Yukon College Home Research & Innovation Pilot Bioreactors Commission and Operation at Minto Mine - 2014 & 2015 Results (Report)

Pilot Bioreactors Commission and Operation at Minto Mine - 2014 & 2015 Results (Report)

Pilot Bioreactors Commission and Operation at Minto Mine - 2014 & 2015 Results (Report)

Amelie Janin

Four (4) pilot anaerobic bioreactors were commissioned at the Minto mine site, in the summer of 2014 by Amelie Janin, NSERC industrial Research Chair at Yukon College, and Capstone staff (Figure 1). Installation was completed on August 7th, 2014 and operation started on August 20th 2014. Bioreactor substrate composition varied amongst the bioreactors and included mixtures of creek sediments, low-grade or river gravel, wood chips or biochar (a coal made out of wood).  Monitoring of the bioreactors stopped on September 23rd 2014 when the bioreactors were dismantled and stored for the winter.
Preliminary results obtained during the one month of operation after commissioning suggested that:
• Bioreactors were able to reduce selenium below Minto Mine’s effluent discharge limits, as regulated under its water use licence (QZ96-006 Amendment #8);
• Copper concentrations were reduced by the bioreactors to a lesser extent than selenium concentrations;
• Two out of the four bioreactors affected the pH of the effluent so that the effluent did not meet the mine effluent discharge limits;
• Chipped wood seemed to release organic acid in the effluent (lower pH, higher Total Organic Content) in the first month of operation; and
• No exceedance of the mine effluent discharge limits were observed for NO3, NO2 and NH3, although high PO4 (not regulated) was observed in the effluent of the biochar amended reactor.

Janin A., Herbert R. and Gjertsen J. 2015. Pilot Bioreactors Commission and Operation at Minto Mine – 2014 & 2015 Preliminary Results, Dec 2016