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‘Magic box' conjures fresh water solution

Update: May, 19/2013 - 04:09

Task team: PhD Ngo Anh Quan (right) and other members of the club of young scientists examine their invention, the water filter, before giving it to soldiers on the Spratly Islands. — VNS File Photos

by Minh Chau

"To people living on the mainland, freshwater has been taken for granted. However, on an island like Bach Long Vi it can be as precious as gold. Only when going to the island and living with the soldiers stationed there can you understand how much they would treasure a source of freshwater," confides Ngo Anh Quan PhD, who has invented an innovative ‘magic box' that can transform salt water into freshwater.

The idea for the box came to Quan's after speaking to a friend, Le Duy Hung Thinh, who had just returned from a trip to Bach Long Vi in the northern coastal province of Hai Phong. Thinh had visited the soldiers living on the remote outpost one of the Truong Sa or Spratly islands and tasked with defending it. He observed the difficult lives they had there with a lack of water, power and natural food sources and was tormented by their struggles. He vowed to find a way of improving their standard of living and so on his return to Ha Noi, he enlisted Quan's help.

Even though the young scientist did not know where to begin, he was determined that he and his friends would achieve something, whatever it took.

"Luckily, I'm an official of Hydraulic Construction Institute, so a lot of research and knowledge was made available to me," Quan says.

He soon learned that there are two popular ways of desalting sea water: using chemicals to separate the salt or using filter devices which can create freshwater by evaporating salt water and collecting the condensation. Some of these devices produced in foreign countries are capable of collecting and converting hundreds of litres of water per hour, but they cost thousands of dollars and require a large supply of electricity or fuel to run. In the difficult conditions on Viet Nam's remote islands, these power sources are scarce. Quan's young team had to simplify their thinking to find a solution.

"Sometimes the enigmatic nature of science and its possibilities can overcomplicate things. If we simply observe the facts of life, it may be easier to find a breakthrough," observes Quan.

Accordingly, he decided to try the most basic method he could think of: using natural condensation. Instead of creating heat with electricity, he could use the one source that is abundant on the islands: sunlight.

Turning heads: Quan (left) introduces the water filter. When placed on a small surface in sunlight (with the temperature ideally over 30 degrees Celcius), the device can collect up to ten litres of fresh water per day.

Quan found that all he needed was a simple glass box covered with a transparent lid. When left out in the sun, salt water in the box vaporises, leaving the salt behind. The vapour then turns into condensation, leaving drops of freshwater clinging under the lid. These drops become bigger, and eventually fall into the box below.

Quan freely admits that the theory is not new. "This is not a considerable invention as it is based on a mechanical method applied by ancient Greek sailors. The key point is transferring this scientific knowledge into something practical that works. We had to select a suitable lid and set it at the appropriate angle for collecting the freshwater. The rest was simple."

Quan's box is 30cm wide and 30cm long and covered with a glass pane. When placed on a small surface in the sunlight (with the temperature ideally over 30 degrees Celcius), the device can collect up to ten litres of freshwater per day. It has already been tested on Bach Long Vi Island, where a positive result was recorded. Twenty filters have now been sent to the island.

With one success under their belt, Quan's club of young scientists has also recently finished another experiment. Soldiers living on island outposts (resembling oil rigs surrounded by sea water) are being given small boxes full of good soil in which they can grow vegetables, creating their own ‘gardens on the sea'.

"There is much more to come from us," Quan says enthusiastically. "We are researching a way of using waste as an organic fertiliser, while our latest invention is an electric generator operated by sea waves. We have finished our first model and we are waiting to experiment with it on the islands. Hopefully, it will mean the island's inhabitants will not have to worry about blackouts anymore."

Thanks to Quan and his dedicated team, one day in the near future the island soldiers will not have much left at all to worry about anymore. — VNS

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