Mainly due to the commercial value and the environmental impact that the heavy metals cause, a lot of studies has been conducted to determine the possibility of removing and recovering them from diluted solutions. The traditional methods for removing heavy metals have many disadvantages when the heavy metals are present in low concentrations. Biosorption, which uses biological materials as adsorbents, has been considered an alternative method. In this study, biosorption of copper onto green macro algae was investigated by batch adsorption technique to have a view of sorption characteristics of Cu(II) ions from aqueous solutions at 25 ºC. These sorption characteristics have been evaluated by means of various chemical treatments, equilibrium and kinetic modelling of the sorption data. Among the various chemical treatments (acid, alkali, formaldehyde alcohol) that has been performed to enhance the removal capacity of the biosorbent, alkali-treatment showed the best performance with an 40% increment in the sorption capacity of green macro algae. Two (Langmuir, Freundlich, Temkin) and three (Sips, Redlich- Peterson, Toth) parameter equilibrium models were used to describe the sorption data. Pseudo-firdt order and pseudo-second order kinetic models have been applied to the experimental data to compare with the theoretical assumptions. During this study, the equilibrium characteristics were compared with the literature samples to show the efficiency of the examined biosorbent, green macro algae.
