Red mud's carbon capture clue

An environmental disaster that occurred in Hungary in 2010 could lead to a new way of removing carbon dioxide emissions from the atmosphere. In October 2010 around 1 million cubic metres of highly caustic 'red mud' sludge was released from a waste containment facility near the Hungarian town of Ajka when a retaining wall failed. The red mud, a by-product of aluminium production, contained substantial quantities of the strong base sodium hydroxide (lye) and resulted in dangerously high pH solutions. It also contained a cocktail of potentially toxic metals such as arsenic, chromium, and vanadium. 10 people died as a result of the incident and over 100 were injured. 4000 hectares of land were affected, with Greenpeace describing it as one of the top three environmental disasters in Europe in the last 20-30 years. As part of initial cleanup efforts contaminated water was dosed with acid and gypsum was added to the streams and soils of the surrounding area.