News / Vancouver

UBC researchers invent cheap, chemical-free way to purify water for rural communities

The water-purification system uses membrane filters and gravity to turn non-potable water into drinking water.

UBC civil engineering professor, Pierre Berube, talks to a fellow researcher about a water purification system that uses membrane filters and gravity to turn non-potable water into drinking water.

UBC Public Affairs/Contributed

UBC civil engineering professor, Pierre Berube, talks to a fellow researcher about a water purification system that uses membrane filters and gravity to turn non-potable water into drinking water.

UBC engineers have found a way to help remote communities gain access to drinking water by creating an affordable water-purification system that doesn’t use chemicals.

The system uses membrane tubes to filter non-potable water into drinkable water, a technique West Vancouver, Abbotsford, and several other B.C. communities already use. But those conventional membrane filters for water use chemicals to keep the membranes from getting clogged up, and UBC professor Pierre Berube has found a way to use gravity to rinse the membranes periodically, erasing the need for chemical cleaners.

It also drops the operational cost of turning grey water into drinking water “to essentially nothing.”

“Often in smaller communities, there is capital available to build the water system but it’s difficult to get operating capital,” said Berube, a civil engineer.

“We’ve eliminated those complex systems.”

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Berube’s water-purification system is essentially self-cleaning, with the only mechanism being a valve that opens and closes, mimicking the effects of turning the system on its head every once in a while to let gravity do its work. Water and air bubbles rush up over the membranes when the valve switches, much like a when a pop bottle is turned upside down, he explained. That movement is enough to dislodge most of clogged debris.

Pierre Berube shows off the membrane tubes that have pores so small even a virus couldn't fit through.

UBC Public Affairs

Pierre Berube shows off the membrane tubes that have pores so small even a virus couldn't fit through.

The lack of chemicals also has the added benefit of allowing microbiology communities to grow on the membranes, surviving on the contaminants stuck on the outside of the tubes.

“Those micro organisms will slowly eat away at those retained contaminants. They munch away on [them],” said Berube.

His team is currently using a test system installed in West Vancouver to put the finishing touches on the design. The water, although 100 per cent safe to drink, is not going to residents, Berube said.

That opportunity will go to a First Nations community on the west side of Vancouver Island when the system is ready, he said. Berube is working with Indigenous and Northern Affairs Canada to bring the technology to that community as well as other remote places. 

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