Marine Algae
611
Part D | 25.1
25. Marine Algae Biomass for Removal
of Heavy Metal Ions
Laura Bulgariu, Dumitru Bulgariu, Constantin Rusu
The increase of industrial activities has accentuated environmental pollution problems, due to
the accumulation of harmful pollutants, such as
heavy metals. In regard to its simplicity, biosorption on nonconventional and low-cost materials
has gained credibility in the last few years, because
it offers an efficient and cost-effective alternative
to the conventional decontamination techniques.
From this perspective, numerous applications of
marine algae biomass have been developed for the
efficient removal of heavy metal ions from aqueous environments. In this chapter, the biosorptive
characteristics of marine algae biomass (marine
algae and marine algae wastes) for different heavy
metal ions from aqueous solution are described,
as a function of experimental conditions (solution
pH, biosorbent dose, contact time, temperature,
etc.) and the experimental procedure used in the
biosorption process. Application of isotherm and
kinetic models used for the mathematical description of experimental data is also reviewed.
The biosorption mechanism has been found quite
complex, including adsorption, surface precipitation, ion exchange and complexation.
25.1 General Remarks ................................. 611
25.2 Chemical Characteristics
of Marine Algae Biomass ...................... 613
25.3 Experimental Methodology .................. 615
25.3.1 Equilibrium Batch
Biosorption Technique ............... 615
25.3.2 Dynamic Continuous-Flow
Biosorption Technique ............... 616
25.4 Influence
of Experimental Parameters ................. 618
25.4.1 Influence
of Experimental Parameters
on Batch-Technique .................. 618
25.4.2 Influence
of Experimental Parameters
in a Dynamic Continuous-Flow
Technique................................. 625
25.5 Modeling of Biosorption Process
in Batch Conditions:
Isotherm and Kinetic Models ................ 628
25.5.1 Equilibrium Modeling
of Biosorption ........................... 629
25.5.2 Kinetic Modeling
of Biosorption ........................... 634
25.6 Modeling of Biosorption Process
in Dynamic Continuous-Flow
Conditions........................................... 637
25.7 Mechanism of Biosorption.................... 639
25.7.1 Ion Exchange ............................ 639
25.7.2 Complexation............................ 641
25.8 Final Remarks...................................... 642
References................................................... 642
25.1 General Remarks
Nowadays, the intensification of industrial activities has
intensified more environmental problems as seen for example in the deterioration of several ecosystems due to
the accumulation of dangerous and harmful pollutants,
such as heavy metals [25.1]. Industrial and municipal
wastewater frequently contain heavy metal ions, and
represent the major sources of natural water pollution
with heavy metals.
Toxic heavy metals are still used in various industries, such as textile, pigments, plastics, mining,
plating, chemical, and smelting, due to their technological importance, and are considered stable and persistent
environmental contaminants, because they cannot be
destroyed or degraded [25.2, 3]. In addition, these metal
ions are reported as priority pollutants due to their mobility, persistency, and accumulation tendency in natu-
611
Part D | 25.1
25. Marine Algae Biomass for Removal
of Heavy Metal Ions
Laura Bulgariu, Dumitru Bulgariu, Constantin Rusu
The increase of industrial activities has accentuated environmental pollution problems, due to
the accumulation of harmful pollutants, such as
heavy metals. In regard to its simplicity, biosorption on nonconventional and low-cost materials
has gained credibility in the last few years, because
it offers an efficient and cost-effective alternative
to the conventional decontamination techniques.
From this perspective, numerous applications of
marine algae biomass have been developed for the
efficient removal of heavy metal ions from aqueous environments. In this chapter, the biosorptive
characteristics of marine algae biomass (marine
algae and marine algae wastes) for different heavy
metal ions from aqueous solution are described,
as a function of experimental conditions (solution
pH, biosorbent dose, contact time, temperature,
etc.) and the experimental procedure used in the
biosorption process. Application of isotherm and
kinetic models used for the mathematical description of experimental data is also reviewed.
The biosorption mechanism has been found quite
complex, including adsorption, surface precipitation, ion exchange and complexation.
25.1 General Remarks ................................. 611
25.2 Chemical Characteristics
of Marine Algae Biomass ...................... 613
25.3 Experimental Methodology .................. 615
25.3.1 Equilibrium Batch
Biosorption Technique ............... 615
25.3.2 Dynamic Continuous-Flow
Biosorption Technique ............... 616
25.4 Influence
of Experimental Parameters ................. 618
25.4.1 Influence
of Experimental Parameters
on Batch-Technique .................. 618
25.4.2 Influence
of Experimental Parameters
in a Dynamic Continuous-Flow
Technique................................. 625
25.5 Modeling of Biosorption Process
in Batch Conditions:
Isotherm and Kinetic Models ................ 628
25.5.1 Equilibrium Modeling
of Biosorption ........................... 629
25.5.2 Kinetic Modeling
of Biosorption ........................... 634
25.6 Modeling of Biosorption Process
in Dynamic Continuous-Flow
Conditions........................................... 637
25.7 Mechanism of Biosorption.................... 639
25.7.1 Ion Exchange ............................ 639
25.7.2 Complexation............................ 641
25.8 Final Remarks...................................... 642
References................................................... 642
25.1 General Remarks
Nowadays, the intensification of industrial activities has
intensified more environmental problems as seen for example in the deterioration of several ecosystems due to
the accumulation of dangerous and harmful pollutants,
such as heavy metals [25.1]. Industrial and municipal
wastewater frequently contain heavy metal ions, and
represent the major sources of natural water pollution
with heavy metals.
Toxic heavy metals are still used in various industries, such as textile, pigments, plastics, mining,
plating, chemical, and smelting, due to their technological importance, and are considered stable and persistent
environmental contaminants, because they cannot be
destroyed or degraded [25.2, 3]. In addition, these metal
ions are reported as priority pollutants due to their mobility, persistency, and accumulation tendency in natu-