Vancouver Sun: Microwave-based system takes stink out of manure management

A spin-off company from the University of British Columbia is promising to make a crap job a good deal easier and cleaner, with a scalable waste-processing system.

Manure management practices on local dairy farms routinely raise a stink from their residential neighbours when the slurry is sprayed on fields, as well as from American farmers who complain of cross-border water pollution resulting from excess nutrient runoff.

Boost Environmental Systems, a new firm, is testing a system that uses microwave heat and hydrogen peroxide to drastically reduce the volume and the composition of manure and sewage solids. The resulting waste is easily digestible with existing systems and the liquid is a rich source of a commercially valuable fertilizer called struvite.

Demonstration-sized units are installed at the UBC Dairy Education Centre in Agassiz and the James Wastewater Treatment Plant in Abbotsford, according to Chief Technology Officer Asha Srinivasan, a post-doctoral fellow at UBC. A third pilot installation is being planned with Metro Vancouver.

“The beauty of the microwave system is that it is very modular and scalable, so we can vary from a 25-kilowatt unit that will serve a small dairy farm or we can stack up additional systems to serve a sewage plant,” she said. “The system we have at the dairy centre is good for 120 milking cows and that is the median size of a dairy farm in the Fraser Valley.”

Manure treatment is more than just a cosmetic — or olfactory — issue, said Srinivasan, who holds a PhD in environmental engineering.

Excess nutrient runoff from applications of manure to crops can lead to algae blooms that kill fish, plus nitrates and pathogens can enter ground and surface drinking water sources where they pose a threat to human health, according to the B.C. Ministry of Environment. Manure spraying also leads to ammonia and particulate air pollution.

The Ministries of Agriculture and Environment are currently working with industry groups to overhaul provincial rules for manure management. A water quality task group led by B.C. and the State of Washington is examining policy and practices to reduce fecal coliform in transboundary waters. Both could help create a hungry market for the Boost system.

Boost technology also has the potential to save communities tens of millions of dollars in infrastructure costs, by massively reducing the volume of waste that must be processed from sewage. 

“The volume of solids that come out of the system is reduced drastically and complex organics are broken down into simpler forms,” she said. That means the volume of material treated with anaerobic digesters is reduced and the time required to process it is reduced by 50 per cent.

“With our system, you don’t need to build huge digesters or increase capacity and that cuts down capital costs,” she said.

The technology used by Boost is licensed from UBC, the result of 14 years of effort by Srinivasan’s co-inventors and business partners engineering professor Victor Lo and Ping Liao. Funding for the research has come from industry partner Opus International Consulting, the Natural Sciences and Engineering Research Council of Canada (NSERC) and Mitacs Canada, a non-profit that funds research innovation companies.

Srinivasan received the Mitacs Global Impact Entrepreneur Award last month.

By: Randy Shore