Curing a bad case of acid rock drainage

UBC’s Deborah Roberts, Professor of Engineering. Photo courtesy of University of British Columbia

by Katherine Moore

Researchers at the University of British Columbia announced that they have identified bacteria linked to acid produced at mining sites. The research more than links bacteria to mine acid production, researchers believe that these organisms actually contribute to acid-rock drainage. According to Mining, “Acid

rock drainage (ARD) or acid mine drain-age refers to the acidic water that is created when sulphide minerals are exposed to air and water and, through a natural chemi-cal reaction, produce sulphuric acid. ARD has the potential to introduce acidity and dissolved metals into water, which can be harmful to fish and aquatic life. Preventing and controlling ARD is a concern at oper-ating mine sites and after mine closure. Advances continue to be made in research and the development of technology to improve ARD prediction, prevention, and treatment.”

The two-year UBC study isolated three types of sulphur oxidizing bacteria and two types of iron-oxidizing microbes that are active at low temperatures and con-tribute to the rapid production of acid in mining waste.

“Mining waste is an environmental concern in many parts of the world and currently costs a great deal of time and money to the companies that deal with it responsibly,” says Deborah Roberts, a pro-fessor of engineering at UBC’s Okanagan campus. “Now that we have isolated the type of micro-organisms contributing to this issue, further research may help us manage them with antibiotics, like other bacterial infections.”

Roberts’ research aims to develop a method of waste rock treatment that does not require the waste to be contained in ponds or to be capped in order to avoid exposure. It is an interesting concept, that a mine can be infected with sulphur or iron oxidizing bacteria giving it a bad case of ARD. Perhaps further research will result in the discovery of an antidote, a sort antibiotic which would kill of the acid drainage producing bacteria.

Roberts’ study was recently published in the Canadian Journal of Microbiology.

Leave a Reply

Your email address will not be published. Required fields are marked *