Environmental problem, acid mine drainage

Although calcium arsenates may readily precipitate in acid mine drainage and form in flue gas treatment systems, Robins and Tozawa (1982) warn that the compounds may not have long-term stability, which could lead to disposal and environmental problems. Besides dissolving under acidic conditions, the presence of carbonate, bicarbonate, or CO2 may decompose calcium arsenates. When calcium arsenates react with CO2, calcium carbonate forms and the arsenic could be released into the environment (Ghimire et al., 2003, 4946 Jing, Korfiatis and Meng, 2003, 5055-5056). 

Acid mine drainage (AMD) from abandoned coal and metal mining is a serious environmental problem that has affected thousands of miles of streams and waterways. AMD is created via the oxidation of sulfide minerals, such as pyrite see reactions (10.13) and (10.14) ... 

Another environmental problem associated with sulfur is called acid mine drainage. Groundwater in both coal and metal sulfide mines can become contaminated with sulfuric acid. This is particularly a problem in the coal mines of the Appalachian Mountains. Coal deposits often contain pyrites. Metal ores can include toxic salts of zinc, lead, arsenic, copper, and aluminum. In both cases, acid mine drainage can kill fish and other aquatic organisms, as well as corrode boats and piers. Streams sometimes turn red in color because of the iron content from the mine... 

Acid mine drainage (AMD) is one of the largest environmental problems faced by mining and mineral industries globally (Akcil and Koldas 2006 Akabzaa et al. 2007). AMD is mainly associated with sulphide-rich metalliferous ore deposits, viz., copper, lead, zinc, gold, nickel, tin, and uranium mines (Naicker et al. 2003 Nieto et al. 2007) and coal mines (Bell et al. 2001 Sahoo et al. 2012), which were formed under marine conditions and contain abundant reactive framboidal pyrite (Carrucio and Fern 1974 Campbell etal. 2001). In Table 1, we present a list of well-known AMD sites worldwide. 

Acid drainage is a persistent environmental problem in many mineralized areas. The problem is especially pronounced in areas that host or have hosted mining activity (e.g., Lind and Hem, 1993), but it also occurs naturally in unmined areas. The acid drainage results from weathering of sulfide minerals that oxidize to produce hydrogen ions and contribute dissolved metals to solution (e.g., Blowes et al., 2005). 

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