Overview
Topic status: We're looking for students to study this topic.
Iron sulphides are contained in a layer of waterlogged soil, under anaerobic conditions, and whilst they remain undisturbed they are relatively harmless. However, when they are disturbed and exposed to oxygen they can produce sulphuric acid in large quantities. One tonne of iron sulphides can produce about 1.5 tonnes of sulphuric acid when oxidised. After flooding, the build-up of sulphuric acid is released and as the acid moves through the soil profile it releases other pollutants such as heavy metals.
The excavation of iron sulphide soils leads to cases of acid run-off in industry. When acid run-off mixes with stream water, the iron dissolved in the acid water precipitates and smothers plants and the streambed. Most aquatic life needs a minimum pH of 6 to survive. Acid run-off can reduce the pH to as low as pH 2.
Acid sulphates soil run-off affects not only the environment but also the economy and communities, through the decline or failure of fishery and aquaculture industries. The seawater neutralisation of red mud process reduces the causticity of red mud through the formation of hydrotalcite (Mg6Al2(OH)16CO3•xH2O). In acidic conditions hydrotalcite will dissolve and provide a source of hydroxyls for the neutralisation of acid run-off.
- Study level
- PhD, Masters
- Supervisors
- QUT
- Organisational unit
Science and Engineering Faculty
- Research area
- Keywords
- acid sulfate water, red mud, neutralisation, treatment, seawater, acid sulphate
- Contact
-
For more information please contact Dr Sara Couperthwaite.
Emeritus Professor Ray Frost
Professor Graeme Millar
