Field Evaluation of a Bactericidal Treatment to Control Acid Drainage.
Symp Surface Min Hyd Sediment and Reclam Lexington Kentucky 1981 Dec; :325-330
The Bureau of Mines demonstrated that inhibition of an iron- oxidizing bacterium, thiobacillus ferrooxidans, slows the rate of pyrite oxidation and thereby reduces acidity in mine drainage from surface mines and coal refuse piles. Long-term inhibition is accomplished at low cost by controlled release of sodium lauryl sulfate (sls), an anionic surfactant, from rubber pellets. In addition, surfactant solution is applied so as to treat each acre- foot of pyritic material with the equivalent of 7 lb of dry surfactant; excess surfactant must be provided to saturate the adsorption capacity of the material. Results of laboratory studies were utilized to optimize both phases of the treatment procedure. Field tests were conducted at inactive, acid-producing surface mines and coal refuse piles at sites in Ohio, Pennsylvania, and west Virginia. Effectiveness of the technique required good infiltration of rainfall. Percolation tests at a partially reclaimed site in West Virginia indicated that overburden that had been compacted may be too impermeable for the surfactant to infiltrate to the pyritic material. In contrast, 50- to 95-pct reductions in acidity were observed in previous small-scale tests at more permeable sites.
Symp. Surface Min. Hyd., Sediment. and Reclam., Lexington, Kentucky, Dec. 7-11, 1981, PP. 325-330