Technology | Technology

Tech Thursday: KNUST filter set to make polluted water safe

People living especially in mining areas are faced with water bodies polluted with dangerous substances such as mercury.

Those in rural parts of the country also battle with cattle for the same source of drinking water with the imminent exposure to deadly germs.

But that will soon be a thing of the past as the Kwame Nkrumah University of Science and Technology (KNUST) has designed a filter that can sieve out not only heavy metals but also bacteria.

According to the Water Resources Commission (WRC), about 60 percent of Ghana’s water bodies have been polluted through illegal mining activities.

A 2017 study by the NGO, Water, Sanitation and Hygiene suggests three out of every five Ghanaian drinking water are contaminated by human waste, putting them at risk of contracting cholera, dysentery, typhoid and polio.

Recently, clay pots have been used in rural homes to make polluted water safe for drinking.

Though it filters out the dirt, heavy metals such as cadmium, mercury and arsenic find their way into the filtered drinking water.

"It had a very good filtration rate but when we did the microorganism and chemical tests they failed," said Dr Bright Kwakye-Awuah of the Department of Physics.

Again the bacteria responsible for food poisoning known as Escherichia Coli is not filtered out.

Dr Bright Kwakye-Awuah

Dr. Kwakye-Awuah and his team began researching into one of the naturally occurring substances in the earth crust known as Zeolite.

Zeolites are commonly used for commercial and domestic water purification.

It has a well-defined pore structure capable of filtering out bacteria and heavy metals.

He collaborated with the Technology consultancy Centre of the University to process this substance and combine with clay to produce what he calls, Zeolite nanopore filters.

The filter is capable of producing a litre of bacteria and heavy metal-free water in an hour.

"For a household, you will need two or more of the filters to meet the requirement of a household of say, five," he hinted.

Interestingly, the filters performed better than ones already on the market including imported ones.

Dr. Awuah is hopeful the filter will reduce cases of waterborne diseases, especially in rural homes.