In the mid-1960s, DON HESKETT, as a consultant of Morton Salt Company, promoted the development of new activated carbon filtration technology. 1972, DON and BILL STEGER developed the original prototype of the non-electronic water softener and applied it to the water treatment industry. These two developments are innovative and ahead of the times. The United States imported KDF 1984, and Tang discovered something new. When using cement as a carbon rubber filter at one time, DON accidentally found that copper-zinc alloy can have a great effect on chlorine. At 4 o'clock in the morning, he stirred some chemicals with a brass ballpoint pen, which contained chlorine. When he noticed that the red color representing the existence of chlorine gradually disappeared, he developed great curiosity. The next day, he experimented with different chemicals and various copper-zinc alloys, until the experimental phenomena he accidentally discovered appeared repeatedly. The electrochemical redox process he discovered is called "redox", in which chlorine is reduced. DON not only discovered a new reaction to remove chlorine from water, but also opened a new era of water treatment. The new method invented by DON, that is, removing heavy metals and chlorine from water by metal, runs counter to the traditional idea of removing metals from water by ion exchange. He soon industrialized his invention, and three years later he obtained many patents in this field. He also authorized the American zinc company to produce KDF processing media. Through his lobbying, face-to-face communication and many successful water treatment examples, the water treatment industry gradually realized the importance and practicability of his "invention". Through media advertising and marketing, many new application fields have been opened up, product sales have also increased steadily, and business has gradually expanded. 199 1 year, the US Environmental Protection Agency (USEPA) closed the KDF liquid treatment company-it was not until DON HEDKETT confirmed to USEPA that KDF used in activated carbon filtration equipment had obvious antibacterial effect that USEPA designated the popular KDF treatment medium as "microbial inhibition device". 1992, KDF85 and KDF55 therapeutic media passed the national sanitation foundation (NSF) certification, meeting the drinking water 6 1 standard. 1997, 10 years later, KDF Liquid Treatment Company became a member of the American Water Quality Alliance, and the American Water Quality Association (WQA) included KDF water treatment media in its team and residential water treatment vocabulary. In the same year, KDF55 treatment medium passed 42 drinking water standards of American National Organization for Standardization (ANSI) and NSF. 1. Scope of application This guide is applicable to municipal tap water treated with chlorine. Including residential (residential), business, schools, public utilities, light industry, construction sites and factories. When tap water is used, the water flow is in the range of 3-324 gallons per minute (1 1- 1226 liters per minute). (Other KDF therapeutic media and user manual can be provided upon request) 2. What is the therapeutic medium of KDF55? KDF water treatment medium is a unique, novel and environmentally friendly water treatment medium. It is an ideal water treatment method at present. The treatment medium of KDF55 is high-purity copper/zinc alloy. Through electrochemical redox (electron transfer) reaction, chlorine and heavy metals in water can be effectively reduced or removed, and the growth and reproduction of microorganisms in water can be inhibited. KDF55 treatment medium meets the requirements of the standards of the Environmental Protection Agency (EPA), the Federal Drug Administration (FDA), the American Water Quality Association (WQA) and the National Health Foundation (NSF) on the maximum zinc and copper content in drinking water. For example, KDF treatment medium can remove chlorine with the concentration of 10ppm in water, but it can still meet the requirements of EPA for the maximum allowable zinc content in drinking water. 3.3 Function and mechanism. The principle of KDF55 treating medium KDF treating water is to use redox reaction, and KDF exchanges electrons with oxidative harmful substances in water, turning many harmful substances into harmless substances. 3. 1 Long service life and reusability (see Category 4 and 5 for details). 3.2 Reducing mineral scaling The influence of KDF treatment medium on calcium carbonate scaling has two aspects. On the one hand, according to the relationship among pH, carbon dioxide concentration and the solubility of calcium carbonate, when carbon dioxide is removed from the solution, the pH value increases, thus reducing the solubility of calcium carbonate; KDF55 also increases the pH value of water and reduces the solubility of calcium carbonate through electrochemical reaction, resulting in easy precipitation of calcium carbonate scale. On the other hand, due to the dissolution of zinc ions in KDF treatment medium, the content of zinc ions in water is increased, and the existence of zinc ions in water can change the crystal growth mechanism of scale, so that calcium carbonate scale in water can be precipitated in the form of aragonite crystals, forming soft scale on the container wall instead of crystallizing into calcite hard scale. Some people have studied the influence of impurities in water on the growth of calcite crystals, and found that even if the zinc ion concentration is very low, it can prevent the formation of calcite crystals. It can be further proved by experiments that KDF treatment medium can prevent the formation and accumulation of mineral hard scale, mainly to prevent the crystallization of calcite calcium carbonate. The crystallographic study by scanning electron microscope and X-ray diffraction shows that the hard scale produced in the water without KDF treatment is some large and regular crystals of needle-like calcium and magnesium salts, with hard texture, low solubility and network structure, which is glass limestone scale. The scale formed in the water of KDF-treated medium fundamentally changes the crystal form of calcium carbonate (magnesium). Scales are relatively small in shape, with oblate, granular and rod-shaped appearance, all of which are composed of soft powder components. These components do not adhere to the surfaces of metals, plastics or ceramics, and can be easily removed by physical filtration. 3.3 Reduce the average particle size of suspended solid KDF55 treatment medium to about 60 meshes, and the minimum particle size is about 1 15 meshes, which can also play a role in removing suspended solids by physical filtration. Generally speaking, KDF55 filter media can effectively remove particles as small as 50μm in diameter. When water pipes made of steel are corroded, iron oxidizes to form FeO colloid. When FeO comes into contact with KDF, redox reaction will also occur. FeO eventually forms Fe2O3 solid precipitate on the surface of KDF, which can be removed by backwashing. The chemical reaction formula is as follows: 2cu+FeO Cu2O+Fe3Fe+3O2Fe2O3 3.4 Removal of oxidant (residual chlorine) KDF55 can remove oxidant in water, such as residual chlorine. This effect is achieved by electrochemical redox reaction. The redox reaction occurs because KDF55 is composed of two different metals. When it comes into contact with water, copper with positive potential in the alloy becomes the cathode, while zinc with negative potential is the anode. The cathode undergoes a reduction reaction and the anode undergoes an oxidation reaction. The zinc anode loses electrons in the reaction, zinc ions enter the solution as a victim, and the reduction reaction of free chlorine occurs on the copper cathode, and the metal copper does not dissolve. Water and residual chlorine become the last electron acceptors, and simultaneously generate hydrogen ions, hydroxide ions and chloride ions. The total reaction formula is as follows: Zn+hocl+H2O+2e-Zn2+Cl-+h+2oh-other oxidants in water, such as ozone. 3.5 Inhibition of microbial reproduction The U.S. Environmental Protection Agency regards KDF55 as a microbial inhibitor, indicating that the treatment medium can inhibit microbial reproduction, but it cannot completely kill microbial populations. KDF55 can control the growth and reproduction of microorganisms not through one mechanism, but through several mechanisms, and achieve the effect of inhibiting microorganisms through their individual or synergistic effects. The main mechanisms include: the change of redox potential, the formation of hydroxyl ions and hydrogen peroxide, and the dissolution of zinc in the medium. In general, when KDF55 treatment medium is used as pretreatment means of reverse osmosis membrane, it can inhibit the reproduction of bacteria, algae and other microorganisms, thus preventing microorganisms from damaging the membrane. 3.5. 1 change of redox potential When water passes through KDF55 to treat the medium, its redox potential changes from +200mV to -500 mV. Under normal circumstances, various types of microorganisms can only grow at a specific redox potential, and a large change in potential can destroy bacterial cells, thus controlling the growth of microorganisms. However, the redox potential of water changes little. To control bacteria with KDF, bacteria must be in direct contact with KDF. The inhibitory effect of KDF on bacteria mainly occurs at the KDF- water interface, so microorganisms cannot be completely controlled by the change of redox potential. 3.5.2 Hydroxyl ions and Hydrogen Peroxide When Notre Dame University of South Bend, Indiana, USA studied the reduction of iron ion concentration in water by KDF treatment medium, it was found that hydroxyl ions and hydrogen peroxide would be produced in the process of oxidizing divalent iron into trivalent iron by KDF, which could inhibit those microorganisms that can survive at low oxidation potential but are sensitive to hydroxyl ions and hydrogen peroxide, but the life span of hydroxyl ions and hydrogen peroxide is short, and they only have high reactivity during filtration. 3.5.3 Control of Zinc Ions on Microorganisms The zinc released in KDF treatment medium has obvious control effect on microorganisms, which can prevent the synthesis of enzymes, thus affecting the normal growth of organisms and achieving the purpose of inhibiting microbial reproduction. In addition, KDF55 medium controls the growth of algae by preventing chlorophyll synthesis. The existence of zinc ions essentially reduces the ability of organisms to produce food through photosynthesis. The food and energy sources of bacterial population depend on algae community, and the decrease of algae will significantly affect the growth of bacteria. 3.6 Removal of Heavy Metals KDF treatment medium can remove heavy metal ions in water, such as lead, mercury, copper, nickel, cadmium, arsenic, antimony, aluminum and other soluble heavy metal ions, and their removal is completed by electrochemical redox reaction and catalysis. The mechanism of removing heavy metal ions by KDF55 is that metal ions are plated on the surface of KDF treatment medium or enter KDF lattice to combine toxic heavy metal pollutants with KDF. For example, lead ions dissolved in water are reduced to insoluble lead atoms and plated on the surface of KDF medium; X-ray diffraction study shows that the removal of mercury forms a copper-mercury alloy. The chemical reaction formula of KDF for treating heavy metal ions is as follows: Zn/Cu/Zn+Pb (NO3) 2Zn/Cu/Pb+Zn (NO3) 2Zn/Cu/Zn+HGCL2Zn/Cu/Hg+ZnCl 2 metal ions can be hydrolyzed to form metal hydroxide precipitation when the pH value of water rises, and metal ions can also be removed. 3.7 Removal of Hydrogen Sulfide When membrane water treatment is used, if groundwater is selected as the water source, hydrogen sulfide may exist in the water. If hydrogen sulfide is oxidized to sulfur, it will pollute the membrane surface. KDF55 filter media has the function of removing hydrogen sulfide, and the generated copper sulfide is insoluble in water, so it can be removed by backwashing KDF55 media. The chemical reaction formula is as follows: Cu/Zn+H2SO4 Cu/Zn+CUS+H2SO4+O2SH2O. Usage and service life of KDF 55 4. 1 When using the backwashing device, a small amount of oxides will be formed in most water based on the electrochemical oxidation-reduction process, and the calcium/magnesium precipitates generated must be removed regularly. Choose a three-stage circulating recoil control valve produced by a well-known manufacturer, and adopt a large-flow recoil device, which can remove any dirt stuck on the surface of KDF, and the recoil speed should reach twice that of normal use. Backwashing time 10 minute, and then cleaning and rinsing for 3 minutes. Backwashing shall be carried out at least twice a week, and it may be increased appropriately if necessary, but the backwashing time shall not exceed 10 minute each time. Backwashing speed is affected by backwashing water temperature, medium type, medium particle size and density. The bulk density of KDF55 treatment medium is 17 1 pound/cubic foot (2.74g/cubic centimeter). In this way, the backwashing water flow rate of high-density medium needs 39gpm/ square foot (2.65cm/s) to reach twice the normal water flow rate. If the water temperature is low, a slightly lower recoil speed can be used. Water with slightly higher temperature recoils at a higher flow rate. If the backwashing water flow rate is less than 2 times of the normal flow rate due to the size limitation of pumps and pipelines, two KDF55 reaction beds should be used, and each bed should reach 1.5 times of the normal flow rate. By analogy, when there are enough KDF reaction beds, backwashing can also be completed with normal water flow speed. (Calculation omitted) Recommended operating conditions (using 3-stage circulating backwashing control valve) Normal water flow rate (10 "bed depth) 15gpm/ square foot (57 liters/minute) backwashing rate 10 minute: twice the normal water flow rate for purification/flushing for 3 minutes; Twice the normal water flow speed: 10 ~ 15% without substrate, 20% with minimum bed depth (6 "), 10ft pH range: 6.5~8.5 > 150ppm (mg/L)/min. Silica sand (SiO2) is undoubtedly the longest-lived filter medium, followed by KDF55. There are two situations that will reduce the service life of KDF55 processing media, and each situation takes a long time. Firstly, when the residual chlorine content in water is much greater than the dissolved amount of zinc, the municipal tap water with residual chlorine concentration of 0.55ppm will only produce 0.25ppm of zinc through KDF55, and the zinc content will not exceed the standard after removing the chlorine of 10ppm. The second is the physical degradation of KDF55, such as corrosion, friction or consumption, but the physical action has little effect on the service life of KDF55. According to conservative estimation, the service life of KDF55 treatment medium is 10 year. The main basis is as follows: * After six years of practical application, KDF 55 consumes 1/3 cubic feet of chlorine, and its service life can reach 25 years from the reduction amount of chlorine. * Accelerated experiments were carried out in the laboratory with water containing 10ppm chlorine, so that KDF55 culture medium was completely consumed, and the expected life of KDF could reach 26.5 years. * 1/3 cubic feet of KDF55 medium was treated with 2 million gallons of tap water containing 0.5~ 1.2ppm chlorine for two years, and its service life was calculated to be 23.4 years. * A family of five (each person consumes 50 gallons of water every day) uses 250 gallons of tap water every day, containing 0.5ppm of chlorine, and the theoretical life is calculated to be 24.4 years by using 1/3 cubic feet of KDF55 medium. 5. How to clean the contaminated KDF55 medium? The contaminated KDF55 medium can be washed with hydrochloric acid. Pay attention to the use of hydrochloric acid in well-ventilated places, and remember not to smoke and open flames, because the hydrogen produced during the treatment is explosive. Cleaning steps include: dissolving concentrated hydrochloric acid in water to prepare dilute acid solution, making the pH value not lower than 2.5, pouring the dilute acid solution into KDF medium bed until the dilute acid solution permeates the medium bed, and then continuing backwashing for about 20 minutes. When the pH value of outflow water is the same as that of inflow water, backwashing is carried out until clear water flows out. Our company strongly recommends the use of KDF55 cleaner produced by Quick Brite Company. Method of quickly cleaning KDF55 culture medium. Cleaner: 1) Drain the water from the water purifier; 2) Add enough Quick Brite and soak it in KDF medium (1 gallon Quick Brite can be cleaned 1/3 cubic feet KDF55); 3) soak for at least 10 minute; 4) stirring the solution and the medium; 5) soak for more than 5 minutes; 6) discharging the cleaning agent into the sewer; 7) backwashing with water, washing clean, and discharging the washing water into the sewer; 8) Repeatedly backwashing, rinsing and draining with fresh water until the fresh water flows out and the pH value reaches the instant value. 6.KDF55 medium medium-sized atomized high-purity copper-zinc alloy is golden in color and appearance. Particle mesh (American mesh) 10 ~ 100 mesh particle size range is 2.00~0. 145mm bulk density is 2.4 ~ 2.9 g/ cubic centimeter (17/kloc- 7. Pretreatment of high purity water with KDF55 treatment medium is a simple and low-consumption method. For microfiltration, ultrafiltration, reverse osmosis membrane, ion exchange resin and granular activated carbon, KDF medium can protect these expensive and fragile water treatment components from chlorine, microorganisms and scaling. In addition, KDF55 medium can remove up to 98% of heavy metals such as lead, cadmium, cerium, silver, argon, aluminum, selenium, copper and mercury. In addition, carbonate, nitrate and sulfate in water can be reduced by redox reaction in KDF medium. It is an indisputable fact that the main problem affecting the efficiency of membrane separation process is the deposition of various pollutants on the membrane surface, which causes the blockage of membrane surface pores. Compared with microfiltration, ultrafiltration, reverse osmosis membrane, ion exchange resin and granular activated carbon, KDF55 medium has more advantages in improving water treatment efficiency and maintaining high efficiency continuously, and its consumption is lower. 8. From kitchen faucet to industrial cooling water treatment, KDF media can be used in many aspects of water pretreatment and sewage treatment. Here are a few examples: 8. 1 domestic research results The feasibility study of reverse osmosis pretreatment system by Beigong Dalu proves (1) that the effect of removing residual chlorine is obvious under experimental conditions, and the effluent can completely meet the requirements of reverse osmosis pretreatment for residual chlorine content. Even at the filtration speed of 96m/min, the removal rate of residual chlorine is still above 99%, which is good for mold and yeast. In addition, it also has the function of delaying sterilization. (2) KDF has a certain removal effect on heavy metal ions. (3) KDF has a certain scale inhibition effect. 8.2 Application abroad (1) Removal of residual chlorine in municipal drinking water KDF treatment medium is increasingly used to replace or combine with activated carbon filter to remove residual chlorine in municipal tap water (up to 99%), and its main feature is long service life. Pretreatment with KDF medium can prolong the service life of granular activated carbon and protect the activated carbon filter layer (bed) from bacterial pollution. At the same time, KDF medium can remove heavy metals such as lead, with a removal rate of 98%. Heavy metal pollution has attracted more and more attention from health departments. (2) Protect the reverse osmosis membrane of the reverse osmosis device from chlorine corrosion. KDF medium can replace activated carbon to protect reverse osmosis device from chlorine and bacteria pollution. Activated carbon filter can also effectively remove residual chlorine, but because activated carbon will be saturated quickly in high chlorine water, the concentration of chlorine in water must be strictly controlled during operation, and activated carbon filter bed is easy to breed bacteria. KDF treatment medium has high chlorine removal rate and can inhibit microbial reproduction, so it can provide stable and long-term protection for reverse osmosis membrane. The reverse osmosis device with the laboratory capacity of 355L/d in the modern midwest outpatient department of the United States is equipped with KDF55 filter material pretreatment equipment, and the service life of the membrane is obviously prolonged. The report of the laboratory operation manager shows that the reverse osmosis membrane has been working for eight years, which has provided a large amount of reagent water for the American College of Pathology, and the effluent quality has been maintained at the first-class level. (3) Inhibit the reproduction of bacteria and algae in cooling water and reduce scaling. The water in cooling towers and water-cooled heat exchangers is often heated and exposed to the air, thus becoming an excellent breeding ground for bacteria and algae (for example, Legionella can be obtained from cooling towers). The traditional chemical method is to control the growth of algae and bacteria in the cooling tower by adding chemicals, which is expensive and the cost of subsequent sewage treatment is also high. The KDF treatment medium has low cost in treating cooling water, does not use chemicals harmful to the environment, and can effectively control the growth of algae and bacteria. In addition, the water treated by KDF medium can reduce the formation of hard scale. (4) KDF media in water purification system such as KDF treatment media can control the reproduction of bacteria and algae in granular activated carbon layer or activated carbon filter element. When activated carbon is used with KDF treatment medium, the ability of activated carbon to remove organic impurities and residual chlorine is enhanced. KDF treatment medium can also replace silver-impregnated activated carbon. Because silver is a toxic metal, activated carbon impregnated with silver must be registered with the US Environmental Protection Agency. KDF media does not need to register with the US Environmental Protection Agency as a toxic microbial inhibitor. KDF treatment medium realizes self-circulation through scrap metal recovery (recycling) system, and its cost is much lower than that of silver-impregnated activated carbon. (5) KDF medium can also effectively protect the expensive ion exchanger from chlorine and microbial pollution. Note: * KDF55 has obtained the health license of the Ministry of Health of China: the importing country is Weizi (1998) JS006 * The manufacturing company is KDF Fluid Treatment Co., Ltd. * US patents 4642192,512274; 5 135654。 Don Heskett, the patent inventor, currently has two main products: KDF55, which is an alloy of 50% copper and 50% zinc; KDF85, which is an alloy of 85% copper and 15% zinc. As a filter medium, KDF has many advantages: long service life; The filtration capacity can be restored to100%; Can remove residual chlorine in water; Can effectively control the growth of microorganisms; Prevent the accumulation of hard scale, etc.
Shanghai Niu Geng Water Treatment Equipment Co., Ltd. sells as an agent.