Whisky waste offers water of life

Villagers from the Manikganj district of Bangladesh queue for their local pump
Villagers from the Manikganj district of Bangladesh queue for their local pump
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IT’S a project worth toasting. Scottish scientists have discovered that an innocuous by-product of whisky can to be used to strip pollutants from contaminated water supplies in a process which could save millions of lives in developing countries.

The treatment system, called Dram (Device for the Remediation and Attenuation of Multiple pollutants), uses compressed barley husks discarded by distillers to remove pollutants, including pesticides, heavy metals and chemicals, from water supplies.

Dr Graem Paton and Dr Leigh Cassidy researchers from Aberdeen University

Dr Graem Paton and Dr Leigh Cassidy researchers from Aberdeen University

Now a charity in Bangladesh plans to use the technology to tackle the life-threatening problem of arsenic in domestic water used for drinking, washing and irrigating crops. A ­pilot project due to start in December will install the Scottish device to deliver clean water to 30 families in the village of Golaidanga, west of the capital Dhaka.

Around 137 million people around the world are affected by arsenic which occurs naturally in groundwater. High levels of the poisonous compound can cause skin, bladder and lung cancer, stillbirth and heart disease and is responsible for tens of thousands of deaths a year.

According to the World Health Organisation, arsenic contaminated water in Bangladesh is “the largest mass poisoning of a population in history”. More than 18 million people in the country are forced to drink contaminated water because of ineffective water purification and sewage systems as well as monsoons and flooding.

Shahreen Raza from the charity Purifaid, which will be overseeing the project in Golaidanga , said: “Right now the only solution to arsenic poisoning in water in Bangladesh is filters which are inadequate, inefficient and costly to maintain. The Dram system has the potential to transform people’s lives by bringing clean water to entire villages at a low cost. A successful pilot project could change the face of the country.”

A warning on a poisonous water standpipe

A warning on a poisonous water standpipe

Dram was invented by Dr Leigh Cassidy, a research fellow at Aberdeen University, and her colleague Professor Graeme Paton, a soil toxicologist, who have formed Epona Technologies to develop the project’s commercial potential.

Cassidy says she came up with the idea of using barley husks to absorb pollutants almost by accident. “I drew up a check list of what qualities a decontamination product would need to have and thought, I know something that would work,” she said.

The scientists secured supplies of husks from Speyside distilleries only too happy to find a good use for an inexpensive waste product.

Although she is reluctant to divulge all the secrets of the system until global patents are in place, Cassidy says Dram is a simple device that uses the modified draff to bind with pollutants, which can then be removed. Once it is decontaminated, the clean water is fed through an outlet to a tap.

Compared with the water filters used in many developing countries, Dram is cheap to maintain, with an estimated life span of 25 years. It is also efficient, decontaminating 1,000 litres of water an hour.

“It allows you to take the chemicals out and make water clean so that fish can survive and plants can grow,” Paton said in a promotional video about the project. “Clean water is the right of every human being, not just something for the western world.”

During the testing stages, Dram successfully removed copper from waste water in Peterhead trawlers and stripped chromium from ground water at a sports field in Glasgow. In laboratory tests the device removed 95 per cent of arsenic from contaminated water.

“One of the problems is that the arsenic contamination in Bangladesh is natural – it is rock derived so it is in all the water. And it means that, because the main staple of the diet there is rice, not only is the rice grown in arsenic contaminated water but they are also using the contaminated water for cooking and drinking. They are getting a treble whammy of this arsenic and it’s quite nasty,” said Cassidy.

“The performance we have achieved in the lab is holding through and we would expect to achieve a 95 per cent removal in Bangladesh. With the other contaminants we have tested we are not really getting any fall off in the field.

“We probably couldn’t get down to the World Health Organisation regulation levels for drinking water. But we could certainly remove the majority of the arsenic.”

Cassidy hopes that if the Bangladesh pilot is successful that the system can be introduced across the Indian sub-continent and in west Africa where arsenic in groundwater poses a serious health problem. “Potentially our device could improve the lives of millions of people in Bangladesh. It could be life changing and even life saving for lots of people,” she said.

• furquhart@scotlandonsunday.com