Heavy Metal Removal Processes by
Sulfate-Reducing Bacteria
13
María Isabel Neria-González and Ricardo Aguilar-López
Abstract
Actually, natural phenomena and anthropogenic activities have led to large
environmental pollution in all kinds of ecosystems. From the above exist the
needed to implement technological actions in order to diminish the pollution
problems. Among these technological actions, the biotechnology processes have
the great advantage of high specificity for the removal of chemical compounds as
heavy metals with low energy consumption. The microorganisms are the
biological agents most used in the treatments of polluting compounds, due to
their degradation capacities of organic and inorganic pollutants, but the metals are
not degraded but only can be modified in their redox state, converting them to less
toxic forms. Precipitation and biosorption are the most employed process for
metal ion removal from water. Microalgae, fungi and bacteria have been used
successfully in the removal of metals, but in the last decade, sulfate-reducing
bacteria (SRB) have taken great relevance in the processes of metal removal from
wastewater. The removal of heavy metals is promoted when hydrogen sulfide is
produced; it reacts with metal ion and forms metal sulfides, which are insoluble
and tend to precipitate; it is not the only mechanism by which metal ions are
removed, biosorption mechanisms can also be carried out (with biomass and
production of exo-polysaccharides), immobilization and enzymatic reduction of
the metal ion to less toxic and insoluble forms, but this will depend on the type of
bacteria and their tolerance to metals.
M. I. Neria-González (*)
División de Ingeniería Química y Bioquímica, Tecnológico de Estudios Superiores de Ecatepec,
Ecatepec de Morelos, Edo. México, Mexico
e-mail: mineriag@tese.edu.mx
R. Aguilar-López
Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Ciudad de México, Mexico
# Springer Nature Singapore Pte Ltd. 2021
R. Prasad (ed.), Environmental Pollution and Remediation, Environmental and
Microbial Biotechnology, https://doi.org/10.1007/978-981-15-5499-5_13
367
Sulfate-Reducing Bacteria
13
María Isabel Neria-González and Ricardo Aguilar-López
Abstract
Actually, natural phenomena and anthropogenic activities have led to large
environmental pollution in all kinds of ecosystems. From the above exist the
needed to implement technological actions in order to diminish the pollution
problems. Among these technological actions, the biotechnology processes have
the great advantage of high specificity for the removal of chemical compounds as
heavy metals with low energy consumption. The microorganisms are the
biological agents most used in the treatments of polluting compounds, due to
their degradation capacities of organic and inorganic pollutants, but the metals are
not degraded but only can be modified in their redox state, converting them to less
toxic forms. Precipitation and biosorption are the most employed process for
metal ion removal from water. Microalgae, fungi and bacteria have been used
successfully in the removal of metals, but in the last decade, sulfate-reducing
bacteria (SRB) have taken great relevance in the processes of metal removal from
wastewater. The removal of heavy metals is promoted when hydrogen sulfide is
produced; it reacts with metal ion and forms metal sulfides, which are insoluble
and tend to precipitate; it is not the only mechanism by which metal ions are
removed, biosorption mechanisms can also be carried out (with biomass and
production of exo-polysaccharides), immobilization and enzymatic reduction of
the metal ion to less toxic and insoluble forms, but this will depend on the type of
bacteria and their tolerance to metals.
M. I. Neria-González (*)
División de Ingeniería Química y Bioquímica, Tecnológico de Estudios Superiores de Ecatepec,
Ecatepec de Morelos, Edo. México, Mexico
e-mail: mineriag@tese.edu.mx
R. Aguilar-López
Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Ciudad de México, Mexico
# Springer Nature Singapore Pte Ltd. 2021
R. Prasad (ed.), Environmental Pollution and Remediation, Environmental and
Microbial Biotechnology, https://doi.org/10.1007/978-981-15-5499-5_13
367