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 co mbination, by dried aerobic activated sludge was studied in a batch system. From the previous studies, the optimum biosorption pH values were determin ed as 4.5 for nickel(II) and as 1.0 for phenol. Adsorption isotherms were d eveloped for both the single- and dual-component systems at these two pH va lues and expressed by the mono- and multi-component Langmuir, Freundlich an d Redlich-Peterson adsorption models and model parameters were estimated by the non-linear regression method. It was seen that the mono-component adso rption equilibrium data fitted very well to the Redlich-Peterson model for both the components and for both the pH values while all the multi-componen t adsorption models adequately predicted the multi-component adsorption equ ilibrium data at moderate ranges of concentration. (C) 2000 Elsevier Scienc e B.V. All rights reserved.