A common weed could help decontaminate water in the developing world

A voracious weed could save the lives of people living in areas with arsenic contaminated water, according to UK researchers.

Using dried roots of the water hyacinth, often labelled an ’environmental plague’ in the tropical and subtropical world, Parvez Haris and colleagues at DeMontfort University quickly reduced arsenic levels in contaminated water to below the World Health Organization’s guideline value of less than 0.01mg/L.

This simple, effective and cheap solution has potential implications in the developing world, where serious contamination of drinking water by natural arsenic in surrounding rocks is threatening the lives of millions. Long term health consequences of arsenic exposure are severe and include skin cancer, nervous system damage and miscarriage.

During a trip to Bangladesh, one of the most seriously affected areas, Haris witnessed firsthand the suffering of victims of arsenic poisoning. In Bangladesh he saw the water hyacinth thriving on many water surfaces in the area. ’That was my "eureka" moment,’ said Haris, explaining what inspired his research.

’Upon returning to the UK, I immediately started working on this plant with my graduate student. To our amazement a powder produced from the root of this plant was able to remove arsenic from water in minutes,’ he said, adding, ’it is particularly pleasing to convert a much hated weed to something that can potentially save human lives.’

Turning concept into reality requires field trials. Ultimately Haris hopes to see water hyacinth roots being used in filtration systems to remove arsenic from drinking and irrigation water. Kathryn Lees