Water Pollution

1. Water Pollution

2. The Universal Solvent

3. Some of the stuff that it dissolves / suspends is good for us Others, not so good Water Pollution

4. Can you name 5 things that dissolve in water? Know of any 2 that can be called ‘pollutants’ – those dangerous to life ?

5. If we drink polluted water, we can get sick Cholera Typhoid Jaundice Cancer Organ failure

6. K S T C G H Figure out some pollutants _ _ _ _ _ _ _ + + _ _ _ _ _ _ _ + Clue: toothpaste + Sounds like _ _ _ _ _ _ _ _ Led Zeppelin Deep Purple _ _ _ _ _ _ _ _ _ _ Black Sabbath Iron Maiden

7. K S T C G H Figure out some pollutants ARSENIC + + NITRATE + Clue: toothpaste + Sounds like FLUORIDE Led Zeppelin Deep Purple Black Sabbath HEAVY METAL Iron Maiden

8. How do we know that water is polluted? Sometimes polluted water changes colour…..but not always Sometimes it stinks……but not always Sometimes it tastes different ……..but not always

9. How do we know that water is polluted? Water pollution can be confirmed only by testing it in a lab

10. Sources of water pollution are generally grouped into two categories Non-point source of pollution: Contamination gathered by water over a large area. Point-source of pollution: Contaminants enter a waterway at a discrete point

11. Water can get polluted naturally When water seeps into the ground, it absorbs different substances depending on the type of soil and rock that it flows through.

12. Water can get polluted naturally Some of these substances (arsenic, iron, fluoride, etc.) can be harmful to our health. Natural pollution is a non-point source of pollution

13. Arsenic In groundwater Fluoride In groundwater Natural pollution can introduce chemicals that collect in our bodies. Over time this can cause chronic problems and even life – threatening diseases.

14. Does Man Pollute Water? This is what a young person like you has to say: “ If you had a bottle of life-preserving fluid on which your life depended, would you pour into it all your sewage and rubbish, along with any other poisonous chemicals you could find? And yet, that is exactly what we are doing to our water supply – all over the world.”

15. Yamuna, when it leaves Delhi, resembles a sewer full of the city’s wastes. A few hundred kms downstream is Agra, where this ‘sewer’ is the main municipal drinking water source. The various ways in which man pollutes water  An example of Point source of pollution Untreated or inadequately treated municipal sewage  YUCK!! eutrophication

16. The various ways in which man pollutes water  Reaches ground water bodies Untreated or inadequately treated municipal sewage An example of Point source of pollution Untreated sewage seeps in and contaminates groundwater aquifers Such aquifers show a higher than acceptable level of nitrate content

17. The various ways in which man pollutes water  Dumping garbage in surface water bodies When garbage is dumped in a landfill, toxic chemicals leach into the soil and groundwater.

18. The various ways in which man pollutes water  Over 10 million people bathe in the Ganga daily! Washing and bathing introduces phosphates and other chemicals into water

19. The various ways in which man pollutes water Agriculture An example of Non- Point source of pollution dissolve in irrigation water or rainwater. They contaminate surface water and groundwater with pollutants like nitrates, phosphates, and non degradable synthetic organic pollutants. Agriculture is a major source of groundwater contamination.

20. The various ways in which man pollutes water  Industry An example of Point source of pollution • Agro industries (sugar, food processing, pulp and paper, distilleries) – their wastes have high concentration of dissolved organic matter. • Chemical Industries – If their wastes are not treated properly, • the chemicals can destroy our soil and water resources. • Petroleum refining – water used in the process needs to be • separated from all the oil before releasing it into • nature……but is that done? Minamata disease

21. The various ways in which man pollutes water  Industry An example of Point source of pollution Thermal power plants – water is needed to cool the process. The water gets hot and when it’s released into a larger water body, it upsets the ecology by modifying the delicate temperature balance. This is called ‘Thermal pollution’

22. Effluent treatment plants Liquid wastes from an industry are treated in effluent treatment plants. Large industries have in-house effluent treatment plants. It’s expensive for small industries to have such plants of their own. In some industrial estates, a group of small industries have a common effluent treatment plant.

23. A RE-CAP Water can be polluted naturally Water can be polluted by man • Sewage in our water bodies • Garbage dumps • Washing and bathing • Pesticides and fertilizers • Industries

24. Hangman Divide the class into 5 teams Draw as many dashes as in the name of a water pollutant or a pollution cause. Team A starts. They guess a letter. The teacher puts in the letter at the correct place, if it is there in that name. Else, the letter is written down on one side. A maximum of 10 wrong guesses are allowed. The team gets as many points as letters on the side (maximum of 10). The team with the lowest number of points wins.

25. Eutrophication (pronounced as you-tro-fi-kay-shun) When wastes with high organic content (such as sewage wastes) are dumped into a water body like a lake or pond, eutrophication can occur, killing all life in the water body. Organic wastes are rich in nutrients (nitrates and phosphates) They stimulate excessive plant growth – especially weedy species

26. Eutrophication On dying, the plants further add to the organic waste in water. Microorganisms that decompose the organic material in water use up a lot of dissolved oxygen. This depletes the available oxygen in the water and upsets the ecological balance, since fish and other life forms perish without adequate oxygen. Eventually all the oxygen is used up.

27. Eutrophication Anaerobic organisms then attack the organic wastes, releasing gases such as methane and hydrogen sulphide. The result is a foul smelling, waste filled body of water, quite like many of the lakes in India. These water bodies are also natural groundwater recharge systems and their contamination also leads to groundwater pollution.

28. Minamata disease Industrial wastewater from the Chisso corporation (manufacturing fertilizers and other chemicals) was released into the Minamata Bay in Japan. The waste water was rich in methyl mercury. Mercury content in shellfish in that region increased. People ate the shellfish and the cats ate the leftovers.

29. Strange things started to happen – cats had convulsions and died, crows fell from the sky, dead fish floated. Young children had convulsions and difficulty in walking and speaking. People died. Investigation showed organic mercury poisoning affecting the nervous system. First discovered in 1956. Lawsuits and claims continue till today.