For tiny, remote communities unable to have a full-scale wastewater treatment plant, or that are located in frigid climates that make sewage lagoons unfeasible, they could be zapping wastewater with electricity instead, say scientists at National Research Council Canada (NRC).
Bioelectrochemical anaerobic sewage treatment — nicknamed BEAST technology — offers low-cost but effective purification with a small energy footprint. Unlike conventional wastewater treatment plants that inject air into bioreactors to accelerate bacterial growth and breakdown organics, BEAST uses very little air and instead applies some 1.5 volts of electricity to speed biodegradation, according to Dr. Boris Tartakovsky, the NRC’s scientific lead on the project.
“Our longstanding relationship with POLAR (Polar Knowledge Canada) has enabled us to move BEAST from the lab onto the field,” said Dr. Tartakovsky in a statement to media. “To further advance the technology and explore different applications, we encourage potential partners from industry, academia and government to collaborate with us as well,” he added.
Not only does the bioelectrical method cost about 50% less and operate well at near-zero temperatures, it can help to recover energy from organic waste, either in the form of biogas or heat to provide a local renewable energy source for fly-in communities that often depend heavily on diesel. The reactor can provide enough gas to heat moderately-sized enclosures such as workshops, storage areas and greenhouses, or run custom generators.
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“The removal rate of organics is generally upwards of 90% within a retention time of less than two days,” explained Tartakovsky, as sewage lagoons typically require weeks or months to achieve such efficiency.
Initial testing on BEAST took place through the Canadian High Arctic Research Station in Cambridge Bay, Nunavut. Larger versions were also tested in a variety of conditions and geographic locations, including Montreal, Alaska and northern Alberta.
Currently, a 300-litre bioelectrochemical sewage treatment and energy recovery reactor is being installed in Nuuk, Greenland, some 180 kilometres across the Davis Strait from Iqaluit. Additionally, a 24,000-litre demonstration plant — the first in the world at this scale — is operational in Bezanson, Alberta.
The technology could be deployed on Arctic cruise ships and other vessels, in northern mines, or during military exercises in the Arctic, according to the National Research Council Canada.