Water by Muhammad Fahad Ansari 12IEEM14

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Muhammad Fahad Ansari 12IEEM14

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Water by Muhammad Fahad Ansari 12IEEM14

  1. 1. Water & Wastewater Engineering Muhammad Fahad Ansari 12IEEM14
  2. 2. • Waste Water = Spoiled water• Wastewater = Passes through its optimum uses 2
  3. 3. Water storage• Some runoff water is trapped for periods of time, for example in lakes.• At high altitude, during winter, and in the far north and south, snow collects in ice caps and glaciers.• Water also infiltrates the ground and goes into aquifers.• This groundwater later flows back to the surface in springs, or more spectacularly in hot springs.• Groundwater is also extracted artificially in wells.• This water storage is important, since clean, fresh water is essential to human and other land-based life.• In many parts of the world, it is in short supply. 3
  4. 4. Sea water• Sea water contains about 3.5% salt on average, plus smaller amounts of other substances.• The physical properties of sea water differ from fresh water in some important respects.• It freezes at a lower temperature (about -1.9oC) and its density increases with decreasing temperature to the freezing point, instead of reaching maximum density at a temperature above freezing. 4
  5. 5. Effects on life• From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances.• All known forms of life depend on water.• Water is vital both as a solvent in which many of the bodys solutes dissolve and as an essential part of many metabolic processes within the body.• Water is thus essential and central to these metabolic processes.• Therefore, without water, these metabolic processes would cease to exist. 5
  6. 6. • Water is also central to photosynthesis and respiration.• Photosynthetic cells use the suns energy to split off waters hydrogen from oxygen.• Hydrogen is combined with CO2 to form glucose and release oxygen.• All living cells use such fuels and oxidize the hydrogen and carbon to capture the suns energy and reform water and CO2 in the process. 6
  7. 7. Effects on human civilization• Civilization has historically flourished around rivers and major waterways.• Most of the civilizations were situated around the major rivers and oceans.• The ancient society of the Egyptians depended entirely upon the Nile.• Large metropolises like London, Montreal, Paris, New York City, Buenos Aires, Shanghai, Tokyo, Chicago, and Hong Kong owe their success in part to their easy accessibility via water and the resultant expansion of trade.• Islands with safe water ports, like Singapore, have flourished for the same reason.06/14/12 7
  8. 8. Aquatic life forms• Earths waters are filled with life.• The earliest life forms appeared in water; nearly all fish live exclusively in water.• There are many types of marine mammals, such as dolphins and whales that also live in the water.• Some kinds of animals, such as amphibians, spend portions of their lives in water and portions on land.• Plants such as algae grow in the water and are the basis for some underwater ecosystems.• Plankton is generally the foundation of the ocean food chain.06/14/12 8
  9. 9. Health and pollution• Water fit for human consumption is called drinking water or potable water.• Water that is not potable can be made potable by filtration or distillation (heating it until it becomes water vapor, and then capturing the vapor without any of the impurities it leaves behind), or by other methods.• Sometimes the term safe water is applied to potable water of a lower quality threshold.• Water that is not fit for drinking but is not harmful for humans when used for swimming or bathing is called by various names other than potable or drinking water, and is sometimes called safe water, or "safe for bathing".06/14/12 9
  10. 10. • This natural resource is becoming scarcer in certain places, and its availability is a major social and economic concern.• Poor water quality and bad sanitation are deadly; some five million deaths a year are caused by polluted drinking water.• The World Health Organization estimates that safe water could prevent 1.4 million child deaths from diarrhea each year.06/14/12 10
  11. 11. • In the developing world, 90% of all wastewater still goes untreated into local rivers and streams.• Some 50 countries, with roughly a third of the world’s population, also suffer from medium or high water stress.• The strain not only affects surface freshwater bodies like rivers and lakes, but it also degrades groundwater resources. 11
  12. 12. Human uses• The human body is anywhere from 55% to 78% water depending on body size.• To function properly, the body requires between one and seven liters of water per day to avoid dehydration; the precise amount depends on the level of activity, temperature, humidity, and other factors.• Most of this is ingested through foods or beverages other than drinking straight water. 12
  13. 13. • It is not clear how much water intake is needed by healthy people, though most advocates agree that 6–7 glasses of water (approximately 2 liters) daily is the minimum to maintain proper hydration.• Medical literature favors a lower consumption, typically 1 liter of water for an average person, excluding extra requirements due to fluid loss from exercise or warm weather. 13
  14. 14. • Humans require water that does not contain too many impurities.• Common impurities include metal salts and oxides (including copper, iron, calcium and lead) and/or harmful bacteria, such as Vibrio.• Some solutes are acceptable and even desirable for taste enhancement. 14
  15. 15. Agriculture• The most important use of water in agriculture is for irrigation, which is a key component to produce enough food.• Irrigation takes up to 90% of water withdrawn in some developing countries and significant proportions in more economically developed countries. 15

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