Separating salt and water

The kids and I are now looking at the subject rain for our school term project.

We discussed about the rain cycle. And we just learned about evaporation

  • the sun heats up the ocean
  • The ocean water evaporates and rises into the air
  • Subhanallah from sat water (and various kind of water), Allah turns it into sweet rain water

Al Waqi’ah 56: 68-70

Then tell Me about the water that you drink. (68) Is it you who cause it from the rainclouds to come down, or are We the Causer of it to come down? (69) If We willed, We verily could make it salt (and undrinkable), why then do you not give thanks (to Allâh)? (70)

We did an experiment to separate salt from water by evaporation. S was the one assigned to write the “lab report”


Allah has put this rule for us to learn from. Humans have also learned this sunatullah and use the same principle to extract water from the ocean (which is full of salt).

This process is called DESALINATION.

Heated water evaporates to become water vapor, leaving salts and impurities behind, and then condenses as it cools to fall as freshwater (aka rain). Distillation plants refine and speed up this process by applying artificial heating and cooling and by evaporating water under lower air and vapor pressure, which significantly reduces its boiling point.

When does one probably need desalination?

1. In a country where water is scarce – most of middle east countries namely Saudi Arabia, Qtar, Kuwait and UAE. Also in the USA and Japan.

2. Also when coastal disasters around the world, like Hurricane Katrina, the 2004 Indonesian tsunami and the 2010 Haiti earthquake.

However this is an expensive technology.

A good read of what is hapenning in Qtar


Gulf countries facing water shortage: report
Publish Date: Friday,2 April, 2010, at 12:32 PM Doha Time

By Pratap John
Chief Business Reporter
The GCC region is facing potential water shortage with limited groundwater resources, which is already facing depletion because of over-use, the Economist Intelligence has said in a report.
The next ten years will see rising water demand, as the GCC’s expanding middle class adopts an increasingly water-intensive lifestyle, featuring private swimming pools, gardens requiring big sprinkler systems, and even a growing interest in golf.
Over the next decade, these countries will be among the world’s ‘highest per-capita users’ of water, it said.
Qtar’s water demand is set to double by the decade-end with EIU projecting a requirement for 104.7bn imperial gallons by 2020. Qtar’s water requirement this year is estimated at 56.22bn imperial gallons. The growth in demand for water in Qtar is among the highest in the GCC countries.
A main issue related to very high per capita consumption is that the bulk of the region’s water is directed into agriculture, a sector that provides less than 5% of GDP. Artificially cheap water has enabled the development of water-intensive crops in a region that has no natural advantage in producing these, but where governments provide generous subsidies to ensure future food supplies.
A few GCC countries are beginning to change this policy, for instance by phasing out energy-intensive crops or limiting the use of land for farming, but there will be pressure to do much more over the next decade.
Industrial demand for water is likely to rise faster than overall economic growth would suggest.
Regionally, a combination of rising temperatures and expanding populations suggests that water will become increasingly scarce in the Middle East, and raises concerns about the long-term possibility of conflicts over water. Some of the less wealthy countries in the region are already looking more seriously at strategies to manage water demand, particularly in agriculture, with the use of drip irrigation.
In the longer term, there are concerns that the increasing salinity of Gulf water will make desalination more difficult and more expensive. Gulf water is already highly saline, as the hot climate causes a high evaporation rate.
There are also concerns about water pollution from coastal industries and sewage, EIU said in its report titled ‘The GCC in 2020: resources for the future’, which is sponsored by Qtar Financial Centre.
To meet the growing demand, the region will rely increasingly on desalinated water, which is expensive and energy-intensive. There is huge scope to make economies more water-efficient.
At present, there are considerable inefficiencies all along the production, distribution and consumption chain, starting with energy-inefficient production and ending with water-inefficient consumption.
The GCC economies account for more than 40% of the world’s water desalination capacity, and much of that capacity is energy-intensive. To meet demand, governments continue to build new desalination plants.
Since these plants run on fossil fuels, efforts to boost the supply of energy, diversify fuel sources and improve energy efficiency will have a strong impact on the provision of water.
“It’s not only that desalination is energy-intensive, but that a lot of energy is wasted,” said Nikolopoulos of Climate Change Capital.
Most of the GCC’s desalination plants use thermal sources, mainly natural gas.
There is significant and ongoing investment in dual-purpose co-generation plants, which produce both electricity and desalinated water through a combined thermodynamic cycle, which is more efficient than separate production processes. These are encouraging initiatives, but there is still a lot of room for further energy savings in the desalination process, the report noted.

From this article you will understand that

1. Qtar has freshwater shortage

2. Qtar is dependent on desalienation process of their ocean water to freshwater

3. This process is very expensive

4. In relative to many other places, the ocean in the middle east area is more saline (high content of salt). Look at the process of evaporating saltwater for salt. the sun is very intense in this region, thus more water are evaporated leaving more salt in the water content.

5. there should be a more serious effort to educate the masses on precious water.

Look at the precipitation level in Qtar in this article The highest level it reaches is in Feb at 0.7 inches.  And no rain at all from June-Oct

Reread surah al waqiah 56: 68-70. Allah tells us to be thankful. Allah can stop this blessings whenever He wills.

1. How stuff works.

2. The STAR report

1 Comment

Filed under Science, Tawhid

One response to “Separating salt and water

  1. Pingback: Water Cycle : Evaporation « Lollies Place

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