power plant had produced no major short—term detrimentàl effects, but that
its long-term ecological effects could not be predicted [24];
Water Is Not Pure in Nature
Approximately half of the known chemical elements have been found dis—
solved in natural water [25]. A clean running stream, even in its unpolluted
state, contains a complex mixture of organic and inorganic substances. In fact,
living things could not survive in pure, distilled water.
Salinity. Although water is essenüally pure when it is evaporated, many
substances become associated With it-as it travels through the atmosphere,
and when water returns «to the earth as rain it contains a number of salts, most
of them in trace amounts. .As these salts
dissolved in water they separate
into electrically—charged particles called ions. These ions include'chlorides,
bromides, iodides, sulfates, phosphate,bicæbonaæ,sodium, calcium, magne—
sium, potassium, and nitrates [26]. Salts and minerals are dissolved in water
when precipitation reaches the earth’s surface and water ows oVer rocks and
through the soil. Every body Of water ows oVer rocks and through the soil.
‘. Every. body of water has a someWhat different “chemical composiüonFSin“ce
each comes into contact with different3g€ologicalformaüons.
J
«.
…
Fresh water is “hard” when it contains i0ns
with soap, making the soap ineffective as a cleans‘et.a Calcium andmagnesium
are the main components responsible for the hardnêss
«
barium, zinc, stronüum, iron, manganese, and other ions that
ness are usually found in small quantities under" natural conditions.
-
-
‘
«
_
Bicarbonate is the: most abundant ion found in U.S…streams, mairy-be—
cause of the solubity of lünestone«(calcium carbonate). and the action on
limestone of the carbonic acid in water, Which we Will discuss later. Sulfates,
calcium, sodium, and chlorides are-found in lessèr amounts. In general, fresh
water is about due—tenth of one percent salt solution, while sea water is 3.5
percent salts by weight, with sodium and chloride ions most abundant. Cal—
cium carbonate in the
been incorporated into animal structures,
such as the shells of marine anirals, -and is found in sediment rather than dis—
solved in the water.
Since plants and animals have become adapted through the course of evo—
.
lution to thexmixüne of substances found in their environment, a change in
the concentrations Of
in water can have serious effects.
While ÿmany Chemicals are necessary
normal cell function, certain chem—.
_
in large quanties. Moreover, an increase or decrease in total
salinitÿ,èrègârdleæ
salt present, can also upset cellular function.
,
'
'
Thus,freshwater
developed inechanisms for
external
salts than their internal environ'ments; mai—.
r1neorgamsms,ontheotherhand,
adapted to life in eriviron‘merits that
contain higher
of salts than their bodilÿ- uids
.
.
that
of change in salinity are
W…PN49
its long-term ecological effects could not be predicted [24];
Water Is Not Pure in Nature
Approximately half of the known chemical elements have been found dis—
solved in natural water [25]. A clean running stream, even in its unpolluted
state, contains a complex mixture of organic and inorganic substances. In fact,
living things could not survive in pure, distilled water.
Salinity. Although water is essenüally pure when it is evaporated, many
substances become associated With it-as it travels through the atmosphere,
and when water returns «to the earth as rain it contains a number of salts, most
of them in trace amounts. .As these salts
dissolved in water they separate
into electrically—charged particles called ions. These ions include'chlorides,
bromides, iodides, sulfates, phosphate,bicæbonaæ,sodium, calcium, magne—
sium, potassium, and nitrates [26]. Salts and minerals are dissolved in water
when precipitation reaches the earth’s surface and water ows oVer rocks and
through the soil. Every body Of water ows oVer rocks and through the soil.
‘. Every. body of water has a someWhat different “chemical composiüonFSin“ce
each comes into contact with different3g€ologicalformaüons.
J
«.
…
Fresh water is “hard” when it contains i0ns
with soap, making the soap ineffective as a cleans‘et.a Calcium andmagnesium
are the main components responsible for the hardnêss
«
barium, zinc, stronüum, iron, manganese, and other ions that
ness are usually found in small quantities under" natural conditions.
-
-
‘
«
_
Bicarbonate is the: most abundant ion found in U.S…streams, mairy-be—
cause of the solubity of lünestone«(calcium carbonate). and the action on
limestone of the carbonic acid in water, Which we Will discuss later. Sulfates,
calcium, sodium, and chlorides are-found in lessèr amounts. In general, fresh
water is about due—tenth of one percent salt solution, while sea water is 3.5
percent salts by weight, with sodium and chloride ions most abundant. Cal—
cium carbonate in the
been incorporated into animal structures,
such as the shells of marine anirals, -and is found in sediment rather than dis—
solved in the water.
Since plants and animals have become adapted through the course of evo—
.
lution to thexmixüne of substances found in their environment, a change in
the concentrations Of
in water can have serious effects.
While ÿmany Chemicals are necessary
normal cell function, certain chem—.
_
in large quanties. Moreover, an increase or decrease in total
salinitÿ,èrègârdleæ
salt present, can also upset cellular function.
,
'
'
Thus,freshwater
developed inechanisms for
external
salts than their internal environ'ments; mai—.
r1neorgamsms,ontheotherhand,
adapted to life in eriviron‘merits that
contain higher
of salts than their bodilÿ- uids
.
.
that
of change in salinity are
W…PN49