- 1.Presented by Dr. B. Victor Water Pollution
2. About the presenter
- Dr.B.Victor is a highly experienced postgraduate biology teacher, recently retired from the reputed educational institution St. Xavier s College, Palayamkottai, India-627001.
- He wasthe dean of sciences and assistant controller of examinations.
- He has more than 32 years of teaching and research experience
- He hastaught a diversity of courses ranging from pre-university to post graduate classes.
- Send your comments to : email@example.com
3. Water is essential to life on earth. 4. Importance of water
- Organisms are composed of much water70%-95%
- Supportive external environment for aquatic organisms
- Cellular medium within which biochemical reactions can occur
- Transport medium for food, oxygen, and other things needed by cells
- Means of support- Turgid plant cells /Hydrostatic animal support systems
5. Three forms of Water.
- Solids:When water becomes very cold and freezes it will change from a liquid to a solid.It has a definite form and shape.
- Liquids: When water takes the shapeof its container it is in a liquid form.
- Gases:When water is seen in a vapor form and has no definite size or shape it is in a gas form.
6. Distribution of global water 7. The earth's water supply
- 97.2% of the Earth's water supply is salt water.
- Only 2.8% is fresh water!
8. Salt and freshwater relationship 9. World Water Supply 97.200% salt water in the oceans 02.014% ice caps and glaciers 00.600% groundwater 00.009% surface water 00.005% soil moisture 00.001% atmospheric moisture 10. Earth as water planet
- Earth is often referred to as`the water planet'.
- Earth is unique amongst planets of our solar system because of its abundant water -in oceans, in the atmosphere, in glaciers and as fresh water on land.
- Without water, life could not exist.
11. Theearth'sfreshwater supply
- Only about3%of Earth's water is fresh.
- Two percentof the Earth's water (about 66% of all fresh water) is in solid form, found in ice caps and glaciers.
- One percent of all the Earth's water in a form useable to humans and land animals.
- This fresh water is found in lakes, rivers, streams, ponds, and in the ground. (A small amount of water is found as vapor in the atmosphere.)
12. Distribution of water
- Ocean Water :The vast majority of water on the planet is the salt water in the oceans and seas.
- Fresh Surface Water :This is the fresh water in rivers, streams, lakes, ponds and similar bodies of water.
- Groundwater :The majority of the planet's liquid freshwater is stored in underground aquifers. Water that enters an aquifer remains there for an average of 1,400 years!
13. Water : A precious Natural Resource
- We use water for drinking, irrigation, industrial purposes and energy production.Water use
- agriculture and energy production - 80%
- industry and public use - 20%
14. Water is used in many ways
- as a nourisher of plant and animal life,
- a prime element of industrial processes, and
- a medium for transportation
15. Significance of water
- Water is an integral part of life on this planet.
- It is an odorless, tasteless, substance that covers more than three-fourths of the Earth's surface.
- Most of the water on Earth, 97% to be exact, is salt water found in the oceans.
- We can not drink salt water or use it for crops because of the salt content.
- We can remove salt from ocean water, but the process is very expensive.
16. Hydrologic cycle - water cycle
- Two main processes: precipitation and evaporation
- Powered by energy from the sun
- Hydrologic cycle purifies water
17. Global hydrologic cycle 18. Water Cycle
- Saltwater evaporates from sun's energy producing fresh water in clouds; leaves salts in ocean.
- Water vapor cools and condenses to precipitation over oceans and land.
- Runoff forms fresh water lakes, streams, ponds, groundwater, and is held in plants and transpired.
19. Water consumption/ countries 20. Human activity disrupts local water cycles
- Loss of minerals through runoff
21. Water consumption/use 22. Daily use of water 23. Pollution of water 24. Water Pollution 25. Where do Water pollutants come from?
- Point Sources A single definable source of the pollution, e.g. a factory, a sewage plant, etc. Point-source pollution is usually monitored and regulated .
- Non-point sources No one single source, but a wide range of sources, e.g. runoff from urban areas, or farmland. Non-point sources are much more difficult to monitor and control.
- 3. Groundwater contamination
27. Sources of Water pollution 28. Water pollutants
- Industrial Effluents This waste water may contain acids, alkalis, salts, poisons, oils and in some cases harmful bacteria.
- Mining and Agricultural Wastes Mines, especially gold and coal mines, are responsible for large quantities of acid water.
- Agricultural pesticides, fertilizers and herbicidesmay wash into rivers and stagnant water bodies.
- Sewage Disposal and Domestic Wastes Sewage as well as domestic and farm wastes were often allowed to pollute rivers and dams.
29. Water pollution 30. Non-persistent (degradable )Water pollutants
31. Non-persistent (degradable) water pollutants
- These compounds can be broken down by chemical reactions or by natural bacteria into simple, non-polluting substances such as carbon dioxide and nitrogen.
- if the pollution load is high, this process can lead to low oxygen levels and eutrophication.
- This damage is reversible.
32. Persistent Water pollutants
- some pesticides (e.g., DDT, dieldrin)
- some leachate components from landfill sites (municipal, industrial)
- petroleum and petroleum products
- PCBs, dioxins, polyaromatic hydrocarbons (PAHs)
- radioactive materials such as strontium-90, cesium-137, radium-226, and uranium
- metals such as lead, mercury, cadmium
33. Persistent Water pollutants
- This is the most rapidly growing type of pollution
- This includes substances that degrade very slowly or cannot be broken down at all;
- Theymay remain in the aquatic environment for years or longer periods of time.
- The damage they cause is either irreversible or repairable only over decades or centuries
34. Otherw ater quality pollutants
- warm water from cooling towers (thermal pollution)
- These physical pollutants interfere mainly with the usability and/or aesthetic appeal of the water. In certain cases, thermal pollution can kill fish.
35. 1 . ClassesofWater pollutants
- Pathogens Bacteria, Viruses, Protozoa, Parasitic Worms, Colliform Bacteria Used As Indicators Of Water Quality
- Oxygen Demanding Wastes Organics That Are Decomposed By Bacteria And That Use A Lot Of O2, Dissolved Oxygen (DO) Decreases, And BOD Increases
- Water Soluble Inorganic Chemicals Acids, Salts, Toxic Metal Compounds Like Mercury, And Lead.
- Inorganic Plant Nutrients Water Soluble Phosphates, Nitrates => Algal Blooms, Decreased Dissolved O2, Increased BOD, Methemoglobinemia (="blue baby syndrome")
36. 2. ClassesofWater pollutants
- Organic Chemicals Oil, Gas, Plastics, Pesticides, Cleaning Solvents, Detergents, Etc.
- Sediment & Suspended Mater Insoluble Soil Particulates & Other Solids.Clouds The Water, Decreasing Photosynthesis, Carries Pesticides And Disrupts Aquatic Food Webs.
- Radioactive Isotopes Are Biologically Amplified To Higher Concentrations In The Food Chain.Ionizing Radiation & Birth Defects, Cancer.
- Warmed Water From Power Plants, Decreases DO And Increases Susceptibility To Diseases And Parasites And Toxic Wastes.
- Alien Species Zebra Mussels, Asiatic Catfish, Sea Lamprey, etc.Out compete Native Species And Ultimately Decrease Biodiversity
37. Industrial Water pollution
- Industries discharge a variety of pollutants in their wastewater including heavy metals , resin pellets, organic toxins, oils, nutrients, and solids.