This paper reports the studies on the simultaneous adsorptive removal of phenol and aniline, and phenol and nitrophenol from aqueous solutions using granular activated carbon (GAC). The effect of operating parameters such as initial component concentrations, temperature, adsorbent dosage and contact time on the adsorption of mixtures of solutes in the binary aqueous solution were studied. Taguchi's method of design of experiments was used to study the effect of each parameter at three levels on the total amount of solutes adsorbed on GAC (q(tot), mmol/g). The analysis of variance shows that the contribution of interactions between initial concentrations of binary components is significant. Confirmation experiments were carried out to check the effectiveness of the Taguchi's methodology at the optimum levels of process parameters. The q(tot) value at optimum condition for P-AN and P-NP systems were found to be 0.85 and 0.88 mmol/g, respectively. (c) 2011 Elsevier B.V. All rights reserved.