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Adsorptive removal of cadmium from aqueous media using Posidonia oceanica biomass: equilibrium, dynamic and thermodynamic studies
Krika, F.; Azzouz, N. & Ncibi, M. C.
Abstract
Posidonia oceanica (L.), a marine biomass, has
been used as an effective and efficient biosorbent for the
removal of Cd(II) from aqueous media. The physicochemical
properties of biosorbent were investigated by
elemental analysis, BET surface area, FT-IR, SEM and
EDX methods before and after adsorption. Batch adsorption
experiments were carried out to investigate the effects
of solution pH, dosage of biosorbent, contact time and
temperature. The biosorbent exhibited the maximum
uptake of 58.82 mg/g under the optimal adsorption condition.
Kinetics experiments indicated that the pseudosecond-
order model displayed the best correlation with
adsorption kinetics data. Besides, experimental data could
be better described by the Langmuir isotherm model.
Desorption experiments were carried out to explore the
feasibility of regenerating the biosorbent. The regeneration
efficiency was 96.03 % using desorption agent of 0.2 M
HCl. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0)
of the cadmium ion uptake onto P.O indicated that the
process is endothermic and proceeds spontaneously. The
findings of the present study indicate that P.O can be
successfully used for separation of Cd(II) from aqueous
solutions. The results suggested that the adsorbent is
promising for use as an effective and economical adsorbent
for Cd(II) ions removal.
Keywords
Biosorption; Cadmium; Posidonia oceanica; Kinetics; Isotherms; Thermodynamics; Desorption
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