Thursday, October 2, 2008: 9:00 a.m.
There are basically three kinds of passive treatment technologies for treating mining influenced water (MIW). Aerobic Cells containing cattails and other plants are typically applicable to coal mine-derived MIW where iron and manganese and mild acidity are problematic. Biochemical Reactors (BCRs) are typically applicable to metal mine drainage with high acidity and a wide range of metals as well as non-traditional parameters like nitrate and selenium. Lastly, Abiotic, Limestone-Based methods for treating net-acidic MIW have been effective in adding alkalinity. Most passive treatment systems employ one or more of these cell types. The track record of aerobic cells and limestone-based methods in treating coal mine drainage is impressive, especially back in the eastern coalfields of the US. BCRs have tremendous potential at metal mines and coal mines but have not seen as wide an application.
This paper presents the advantages and disadvantages the various passive treatment approaches and is an introduction to the wide range of remediation design options available to practitioners of passive treatment. Rather than propose “cookbook” designs, the paper details a recommended staged-approach of laboratory-, bench-, and pilot-scale testing which has been shown to increase the likelihood of a successful design, especially for MIW with complex chemistry.
Additional Key Words: Constructed wetlands, acid mine drainage, heavy metals, sulfate reducing bioreactors