TECHNICAL PAPERS
Industrial Scale Non-Biological Selenate Removal
This paper explores how industrial scale selenium water treatment achieves ultra-low discharge limits using non-biological processes. It focuses on the removal of selenate from mine-impacted water and outlines how technologies like Selen-IX overcome the limitations of biological treatment systems in mining environments.
TECHNOLOGY
Selen-IX™ (Ion Exchange + Electro-reduction)
APPLICATION
Industrial selenium removal from mine water
LOCATION
Canada and USA (multiple sites)
PUBLISHED
Mine Water Solutions 2022
AUTHORS
David Kratochvil, H.C. Liang, Brent Baker, Veneil Sundar
SCOPE
Industrial implementation, pilot validation, process selection criteria
KEY TOPICS COVERED
- Industrial scale selenate removal using non-biological treatment
- Limitations of biological selenium treatment systems
- Selen-IX™ process combining ion exchange and electro-reduction
- Case examples including Kemess and coal ash pond treatment
- Criteria for selecting non-biological selenium treatment
TECHNICAL SUMMARY
Selenium management in mining operations has become increasingly complex due to stricter environmental regulations and long-term risks linked to bioaccumulation. Modern standards now go beyond water quality to include fish tissue criteria, making dilution alone insufficient for compliance.
Historically, biological treatment systems were widely used, but these have shown limitations including instability under variable flow conditions, production of harmful organo-selenium compounds, and uncertainty around long-term residue stability.
This paper outlines the development of non-biological selenate removal using the Selen-IX™ process, which combines ion exchange to selectively remove and concentrate selenate, followed by electro-reduction to convert it into a stable solid residue.
At the Kemess site, the system achieved selenium concentrations below 2 ppb, with results even reaching below 0.5 ppb. Additional applications include coal ash pond treatment and combined sulphate and selenium removal systems, demonstrating flexibility, scalability, and reliable performance under varying operating conditions.
The paper concludes with criteria for selecting non-biological treatment, particularly where ultra-low discharge limits, operational flexibility, and long-term environmental stability are required.
KEY FINDINGS
- Achieved selenium concentrations below 2 ppb, with results below 0.5 ppb in industrial operation
- Eliminated reliance on dilution to meet environmental compliance
- Successfully scaled non-biological selenate removal across multiple industrial sites (2020–2022)
- Established clear criteria for selecting non-biological treatment over biological systems