Modelling of simultaneous biosorption of phenol and nickel(II) onto dried aerobic activated sludge

The equilibrium uptake of phenol and nickel(If) ions, both singly and in combination, by dried aerobic activated sludge was studied in a batch system. From the previous studies, the optimum biosorption pH values were determined as 4.5 for nickel(II) and as 1.0 for phenol. Adsorption isotherms were developed for both the single- and dual-component systems at these two pH values and expressed by the mono- and multi-component Langmuir, Freundlich and Redlich-Peterson adsorption models and model parameters were estimated by the non-linear regression method. It was seen that the mono-component adsorption equilibrium data fitted very well to the Redlich-Peterson model for both the components and for both the pH values while all the multi-component adsorption models adequately predicted the multi-component adsorption equilibrium data at moderate ranges of concentration. (C) 2000 Elsevier Science B.V. All rights reserved.