RETRACTED: Modeling of adsorption isotherms of heavy metals onto Apricot stone activated carbon: Two-parameter models and equations allowing determination of thermodynamic parameters

Abstract

Abstract The main objective of this manuscript was to investigate the adsorption potential of Apricot Stone Activated Carbone (ASAC) for the removal of Heavy Metals (Cobalt and Lead) ions from aqueous solution in a batch mode operation. The adsorbent was characterized by FTIR, BET, X-fluorescence and X-ray diffraction. A comparison between several models on the overall adsorption rate showed that the kinetic of adsorption was better described by the pseudo-second order model. The Langmuir, Freundlich and Temkin models were used to depict the adsorption of metal ions onto ASAC. The smaller RMSE values obtained for the Langmuir Isotherm model indicate the better curves fitting. The maximum monolayer adsorption capacity of the ASAC were found to be 80.628 mg/g at pH 8 and 25.22 mg/g at pH 9 for Pb2+ and Co2+ respectively. The thermodynamic results showed that the adsorption process was exothermic and spontaneous in nature. The study in tiny batch gave rise to encouraging results, and we wish to achieve the adsorption tests in column mode under the conditions applicable for the treatment of industrial effluents.