Water pollution
WATER “the sleeping tiger of the world’s environmental
problems”
Percentage of earth’s water storage
Oceans
Ice & Snow
Ground water (1km)
Lakes & reservoirs
Saline lakes
Soil moisture
Atmosphere
Swamps & Marshes
Rivers & Streams
97.6 %
2.07 %
0.28 %
0.009 %
0.007 %
0.005 %
0.001 %
0.003 %
0.0001 %
For about 80 countries with 40% of the world’s population lack
of water is a constant threat.
2
POLLUTION accelerates the problem of water deficit.
In developing countries 95% of the sewage is left untreated
into rivers etc.
200 million liters of sewage drain into the river Yamuna every
year.
Yamuna
- coliform bacteria 7500 / 100 ml
24 million/100ml
TAMILNADU 39,200 tanks - > 50% not in use.
3
Eutrophication
• It is a form of water pollution and like all
other forms of pollution is the result of
human activities influencing ecological cycles.
Oligotrophic Aquatic Ecosystems
• A clear water stream or deep
blue lake contains enough
bacteria to decompose organic
material from organisms that
die.
• Water is neither acidic or basic.
• Inorganic nutrients are present
in low concentrations.
• Ammonia produced by animals
and bacteria is taken up and
used for plant growth.
• Eutrophication is a process whereby water
bodies, such as lakes, or slow-moving streams
receive excess nutrients that stimulate excessive
plant growth -(algae, and nuisance plants
weeds).
• Nutrients can come from many sources, such as
fertilizers ,sewage treatment plant discharges.
• This enhanced plant growth, reduces dissolved
oxygen in the water when dead plant material
decomposes and can cause other organisms to
die.
• Rapid growth of algae and other
biomass resulting in a decrease in the
concentration of dissolved oxygen.
• Turbidity (cloudiness) of water increases
as does rate of sedimentation.
Nutrients Stimulate Algal Blooms
• Nitrogen and
phosphorus from
runoff and effluents
or decay of organic
matter stimulates
aquatic plant growth.
• In particular, algal
“blooms” give the
water a green or bluegreen color.
NOXIOUS GASES LIKE AMMONIA & HYDROGEN
SULPHIDE ARE GIVEN OUT
Effects on water quality- Oxygen
depletion:
• penetration of light into the water is
diminished -the algae forms mats as a
result of being produced faster than
they are consumed.
• Diminished light penetration decreases
the productivity of plants living in the
deeper waters and hence their
production of oxygen.
Low Oxygen Levels Cause Die-off
• Rapidly growing
bacterial populations
need exponentially
increasing amounts
of oxygen.
• Once dissolved
oxygen levels
become too low, fish
and many freshwater
invertebrates die,
thus adding more
organic matter.
Plants Die, Bacteria Grow, Deplete
Oxygen, Fish Die
1. Plants exhaust
nutrients and die.
2. Bacteria thrive on
organic decay of
plants and lower
dissolved oxygen.
3. Fish and invertebrates
die when oxygen gets
too low.
• As the water becomes depleted in oxygen,
the abundant algae and fish die and
decompose, further oxygen is consumed by
this process
• Bad taste and odor : some of the algal species
that "bloom" produce toxins), water taste
and odor deteriorates.
MINING
• The first step in mining is to locate a
subterranean ore deposit and bring it to the
surface.
• it’s cheaper to do this by blasting away the soil
and surface rock, called“overburden,” rather
than by digging underground shafts.
• open-pit mines destroys the surrounding
landscape and open up vast craters.
• The world’s largest open pit, the Bingham
Canyon mine in Utah, measures 1.5 kilometers
(1 mile) deep and 4 kilometers (2.5 miles) wide.
• Open-pit mines produce 8 to 10 times as
much waste rubble as underground mines.
This rubble is generally piled into enormous
mounds, some of them reaching heights of
100 meters
• 97 percent of all metals are now mined in
open pits.
• Gold and silver are among the most wasteful
metals, with more than 99 percent of ore
extracted ending up as waste.
By contrast, iron mining is less wasteful, with
approximately 60 percent of the ore extracted
processed as waste (Da Rosa, 1997;
Sampat, 2003).
Quick facts about gold mining:
• A single gold ring leaves in its wake at least 20 tons of
mine waste
• Open-pit gold mines damage the landscape - vast craters,
flattening or even inverting mountaintops, and producing
8 to 10 times more waste than underground mining.
• Cyanide is used by large mining operations to separate
gold from ore. Cyanide pollution is a major concern. A
rice-grain sized dose of cyanide can be fatal to humans;
concentrations of 1 microgram (one-millionth of a gram)
per liter of water can be fatal to fish.
MINE WASTES
e-waste
• Electronic waste, e-scrap, or waste electrical and
electronic equipment (WEEE) describes
discarded electrical or electronic devices
• E-waste” refers to any unwanted electronic
device electronic devices or Cathode Ray Tube
(CRT) and is classified as universal waste.
• E-waste frequently contains hazardous
materials predominantly lead and mercury
• Cathode Ray tubes (CRTs) are considered one of
the hardest types to recycle- high concentration
of lead
• An estimated 50 million tons of E-waste are
produced each year.
• The USA discards 30 million computers each
year and 100 million phones are disposed of
in Europe each year.
• The Environmental Protection Agency
estimates that only 15-20% of e-waste is
recycled, the rest of these electronics go
directly into landfills and incinerators