(395c) Batch and Column Biosorption of Cu (II) Onto Spent Coffee Ground: Equilibrium and Dynamic Modeling

Batch and column biosorption of copper ions was performed by using spent coffee ground as biosorbent. The equilibrium sorption in batch system was evaluated at acidic conditions (pH = 4.5) and the maximum biosorption capacity was found to be 0.214 mmol/g. The ion-exchange multicomponent model was able to predict the isotherm biosorption according to the low error value (SAE = 0.014). The biomass regeneration was studied using three different eluent (nitric acid, citric acid and sodium chloride) at initial concentration of 0.1 mM. The complete desorption of the copper ions has been realized by the nitric acid over four adsorption-desorption cycles. For dynamics biosorption experiments, the effect of the flow rate was analyzed at different empty bed contact times (5.5, 7.3, 11 and 22 min) in order to increase the biosorption column efficiency. Breakthrough curves were described by the Bed depth service time and the Thomas models. In addition, a mass transfer model for biosorption of copper ions in a fixed bed of spent coffee ground including film diffusion was found to agree with the experimental data well.