POLLUTION AND WATER CONTAMINATION
Is
Water Pollution And Water Contamination The Same Thing?
You may think of pollution and
contamination as being the same thing. Perhaps in a general term,
they are.
But
when it comes to specifically talking about your water, the two, and their
causes are very different.
WATER POLLUTION
Pollution is due to the influence or activities of
people, where contamination may be natural.
There
are many specific causes of water pollution, but before we list the toppers,
it's important to understand two broad categories of water pollution:
- “Point source” — occurs when harmfulsubstances are emitted directly into a body of water.
- “Nonpoint source” — delivers pollutants
indirectly through transport or environmental change.
An
example of a point source of water pollution is a pipe from an industrial
facility discharging effluent directly into a river.
An
example of a nonpoint-source of water pollution is when fertilizer from a farm
field is carried into a stream by rain (i.e. run-off).
Point-source
pollution is usually monitored and regulated, at least in Western countries,
though political factors may complicate how successful efforts are at true
pollution control.
Nonpoint
sources are much more difficult to monitor and control, and today they account
for the majority of contaminants in streams and lakes.
There
are many sources of water pollution; some being oil spills, pesticides and
herbicidal usage and clear-cutting of forestry.
But by
and large, an annual offender is clearly industrial chemical pollution. Almost
all bodies of water in the world have some level of pollution from chemicals
and industrial waste.
In the
United States, 34 billion liters per year (60%) of the most hazardous liquid
waste—solvents, heavy metals, and radioactive materials—is injected directly
into deep groundwater via thousands of "injection wells."
Although
the EPA requires that these effluents be injected below the deepest source of
drinking water, some pollutants have already entered underground water supplies
in Florida, Texas, Ohio, and Oklahoma.
The US
is not alone in careless treatment of its groundwater.
In the
late 1990s, India's Central Pollution Control Board found that groundwater was
unfit for drinking in all 22 major industrial zones it surveyed.
WATER CONTAMINATION
On the other hand, water contamination is often used to
refer to impurities in water regardless of the source or events that led to the
impurities being in the water.
TOTAL DISSOLVED SOLIDS (TDS)
A common impurity or contamination in water is its TDS
count.
TotalDissolved Solids (TDS) consist mainly of carbonates, dissolved bicarbonates,
chlorides, sulfates, phosphates, nitrates, calcium, magnesium, sodium,
potassium, iron, manganese, and a few others.
They
do not include gases, colloids, or sediment.
The
TDS can be estimated by measuring the specific conductance of the water.
Dissolved solids in natural waters range from less than 10 mg/l for rain to
more than 100,000 mg/l for brines.
Since
TDS is the sum of all materials dissolved in the water, it has many different
mineral sources.
TURBIDITY
Turbidity is often a contaminant or impurity of waters.
Turbidity
is the term given to anything that is suspended in a water supply. It is found
in most surface waters, but usually does not exist in ground waters except in
shallow wells and springs after heavy rains.
Turbidity
gives the water a cloudy appearance or shows up as dirty sediment.
Undissolved
materials such as sand, clay, silt or suspended iron contribute to turbidity.
Turbidity
can cause the staining of sinks and fixtures as well as the discoloring of
fabrics.
Usually
turbidity is measured in NTUs (nephelometric turbidity units).
Typical
drinking water will have a turbidity level of 0 to 1 NTU.
Turbidity
can also be measured in ppm (parts per million) and it's size is measured in
microns.
Turbidity
can be particles in the water consisting of finely divided solids, larger than
molecules, but not visible by the naked eye; ranging in size from .001 to .150
mm (1 to 150 microns).
The US
EPA has established an MCL for turbidity to be 0.5 to 1.0 NTU, because it
interferes with disinfection of the water.
The
treatment for turbidity can be reduced to 75 microns with a cyclone separator,
then reduced down to 20 micron with standard backwashable filter, however flow
rates of 5 gpm/ sq. ft. are recommended maximum.
Turbidity
can be reduced to 10 micron with a multimedia filter while providing flow rates
of 15 gpm/sq. ft.
Cartridge
filters of various sizes are also available down into the submicron range.
Ultrafiltration
also reduces the turbidity levels of process water.
By and
large it is the man-made pollutions of waters that get the most attention, and
perhaps rightfully so.
But
what is also important is the overall contamination, or natural quality of water
that will help determine the treatments necessary to make a water safe for
public consumption.
RELATED POSTS:
.
CLICK HERE . . .
.
. .
.CLICK
HERE . . .
.
.
Freshwater
Ecosystems
.
CLICK
HERE . . .
.
.
GS Series Submersible Pump |
No comments:
Post a Comment