Abstract: A biological treatment plant is utilized at the Homestake Mine in Lead, SD, to effect detoxification of a daily discharge of 4 million gallons of wastewater. The wastewater matrix requiring treatment contains cyanide, ammonia, toxic heavy metals, anda variable component of toxic chemicals associated with extractive metallurgy and mining operations. Rotating biological contactors (RBCs) are used to attach the biofilm. Cyanides and heavy metals concentrations are reduced by 95-98%. The treated discharge makes up as much as 60% of the total flow in a cold-water trout fishery. This receiving stream, which remained lifeless for over 100 years as a mine drainage, has now become an established trout fishery and recently yielded a state record trout.

Abstract: Spent mushroom substrate (SMS) has been used widely in coal mining regions of the USA as the primary substrate in constructed wetlands for the treatment of coal mine drainage. In laboratory and mesocosm studies, SMS has emerged as one of the substrates for mine water treatment. Provided the pH of the mine water does not fall below 3.0, SMS can be used in the mitigation plan. However, neither Mn nor dissolved ferric Fe appears to be treatable using reducing SMS wetlands. Since after a few years much of the nonrefractive organic carbon in SMS wil have been decomposed and metabolized, carbon supplementation can significantly extend the life of the SMS treatment wetland and improve water treatment. -from Authors