The microbiological diversity associated with mining environments is a very
well proven fact. One of the communities appearing in these environments i
s that formed by anaerobic sulphate-reducing bacteria (SRB) which can be us
ed for the decontamination of acid mine drainage waters. In this work, the
potential of a mixed population of SRB, isolated from the bottom of a pyrit
ic tailing pond situated in the Spanish pyritic Belt, has been investigated
with the main objective of treating the effluent generated in the same dis
posal site. The efficiency of the system is based on the presence of an imp
ortant amount of reducing agents contained in the acid mine drainage receiv
ed in the pond Results showed that this option is effective for the precipi
tation of the dissolved metals (copper and iron), for the reduction and rem
oval of sulphates and even for the alkalising of the waters. SRB were able
to remove up to 9,000 ppm of sulphate ion efficiently, to grow in the prese
nce of up to 100 ppm of copper and 30 ppm of iron, and alkalise the medium,
provided that this was not extremely acidic (pH >4). Finally, according to
the results obtained, the possibility of applying this method to the treat
ment of a real effluent is discussed. (C) 2001 Elsevier Science Ltd. All ri
ghts reserved.