Overview
- The Heriot-Watt University and University of South Africa team presented the findings at the International Mine Water Association 2025 conference.
- Magnesium oxide nanoparticles made from locally sourced magnesite precipitated ferric iron, which was then reacted with hydrochloric acid to produce the coagulant.
- In laboratory trials, the recovered chemical removed over 99% of aluminum, iron, and chromium from river water under SANAS/ISO/IEC 17025 verification.
- Test samples included drainage from an active coal mine in Mpumalanga, underscoring a national challenge of about 400 million liters of acidic effluent discharged daily.
- The researchers describe the approach as a circular-economy, low-energy option with potential for industrial scale-up following pilots in rural and peri-urban areas.