Batch and Fixed Bed Biosorption of Copper by Acidified Algae Waste Biomass

The aim of this work is to investigate the biosorption of Cu­(II) by an acidified waste product from the alginate extraction of algae in batch system and fixed bed columns. The results showed that the maximum copper biosorption capacity verified for the acidified biosorbent at 313 K was 3.580 mmol g–1 and equilibrium isotherms were best described by the Dubinin–Radushkevich model. Thermodynamic analysis showed that the process presented positive values of biosorption enthalpy (22.91 kJ mol–1) and biosorption entropy (114.98 J mol–1 K–1), indicating that the process is endothermic with dissociative mechanisms. Fixed bed experiments provided a higher percentage removal of copper at the feed flow rate of 0.5 mL min–1 and the inlet concentration of 1.0 mmol L–1. Column data were best described by the Yan et al. model. Copper desorption was performed using four different eluents. Among the eluents, HNO3 presented the highest value of elution efficiency in batch system