species having high biosorption, biodegradation, and dye decolorization capacity of
industrial effluents (Dubey et al. 2011; Mona et al. 2011).
Considering the biosorptive potential of cyanobacteria, many studies utilized
their properties to derive maximum benefits from the system in an environmental
friendly way. Bioremediation is a process in which beneficial microbiological
agents, such as cyanobacteria, green algae, yeast, fungi, or bacteria, are used to
clean up contaminated soil and water. It is defined as the elimination, attenuation, or
transformation of polluted or contaminated substances by the application of biological processes. Many microbial species like bacteria (Pseudomonas,
Flavobacterium, Alcaligenes sp., Acinetobacter sp., Zooglea sp. and
Enterobacteriaceae), fungi (Trichoderma, Aspergillus), yeast, and their consortia
also have potential applications for the bioremediation of heavy metals, municipal
sewage water, paper and pulp mill effluents, textile effluents, tannery effluents, sugar
mill effluents, COD and BOD removal, etc. (Kappesser et al. 1989; Pala and Sponza.
1996; Kamika and Mumba 2012; Sangitha et al. 2012; Buvaneswari et al. 2013;
Mahmood et al. 2013; Krishnaveni et al. 2013). Contaminated water destroys aquatic
life and reduces their reproductive ability of aquatic organisms, and water becomes
unsuitable for human consumption or domestic usage.
Cyanobacteria are gram-negative, planktonic, and non-motile organisms. They
are capable of consuming CO 2 , a greenhouse gas which contributes to global
warming and released O 2 which is vital for cellular respiration (Badger and Price
2003). Their ability to use inorganic acid and phosphorus makes them grow well in
wastewater. This indicates their potential ability in wastewater treatment. One of the
major problems facing cyanobacterial wastewater treatment is the separation of the
cyanobacteria from the wastewater. The use of immobilized technique does not only
solve this problem but also has shown to have higher pollutant uptake than using free
biomass.
In the present section, species of cyanobacteria were reviewed for their tolerance
to metals, dyes, crude oil, and pesticides. Cyanobacterial species with very good
tolerance to the toxicants were selected as a model system for sequestration of
contaminants, pollutants, and toxicants in biosorption studies (Mona et al. 2011).
3.1 Role of Cyanobacteria in Bioremoval of Metals and Dyes
from Wastewaters
Bioremoval of pollutants from simulated or trade effluents can be due to
bioaccumulation, biosorption, or biodegradation. Though several microorganisms
have been studied for various purposes like bioremediation, however, cyanobacteria
have been found to be of special advantages over other microorganisms:
• Cyanobacteria have simple growth requirements and many of them can fix N 2 .
• Their growth does not require energy-rich compounds.
• These are environment-friendly and generally nontoxic microorganisms.
16 Cyanobacteria: The Eco-Friendly Tool for the Treatment of Industrial Wastewaters
397
industrial effluents (Dubey et al. 2011; Mona et al. 2011).
Considering the biosorptive potential of cyanobacteria, many studies utilized
their properties to derive maximum benefits from the system in an environmental
friendly way. Bioremediation is a process in which beneficial microbiological
agents, such as cyanobacteria, green algae, yeast, fungi, or bacteria, are used to
clean up contaminated soil and water. It is defined as the elimination, attenuation, or
transformation of polluted or contaminated substances by the application of biological processes. Many microbial species like bacteria (Pseudomonas,
Flavobacterium, Alcaligenes sp., Acinetobacter sp., Zooglea sp. and
Enterobacteriaceae), fungi (Trichoderma, Aspergillus), yeast, and their consortia
also have potential applications for the bioremediation of heavy metals, municipal
sewage water, paper and pulp mill effluents, textile effluents, tannery effluents, sugar
mill effluents, COD and BOD removal, etc. (Kappesser et al. 1989; Pala and Sponza.
1996; Kamika and Mumba 2012; Sangitha et al. 2012; Buvaneswari et al. 2013;
Mahmood et al. 2013; Krishnaveni et al. 2013). Contaminated water destroys aquatic
life and reduces their reproductive ability of aquatic organisms, and water becomes
unsuitable for human consumption or domestic usage.
Cyanobacteria are gram-negative, planktonic, and non-motile organisms. They
are capable of consuming CO 2 , a greenhouse gas which contributes to global
warming and released O 2 which is vital for cellular respiration (Badger and Price
2003). Their ability to use inorganic acid and phosphorus makes them grow well in
wastewater. This indicates their potential ability in wastewater treatment. One of the
major problems facing cyanobacterial wastewater treatment is the separation of the
cyanobacteria from the wastewater. The use of immobilized technique does not only
solve this problem but also has shown to have higher pollutant uptake than using free
biomass.
In the present section, species of cyanobacteria were reviewed for their tolerance
to metals, dyes, crude oil, and pesticides. Cyanobacterial species with very good
tolerance to the toxicants were selected as a model system for sequestration of
contaminants, pollutants, and toxicants in biosorption studies (Mona et al. 2011).
3.1 Role of Cyanobacteria in Bioremoval of Metals and Dyes
from Wastewaters
Bioremoval of pollutants from simulated or trade effluents can be due to
bioaccumulation, biosorption, or biodegradation. Though several microorganisms
have been studied for various purposes like bioremediation, however, cyanobacteria
have been found to be of special advantages over other microorganisms:
• Cyanobacteria have simple growth requirements and many of them can fix N 2 .
• Their growth does not require energy-rich compounds.
• These are environment-friendly and generally nontoxic microorganisms.
16 Cyanobacteria: The Eco-Friendly Tool for the Treatment of Industrial Wastewaters
397