The U.S. Bureau of Mines Salt Lake City Research Center has developed porous polymeric beads containing immobilized nonliving biological materials for extracting metal contaminants from waste waters. Immobilized biological materials include peat moss, algae, biological polymers, and other materials that demonstrate high affinities for heavy metals. The beads, designated as bio-fix beads, have distinct advantages over traditional methods of utilizing biological materials in that they have excellent handling characteristics and can be used in conventional processing equipment or low-maintenance systems. Toxic metals such as copper, cadmium, zinc, lead, and mercury are several of the many heavy metals effectively removed from mine waste waters using bio-fix beads. Continuous cyclic testing indicated that the beads continued to produce treated effluents that met national drinking water standards (ndws) after 150 loading-elution cycles. Adsorbed metals were removed from the beads using dilute mineral acids. In many cases, the extracted metals were further concentrated to enable processors to reclaim the metals, thus minimizing the generation of a hazardous sludge. Tests indicated that use of the beads in a low-maintenance system was particularly effective for treating remote acid mine drainage waters and small toxic seeps from hard-rock mining districts.
Paper in Randol Gold Forum, Cairns '91. Randol, Golden, Colorado, PP. 113- 118