Control of Acid Mine Drainage Using Anionic Surfactants.
Proc 1st Int Mine Water Congr Budapest Hungary 1982 Apr; :51-63
The U.S. Bureau of Mines determined that inexpensive bactericides can be used to control the rate of pyrite oxidation and thereby reduce the acidity of drainage. At concentrations of 25 mg/l or greater, certain biodegradable anionic surfactants, such as sodium lauryl sulfate, kill the acidophilic iron-oxidizing bacteria in the pyritic material. To prevent repopulation, the surfactant was incorporated into rubber pellets, from which the surfactant is gradually released over time. After an initial application of surfactant solution, these pellets were placed so as to intercept and treat infiltrating rainwater on a surface mine or refuse pile. The technique was tested in small-scale laboratory and field experiments. Treatment resulted in titratable acidities that were 75 pct lower than those of controls in laboratory simulations, 67 pct lower when one of two 25-metric-ton coal refuse piles was treated, and 95 pct lower when a test was conducted on isolated sections of an acid-producing surface mine. Large-scale field tests were conducted to provide information on adsorption of the surfactant by fine-grained particles and to determine if downstream concentrations of surfactant pose a potential environmental problem. Preliminary results indicated surfactant concentrations of the effluent of 0.1 Mg/l or less, well within the world health organization's suggested stream concentrations of less than 1.0 Mg/l.
Proc. 1st Int. Mine Water Congr., Budapest, Hungary, Apr. 19-23, 1982, PP. 51-63