Scientists use llama droppings to help combat water pollution Scientists from Newcastle University are using llama droppings to help combat environmental problems caused by polluted water seeping from abandoned silver and tin mines in the Bolivian Andes.

The project is being spearheaded by Paul Younger, Professor of Hydrogeochemical Engineering at Newcastle University. It has been adapted from a community-based natural regeneration technique which uses waste materials to treat polluted mine waters. Professor Younger pioneered the technique, along with scientists and engineers from the University working in partnership with the residents of former mining communities in North East England, who called him in to help them address the threat to their environment caused by polluted water draining from disused mines.

Mine water has a high acid content and is extremely damaging to the ecology of the surrounding areas. The scientific basis for the regeneration technique, which involves the creation of 'low-tech' bioreactors constructed in the form of wetlands with a substrata of compost and limestone, is called bacterial sulphate reduction. Bacteria living in the compost and limestone use dissolved sulphate, found in abundance in mine water, as an energy source, producing sulphide. The sulphide then reacts with the dissolved iron and traps it, as iron sulphide, in the compost bed. This process also raises the pH in the water and generates alkalinity.

This technique has been so successful in the North East of England that it is now being customised and exported for similar problems in other countries and is helping to make Newcastle University Europe's leading centre for minewater research.

In the Cordillera Real of the Andes, perennial drainage from abandoned tin and silver mines is grossly polluting the main water supply of the capital city, La Paz. Some of this extremely polluted water is used untreated by impoverished local residents for
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Contact: Melanie Reed
press.office@ncl.ac.uk
44-191-222-5791
University of Newcastle upon Tyne
30-Jan-2002