Aluminum biosorption using non-viable biomass of Pseudomonas putida immobilized in agar–agar: Performance in batch and in fixed-bed column

Non-viable biomass of Pseudomonas putida immobilized in agar–agar was used as adsorbent to remove aluminum from aqueous solutions. In batch assays, adsorption equilibrium was reached after 45 min and 95% of 2.7 mg/L Al3+ were adsorbed. Immobilized biomass was packed to obtain a fixed-bed column and the dynamic behavior in continuous mode was established through breakthrough curves. At different flow rates (0.5 and 1.0 mL/min) the adsorption capacity of the column did not change, but removal percentage was higher at the lowest flow rate (64.92% and 44.34%, respectively). The fixed-bed column presented a higher biosorption capacity than that obtained in batch experiments (0.15 and 0.09 mg Al3+/g beads, respectively), and showed stability for up to 12 successive adsorption/desorption cycles with negligible loss in adsorption efficiency. We concluded that this packed biosorbent could be a good alternative for the removal of Al3+ from aqueous solutions.