Abstract: Permeable reactive barriers are an emerging alternative to traditional pump and treat systems for groundwater remediation. This technique has progressed rapidly over the past decade from laboratory bench-scale studies to full-scale implementation. Laboratory studies indicate the potential for treatment of a large number of inorganic contaminants, including As, Cd, Cr, Cu, Hg, Fe, Mn, Mo, Ni, Pb, Se, Tc, U, V, NO3, PO4 and SO4. Small-scale field studies have demonstrated treatment of Cd, Cr, Cu, Fe, Ni, Pb, NO3, PO4 and SO4. Permeable reactive barriers composed of zero-valent iron have been used in full-scale installations for the treatment of Cr, U, and Tc. Solid-phase organic carbon in the form of municipal compost has been used to remove dissolved constituents associated with acid-mine drainage, including SO4, Fe, Ni, Co and Zn. Dissolved nutrients, including NO3 and PO4, have been removed from domestic septic-system effluent and agricultural drainage.

Abstract: BASX Systems LLC has developed a treatment system based on ceramic membranes for the removal of heavy metals from an acid mine drainage stream. This stream also contained volatile organic compounds that were required to be removed prior to discharge to a Colorado mountain stream. The removal of heavy metals was greater than 99% in most cases. A decrease of 30% in chemicals required for treatment and a reduction by more than 75% in labor over a competing technology were achieved. These decreases were obtained for operating temperatures of less than 5 degrees C. This system of ceramic microfiltration is capable of treating many different types of acid mine waste streams for heavy metals removal.