chem ppt riddhi
TRANSCRIPT
WATER POLLUTION
A PRESENTATION BY:-RIDDHIKA PRAJAPATI
EE-B(1),2 SEM,MAIIT
(water is a excellent wealth awarded by god save it !!!)
Indroduction
Water pollution occurs when harmful substances are released into the water in large quantities which cause damage to people, wildlife, or habitat or indirectly into water bodies without proper treatment to remove harmful compounds.
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Industry- Waterpollution
What is water pollution?
Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired usage.
India’s Ganges RiverHoly River (1 million
take daily holy dip)350 million (1/3rd of pop)
live in watershedLittle sewage treatmentUsed for bathing,
drinking etc.Bodies (cremated or
not) thrown in riverGood news is the Indian
government is beginning to work on problem
Case Study: India’s Ganges River: Religion, Poverty, and HealthReligious beliefs, cultural traditions, poverty, and a large
population interact to cause severe pollution of the Ganges River in India.Very little of the sewage is treated.Hindu believe in cremating the dead to free the soul and
throwing the ashes in the holy Ganges.Some are too poor to afford the wood to fully cremate.Decomposing bodies promote disease and depletes DO.
Daily, more than 1 million Hindus in India bathe, drink from, or carry out religious ceremonies in the highly polluted Ganges River.
Case Study: India’s Ganges River: Religion, Poverty, and Health
Pathogens are another type of pollution that prove very harmful. They can cause many illnesses that range from typhoid and dysentery to minor respiratory and skin diseases. Pathogens include such organisms as bacteria, viruses, and protozoan. These pollutants enter waterways through untreated sewage, storm drains, septic tanks, runoff from farms, and particularly boats that dump sewage.
OCEAN POLLUTIONOceans can disperse and
break down large quantities of degradable pollution if they are not overloaded.
Pollution worst near heavily populated coastal zones
Wetlands, estuaries, coral reefs, mangrove swamps
40% of world’s pop. Live within 62 miles of coast
OCEAN POLLUTION Large amounts of
untreated raw sewage (viruses)
Leaking septic tanks Runoff Algae blooms from
nutrients Dead zones NO DO Airborne toxins Oil spills
Ground Water Pollution Interactions
between groundwater and surface water are complex. Consequently, groundwater pollution is not as easily classified as surface water pollution.
Effects of water pollution Water pollution is a major
problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily.
An estimated 700 million Indians have no access to a proper toilet,
and 1,000 Indian children die of diarrhea sickness every day.
Some 90% of China's cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water.
PURIFICATION OF WATER Purification of water
involves physical, biological and chemical processes such as:-
1.Filtration2.Sedimentation3.Chlorination4.Slow sand filters5.Activated Sludge6.Flocculation
Physical processes
Filtration is a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass.
Sedimentation is the tendency for particles in suspension or molecules in solution to settle out of the fluid in which they are entrained, and come to rest against a wall.
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water. Water which has been treated with chlorine is effective in preventing the spread of water born disease.
Biological processes
Slow sand filters are used in water purification for treating raw water to produce a potable product. They are typically 1 to 2 metres deep, can be rectangular or cylindrical in cross section and are used primarily to treat surface water.
Activated sludge is a process dealing with the treatment of sewage and industrial wastewaters and developed around 1912-1914.Atmospheric air or pure oxygen is introduced to a mixture of primary treated or screened sewage (or industrial wastewater) combined with organisms to develop a biological floc which reduces the organic content of the sewage.
Chemical processFlocculation is, in the field of
chemistry, a process where colloids come out of suspension in the form of floc or flakes. The action differs from precipitation in that, prior to flocculation, colloids are merely suspended in a liquid and not actually dissolved in a solution.
Stopping the cycle
There are ways to interrupt the natural water cycle and prevent pollution
In some places simply filtering water before allowing it to continue its natural flow may be sufficient .A natural and beautiful method of doing this is
being used in many places. They are called rain gardens. They are specifically designed
with plants that will absorb water that otherwise would have runoff into waterways. This measure also stops contaminants that
may have been washed into those waterways.
Water cycle
Chemical & other contaminants
Inorganic water pollutants include:- Acidity caused by industrial discharges
(especially sulphur dioxide from power plants) Ammonia from food processing waste Chemical waste as industrial by-products Fertilizers containing nutrients--nitrates and
phosphates--which are found in storm water run off from agriculture, as well as commercial and residential use
Fig. 21-10, p. 505
Healthy zoneClear, oxygen-richwaters promote growthof plankton and sea grasses,and support fish.
Oxygen-depleted zoneSedimentation and algaeovergrowth reduce sunlight,kill beneficial sea grasses, useup oxygen, and degrade habitat.
Red tidesExcess nitrogen causesexplosive growth of toxicmicroscopic algae,poisoning fish andmarine mammals.
FarmsRunoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus.
Toxic sedimentsChemicals and toxic metals contaminate shellfish beds, kill spawning fish, andaccumulate in the tissues of bottom feeders.
Construction sitesSediments are washed intowaterways, choking fish and plants, clouding waters, and blocking sunlight.
Urban sprawlBacteria and viruses fromsewers and septic tanks contaminate shellfish beds
Oxygen-depletedzone
Closedbeach
CitiesToxic metals and oil from streets and parking lots pollute waters;
IndustryNitrogen oxidesfrom autos andsmokestacks,toxic chemicals,and heavy metals in effluents flow into bays and estuaries.
Closedshellfish beds
Fig. 20-15
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•Keep lakes clean•Take your used motor oil to a drop off place•Use latex paint instead of oil and rinse your brushes in the sink rather than the yard•Fill a spray bottle with soapy water instead of bug spray•Plant trees to prevent soil erosion•Keep litter, pet waste, leaves, and grass clippings out of gutters and storm drains.
solution
What Can You Do?Water Pollution
• Fertilize garden and yard plants with manure or compost instead of commercial inorganic fertilizer.• Minimize your use of pesticides.
• Do not apply fertilizer or pesticides near a body of water.
• Grow or buy organic foods.
• Do not drink bottled water unless tests show that your tap water is contaminated. Merely refill and reuse plastic bottles with tap water.
• Compost your food wastes.
• Do not use water fresheners in toilets.
• Do not flush unwanted medicines down the toilet.
• Do not pour pesticides, paints, solvents, oil, antifreeze, or other products containing harmful chemicals down the drain or onto the ground.
Water makes us unique and gives life to Earth.