Treating water in the oil sands with electricity instead of chemicals

Researchers at the Schulich School of Engineering are developing an electrochemical process to remove and destroy contaminants from treated water without adding chemicals or producing secondary wastes—a process that will reduce costs, increase recycling of water and decrease environmental impacts in the oil sands.

“One of the ways to treat water is to add chemicals, we want to replace that by using electrical currents,” says Ted Roberts in the Department of Chemical and Petroleum Engineering. “You pass a DC current through the water that you’re treating and you carry out reactions to remove contaminants.”

Roberts and co-investigator, Maen Husein, have received CFI funding to set up a lab to develop sustainable electrochemical technology to treat produced water in the oil sands, such as the water that’s used for SAGD (steam-assisted gravity drainage) operations.  

Current chemical treatment processes produce secondary waste and sludges which need to be disposed of, whereas the electrochemical process will produce far less or no waste at all. The current process of adding chemicals to the water also makes it difficult for operators to recycle the water.

"With this electrical process, operators would add less chemicals to the water, and in principle we may be able to increase the recycle rates which means you’re fresh water demand is going to be lower,” says Roberts. “You can take less water out of the Athabasca River”

The electrochemical process will use electrical energy, but that will generally cost less than chemicals used now. “With any new technology, you’re not going to get it implemented unless it’s cost effective or cost competitive with existing technologies,” says Roberts. “So although the environmental benefits are important you’ve got to try to find a solution that’s cost effective.”

He says so far, the oil and gas industry doesn’t employ a lot of electrochemical technology, something that he hopes will change with the development of cost effective electrochemical technology to treat water.