PHA-Exchange> UNESCO INTRODUCES LOW-COST WATER FILTER TO REMOVE ARSENIC

[Claudio]

From: "Vern Weitzel" <vern.weitzel at undp.org>

> With potentially poisonous arsenic in drinking water being both a natural
phenomena and a toxic
> by-product of mining, mineral extraction and coal-burning electricity
production, the United Nations
> Educational, Scientific and Cultural Organization (UNESCO) today unveiled
a low-cost filter, made
> from an industrial waste product that is designed to remove the harmful
substance.
>
> Prevention is the only recourse since there is no medical treatment for
intoxication by
> arsenic-contaminated water, the agency
>
<"http://portal.unesco.org/en/ev.php-URL_ID=30103&URL_DO=DO_TOPIC&URL_SECTIO
N=201.html">said in
> launching the innovation at its Paris headquarters.
>
> "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," said
Branislav Petrusevski, Director of
> the UNESCO-IHE Institute in Delft, The Netherlands, which offers
post-graduate training and research
> programmes on water and the environment to developing country
professionals.
>
> Instead, the Institute team recycled iron oxide coated sand produced as a
by-product in groundwater
> treatment plants. The filter is easy to use, requires no power and can be
produced locally. The
> "family" filter produces 100 litres of arsenic-free water per day, enough
to supply the needs of 20
> people.
>
> "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," Mr. Petrusevski said.
>
> He pointed out that the UN World Health Organization
(<"http://www.who.int/en/">WHO) has set the
> healthy maximum of arsenic in water at 0.01 milligrams per litre, but
added that according to WHO
> estimates "arsenic levels in groundwater in Bangladesh, for example, are
as high as 1.8 milligrams
> per litre."
>
> Since February 2004, 14 "family filters" have been tested in rural
Bangladesh where
> highly-contaminated groundwater has arsenic levels of up to 0.5 milligrams
per litre. After more
> than 18 months of daily use, 12 of them were still producing arsenic-free
water without needing
> replacement of the sand absorbent. Another 1,000 filters would be
distributed in Bangladesh in the
> project's second phase.
>
> Arsenic is a serious problem in many other countries, including Argentina,
Chile, China, Ghana,
> Hungary, India, and Mexico and the United States.
> For more details go to UN News Centre at http://www.un.org/news