Adsorption of Bisphenol A from Water-Ethanol Mixtures on Pulverized Activated Carbon

The effect of ethanol concentration on the removal of bisphenol A (BPA) from water-ethanol mixtures using pulverized activated carbon (PAC) was studied. Adsorption equilibria and kinetics were measured using batch uptake experiments. Equilibrium and kinetic data were correlated with the Langmuir model and the non-ideal competitive adsorption (NICA) model. Finally, BPA removal in an adsorption-microfiltration hybrid system was tested and simulated with a non-steady model. Ethanol has a strong influence on the binding capacity of BPA on PAC and the uptake from 10mol/L (50.4 wt-%) aqueous ethanol is less than 10% of the value measured in water. The experimental adsorption isotherms were modeled using several isotherm models and by considering the effect of ethanol on solution activity coefficients. The best correlation was obtained with the NICA model assuming that part of the binding sites is inaccessible for BPA. The BPA adsorption rate was described using a pore diffusion model and reasonably good correlation with the experimental data was obtained provided that changes in solution viscosity were taken into account. Moreover, the estimated equilibrium and mass transport parameters describe reasonably well the removal of BPA in the adsorption-microfiltration hybrid system from water-ethanol mixtures.