Azolla pinnata, a fresh water macro alga, was tested for its ability to remove acid red 88 (AR88) from aqueous solution. Batch equilibrium tests at different pH conditions showed that at pH 3, a maximumAR88 uptake of 55.0 mg/g was observed according to the Toth model. The ability of A. pinnata to biosorb AR88 in a packed column was investigated, as well. The experiments were conducted to study the effect of important design parameters such as bed height flow rate and initial dye concentration. At optimum bed eight (25 cm), flow rate (5 mL/min) and initial dye concentration (100 mg/L), A. pinnata exhibited for AR88. The Thomas model was used to analyze the experimental data and the model parameters were evaluated.

KEYWORDS: Azolla pinnata, non linear isotherms, biosorption, packed bed column