The NRC's BEAST gives Arctic wastewater a clean slate

New NRC technology helps small and remote communities treat wastewater effectively – and uncover hidden energy.

Mechanical sewage treatment plants in large municipalities take care of business out of sight and mind. These sophisticated facilities remove contaminants and expel clean water into nearby rivers and lakes.

But the scene in small, remote communities is very different. They rarely have the resources to build such facilities – or local specialists to operate them. And running them takes diesel-generated electricity that inflates operating costs and boosts greenhouse gas (GHG) emissions.

Many remote and fly-in communities across Canada's North have opted for sewage lagoons that are less expensive, simple to operate and easy to maintain. They reduce organic impurities and bacteria in wastewater before discharging it into rivers, lakes or oceans. But these open lagoons are frozen for most of the year, so often cannot provide an acceptable level of wastewater purification.

Scientists at the National Research Council of Canada (NRC) have launched a custom solution to tackle these challenges. The NRC’s new and recently patented BioElectrochemical Anaerobic Sewage Treatment (BEAST) technology promises lower-cost but effective purification with a small energy footprint. As a stand-alone facility or integrated into existing sewage lagoons, it is easy to operate and maintain.

Robert Cooke, Manager of Clean Energy and Infrastructure, Polar Knowledge Canada (POLAR) points out that in stakeholder engagement meetings across the Canadian Territories and Inuit Nunangat, participants emphasized that they wanted a cleaner and healthier environment, safe drinking water and better waste management. When POLAR looked into solutions for addressing some of these concerns, they realized that the NRC had already developed technology that could meet their expectations.

"The NRC's BEAST reactor is ideal for tackling these challenges," he adds. "It can customize wastewater treatment solutions to the unique needs of northern communities and help reduce reliance on fossil fuels for energy generation."

Unlike conventional wastewater treatment plants, which inject air into bioreactors to accelerate the growth of bacteria that decompose organics, BEAST uses very little air. Instead, it applies 1.2 to 1.5 volts of electricity to speed biodegradation. This method costs about 50% less and works even at near-zero temperatures.

According to Dr. Boris Tartakovsky, the NRC's scientific lead on the project, a key feature of the recently patented technology is its ability to recover energy from organic waste, either in the form of biogas or heat. "This provides a local renewable energy source that can help reduce communities' diesel consumption," he says.

Boots on the ground

In 2020, Dr. Tartakovsky and NRC researcher Dr. Yehuda Kleiner sent the first bench-scale BEAST reactor from Montréal to the Canadian High Arctic Research Station (CHARS) in Cambridge Bay, Nunavut. After initial test results confirmed its effectiveness, it was installed on the CHARS campus in a triplex that houses visiting researchers and students.

POLAR science ranger Jason Etuangat operated the BEAST during the pilot, sending samples to the NRC in Montréal for analysis. He reports that the reactor is easy to run and maintain – and "you can see dirty water go in and clean water come out."

Larger versions were also tested in a variety of conditions and geographic locations, including Montréal, Alaska and northern Alberta. Dr. Tartakovsky reports that experiments with BEAST reactors in a range of sizes have shown promising results. "The removal rate of organics is generally upwards of 90% within a retention time of less than 2 days," he says. Sewage lagoons typically require weeks or months to achieve such efficiency.

Currently a 300-litre bioelectrochemical sewage treatment and energy recovery reactor is being installed in Nuuk, Greenland – 180 kilometres across Davis Strait from Iqaluit. In addition, a 24,000-litre demonstration plant, the first in the world at this scale, is operational in Bezanson, Alberta.

Cleaning up the future

Preparations are underway for further trials in different configurations and venues in the Canadian North. The technology can be easily sized to meet various needs, whether servicing one house or a community of thousands.

On a larger scale, the BEAST reactor can provide enough gas to heat moderately-sized enclosures such as workshops, storage areas and greenhouses – or run specially designed power generators. Future research at community levels will address effective ways to handle the biomethane it produces.  

The NRC sees much more potential ahead. The technology could be deployed on Arctic cruise ships and other vessels, in northern mines or during military exercises in the Arctic. With its low energy requirement, it can run on solar power alone. This opens up possibilities for small and remote communities in the developing world that are not connected to an electrical grid.

"Our long-standing relationship with POLAR has enabled us to move BEAST from the lab onto the field," says Dr. Tartakovsky. "To further advance the technology and explore different applications, we encourage potential partners from industry, academia and government to collaborate with us as well."