8) (Please read the notes on the back before filling out this page) 8. Remove 0.1 ml from each bottle and add 1 ml to 9 ml sterile Water was continuously diluted to lx 102 CFU / tube, and then 0.1 ml spreading plates were taken as the number of bacteria after shaking culture, and the number of bacteria was calculated every other day. 9. Pour out the solution in the bottle and rinse the filter medium 7 times with 100 ml of sterile water. 10. Add 100 ml of sterile water to each bottle. 1 1. Shake the bottle for 24 hours and measure the number of bacteria. Table 1 Aggregation effect of different water filtration materials on Pseudomonas aeruginosa Composite particles Chitosan Total silver-containing activated carbon bacterial count < 103 2.75χ105 < 103 Table 1 Results show that composite particle water filtration materials do not have In the case of Pseudomonas aeruginosa aggregation, the effect is the same as in the case of using silver-containing activated carbon alone, but it is better than using chitosan alone. This indicates that silver-containing activated carbon can improve the bacteria collection of chitosan. The consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed the composite particulate water filter material prepared in Example 1 to test the adsorption capacity for heavy metals (lead and mercury), and measured the release concentration of silver ions during the adsorption process. Experimental steps As follows: 1 Prepare 200 ml of lead nitrate (Pb (N03) 2) and mercury nitrate (Hg (N03) 2 · 2H20) solutions. 2. Add 1 gram of composite particles and silver-containing activated carbon to the above solution. The size of this paper is applicable to China National Standard (CNS) A4 (210X297 mm). Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs. Description of the invention () 24 hours. 3. Take out the solution and analyze the concentration of lead, mercury and silver ions by atomic absorption spectrometer (AAS). 4. Calculate the adsorption capacity of the filter material according to the following equation:

Co-Ce

q = -x V

W q: adsorption amount (mg / g) C〇: initial metal concentration (ppm)

Ce: concentration after metal reaction (ppm) W: weight of adsorbent (g) V: reaction volume (L) Table 2 Adsorption and release of silver ions by composite particles and silver-containing activated carbon on silver-containing activated carbon composite Initial particle ion concentration (ppm) 2.395 2.395 Lead concentration after reaction (ppm) 1.365 0.255 Adsorption amount (mg Pb2 + / g) 0.206 0.428 Silver ion release amount (ppm) 0.23 0.007 -12- This paper's dimensions are applicable to Chinese national standards (CNS) A4 specification (210 X 297 mm) -------------------- Order --------- Line 4 ^ (Please read the back first (Notes on this page, please fill in this page) 592779 A7 B7_____ 10 V. Description of the invention () Table 3 Adsorption and release of silver ions on composite particles and silver-containing activated carbon for mercury ions Initial concentration of final ions (PPm ) 15.082 15.082 Mercury concentration after reaction (ppm) 0.4154 0.204 Adsorption amount (mg Hg2 + / g) 2.933 2.976 Release amount of silver ion (ppm) 0.3 0.009 Printed by the Consumers' Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs. It is known that because the composite particles contain chitosan, the adsorption capacity is higher than that of using silver alone. High carbon, chitosan and silver ions released from the activated carbon is also capable of adsorption. Therefore, the composite particle water filtering material can improve the adsorption force for heavy metals and reduce the release amount of silver ions. The third embodiment uses the composite particulate water filter material of Example 1 as a material, and tests the release concentration of silver ions at different times, and compares it with silver-containing activated carbon: 1. 50 ml of pure water is added to 1 g of the composite Granules and antibacterial activated carbon. 2. Stir at 500 rpm, and filter out the composite particles and silver-containing activated carbon at 1 minute, 60 minutes, and 24 hours, leaving the filtrate. 3. Concentrate the filtrate to 10 ml. 4. Measure the silver ion concentration in water with atomic absorption spectrometer. -13- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) Order !!!! Line i Consumer Property Cooperatives, Intellectual Property Bureau, Ministry of Economic Affairs Printed 592779 A7 _____ B7 ^ _ 5. Description of the invention (U) Table 4 Silver ion release concentration of composite particles and silver-containing activated carbon at different times Response time silver ion concentration (ppm) Silver-containing activated carbon antibacterial filter material 0.08 minutes 0.0008 6 0 minutes 0.078 0.0012 24 hours 0.081 0.0026 The results in Table 4 show that silver-containing activated carbon will release silver ions, but if it is wrapped with chitosan, the amount of release can be greatly reduced by 30 to 60 times. According to the comparison results in Tables 2, 3, and 4, it was found that during the process of adsorbing heavy metals on the composite particles and silver-containing activated carbon, a similar ion exchange reaction occurs, and the silver ions in the particles are exchanged out. Therefore, for Example 2, the overall silver ion concentration is higher than that in the absence of heavy metals (Example 3). However, compared to silver-containing activated carbon, it can be found that no matter the presence of heavy metals in the water, the silver ion concentration of the composite particles is significantly lower. This phenomenon represents that chitosan will adsorb the free silver ions, so that the amount of silver ions released accords飮 Water standard (< 0.05 PPm). The composite particles not only adsorb silver ions, but also the silver ions adsorbed by the composite particles and the residual silver ions containing silver activated carbon can make the composite particles have a function of preventing bacteria (Example 1). In summary, the present invention is a creation that can immediately benefit the Lord. Silver-containing activated carbon is now widely used in countries around the world. The main purpose is to overcome the shortcomings of activated carbon that is easy to breed bacteria with silver ions, but at the same time, it also generates the concern of excessive release of silver ions, causing hidden concerns for users' health. The present invention uses chitosan-14- this paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) (please read the precautions on the back before filling this page) 11 ---- order—1 · ----- line · ^ 2779 A7 B7 V. Explanation of the invention (12) Combined with silver-containing activated carbon, not only can effectively reduce the release of silver ions by 30 to 60 times, but also improve the ability of the filter material to adsorb heavy metals, and The ability to adsorb odors, pesticides, etc., is a highly commercial invention. (Please read the notes on the back before filling this page) ------- Order ·! 1 · 1! · Line. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm), Ί rli i4, n rP ί * .jr. This?----A- " ™ *; nr 丨 No application date 1 Λ Factory on the case No. 1 ί \ {[ιχ ^ Category β-ί〇 (The above columns are filled in by the Bureau) A4 C4 592779 New % Patent specification Chinese invention new name invention creation / chitosan-silver-containing activated carbon composite material that can be used as water filter

Composite of chitosan and silver-containing activated carbon for use ^ is-a-water filtration material-- Last name% Li Zhengming Shen Zhilong Mjm Shao Huizhen Nationality Feng Zhi Republic of China (ROC) Hsinchu Science Park Hsinchu No. 17 No. 17, Chuangxin 1st Road, Hsinchu Science Park, No. 17, Chuangxin 1st Road, Hsinchu Science Park, Hsinchu Science Park, No. 100, University Road, Hsinchu City, No. 1003_0, Hsinchu. Residence, Residence (Office) Name of Representative Kadison Technology Co., Ltd. ROC Hsinchu Science Park No. 17 Chuangyi 1st Road, Li Zhengming Line This paper applies Chinese National Standard (CNS) A4 specifications (210X297 mm)

Claims (1)

592779 fT, _έ_ Α8, B8, C8, D8, TP stopped in January, 2004. VI. Application for patent scope 1. A chitosan-silver-containing activated carbon composite material that can be used as a water filter, including: silver-containing activity Carbon; and chitosan, wherein chitosan is silver-containing. The weight ratio of carbon is 1: 9 to 9: 1; when the chitosan is the main component of the composite, the silver-containing The activated carbon is substantially embedded in the chitosan or is bound by the chitosan; when the silver-containing activated carbon is the main component of the composite material, the chitosan is attached to the silver-containing activity On the surface of carbon, wherein the chitosan has a deacetylation degree of 60% -99%, and a molecular weight of 10,000 to 1,000,000,00; and the silver-containing activated carbon contains 0.01% by weight ~ 15% by weight of silver. 2. The composite material according to item 1 of the scope of patent application, wherein the silver-containing activated carbon is powdery or fibrous. 3. The composite material according to item 2 of the scope of patent application, wherein the chitosan is the main component of the composite material, and the chitosan is granulated, and the powdery or fibrous silver-containing activated carbon coating Buried in this chitosan. 4. The composite material as claimed in claim 3, wherein the composite material is obtained by mixing the powdery or fibrous silver-containing activated carbon with an acidic aqueous solution of chitosan; adding a base to the obtained The mixture is prepared by converting chitosan into insoluble particles; and isolating and drying the formed insoluble chitosan particles. 5. The composite material according to item 1 of the patent application scope, wherein the composite material has a particle, fiber, film, square or irregular block shape. -16 · This paper size applies to China National Standard (CNS) A4 (21 × 297 mm) (Please read the precautions on the back before filling this page)-Order _ · --Line ·