This project compared three methods for removing salts and minerals from brackish groundwater to make it suitable for drinking. Brackish water is water with more salt than fresh water, but less than seawater.
We partnered with Northern Cross (Yukon) Ltd., on the research because the company is looking into treatment options for drinking water at its remote camp site at Eagle Plains in Northern Yukon. However, the results of this experiment could greatly reduce the environmental footprint of any industry or individual needing to treat brackish water.
We tested the three methods in the Yukon Research Centre lab. Option A was a ''classic'' ion exchange treatment. Option B used capacitive deionization, which works by passing water between two carbon electrodes. This treatment method is used on a large scale in Spain to turn seawater into drinking water, and in China to recover drinking water from wastewater. We tested a portable unit that requires a low voltage and can be powered by a solar panel, making it ideal for remote use in Yukon. Option C used a type of sand filtration and reverse osmosis with an added anti-scaling product.
All three treatment methods had advantages and disadvantages. Method A needed excessive quantities of salt, making it expensive and challenging to operate, especially in a remote location. Option B used the least chemical and energy input, and was most efficient when applied to pre-filtered water. Sand filtration proved efficient at removing high amounts of iron and manganese, and reverse osmosis is already known to be cost effective at polishing pre-treated water to achieve drinking water standards.
In the end, we recommended a combined treatment that involves sand filtration, capacitive deionization and reverse osmosis used in series. This composite method provides drinking water for the least cost, with minimal waste.
Dr. Amelie Janin, NSERC Industrial Research Chair for Colleges in Mine Life Cycle, Yukon Research Centre
Michel Duteau, Research Technician, Yukon Research Centre
Catherine Mallet, Instructor/Coordinator, Yukon Water and Wastewater Operator Program
Tony Radford and Jordan Lord, students, Yukon Water and Wastewater Operator Program, Yukon College
- Duteau M., Janin A. and Mallet C. 2015. Treatment Options for Drinking Water Production from Brackish Well Water at Eagle Plain Base Camp, January 2015, 50 p. 2. Mossad M and Zou L. 2012. A study of the capacitive deionisation performance under various operational conditions. J Hazard Mater 213– 214:491-7. 3. Solis-Correa H, Gomez-Lara J. 1987. Approximation of spherical polyatomic thermochemical radii of general formula MX n z. J Chem Educ 64: 942-943
- Duteau M., Janin A. and Mallet C. 2015. Treatment Options for Drinking Water Production from Brackish Well Water at Eagle Plain Base Camp, January 2015, 50 p.