محمود نیاد

The biosorption of the zinc ion by padina boergeseni as brown alga was studied with respect to the contact time, temperature, pH, initial biomass dosage, initial zinc concentration, ionic strength and ionic radius. The maximum of biosorption was found in the first 60 minutes, the most favorable temperature was 45°C and optimum pH was 6. The kinetics of biosorption was fitted with a pseudo-second order. model, several two, three, four and five parameters isotherm models were studied, that in among of all models, the Freundlich isotherm model was in the best agreement with equilibrium data. The kinetics biosorption parameters, (Ea, ?H‡, ?S‡ and ?G‡) and the thermodynamic biosorption parameters, (?H?, ?S? and ?G?) were calculated in several temperatures. Also, by using Response Surface Methodology from Minitab software, the optimum experimental conditions were obtained. Finally, the recovery of zinc ion from the padina boergeseni as biomass was studied.