adsorption thermodynamics of copper on dried activated sludge

This study was performed using activated sludge of the systems of wastewater refining of Non-alcohlic carbonated soda (Soft drink) industries. Adsorption tests have indicated that the percentage of adsorption decreased with the increase in the concentration of solution and was higher at the beginning time. The adsorption thermodynamics of Cu(II) by activated sludge was carried out at 303.15 ± 2, 318.15 ± 2 and 333.15 ± 2K, and the thermodynamic parameters, such 0 as equilibrium constant (KL), standard free energy hanges ( f).G ), standard enthalpy change ( f).H 0 ) and standard entropy change ( f).S 0 ), were obtained. These parameters showed that the adsorption of Cu(II) by activated sludge was feasible, endothermic and was not spontaneous at 30 to 600C. The experimental data were analysed by the Langmuir and Freundlich models of adsorption. For the adsorption of Copper ion, the Langmuir isotherm model fitted to equilibrium data better than the Freundlich isotherm model. The dimensionless separation factor (RL) showed that the activated sludge of Soft drink factory can be used for the removal of copper ions from aqueous solutions. The results (n, RL) represented good and favorable adsorption. Therefore, the activated sludge could remove Cu(II) ions effectively from aqueous solution.

Keywords:

adsorption , biosorption , activated sludge , langmuir model , freundlich model , cu II