Part D | 25
642 Part D Marine Algal Biotechnology
25.8 Final Remarks
Biosorption can be successfully used for the removal
of heavy metal ions from aqueous environments. The
major advantages of this method over the conventional
treatment methods include:
Economic viability
High efficiency of heavy metal removal from dilute
solutions
Minimization of chemical and/or biological waste
Easy regeneration of biosorbents
Possibility of heavy metal ions recovery.
The marine algae are available in large quantities in
many regions of the world, being a kind a promising biological resources, and their utilization as biosorbents
in biosorption processes are mainly due to: (i) the variety of functional groups from the biosorbent surface,
(ii) relatively small and uniform distribution of binding
sites on biosorbent surface, and (iii) the preference of
alkali and alkali-earth metal ions for the binding sites is
less than in the case of ion exchange resins. In addition,
the wastes obtained after extraction from marine algae
of different compounds, can also be used as biosorbents, because their biosorptive characteristics are not
very much changed.
In the design of the biosorption process for the removal of heavy metal ions, the biosorption/desorption
performances of marine algae biomass and some of
their essential characteristic (such as mass transfer,
chemical stability, etc.) should be well known. Thus, the
experiments must be started in batch conditions, when
some basic information is obtained, and then the possible applicability of biosorption systems at large level
should be tested under dynamic continuous-flow conditions. The performances assessment of biosorption
systems and prediction based on both equilibrium as
well as dynamic studies eventually leads to sizing of
the equipment.
In the future development of the biosorption processes for the removal of heavy metal ions from
aqueous environments, two trends can be mentioned,
according to the studies from the literature. The first
one concern to the use of hybrid technologies, where
the biosorption processes will be a step in the overall removal process of heavy metal ions from aqueous environment. This trend is mainly determined by
the difficulties existing in the utilization of biosorption processes, that made to be considered the applying the hybrid technologies to treat industrial wastewater. Unfortunately, until now no one variant was
found to be economical viable. The second trend is
to develop good commercial biosorbents derived from
marine algae biomass, just like a kind of ion exchange resins that can be easily sale in the market.
The failure of the marine algae biomass commercialization as biosorbents is mainly due to nontechnical barriers involved in commercialization of technological innovations. For implementation of innovative processes, a solid capitalization is always required, and this makes that choice of partners to be
critical.
However, the utilization of biosorption processes
along with other conventional methods (including
chemical precipitation, flotation, membrane-related
processes, electrochemical techniques, etc.) may also
be helpful in the treating of industrial effluents at
large scale, even for the simultaneous removal of organic substances and heavy metal ions from aqueous
environments.
References
25.1
J.W. Patterson: Industrial Wastewater Treatment
Technology (Butterworth Publishers, Stoneham
1985)
25.2
C.A. Mendoza, G. Cortes, D. Munoz: Heavy metal
pollution in soils and sediments of rural developing district 063, Mexico, Environ. Toxicol, Water
Qual. 11(4), 327–333 (1998)
25.3
A. Lyer, K. Mody, B.K. Jha: Biosorption of heavy
metals by a marine bacterium, Mar. Pollut. 50,
175–179 (2005)
25.4
B. Volesky, Z.R. Holan: Biosorption of heavy metals, Biotechnol. Prog. 11, 235–250 (1995)
25.5
S. Qaiser, A.R. Saleemi, M.M. Ahmad: Heavy metal
uptake by agro based waste materials, Environ.
Biotechnol. 10, 409–416 (2007)
25.6
A. Aklil, M. Mouflih, S. Sebti: Removal of heavy
metal ions from water by using calcined phosphate as a new adsorbent, J. Hazard. Mater. A 112,
183–190 (2004)
25.7
H. Aydin, Y. Bulut, C. Yerlikaya: Removal of copper(II) from aqueous solution by adsorption onto
low-cost adsorbents, J. Environ. Manag. 87, 37–
45 (2008)
642 Part D Marine Algal Biotechnology
25.8 Final Remarks
Biosorption can be successfully used for the removal
of heavy metal ions from aqueous environments. The
major advantages of this method over the conventional
treatment methods include:
Economic viability
High efficiency of heavy metal removal from dilute
solutions
Minimization of chemical and/or biological waste
Easy regeneration of biosorbents
Possibility of heavy metal ions recovery.
The marine algae are available in large quantities in
many regions of the world, being a kind a promising biological resources, and their utilization as biosorbents
in biosorption processes are mainly due to: (i) the variety of functional groups from the biosorbent surface,
(ii) relatively small and uniform distribution of binding
sites on biosorbent surface, and (iii) the preference of
alkali and alkali-earth metal ions for the binding sites is
less than in the case of ion exchange resins. In addition,
the wastes obtained after extraction from marine algae
of different compounds, can also be used as biosorbents, because their biosorptive characteristics are not
very much changed.
In the design of the biosorption process for the removal of heavy metal ions, the biosorption/desorption
performances of marine algae biomass and some of
their essential characteristic (such as mass transfer,
chemical stability, etc.) should be well known. Thus, the
experiments must be started in batch conditions, when
some basic information is obtained, and then the possible applicability of biosorption systems at large level
should be tested under dynamic continuous-flow conditions. The performances assessment of biosorption
systems and prediction based on both equilibrium as
well as dynamic studies eventually leads to sizing of
the equipment.
In the future development of the biosorption processes for the removal of heavy metal ions from
aqueous environments, two trends can be mentioned,
according to the studies from the literature. The first
one concern to the use of hybrid technologies, where
the biosorption processes will be a step in the overall removal process of heavy metal ions from aqueous environment. This trend is mainly determined by
the difficulties existing in the utilization of biosorption processes, that made to be considered the applying the hybrid technologies to treat industrial wastewater. Unfortunately, until now no one variant was
found to be economical viable. The second trend is
to develop good commercial biosorbents derived from
marine algae biomass, just like a kind of ion exchange resins that can be easily sale in the market.
The failure of the marine algae biomass commercialization as biosorbents is mainly due to nontechnical barriers involved in commercialization of technological innovations. For implementation of innovative processes, a solid capitalization is always required, and this makes that choice of partners to be
critical.
However, the utilization of biosorption processes
along with other conventional methods (including
chemical precipitation, flotation, membrane-related
processes, electrochemical techniques, etc.) may also
be helpful in the treating of industrial effluents at
large scale, even for the simultaneous removal of organic substances and heavy metal ions from aqueous
environments.
References
25.1
J.W. Patterson: Industrial Wastewater Treatment
Technology (Butterworth Publishers, Stoneham
1985)
25.2
C.A. Mendoza, G. Cortes, D. Munoz: Heavy metal
pollution in soils and sediments of rural developing district 063, Mexico, Environ. Toxicol, Water
Qual. 11(4), 327–333 (1998)
25.3
A. Lyer, K. Mody, B.K. Jha: Biosorption of heavy
metals by a marine bacterium, Mar. Pollut. 50,
175–179 (2005)
25.4
B. Volesky, Z.R. Holan: Biosorption of heavy metals, Biotechnol. Prog. 11, 235–250 (1995)
25.5
S. Qaiser, A.R. Saleemi, M.M. Ahmad: Heavy metal
uptake by agro based waste materials, Environ.
Biotechnol. 10, 409–416 (2007)
25.6
A. Aklil, M. Mouflih, S. Sebti: Removal of heavy
metal ions from water by using calcined phosphate as a new adsorbent, J. Hazard. Mater. A 112,
183–190 (2004)
25.7
H. Aydin, Y. Bulut, C. Yerlikaya: Removal of copper(II) from aqueous solution by adsorption onto
low-cost adsorbents, J. Environ. Manag. 87, 37–
45 (2008)