The U.S. Bureau of Mines has developed porous polymeric beads containing immobilized biological materials. The beads, designated as bio-fix beads, readily remove cadmium, zinc, manganese, copper, and other metals from acid mine drainage waters. The beads are fabricated from abundant and inexpensive raw materials, demonstrate long-term chemical stability, and are easily regenerated using dilute sulfuric acid. Owing to these characteristics and their physical stability in varied climatic situations, bio-fix beads were utilized for wastewater treatment in a column circuit and in a low- maintenance system. The low-maintenance system consisted of enclosing beads in porous polypropylene bags, placing the bags in a trough or directly in a waste stream, and allowing wastewater to flow through the bags. Initial field tests indicated that beads containing sphagnum peat moss beads sorbed toxic and heavy metal ions from small seeps and acid mine drainage waters. Parameters investigated included equilibrium metal loadings, metal sorption rates, and ph and temperature effects on metal loading. Data from these initial tests will be used to design and operate pilot-scale treatment circuits.
Proceeds 2nd Int'l. Conf. Abatement of Acidic Drainage. Quebec, Canada, V. 1, PP. 283-299