چكيده لاتين :
Biosorption equilibrium of zinc ions to Spirulina plutensis both in free and immobilized forms were studied in
batch system with respect to pH, metal ion concentration. algal dosages and time. The maximum adsorption was
observed at pH~8, optimummetal ion concentration and algal dose were 100mg/L and 1gil OOmL, respectively.
Biosorption equilibrium was established in 90 minutes. The maximum attainable biosorption was found to be
97.1% for Spirulina platensis. The equilibrium adsorption capacities of adsorbents used for zinc ions were
measured and extrapolated using Langmuir and Freundlich isotherms models. Langmuir model was found to be
in better correlation with experimental data. The maximum Langmuir constantsQ, (mg/g) and b were 92.93 and
0.0012, respectively for Spiralina platensis embedded in calcium alginate matrix. The immobilized Spirulina
platensis in calcium of alginate matrix was the best biosorbent, 0.1 M EDTA was used as an eluant, which allowed
the reuse of biomass in three biosorption-desorption cycles without considerable loss in biosorption capacity. 8995
~/o zinc ions יAיCfC desorbed with EDTA. The functional groups involved in zinc biosorption were identified
by using Fourier Transform Infra Red spectroscopy. Spectroscopic analysis of algae revealed the presence of
carboxyl. hydroxyl, amino, amide and imine groups, which were responsible for biosorption of zinc ions.
