Abstract
Immobilized forms of two marine cyanobacteria,
Oscillatoria
sp. NTMS01 and
Phormidium
sp. NTMS02, were selected for the removal of chromium (VI) ions from an aqueous solution. Biosorption was studied as a function of pH (1–6), contact time (5–180 min) and initial chromium concentration (1–3 mg/L) to compare the maximum capacity of two immobilized marine cyanobacteria. These organisms were found to be efficient sorbents for the removal of chromium (VI) ions in lower concentrations. Biosorption equilibrium was established in about 30 min. Maximum adsorption was observed at pH 3. The biosorption was performed as described in terms of Langmuir and Freundlich isotherms. These organisms were found to fit better by the Freundlich isotherm, which indicated heterogeneity of the algal surface.