Water pollution

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WATER “the sleeping tiger of the world’s environmental problems”

Percentage of earth’s water storage

Oceans 97.6 %Ice & Snow 2.07 %Ground water (1km) 0.28 %Lakes & reservoirs 0.009 %Saline lakes 0.007 %Soil moisture 0.005 %Atmosphere 0.001 %Swamps & Marshes 0.003 %Rivers & Streams 0.0001 %

For about 80 countries with 40% of the world’s population lack of water is a constant threat.

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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.

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 blue-green 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, withapproximately 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