Water home treatment

Home Water Treatment Using Activated Carbon - Discussion and guidelines from a 1997 article from the Michigan State University Extension, http //www. msue. msu. edu/msue/imp/modwq/w. 

In addition to faucet units for water treatment, activated carbon filters are used with water jugs and in portable water treatment systems for use in remote areas. Of the home water treatment units, there are point-of-entry units that are placed in line and treat water supplies to whole households and commercial buildings. Both point-of-use and point-of-entry filters often contain a combination of activated carbon for the removal of organics and Cryptosporidium and ion exchange resins for the removal of metals and inorganic compounds. 

In spite of all the efforts taken to purify public water supplies, many consumers are concerned about the quahty of the water that comes out of the taps in their homes, schools, and places of business. Parents of small children are especially worried about chemicals such as lead and carcinogenic organic compounds that are chlorine disinfection by-products. Many have turned to bottled water or home water treatment devices. 

The FDA regulates the quality of bottled water. The water passes through one or more purification steps (Figure 11.12). The three purification methods (which can also be done in home treatment systems)—distillation, carbon filtration, and reverse osmosis— have already been discussed as methods used for treating municipal water. The maximum levels of contaminants allowed by the EPA after these treatments are listed in Table 11.10. Each of these methods is expensive and results in a high cost per gallon of treated water. In the case of bottled water or home water treatment, the cost of treatment is not the major factor, because only the small amount of water needed for human consumption needs to be specially purified. Figure 11.12 shows... 

A number of companies offer home water treatment to improve the quality of tap water. You may wonder if home water treatment is necessary. Is your tap water safe to drink If you receive your drinking water from a public water provider, the EPA believes that home treatment for the protection of health is not necessary. According to the EPA, you may want to treat your water for other reasons— such as hardness, poor clarity, or undesirable taste-but the EPA maintains that unless you get a notice from your water provider stating otherwise, the water from your tap is safe to drink over a lifetime. 

A number of groups, however, disagree with the EPA on this point. They argue that home water treatment will at least give you clearer, better-tasting water and may remove unhealthful compounds overlooked by your local water provider. 

Perhaps the most common home water treatment is water softening. Several companies will install these units in your home and maintain them on a regular... 

Is home water treatment necessary for health reasons Why would it be desirable ... 

Explain how each of the following home water treatments works and what impurities are eliminated a. carbon filtration... 

Of the water treatment teehnologies diseussed in this ehapter, whieh ones eould be applied eeonomieally to small seale applieations like home use ... 

Other suggestions on distributed processing reach beyond the capabilities of today s micro reactors, and hence are of more visionary character [5]. These include desktop pharmacies, home-recycle factories, mobile factories, house-water treatment plants, processing cereal crops at the combine, purification of blood in the body, recycling of plastics in the collection vehicle and more [5]. 

At NSF, a great deal of work is done on the development and implementation of NSF standards and criteria for health-related equipment. The majority of NSF standards relate to water treatment and purification equipment, products for swimming pool applications, plastic pipe for potable water as well as drain, waste, and vent (DWV) uses, plumbing components for mobil homes and recreational vehicles, laboratory furniture, hospital cabinets, polyethylene refuse bags and containers, aerobic waste treatment plants, and other products related to environmental quality. 

Water softening is the most important application for ion exchange. In the operation, sodium ions in the resins exchange with calcium, magnesium, and other polyvalent cations in the water. As a result, hardness (calcium and magnesium) is significantly reduced. The process scale can be small, such as home use and laboratory use, or large, such as water treatment plant use. 

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Union Carbide on October 31, 1984 announced a significant, unprecedented program to provide activated carbon filters for home-owners whose wells are contaminated with aldicarb above the recommended action level. This is the first time in California that a pesticide manufacturer has provided water treatment systems to clean up private domestic well water contaminated by their product. It should provide added incentive for other manufacturers to thoroughly... 

Chlorination of phenol is an example of electrophilic aromatic substitution phenol is so much more reactive than, let us say, benzene that no Lewis acid catalyst is required, and the reaction takes place rapidly even in aqueous solution. The odor-causing 2-, 2,4-, and 2,6-chlorinated phenols are among the by-products because phenol is chlorinated preferentially in the ortho- and para-positions. In cases where phenols are present in the water supply, the options are to use other disinfectants than chlorine, or to remove the contaminants by the use of activated charcoal as a water filter either in water treatment plant or in home ontlets (see below). 

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