India Environment Portal Knowledge for change

Big Ben

• 29/09/2003
• Down To Earth

a recent find may prove to be the miracle of ingenuity to combat the menace of arsenic. Researchers from Australia's La Trobe University have unearthed 13 bacterial strains that convert arsenite present in water into arsenate. "Arsenite and arsenate are the two soluble forms of arsenic. Arsenite is 100 times more toxic than arsenate (which can be easily removed from water using safe chemicals),' says Joanne Marie Santini, who headed the research team.

The bacteria were isolated from arsenopyrite rocks containing iron, sulphur and arsenic. Since the discovery was made in Bendigo and Northern Territory areas of Australia, the researchers named the bacteria nt or Ben. The process of treating arsenic-tainted water can now become quite cheap. For instance, a hollow bamboo stem can be filled with pebbles on which the bacteria can be cultured. A sieve/filter can be fitted on one end of the stem. Once arsenite has been converted into arsenate, the water can be further treated with iron hydroxide.

At present the researchers are scrutinising the conversion mechanism. With financial support from the World Health Organization (who) or the World Bank, Santini hopes the bacteria can be used in Bangladesh and West Bengal, where thousands of people are dying due to arsenicosis (see: