Water is
the common name applied to the liquid form (state) of the hydrogen and oxygen
compound H2O. Pure water is an odorless, tasteless, clear liquid. Water is one
of nature's most important gifts to mankind. Essential to life, a person's
survival depends on drinking water. Water is one of the most essential elements
to good health -- it is necessary for the digestion and absorption of food;
helps maintain proper muscle tone; supplies oxygen and nutrients to the cells;
rids the body of wastes; and serves as a natural air conditioning system.
Health officials emphasize the importance of drinking at least eight glasses of
clean water each and every day to maintain good health.
Since
water contains no calories and can serve as an appetite suppressant and helps
the body metabolize stored fat, it may possibly be one of the most significant
factors in losing weight. In his book, titled "The Snowbird Diet" Dr.
Donald Robertson says the body will not function properly without enough water
and discusses the importance of drinking plenty of water for permanent weight
loss: "Drinking enough water is the best treatment for fluid retention;
the overweight person needs more water than the thin one; water helps to
maintain proper muscle tone; water can help relieve constipation; drinking
water is essential to weight loss."
Water is
a key component in determining the quality of our lives. Today, people are
concerned about the quality of the water they drink. Although water covers more
than 70% of the Earth, only 1% of the Earth's water is available as a source of
drinking. Yet, our society continues to contaminate this precious resource.
Water is known as a natural solvent. Before it reaches the consumer's tap, it
comes into contact with many different substances, including organic and inorganic
matter, chemicals, and other contaminants. Many public water systems treat
water with chlorine to destroy disease-producing contaminants that may be
present in the water. Although disinfection is an important step in the
treatment of potable water, the taste and odor of chlorine is objectionable.
And, the disinfectants that are used to prevent disease can create byproducts
which may pose significant health risks. Today, drinking water treatment at the
point-of-use is no longer a luxury, it is a necessity! Consumers are taking
matters into their own hands and are now determining the quality of the water
they and their families will drink by installing a drinking water system that
will give them clean, refreshing, and healthier water.
Properties:
The freezing point of water is 0° C (32° F), and its boiling point is 100° C
(212° F). Water reaches its maximum density at 4° C (39° F) and expands upon
freezing. Water combines with salts to form hydrates and reacts with metal
oxides to form acids (see Acids and Bases).
Occurrence:
Water is the only substance that occurs at ordinary temperatures in all three
states of matter: solid, liquid, and gas. As a solid, ice, it forms glaciers,
frozen lakes and rivers, snow, hail, and frost. It is liquid as rain and dew,
and it covers three-quarters of the earth's surface in swamps, lakes, rivers,
and oceans. Water also occurs in the soil and beneath the earth's surface as a
vast groundwater reservoir. As gas, or water vapor, it occurs as fog, steam,
and clouds.
Water in
Life: Water makes up 50 to 90 percent of the weight of living things.
Protoplasm is a solution of water and fats, carbohydrates, proteins, and salts.
Water transports, combines, and chemically breaks down these substances. Water
also aids the metabolic breakdown of proteins and carbohydrates.
Natural
Water Cycle: The continuous movement of water between the earth and the
atmosphere is the hydrological cycle. Water vapor from water and land surfaces
and from living cells circulates through the atmosphere and falls as rain or
snow. When it reaches the earth, water either flows into streams and then into
oceans or lakes, or it enters, or infiltrates the soil. Some water becomes soil
moisture, which may evaporate directly or move up through the roots of plants
and be released by leaves. Some water percolates downward, accumulating in the
so-called zone of saturation to form the groundwater reservoir, the upper
surface of which is the water table. Under natural conditions, the water table
rises in response to inflowing water and then declines as water drains into
natural outlets such as wells and springs.
Composition:
Because water dissolves numerous substances in large amounts, pure water rarely
occurs in nature. Precipitation absorbs carbon dioxide and other gases, as well
as traces of organic and inorganic material from the atmosphere. Because water
reacts with minerals in the soil and rocks, surface and groundwater may contain
many different dissolved substances. Surface waters may also contain domestic
sewage and industrial wastes. Groundwater from shallow wells may contain
nitrogen compounds and chlorides, but water from deep wells generally contains
only dissolved minerals. Seawater contains many soluble compounds in addition
to salt.
Water
Purification: Impurities are removed from water by screening, sedimentation,
filtration, chlorination, or irradiation. See also Sewage Disposal. Aeration
saturates water with air, usually by spraying fountains of water into the air.
Aeration removes odors and tastes caused by decomposing organic matter,
industrial wastes, and some gases. Various salts and metals cause hardness in
water. Hardness may be removed by boiling, by adding sodium carbonate and lime,
or by filtering through natural or artificial zeolites.
Water
Desalinization: Three desalinization processes, which involve evaporating salt
water and then condensing the resulting steam, are known as multiple-effect
evaporation, vapor-compression distillation, and flash evaporation. Freezing is
another desalinization method, based on the different freezing points of fresh
and salt water. Ice crystals are separated from the salt brine, washed, and
melted into fresh water. In reverse osmosis, pressure forces fresh water
through a membrane that does not allow minerals to pass. In electrodialysis,
the positive and negative ions of the dissolved salt are removed from water by
an electric current through special membranes.
These
fine drinking water systems reduce a wide range of contaminants of health
concern for a low cost per gallon. The superior effectiveness of solid carbon
block systems is confirmed by testing and certification by NSF International;
independent laboratory tests; certification by the State of California
Department of Health Services; and more importantly, by the more than two
million satisfied customers throughout the world. The performance of the solid carbon block filter technology
exceeds that of all other filter types and meets only the highest standards for
quality.
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