Environmental Control Technology Program Studies at Argonne National Laboratory: Surface Mine Effluents

摘要

The chemical quality of surface waters in areas characterized by coal strip mining is the result of both local and regional factors, including composition of coal, overburden, and underclay; mobility of selected chemical constituents in rocks, sediments, and minesoils; activity of chemoautotrophic bacteria; mining and reclamation methods and equipment; density of mining operations in a given watershed; seasonal fluctuations in regional stream discharges; and control technologies implemented to treat mine effluents. The major problems associated with mine effluents in the eastern region are acid mine drainage, generated by the oxidation and subsequent hydrolysis of iron disulfide minerals, and high concentrations of dissolved metals and suspended solids. Control technologies commonly utilized to ameliorate these problems include (1) the addition of alkaline reagents such as hydrated lime, soda ash, or sodium hydroxide to neutralize the acid and promote the precipitation of dissolved metals; and (2) the construction of settling ponds to promote the sedimentation of suspended solids. (ERA citation 03:020911)