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Passive Treatment of Acid Mine Drainage in Bioreactors using Sulfate‐Reducing Bacteria
Author(s) -
Neculita CarmenMihaela,
Zagury Gérald J.,
Bussière Bruno
Publication year - 2007
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2006.0066
Subject(s) - acid mine drainage , bioreactor , sulfate reducing bacteria , sulfate , effluent , sulfide , environmental science , environmental chemistry , chemistry , bioremediation , metal toxicity , pulp and paper industry , waste management , environmental engineering , contamination , heavy metals , ecology , organic chemistry , engineering , biology
ABSTRACT Acid mine drainage (AMD), characterized by low pH and high concentrations of sulfate and heavy metals, is an important and widespread environmental problem related to the mining industry. Sulfate‐reducing passive bioreactors have received much attention lately as promising biotechnologies for AMD treatment. They offer advantages such as high metal removal at low pH, stable sludge, very low operation costs, and minimal energy consumption. Sulfide precipitation is the desired mechanism of contaminant removal; however, many mechanisms including adsorption and precipitation of metal carbonates and hydroxides occur in passive bioreactors. The efficiency of sulfate‐reducing passive bioreactors is sometimes limited because they rely on the activity of an anaerobic microflora [including sulfate‐reducing bacteria (SRB)] which is controlled primarily by the reactive mixture composition. The most important mixture component is the organic carbon source. The performance of field bioreactors can also be limited by AMD load and metal toxicity. Several studies conducted to find the best mixture of natural organic substrates for SRB are reviewed. Moreover, critical parameters for design and long‐term operation are discussed. Additional work needs to be done to properly assess the long‐term efficiency of reactive mixtures and the metal removal mechanisms. Furthermore, metal speciation and ecotoxicological assessment of treated effluent from on‐site passive bioreactors have yet to be performed.