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Water Desalination

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Desalination, the process of removing salts from seawater.
To overcome the water scarcity different desalination processes are used over the word.Some the most common methods are described in it.

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Water Desalination

  1. 1.  Obtaining reliable fresh water supplies from challenging water sources.
  2. 2. Adnan Aslam  B.sc Mechanical Engineering  HITEC university Taxila, Islamabad Pakistan
  3. 3. Desalination: The process of removing dissolved salts from water, thus producing fresh water from seawater or brackish water.
  4. 4.  71% of the Earth’s surface is covered by water.  97.5% of that water is oceans.  Only 1% is available for drinking.  80 countries suffered from water scarcity by the mid- 1990s.
  5. 5. Economic expansion Agriculture and food Public health Quality of life
  6. 6.  Small quantities are not harmful, but it is counterproductive (it just makes you more thirsty!)  Eventually, it can be dangerous, ultimately producing fatal seizures, heart arrhythmias and kidney failure The Rime of the Ancient Mariner Water, water, everywhere And all the boards did shrink Water, water, everywhere Nor any drop to drink
  7. 7.  2 gallons of seawater = 1 gallon of high quality drinking water  Pre-treatment and RO removes contaminants, including mercury and other contaminants in the Bay  MMWD will use “dual pass” RO
  8. 8.  Forward osmosis utilizes the osmotic process , a substance moving from an area of low concentration to an area of high concentration.  It generally requires about half of the cost of reverse osmosis.
  9. 9.  Electro dialysis  Electro dialysis reversal utilizes a membrane, like that in reverse osmosis.  It sends an electric charge through the solution to draw metal ions to the positive plate on one side, and other ions (like salt) to the negative plate on the other
  10. 10.  Thermal Desalination  Thermal desalination is a method of cleaning water that can occur through many different processes.  In this process we heat the water solution and gathers the pure water when the vapors cools and condensation occurs.
  11. 11. o Desalinated water is an important contributor to alleviate water shortage. o Today’s world contracted capacity of desalinated plants is 80.2 million m3/day and commissioned capacity 74.6 million m3/day. o 632 new plants were added last year (mid 2011 to August 2012) in the world
  12. 12. Total Installed Desalination Capacity by Region, Worldwide Middle East 53.40% Central America, South America, & Australia; 2.80% Africa 6.20% Asia, 10.60% Europe 10.10% North America, 17.00%
  13. 13. Desalination in Middle East  4.4% of the world’s population inhabit the Middle East(AQUASTAT 2005)  it only receives 1.1% of the global renewable water resources.  70% of the world’s desalination plants are located in the Middle East  Saudi Arabia alone is producing 20% of the world’s desalinated water.
  14. 14. WHEN &WHERE?
  15. 15. ”DHA Desalination and Power Plant” It is the first project of its kind in Pakistan which desalinates water from the Arabian Sea for human consumption as well as provides Electrical Power to the KESC grid. Manora Water Desalination plant(Karachi): • Capacity: 200,000 to 250,000 gallons of water per day for Navy.
  16. 16.  The Pakistan Water and Power Development Authority (WAPDA) has installed 12 desalination plants along Manchar lake for providing potable water to the populace residing in the areas adjacent to the lake.  The water treatment plants have cumulative design capacity of 15000 liters per hour. Over 4,000 families of fishermen folk (about 32,000 to 40,000 persons) are being facilitated with high quality potable water.
  17. 17.  A desalination plant was installed in 1987 in SaindakCopperMinesin Balochistan. It uses the brackish water Reverse Osmosis (BWRO) process.  Another desalination plant was installed in 1995 and commissioned in 1996 at the HUBCOpower stationoutside Karachi. This plant uses Reheat type Multi-effect distillation (MED) desalination.  KANUPP near Karachi operates a Sea Water Reverse Osmosis (SWRO) desalination plant to meet its operating requirements.
  18. 18. THANK YOU………….

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