Water Desalination
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Transcript of Water Desalination
Water Desalination
Obtaining reliable fresh water supplies from challenging water sources.
“Composer”
Adnan Aslam B.sc Mechanical Engineering HITEC university Taxila, Islamabad Pakistan
What Is
Desalination…???
Desalination:
The process of
removing dissolved salts from
water, thus producing fresh
water from seawater or
brackish water.
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.
Why Desalination…???
Economic expansion
Agriculture and food
Public health
Quality of life
Fresh Water Needs..!!!!!
Can we drink salt water..??
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 MarinerWater, water, everywhere
And all the boards did shrinkWater, water, everywhere
Nor any drop to drink
Desalination By Reverse Osmosis
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
Flow at the Membrane
Forward Osmosis
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.
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
Thermal DesalinationThermal 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.
Desalination Plants around the World
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
Total Installed Desalination Capacity by Region, Worldwide
Middle East 53.40%
Central America, South America, & Australia; 2.80%
Africa6.20%Asia; 10.60%
Europe10.10%
North America; 17.00%
Desalination in Middle East4.4% 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.
DESALINATION IN PAKISTAN
WHEN &WHERE?
”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.
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.
A desalination plant was installed in 1987 in Saindak Copper Mines in Balochistan. It uses the brackish water Reverse Osmosis (BWRO) process.
Another desalination plant was installed in 1995 and commissioned in 1996 at the HUBCO power station outside 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.
THANK YOU………….