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Chloramination is the treatment of drinking water with a chloramine disinfectant. [1] Both chlorine and small amounts of ammonia are added to the water one at a time which react together to form chloramine (also called combined chlorine), a long lasting disinfectant. Chloramine disinfection is used in both small and large water treatment plants.
In the United States, the maintenance of what is called a "residual" of disinfectant that stays in the water distribution system while it is delivered to people's homes is required by the Environmental Protection Agency (EPA).
The EPA regulations give two choices for disinfectant residual — chlorine or chloramine. Many major water agencies are changing to chloramine to better meet current and anticipated federal drinking water regulations and to protect the public health.
There are many similarities between chlorine and chloramine. Both provide effective residual disinfection with minimal risk to public health. Both are toxic to fish and amphibians. Both chlorine and chloramine react with other compounds in the water to form what are called "disinfection byproducts".
The difference is that chlorine forms many byproducts, including trihalomethanes (THM) and haloacetic acids (HAA), whereas chloramine forms a significantly lower amount of THMs and HAAs but also forms N-nitrosodimethylamine (NDMA). One of the principal benefits of chloramine is that its use reduces the overall levels of these regulated contaminants compared to chlorine.
Chloramine is toxic to fish and amphibians. Chloramine, like chlorine, comes in direct contact with their bloodstream through fish gills and must be removed from water added to aquariums and fish ponds. It must also be removed from water prior to use in dialysis machines, since water comes into direct contact with the bloodstream during treatment. Since the 1980s, most dialysis machines are built with filters to remove chloramines. [2]
Chloramine is generally considered a problem in brewing beer; like chlorine it can react with and change some of the natural plant flavors that make up the beer, and it may slow or alter the yeast. Because chloramine dissipates much more slowly than chlorine from water, beer-makers prefer carbon filtration and / or Campden tablets to neutralize it in the water. [3]
People have no trouble digesting chlorine or chloramine at the levels found in public drinking water; this water is not introduced directly into the human bloodstream. In the United States, the United States Environmental Protection Agency set minimum and maximum health-based safe levels for chloramine in drinking water. [4] Elsewhere, similar oversight agencies may set drinking water quality standards for chloramine.
Two home builders filed lawsuits against Moulton Niguel Water District in 2012, (in Orange County CA), arguing that pinhole leaks in copper water piping in their homes was due to faulty water treatment with chloramine. Pinhole leaks cause expensive damage to people's homes, and the builders claim that they must repipe houses at great expense to deal with the problem. Officials observed that only the two builders have filed suit, but as of late 2013 the number of lawsuits had expanded. [5] [6]
Nitrogenous disinfection by-products are liable to convert to nitrosamines by the action of chlorination and chloramination. Other NDBPs include halonitroalkanes, halonitriles, and haloamides. [7]
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Chloramines should be removed from water for dialysis, aquariums, hydroponic applications, and homebrewing beer.[ citation needed ]. Chloramine must be removed from water prior to use in kidney dialysis machines because it can cause hemolytic anemia if it enters the blood stream. [8] In hydroponic applications, chloramine stunts the growth of plants. [9]
When a chemical or biological process that changes the chemistry of chloramines is used, it falls under reductive dechlorination. Other techniques use physical—not chemical—methods for removing chloramines.[ citation needed ]
The use of ultraviolet light for chlorine or chloramine removal is an established technology that has been widely accepted in pharmaceutical, beverage, and dialysis applications. [10] UV is also used for disinfection at aquatic facilities. [11]
Ascorbic acid (vitamin C) and sodium ascorbate completely neutralize both chlorine and chloramine, but degrade in a day or two, which makes them usable only for short-term applications. SFPUC determined that 1000 mg of vitamin C tablets, crushed and mixed in with bath water, completely remove chloramine in a medium-size bathtub without significantly depressing pH. [12]
Activated carbon has been used for chloramine removal long before catalytic carbon, a form of activated carbon, became available[ citation needed ]; standard activated carbon requires a very long contact time, which means a large volume of carbon is needed. For thorough removal, up to four times the contact time of catalytic carbon may be required.[ citation needed ]
Most dialysis units now depend on granular activated carbon (GAC) filters, two of which should be placed in series so that chloramine breakthrough can be detected after the first one, before the second one fails. [13] Additionally, sodium metabisulfite injection may be used in certain circumstances. [14] [ full citation needed ]
Home brewers use reducing agents such as sodium metabisulfite or potassium metabisulfite (both proprietorially sold as Campden tablets) to remove chloramine from brewing fermented beverages. However, residual sulfite can cause off flavors in beer [15] so potassium metabisulfite is preferred.
Sodium thiosulfate is used to dechlorinate tapwater for aquariums or treat effluent from wastewater treatments prior to release into rivers[ citation needed ]. The reduction reaction is analogous to the iodine reduction reaction. Treatment of tapwater requires between 0.1 and 0.3 grams of pentahydrated (crystalline) sodium thiosulfate per 10 L of water[ citation needed ]. Many animals are sensitive to chloramine, and it must be removed from water given to many animals in zoos.[ citation needed ]
Chloramine, like chlorine, can be removed by boiling and aging. However, time required to remove chloramine is much longer than that of chlorine. The time required to remove half of the chloramine (half-life) from 10 US gallons (38 l; 8.3 imp gal) of water by boiling is 26.6 minutes, whereas the half-life of free chlorine in boiling 10 gallons of water is only 1.8 minutes. [16] Aging may take weeks to remove chloramines, whereas chlorine disappears in a few days. [17] [18]
Sodium hypochlorite, commonly known in a dilute solution as (chlorine) bleach, is an inorganic chemical compound with the formula NaOCl, comprising a sodium cation and a hypochlorite anion. It may also be viewed as the sodium salt of hypochlorous acid. The anhydrous compound is unstable and may decompose explosively. It can be crystallized as a pentahydrate NaOCl·5H
2O, a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated.
Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water that is fit for specific purposes. Most water is purified and disinfected for human consumption, but water purification may also be carried out for a variety of other purposes, including medical, pharmacological, chemical, and industrial applications. The history of water purification includes a wide variety of methods. The methods used include physical processes such as filtration, sedimentation, and distillation; biological processes such as slow sand filters or biologically active carbon; chemical processes such as flocculation and chlorination; and the use of electromagnetic radiation such as ultraviolet light.
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, including being safely returned to the environment. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use. This treatment is crucial to human health and allows humans to benefit from both drinking and irrigation use.
Chlorine dioxide is a chemical compound with the formula ClO2 that exists as yellowish-green gas above 11 °C, a reddish-brown liquid between 11 °C and −59 °C, and as bright orange crystals below −59 °C. It is usually handled as an aqueous solution. It is also commonly used as a bleach. More recent developments have extended its applications in food processing and as a disinfectant.
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life. Disinfectants are generally distinguished from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocides—the latter are intended to destroy all forms of life, not just microorganisms. Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism. It is also a form of decontamination, and can be defined as the process whereby physical or chemical methods are used to reduce the amount of pathogenic microorganisms on a surface.
Campden tablets are a sulphur-based product that is used primarily to sterilize wine, cider and in beer making to kill bacteria and to inhibit the growth of most wild yeast: this product is also used to eliminate both free chlorine and the more stable form, chloramine, from water solutions. Campden tablets allow the amateur brewer to easily measure small quantities of sodium metabisulfite, so it can be used to protect against wild yeast and bacteria without affecting flavour. Untreated cider must frequently suffers from acetobacter contamination causing vinegar spoilage. Yeasts are resistant to the tablets but the acetobacter are easily killed off, hence treatment is important in cider production.
Total organic carbon (TOC) is an analytical parameter representing the concentration of organic carbon in a sample. TOC determinations are made in a variety of application areas. For example, TOC may be used as a non-specific indicator of water quality, or TOC of source rock may be used as one factor in evaluating a petroleum play. For marine surface sediments average TOC content is 0.5% in the deep ocean, and 2% along the eastern margins.
Monochloramine, often called chloramine, is the chemical compound with the formula NH2Cl. Together with dichloramine (NHCl2) and nitrogen trichloride (NCl3), it is one of the three chloramines of ammonia. It is a colorless liquid at its melting point of −66 °C (−87 °F), but it is usually handled as a dilute aqueous solution, in which form it is sometimes used as a disinfectant. Chloramine is too unstable to have its boiling point measured.
Portable water purification devices are self-contained, easily transported units used to purify water from untreated sources for drinking purposes. Their main function is to eliminate pathogens, and often also of suspended solids and some unpalatable or toxic compounds.
Electrolysed water is produced by the electrolysis of ordinary tap water containing dissolved sodium chloride. The electrolysis of such salt solutions produces a solution of hypochlorous acid and sodium hydroxide. The resulting water can be used as a disinfectant.
Swimming pool sanitation is the process of ensuring healthy conditions in swimming pools. Proper sanitation is needed to maintain the visual clarity of water and to prevent the transmission of infectious waterborne diseases.
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically to a dilute solution of sodium hypochlorite, also called "liquid bleach".
Disinfection by-products (DBPs) result from chemical reactions between organic and inorganic matter in water with chemical treatment agents during the water disinfection process.
Drinking water quality in the United States is generally safe. In 2016, over 90 percent of the nation's community water systems were in compliance with all published U.S. Environmental Protection Agency (EPA) standards. Over 286 million Americans get their tap water from a community water system. Eight percent of the community water systems—large municipal water systems—provide water to 82 percent of the US population.
CT Values are an important part of calculating disinfectant dosage for the chlorination of drinking water. A CT value is the product of the concentration of a disinfectant and the contact time with the water being disinfected. It is typically expressed in units of mg-min/L.
Michael John McGuire is an American environmental engineer and writer whose career has focused on drinking water quality improvement. He has been recognized for his expertise in the control of trace organic and inorganic contaminants and microbial pathogens in water. He is also known for his work in the identification, control and treatment of taste and odor problems in drinking water. He has published numerous articles in professional journals and he has been the co-editor of five books and compilations of articles. He published a book that documented the first continuous disinfection of a drinking water supply in the U.S. With Marie S. Pearthree, he wrote a book on the corrosive water debacle in Tucson, Arizona in 1992–94. He has been active in the American Water Works Association, and he has served as a volunteer and officer in that organization. In 2009, he was elected to the National Academy of Engineering.
Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. This method is used to kill bacteria, viruses and other microbes in water. In particular, chlorination is used to prevent the spread of waterborne diseases such as cholera, dysentery, and typhoid.
Mixed oxidant solution is a type of disinfectant which is used for disinfecting, sterilization and eliminating pathogenic microorganisms in water and in many other applications. Using a mixed oxidant solution for water disinfection, compared to other methods, may have various benefits such as higher disinfecting power, stable residual chlorine in water, improved taste and smell, elimination of biofilm, and safety. A mixed-oxidant solution is produced by electrolysis of sodium chloride and is a mixture of disinfecting compounds. The main component of this product is chlorine and its derivatives (ClO−, HClO and Cl2 solution). It may also contain high amounts of chlorine dioxide solution, dissolved ozone, hydrogen peroxide, and oxygen, from which the name "mixed oxidant" is derived.
Chlorine-releasing compounds, also known as chlorine base compounds, is jargon to describe certain chlorine-containing substances that are used as disinfectants and bleaches. They include the following chemicals: sodium hypochlorite, chloramine, halazone, and sodium dichloroisocyanurate. They are widely used to disinfect water and medical equipment, and surface areas as well as bleaching materials such as cloth. The presence of organic matter can make them less effective as disinfectants. They come as a liquid solution, or as a powder that is mixed with water before use.
Stuart William Krasner, was the Principal Environmental Specialist (retired) with the Metropolitan Water District of Southern California, at the Water Quality Laboratory located in La Verne, California. In his 41 years with Metropolitan, he made revolutionary changes in the field's understanding of how disinfection by-products occur, are formed and how they can be controlled in drinking water. His research contributions include the study of emerging DBPs including those associated with chlorine, chloramines, ozone, chlorine dioxide and bromide/iodide-containing waters. He made groundbreaking advances in understanding the watershed sources of pharmaceuticals and personal care products (PPCPs) and wastewater impacts on drinking-water supplies. For DBPs and PPCPs, he developed analytical methods and occurrence data and he provided technical expertise for the development of regulations for these drinking water contaminants. In the early 1990s, Krasner developed the 3x3 matrix illustrating removal of total organic carbon from drinking water as a function of water alkalinity and initial total organic carbon concentration. The matrix was revised by him and included in the USEPA Stage 1 D/DBP regulation as the enhanced coagulation requirement. Every water utility in the U.S. that is subject to this regulation is required to meet total organic carbon removal requirements along with their exceptions.
{{cite web}}: CS1 maint: archived copy as title (link)Water that contains chloramine is safe for people to drink, bathe, and cook in because the digestive process neutralizes it. Chloramine can, however, easily harm patients if it enters the blood stream during the dialysis process causing hemolytic anemia.