VietNamNet Bridge – Students Nguyen Anh Hung and Truong Quoc Vi from the Industrial University of Ho Chi Minh City know what it's like to be without fresh water in flood ravaged, contaminated areas.

Inventive minds: Nguyen Anh Hung (L) and Truong Quoc Vi (R), creators of the coconut fibre filter.

"We were born in central Viet Nam, the epi-centre of flooding, with constantly contaminated water supplies," they say. "This really motivated us to invent a water-filtering device from recyclable materials for our hometown."

Hung and Vi's water-filter is composed of simple materials: four transparent 1,5-litre plastic bottles, coconut fibre, sand, pebbles and active coal.

The total cost for each filter is just about VND10,000 (US$0,5).

The first bottle, placed at the highest position, contains contaminated water.

The second, the top of which is placed about 5cm lower than the bottom of the first, contains coconut fibre to absorb heavy metals.

The next bottle contains the filtering materials; including sand, pebbles and active coal; which are used to deodorize and to eliminate organic waste and contaminants. The top is 25cm lower than the first bottle and 20cm lower than the second.

The last bottle, placed in the lowest position, contains filtered water.

When the whole system is placed in an airy location with lots of sunlight from four to five hours, the process of natural sterilization takes place. Under the effects of sunlight, 98 per cent of pathogenic microorganisms are eradicated.

Despite its simplicity, Vi and Hung's filtering system can be used for up to six months.

Applying coconut fibre in filtering water is a fresh take on water filtration, because this popular material, which is often neglected, has the capacity to absorb heavy metals.

Contained in the third bottle is a mixture of filtering materials of five layers, each of which is arranged from top to bottom, each five centimetres thick. When the contaminated water runs through it, the organic waste is caught in the top layer, and the bad odor is absorbed by the active coal, while the water is purified by the other layers.

Bottled up: The filtering system is very simple, consisting of four plastic bottles containing filtering materials, but can be used up to six months.

The four filtering bottles are connected with each other with plastic pipes. All the materials, before being filled into the bottles, are washed clean, classified according to size and sterilized with sunlight for six hours.

Although Vi and Hung's filtering system is very simple, they sometimes have to starve themselves to save money for materials for studying and testing their invention.

As students, they try to balance study and research, and the system is their application of the knowledge they have gained at school.

After three months of research, Hung and Vi finished their product. Initially, it has shown immense effectiveness in purifying water in flood-stricken or contaminated areas.

"Growing up in the poor area of the central province, we thoroughly understand the difficulties of those living here; particularly the shortage of fresh water during the floods," says Vi.

"Our filtering system is aimed to improve their life and their access to water, by instructing them how to deal with contaminated waters after the flood themselves," Vi adds.

Their simple water filter was among other products to make the final of the Competition of designing recyclable products held by Ho Chi Minh Youth Organisation last September.

After the success of the first model, they have applied the system in several households. Some have wanted to buy their products but they have decided to give them away for nothing.

"We hope that we can receive sponsorship so that we can expand its effectiveness on a larger scale," Hung says.

Source: VNS