ADDING SODIUM-HYDROXIDE TO STUDY METAL REMOVAL IN A STREAM AFFECTED BY ACID-MINE DRAINAGE

Fisher Creek, a stream affected by acid mine drainage in the Beartooth Mountains of Montana, was studied to determine the extent to which co pper and zinc would be removed from stream water when pH was increased by a pulse of sodium hydroxide. As stream pH increased, copper and zi nc were rapidly and completely removed from stream water by adsorption or coprecipitation with freshly precipitated hydrous ferric oxide. In practice, the best way of increasing the pH of streams impacted by ac id mine drainage would be to increase the alkalinity of tributaries by lining their channels with limestone rock.