HORIZON INTERNATIONAL SOLUTIONS SITE

A filter that removes arsenic from water and that could save tens of millions of lives was launched today at UNESCO Headquarters in Paris. Simple and ecologically sound, the filter uses an absorbent recycled by-product available at no cost almost everywhere in the world. It was developed by the UNESCO-IHE Institute for Water Education*. Arsenic in drinking water is both a natural phenomenon and the result of human activity (mining, extraction of minerals, coal-burning electricity production). There is no medical treatment for intoxication by arsenic-contaminated water.

A woman shows her hands ravaged by blisters, a telltale sign of arsenic poisoning. Photo © Gamma/Hachette Filipacchi/Lathigra F.S.P.

Prevention is the only recourse. It is a serious problem in many countries around the world including Bangladesh and the United States, as well as Argentina, Chile, China, Ghana, Hungary, India, and Mexico.

“A concentration of arsenic up to 15 to 20 times higher than the acceptable maximum has been found in drinking water in many countries, in Greece and Serbia and Montenegro, for instance ” says Branislav Petrusevski, Director of the UNESCO-IHE project. He pointed out that the maximum proposed by the World Health Organization (WHO) is 0.01 mg per litre, however, “arsenic levels in groundwater in Bangladesh for example, are as high as 1.8 mg per litre,” Petrusevski added. The problem affects some 30 million people in the country, according to WHO.

“Recent medical research shows, moreover, that long-term exposure to very low arsenic concentrations can cause cancer and have a variety of other adverse effect on human health,” he continued.

Petrusevski, director of the international team that has studied the problem for five years, goes on to explain that “The technology we developed is based on arsenic absorption with Iron Oxide Coated Sand. If you produce the material commercially it is very expensive. And when its absorption capacity is exhausted, you have to replace it and dispose of the waste.”

The Institute team instead recycled Iron Oxide Coated Sand produced as a by-product in groundwater treatment plants. “Plants in many countries around the world use natural sand for iron removal and have to replace it after a certain number of years. We found that this material, now coated with iron oxides, is an excellent absorbent for removing arsenic from water. It is free of charge and consequently the technology based on its use is cheap,” said Petrusevski. It is also easy to use, requires no power and can be produced locally. Producing 100 liters of arsenic-free water per day, which is enough to supply the needs of 20 people, it is ideal for household use.

Since February 2004, 14 “family filters” have been tested in rural areas in Bangladesh where groundwater is highly-contaminated groundwater with arsenic levels up to 0.5 mg per litre. After more than a year and a half of daily use, 12 of them are still producing arsenic-free water without needing replacement of the absorbent. Another 1,000 filters will be distributed in Bangladesh I the project’s second phase.

“In parallel, we also developed a simple and cheap regeneration procedure for exhausted adsorbent. Such a procedure is of particular importance for centralized arsenic removal applications,” says Petrusevski. . The centralized arsenic removal technology, destined for water supply companies, is being tested in Greece and Hungary. Its cost is comparable to conventional groundwater treatment, with reduced environmental impact.

During the presentation of the activities of the UNESCO-IHE Institute and UNESCO’s International Hydrological Programme, their respective directors, Richard A. Meganck and Andras Szollosi-Nagy, emphasized the new technology’s innovative benefits and called for donors to support its mass production.

*The UNESCO-IHE Institute (Delft, The Netherlands) offers post-graduate training and research programmes in the fields of water and the environment to professionals from developing countries.