However, with subsequent increased koh concentration, impregnation and adsorption of koh decreases due to increased solution viscosity
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An activated carbon (AC) with a specific surface area of 700m2 g−1 was prepared by KOH activation of tyre pyrolysis char (TPC) and tested to remove Bisphenol A (BPA) from aqueous solutions. BPA adsorption on this AC was evaluated by studying both the adsorption isotherms at three different temperatures and the decrease of BPA concentration with time, in order to determine the thermodynamic and the kinetic arameters, respectively. The results were compared with those obtained with pristine TPC and with a multipurpose commercial activated carbon (CAC) recommended for BPA adsorption. The present KOH-activated TPC showed a great potential to adsorb BPA with a monolayer capacity as high as 123 mg g−1, higher than that of the CAC used as a reference. BPA adsorption equilibrium data were fitted using different isotherm models with two or three parameters, and the best fitting models were those of Langmuir and Radke-Prausnitz. BPA adsorption was an exothermic process, and the adsorption capacity decreased with increasing temperature. The adsorption kinetics of BPA was adequately described by a pseudo-second order model.