Nickel, manganese and copper removal by a mixed consortium of sulfate reducing bacteria at a high COD/sulfate ratio.
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Data
2014
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Resumo
The use of sulfate-reducing bacteria (SRB) in
passive treatments of acidic effluents containing heavy
metals has become an attractive alternative biotechnology.
Treatment efficiency may be linked with the effluent conditions
(pH and metal concentration) and also to the amount
and nature of the organic substrate. Variations on organic
substrate and sulfate ratios clearly interfere with the biological
removal of this ion by mixed cultures of SRB. This
study aimed to cultivate a mixed culture of SRB using different
lactate concentrations at pH 7.0 in the presence of Ni,
Mn and Cu. The highest sulfate removal efficiency obtained
was 98 %, at a COD/sulfate ratio of 2.0. The organic acid
analyses indicated an acetate accumulation as a consequence
of lactate degradation. Different concentrations of metals
were added to the system at neutral pH conditions. Cell
proliferation and sulfate consumption in the presence of
nickel (4, 20 and 50 mg l-1), manganese (1.5, 10 and
25 mg l-1) and copper (1.5, 10 and 25 mg l-1) were measured.
The presence of metals interfered in the sulfate biological
removal however the concentration of sulfide
produced was high enough to remove over 90 % of the
metals in the environment. The molecular characterization of
the bacterial consortium based on dsrB gene sequencing
indicated the presence of Desulfovibrio desulfuricans,
Desulfomonas pigra and Desulfobulbus sp. The results here
presented indicate that this SRB culture may be employed for
mine effluent bioremediation due to its potential for
removing sulfate and metals, simultaneously.
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Palavras-chave
Organic acids, Bioremediation, Lactate degradation, Metal resistance
Citação
BARBOSA, L. P. et al. Nickel, manganese and copper removal by a mixed consortium of sulfate reducing bacteria at a high COD/sulfate ratio. World Journal of Microbiology & Biotechnology, p. 1-10, 2014. Disponível em: <http://link.springer.com/article/10.1007%2Fs11274-013-1592-x>. Acesso em: 10 jan. 2017.