LaMotte Water & Soil pH - Manual (Page 2)

WHAT IS WA TER?
Water, a substance which covers approximately 75% of the Earth’s surface,
exists in three forms: solid, liquid and gas. In the solid form, ice, water is
used to cool drinks and other solutions, while the gas form, steam, can be
used to power turbines and engines. As a liquid, water is used in many
ways, from drinking to agriculture to providing homes for many kinds of
aquatic life.
Known as the universal solvent, “pure” water is able to combine with
other substances to form solutions. Even “natural” water found in the
environment contains dissolved gases, such as oxygen and carbon dioxide,
and dissolved minerals, such as iron and calcium. Most of these substances
are not harmful at the levels commonly found, but some substances are
toxic, or poisonous, to living things. Tests are available to determine levels
of many toxic and nontoxic substances in water.
If dangerous or unhealthy substances are discovered, the water can be
treated to remove or destroy them. Treatment is not necessary in many
industries, such as agriculture, but others require water be purified before
use. For instance, many drinking water systems treat the water with
chlorine to disinfect and kill bacteria, making it safe for consumption.
Other industrial processes add dangerous chemicals or bacteria to the
water, which must be removed or rendered harmless before returning it to
the environment.
As the human population increases concern over the availability of usable
water increases as well. Polluted water will purify itself naturally over time,
but as more and more untreated, polluted water is returned to the
environment the system is overloaded and unable to cope. Water
treatment processes, either chemical, biological or filtration, may be used
to supplement the natural purification process.
To determine the efficiency of treatment, and levels of toxic and nontoxic
substances, the water must be frequently tested. When establishing a
testing program it is important to take samples over a period of time
because the character of the water constantly changes. By taking several
samples, determining their composition and keeping accurate records,
scientists are better able to understand water.
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