Biosorption of Cu 2+ and Ni 2+ by Arthrospira platensis with different biochemical compositions
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Ημερομηνία
2015
Συγγραφείς
Chrysikopoulos Constantinos
Χρυσικοπουλος Κωνσταντινος
Dimitris Georgakakis
Hüseyin Bozkurt
Abuzer Çelekli
Dimitris Mitrogiannis
Giorgos Markou
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
This study is focused on copper and nickel biosorption onto Arthrospira platensis biomass of different biochemical
compositions. Four types of A. platensis were employed, namely: (1) typical dry biomass (TDB),
(2) carbohydrate-enriched dry biomass (CDB), (3) typical living biomass (TLB), and (4) carbohydrateenriched
living biomass (CLB). The CDB was produced using a cultivation mode where phosphorus was
the limiting nutrient. The biosorption of both metals investigated was shown to be very fast. Most of
the metal sorption capacity of the biomass was filled within 15–30 min, and equilibrium was achieved
within 30–60 min. The cultivation conditions (nutrient repletion or depletion) did not affect the pattern
of copper and nickel biosorption kinetics. The capacity for copper ions biosorption was significantly positively
affected by the accumulation of carbohydrates in the dry biomass, but was negatively affected by
the accumulation of carbohydrates in the living biomass. For nickel ions, the alteration of biomass had a
little but positive effect on the dry biomass, and a greater negative effect (about 30% lower biosorption
capacity) on the living biomass. Living biomass exhibited a higher biosorption capacity than dry biomass,
for both metals. The biosorption of copper and nickel onto A. platensis biomass occurred mainly due to the
mechanisms of ion exchange and complexation, and less to physical adsorption.
Περιγραφή
This study employed for the first time carbohydrate-enriched
dry and living biomass of A. platensis as biosorbent for copper or
nickel ions. The results show that the various biomass compositions
of A. platensis obtained from cultivation under different phosphorus
concentrations had a diverse effect on Cu2+ and Ni2+
biosorption capacity. The experiments with dry biomass show that
the accumulation of carbohydrates slightly improved the biosorption
capacity for nickel, but significantly improved the biosorption
capacity for copper. In contrast, the experiments with living biomass
show that the accumulation of carbohydrates decreased the
biosorption capacity for both metals. A. platensis showed greater
biosorption capacity for Ni2+ than for Cu2+. For all biomass types
investigated, the pseudo-second order kinetics model fitted better
the experimental data, but underestimated slightly the early time
data (first 15 min). It was observed that the intra-particle diffusion
was not a limited process, and that intra-particle diffusion model
described well the experimental data for the first 15 min. Also, it
was observed that the Freundlich model represents better the
biosorption onto living biomass due to the presence of possible
bioaccumulation, whereas, the Langmuir model fits better the
experimental data with dry biomass. The results show that the
main sorption mechanisms involved were ion exchange and
complexation. In general, the carbohydrate-enriched biomass contributed
to a weak ion-exchange sorption.
Λέξεις-κλειδιά
Παραπομπή
G.Markou , D. Mitrogiannis , A. Çelekli , H. Bozkurt , D. Georgakakis ,C. V. Chrysikopoulos , "Biosorption of Cu 2+ and Ni 2+ by Arthrospira platensis with different biochemical compositions "Che.Engin. J.,vol. 259, pp. 806–813,2015.doi 10.1016/j.cej.2014.08.037