Lack of water, science race to filter seawater into fresh water

Facing the prospect of not having enough water to drink, scientists have aimed to turn seawater into fresh water although the technology is expensive.

With climate change, rainfall is becoming less and more dry and prolonged, water shortage becomes severe.

"Currently watering your lawn is not a good idea. Don't waste precious water. There is a risk of lack of historic water." Belgium is warning the situation of serious water shortage.

Last winter it rained less than last year, not enough to compensate for the water shortage. Professor Patrick Willems of KU Leuven University (Belgium) clicked his tongue and remarked: "We have never seen this in the past few decades."

Researcher Marjolein Vanoppen tested seawater in the laboratory - (Photo: natuurenbos.be).

Use membrane technology

In the agricultural province of West-Vlaanderen (western Belgium), the provincial governor Carl Decaluwé declared that if it did not provide enough water, one place could get water.

The province is implementing a pilot project to filter seawater for fresh water. Scientists at Ghent University have researched and found that it is possible to implement the project, but at a high cost.

Biological engineer Marjolein Vanoppen commented: "This is inevitable because drought will occur more often."

She explained: "Since the Middle Ages people have used distillation to separate salt from seawater. The steam is used to drink. This way takes a lot of energy. Want to produce 1,000 liters of fresh water from 2,000 liters of water The sea needs 15-30 kWh of electricity.

For comparison, a Belgian person only uses 2-4 kWh per day on average, how much is the electricity consumption. "

She studied a low-power solution rather than membrane technology based on reverse osmosis. Semi-permeable membrane has small holes that retain salt molecules. If using a powerful pump, 500 liters of fresh water can be obtained from 1,000 liters of seawater.

Middle Eastern countries are harvesting huge amounts of water by the above method. In Europe, Spain and Cyprus pioneered in this area. Australia also recently built one of the world's largest desalination plants.

Filter seawater with the sun

However, compared to pumping and filtering river water, well water filters seawater into fresh water which uses much more energy. Engineers at Torino Polytechnic University (Italy) have tested a new technology that is cheaper to use because of solar energy.

The principle of operation is simple, imitating the principle of putting water from the roots to the leaves through capillary and evapotranspiration. Floating seawater equipment is made of cheap foam. Seawater warming with solar energy will help remove salt from the sea.

With fixed solar energy, new technology can produce twice the amount of water.

Conventional desalination technology requires expensive mechanical or electrical components such as pump pipes, control systems and assembly and maintenance technicians. New technology is based on spontaneous processes and no need for assistance.

Productivity of at least 20 liters of drinking water per day on 1m2 of sunlight exposure. The device is less expensive, easy to install, easy to repair, suitable for coastal areas that often lack water, lack of infrastructure and investment capital.

Waste water reuse solution

Reusing wastewater is also a solution for freshwater production. At Koksijde (West-Vlaanderen province), IWVA drinking water manufacturer proves that it can clean waste water naturally.

Treated sewage is pumped into sand dunes, then the filtered water is pumped back until it is completely clean. IWVA is continuing to experiment with turning urine into drinking water. The problem of free technology, there is only psychological barrier because few people want to drink waste water or urine.

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