As Guillaume Nielsen peels back the plastic seal on a glass jar, a powerful stench wafts free.
It smells like a combination of rotten eggs and a mouldy coffee cup that’s been left unwashed for far too long.
“It’s good,” Nielsen says, laughing. “When it smells bad, it means the bacteria is working.”
Bacteria. Most of us think of it only as something to be destroyed, sanitized, washed away. We reach for the penicillin, but Nielsen reaches for another pipette to sample his biological brews.
He is a PhD student with the Institut National de la Recherche Scientifique, and he has 100 jars full of bacteria, rocks, gravel, and – most importantly – waste water from the Keno mine site.
Working in collaboration with Yukon College’s Centre for Northern Innovation in Mining and the Yukon Research Centre’s Cold Climate Innovation group, Nielsen is testing the bacteria’s ability to remove heavy metals from contaminated water sources, and if the system will work in the North’s harsh climate.
If he gets it right, bioremediation could be used as a cost-effective way to clean up mine sites across the North.
The way it works is actually quite simple. The bacteria, if provided with the right mix of environmental substrates – like rocks, gravel, biochar, vegetation and oxygen – will eat up the heavy metals and essentially poop out organic matter and water.
“The game is to find the right balance of ingredients to keep the bacteria happy,” Nielsen explained.
The experiments start off with small samples placed in re-used jam jars where they are allowed to ferment for a while. After that, the most successful concoctions are placed in larger bioreactors, which look like pieces of clear sewer pipe stacked together. The substrates are added to the tubes, and contaminated mine water is poured in from the top.
As the water filters down through the bioreactors and the bacteria do their work, it eventually comes out the bottom to be sampled and compared to the unfiltered water.
Scientists have been studying using bacteria to clean up contamination in the mining industry for almost three decades, explained Nielsen’s PhD supervisor, Amelie Janin. The trick for Nielsen’s project is to find a way to make it work in the Yukon’s frigid winters.
That’s never been done before, she said.
“To try to apply this research in cold climates is exciting and very new,” Nielsen said.
“We know that the temperature affects a lot – how the bacteria lives. It grows more slowly, and is less efficient. We also want the substrates to be easily found in Northern environments,” he said.
That’s important, because for isolated Northern industry sites, companies need to be able to use whatever materials are around when it comes time to remediate closed mines.
If Nielsen’s research is cutting-edge, so is the program allowing him to do it.
A lot of PhD work is done in the silo of academia, with students earning their degrees in isolation from the working world. They end up teaching other students, and knowledge developed sometimes has a hard time reaching the outside, Janin said.
Nielsen’s project is different. It’s being done as a partnership between the INRS and Yukon College, with help and funding from Alexco Resources. The money allows Nielsen’s work to progress, but Nielsen also has the added benefit of using the company’s Keno Hill mine site for large-scale testing once he gets the recipe close to completion.
“By incorporating Nielsen’s focus and expertise, we’ll work toward solving mine water treatment challenges by using local products, thereby limiting the need to ship materials to remote mining sites from outside the Yukon,” said Jim Harrington, president of the Alexco Environmental Group, in a release.
The project is expected to last three years.
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